# coding=utf-8
# (The line above is necessary so that I can use 世界 in the
# *comment* below without Python getting all bent out of shape.)

# Copyright 2007-2009 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#	http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

'''Mercurial interface to codereview.appspot.com.

To configure, set the following options in
your repository's .hg/hgrc file.

	[extensions]
	codereview = path/to/codereview.py

	[codereview]
	server = codereview.appspot.com

The server should be running Rietveld; see http://code.google.com/p/rietveld/.

In addition to the new commands, this extension introduces
the file pattern syntax @nnnnnn, where nnnnnn is a change list
number, to mean the files included in that change list, which
must be associated with the current client.

For example, if change 123456 contains the files x.go and y.go,
"hg diff @123456" is equivalent to"hg diff x.go y.go".
'''

from mercurial import cmdutil, commands, hg, util, error, match
from mercurial.node import nullrev, hex, nullid, short
import os, re, time
import stat
import subprocess
import threading
from HTMLParser import HTMLParser
try:
	from xml.etree import ElementTree as ET
except:
	from elementtree import ElementTree as ET

try:
	hgversion = util.version()
except:
	from mercurial.version import version as v
	hgversion = v.get_version()

try:
	from mercurial.discovery import findcommonincoming
except:
	def findcommonincoming(repo, remote):
		return repo.findcommonincoming(remote)

oldMessage = """
The code review extension requires Mercurial 1.3 or newer.

To install a new Mercurial,

	sudo easy_install mercurial

works on most systems.
"""

linuxMessage = """
You may need to clear your current Mercurial installation by running:

	sudo apt-get remove mercurial mercurial-common
	sudo rm -rf /etc/mercurial
"""

if hgversion < '1.3':
	msg = oldMessage
	if os.access("/etc/mercurial", 0):
		msg += linuxMessage
	raise util.Abort(msg)

def promptyesno(ui, msg):
	# Arguments to ui.prompt changed between 1.3 and 1.3.1.
	# Even so, some 1.3.1 distributions seem to have the old prompt!?!?
	# What a terrible way to maintain software.
	try:
		return ui.promptchoice(msg, ["&yes", "&no"], 0) == 0
	except AttributeError:
		return ui.prompt(msg, ["&yes", "&no"], "y") != "n"

# To experiment with Mercurial in the python interpreter:
#    >>> repo = hg.repository(ui.ui(), path = ".")

#######################################################################
# Normally I would split this into multiple files, but it simplifies
# import path headaches to keep it all in one file.  Sorry.

import sys
if __name__ == "__main__":
	print >>sys.stderr, "This is a Mercurial extension and should not be invoked directly."
	sys.exit(2)

server = "codereview.appspot.com"
server_url_base = None
defaultcc = None
contributors = {}
missing_codereview = None

#######################################################################
# RE: UNICODE STRING HANDLING
#
# Python distinguishes between the str (string of bytes)
# and unicode (string of code points) types.  Most operations
# work on either one just fine, but some (like regexp matching)
# require unicode, and others (like write) require str.
#
# As befits the language, Python hides the distinction between
# unicode and str by converting between them silently, but
# *only* if all the bytes/code points involved are 7-bit ASCII.
# This means that if you're not careful, your program works
# fine on "hello, world" and fails on "hello, 世界".  And of course,
# the obvious way to be careful - use static types - is unavailable.
# So the only way is trial and error to find where to put explicit
# conversions.
#
# Because more functions do implicit conversion to str (string of bytes)
# than do implicit conversion to unicode (string of code points),
# the convention in this module is to represent all text as str,
# converting to unicode only when calling a unicode-only function
# and then converting back to str as soon as possible.

def typecheck(s, t):
	if type(s) != t:
		raise util.Abort("type check failed: %s has type %s != %s" % (repr(s), type(s), t))

# If we have to pass unicode instead of str, ustr does that conversion clearly.
def ustr(s):
	typecheck(s, str)
	return s.decode("utf-8")

# Even with those, Mercurial still sometimes turns unicode into str
# and then tries to use it as ascii.  Change Mercurial's default.
def set_mercurial_encoding_to_utf8():
	from mercurial import encoding
	encoding.encoding = 'utf-8'

set_mercurial_encoding_to_utf8()

# Even with those we still run into problems.
# I tried to do things by the book but could not convince
# Mercurial to let me check in a change with UTF-8 in the
# CL description or author field, no matter how many conversions
# between str and unicode I inserted and despite changing the
# default encoding.  I'm tired of this game, so set the default
# encoding for all of Python to 'utf-8', not 'ascii'.
def default_to_utf8():
	import sys
	reload(sys)  # site.py deleted setdefaultencoding; get it back
	sys.setdefaultencoding('utf-8')

default_to_utf8()

#######################################################################
# Change list parsing.
#
# Change lists are stored in .hg/codereview/cl.nnnnnn
# where nnnnnn is the number assigned by the code review server.
# Most data about a change list is stored on the code review server
# too: the description, reviewer, and cc list are all stored there.
# The only thing in the cl.nnnnnn file is the list of relevant files.
# Also, the existence of the cl.nnnnnn file marks this repository
# as the one where the change list lives.

emptydiff = """Index: ~rietveld~placeholder~
===================================================================
diff --git a/~rietveld~placeholder~ b/~rietveld~placeholder~
new file mode 100644
"""

class CL(object):
	def __init__(self, name):
		typecheck(name, str)
		self.name = name
		self.desc = ''
		self.files = []
		self.reviewer = []
		self.cc = []
		self.url = ''
		self.local = False
		self.web = False
		self.copied_from = None	# None means current user
		self.mailed = False

	def DiskText(self):
		cl = self
		s = ""
		if cl.copied_from:
			s += "Author: " + cl.copied_from + "\n\n"
		s += "Mailed: " + str(self.mailed) + "\n"
		s += "Description:\n"
		s += Indent(cl.desc, "\t")
		s += "Files:\n"
		for f in cl.files:
			s += "\t" + f + "\n"
		typecheck(s, str)
		return s

	def EditorText(self):
		cl = self
		s = _change_prolog
		s += "\n"
		if cl.copied_from:
			s += "Author: " + cl.copied_from + "\n"
		if cl.url != '':
			s += 'URL: ' + cl.url + '	# cannot edit\n\n'
		s += "Reviewer: " + JoinComma(cl.reviewer) + "\n"
		s += "CC: " + JoinComma(cl.cc) + "\n"
		s += "\n"
		s += "Description:\n"
		if cl.desc == '':
			s += "\t<enter description here>\n"
		else:
			s += Indent(cl.desc, "\t")
		s += "\n"
		if cl.local or cl.name == "new":
			s += "Files:\n"
			for f in cl.files:
				s += "\t" + f + "\n"
			s += "\n"
		typecheck(s, str)
		return s

	def PendingText(self):
		cl = self
		s = cl.name + ":" + "\n"
		s += Indent(cl.desc, "\t")
		s += "\n"
		if cl.copied_from:
			s += "\tAuthor: " + cl.copied_from + "\n"
		s += "\tReviewer: " + JoinComma(cl.reviewer) + "\n"
		s += "\tCC: " + JoinComma(cl.cc) + "\n"
		s += "\tFiles:\n"
		for f in cl.files:
			s += "\t\t" + f + "\n"
		typecheck(s, str)
		return s

	def Flush(self, ui, repo):
		if self.name == "new":
			self.Upload(ui, repo, gofmt_just_warn=True, creating=True)
		dir = CodeReviewDir(ui, repo)
		path = dir + '/cl.' + self.name
		f = open(path+'!', "w")
		f.write(self.DiskText())
		f.close()
		if sys.platform == "win32" and os.path.isfile(path):
			os.remove(path)
		os.rename(path+'!', path)
		if self.web and not self.copied_from:
			EditDesc(self.name, desc=self.desc,
				reviewers=JoinComma(self.reviewer), cc=JoinComma(self.cc))

	def Delete(self, ui, repo):
		dir = CodeReviewDir(ui, repo)
		os.unlink(dir + "/cl." + self.name)

	def Subject(self):
		s = line1(self.desc)
		if len(s) > 60:
			s = s[0:55] + "..."
		if self.name != "new":
			s = "code review %s: %s" % (self.name, s)
		typecheck(s, str)
		return s

	def Upload(self, ui, repo, send_mail=False, gofmt=True, gofmt_just_warn=False, creating=False, quiet=False):
		if not self.files and not creating:
			ui.warn("no files in change list\n")
		if ui.configbool("codereview", "force_gofmt", True) and gofmt:
			CheckFormat(ui, repo, self.files, just_warn=gofmt_just_warn)
		set_status("uploading CL metadata + diffs")
		os.chdir(repo.root)
		form_fields = [
			("content_upload", "1"),
			("reviewers", JoinComma(self.reviewer)),
			("cc", JoinComma(self.cc)),
			("description", self.desc),
			("base_hashes", ""),
		]

		if self.name != "new":
			form_fields.append(("issue", self.name))
		vcs = None
		# We do not include files when creating the issue,
		# because we want the patch sets to record the repository
		# and base revision they are diffs against.  We use the patch
		# set message for that purpose, but there is no message with
		# the first patch set.  Instead the message gets used as the
		# new CL's overall subject.  So omit the diffs when creating
		# and then we'll run an immediate upload.
		# This has the effect that every CL begins with an empty "Patch set 1".
		if self.files and not creating:
			vcs = MercurialVCS(upload_options, ui, repo)
			data = vcs.GenerateDiff(self.files)
			files = vcs.GetBaseFiles(data)
			if len(data) > MAX_UPLOAD_SIZE:
				uploaded_diff_file = []
				form_fields.append(("separate_patches", "1"))
			else:
				uploaded_diff_file = [("data", "data.diff", data)]
		else:
			uploaded_diff_file = [("data", "data.diff", emptydiff)]
		
		if vcs and self.name != "new":
			form_fields.append(("subject", "diff -r " + vcs.base_rev + " " + getremote(ui, repo, {}).path))
		else:
			# First upload sets the subject for the CL itself.
			form_fields.append(("subject", self.Subject()))
		ctype, body = EncodeMultipartFormData(form_fields, uploaded_diff_file)
		response_body = MySend("/upload", body, content_type=ctype)
		patchset = None
		msg = response_body
		lines = msg.splitlines()
		if len(lines) >= 2:
			msg = lines[0]
			patchset = lines[1].strip()
			patches = [x.split(" ", 1) for x in lines[2:]]
		if response_body.startswith("Issue updated.") and quiet:
			pass
		else:
			ui.status(msg + "\n")
		set_status("uploaded CL metadata + diffs")
		if not response_body.startswith("Issue created.") and not response_body.startswith("Issue updated."):
			raise util.Abort("failed to update issue: " + response_body)
		issue = msg[msg.rfind("/")+1:]
		self.name = issue
		if not self.url:
			self.url = server_url_base + self.name
		if not uploaded_diff_file:
			set_status("uploading patches")
			patches = UploadSeparatePatches(issue, rpc, patchset, data, upload_options)
		if vcs:
			set_status("uploading base files")
			vcs.UploadBaseFiles(issue, rpc, patches, patchset, upload_options, files)
		if send_mail:
			set_status("sending mail")
			MySend("/" + issue + "/mail", payload="")
		self.web = True
		set_status("flushing changes to disk")
		self.Flush(ui, repo)
		return

	def Mail(self, ui, repo):
		pmsg = "Hello " + JoinComma(self.reviewer)
		if self.cc:
			pmsg += " (cc: %s)" % (', '.join(self.cc),)
		pmsg += ",\n"
		pmsg += "\n"
		repourl = getremote(ui, repo, {}).path
		if not self.mailed:
			pmsg += "I'd like you to review this change to\n" + repourl + "\n"
		else:
			pmsg += "Please take another look.\n"
		typecheck(pmsg, str)
		PostMessage(ui, self.name, pmsg, subject=self.Subject())
		self.mailed = True
		self.Flush(ui, repo)

def GoodCLName(name):
	typecheck(name, str)
	return re.match("^[0-9]+$", name)

def ParseCL(text, name):
	typecheck(text, str)
	typecheck(name, str)
	sname = None
	lineno = 0
	sections = {
		'Author': '',
		'Description': '',
		'Files': '',
		'URL': '',
		'Reviewer': '',
		'CC': '',
		'Mailed': '',
	}
	for line in text.split('\n'):
		lineno += 1
		line = line.rstrip()
		if line != '' and line[0] == '#':
			continue
		if line == '' or line[0] == ' ' or line[0] == '\t':
			if sname == None and line != '':
				return None, lineno, 'text outside section'
			if sname != None:
				sections[sname] += line + '\n'
			continue
		p = line.find(':')
		if p >= 0:
			s, val = line[:p].strip(), line[p+1:].strip()
			if s in sections:
				sname = s
				if val != '':
					sections[sname] += val + '\n'
				continue
		return None, lineno, 'malformed section header'

	for k in sections:
		sections[k] = StripCommon(sections[k]).rstrip()

	cl = CL(name)
	if sections['Author']:
		cl.copied_from = sections['Author']
	cl.desc = sections['Description']
	for line in sections['Files'].split('\n'):
		i = line.find('#')
		if i >= 0:
			line = line[0:i].rstrip()
		line = line.strip()
		if line == '':
			continue
		cl.files.append(line)
	cl.reviewer = SplitCommaSpace(sections['Reviewer'])
	cl.cc = SplitCommaSpace(sections['CC'])
	cl.url = sections['URL']
	if sections['Mailed'] != 'False':
		# Odd default, but avoids spurious mailings when
		# reading old CLs that do not have a Mailed: line.
		# CLs created with this update will always have 
		# Mailed: False on disk.
		cl.mailed = True
	if cl.desc == '<enter description here>':
		cl.desc = ''
	return cl, 0, ''

def SplitCommaSpace(s):
	typecheck(s, str)
	s = s.strip()
	if s == "":
		return []
	return re.split(", *", s)

def CutDomain(s):
	typecheck(s, str)
	i = s.find('@')
	if i >= 0:
		s = s[0:i]
	return s

def JoinComma(l):
	for s in l:
		typecheck(s, str)
	return ", ".join(l)

def ExceptionDetail():
	s = str(sys.exc_info()[0])
	if s.startswith("<type '") and s.endswith("'>"):
		s = s[7:-2]
	elif s.startswith("<class '") and s.endswith("'>"):
		s = s[8:-2]
	arg = str(sys.exc_info()[1])
	if len(arg) > 0:
		s += ": " + arg
	return s

def IsLocalCL(ui, repo, name):
	return GoodCLName(name) and os.access(CodeReviewDir(ui, repo) + "/cl." + name, 0)

# Load CL from disk and/or the web.
def LoadCL(ui, repo, name, web=True):
	typecheck(name, str)
	set_status("loading CL " + name)
	if not GoodCLName(name):
		return None, "invalid CL name"
	dir = CodeReviewDir(ui, repo)
	path = dir + "cl." + name
	if os.access(path, 0):
		ff = open(path)
		text = ff.read()
		ff.close()
		cl, lineno, err = ParseCL(text, name)
		if err != "":
			return None, "malformed CL data: "+err
		cl.local = True
	else:
		cl = CL(name)
	if web:
		try:
			f = GetSettings(name)
		except:
			return None, "cannot load CL %s from code review server: %s" % (name, ExceptionDetail())
		if 'reviewers' not in f:
			return None, "malformed response loading CL data from code review server"
		cl.reviewer = SplitCommaSpace(f['reviewers'])
		cl.cc = SplitCommaSpace(f['cc'])
		if cl.local and cl.copied_from and cl.desc:
			# local copy of CL written by someone else
			# and we saved a description.  use that one,
			# so that committers can edit the description
			# before doing hg submit.
			pass
		else:
			cl.desc = f['description']
		cl.url = server_url_base + name
		cl.web = True
	set_status("loaded CL " + name)
	return cl, ''

global_status = None

def set_status(s):
	# print >>sys.stderr, "\t", time.asctime(), s
	global global_status
	global_status = s

class StatusThread(threading.Thread):
	def __init__(self):
		threading.Thread.__init__(self)
	def run(self):
		# pause a reasonable amount of time before
		# starting to display status messages, so that
		# most hg commands won't ever see them.
		time.sleep(30)

		# now show status every 15 seconds
		while True:
			time.sleep(15 - time.time() % 15)
			s = global_status
			if s is None:
				continue
			if s == "":
				s = "(unknown status)"
			print >>sys.stderr, time.asctime(), s

def start_status_thread():
	t = StatusThread()
	t.setDaemon(True)  # allowed to exit if t is still running
	t.start()

class LoadCLThread(threading.Thread):
	def __init__(self, ui, repo, dir, f, web):
		threading.Thread.__init__(self)
		self.ui = ui
		self.repo = repo
		self.dir = dir
		self.f = f
		self.web = web
		self.cl = None
	def run(self):
		cl, err = LoadCL(self.ui, self.repo, self.f[3:], web=self.web)
		if err != '':
			self.ui.warn("loading "+self.dir+self.f+": " + err + "\n")
			return
		self.cl = cl

# Load all the CLs from this repository.
def LoadAllCL(ui, repo, web=True):
	dir = CodeReviewDir(ui, repo)
	m = {}
	files = [f for f in os.listdir(dir) if f.startswith('cl.')]
	if not files:
		return m
	active = []
	first = True
	for f in files:
		t = LoadCLThread(ui, repo, dir, f, web)
		t.start()
		if web and first:
			# first request: wait in case it needs to authenticate
			# otherwise we get lots of user/password prompts
			# running in parallel.
			t.join()
			if t.cl:
				m[t.cl.name] = t.cl
			first = False
		else:
			active.append(t)
	for t in active:
		t.join()
		if t.cl:
			m[t.cl.name] = t.cl
	return m

# Find repository root.  On error, ui.warn and return None
def RepoDir(ui, repo):
	url = repo.url();
	if not url.startswith('file:'):
		ui.warn("repository %s is not in local file system\n" % (url,))
		return None
	url = url[5:]
	if url.endswith('/'):
		url = url[:-1]
	typecheck(url, str)
	return url

# Find (or make) code review directory.  On error, ui.warn and return None
def CodeReviewDir(ui, repo):
	dir = RepoDir(ui, repo)
	if dir == None:
		return None
	dir += '/.hg/codereview/'
	if not os.path.isdir(dir):
		try:
			os.mkdir(dir, 0700)
		except:
			ui.warn('cannot mkdir %s: %s\n' % (dir, ExceptionDetail()))
			return None
	typecheck(dir, str)
	return dir

# Turn leading tabs into spaces, so that the common white space
# prefix doesn't get confused when people's editors write out 
# some lines with spaces, some with tabs.  Only a heuristic
# (some editors don't use 8 spaces either) but a useful one.
def TabsToSpaces(line):
	i = 0
	while i < len(line) and line[i] == '\t':
		i += 1
	return ' '*(8*i) + line[i:]

# Strip maximal common leading white space prefix from text
def StripCommon(text):
	typecheck(text, str)
	ws = None
	for line in text.split('\n'):
		line = line.rstrip()
		if line == '':
			continue
		line = TabsToSpaces(line)
		white = line[:len(line)-len(line.lstrip())]
		if ws == None:
			ws = white
		else:
			common = ''
			for i in range(min(len(white), len(ws))+1):
				if white[0:i] == ws[0:i]:
					common = white[0:i]
			ws = common
		if ws == '':
			break
	if ws == None:
		return text
	t = ''
	for line in text.split('\n'):
		line = line.rstrip()
		line = TabsToSpaces(line)
		if line.startswith(ws):
			line = line[len(ws):]
		if line == '' and t == '':
			continue
		t += line + '\n'
	while len(t) >= 2 and t[-2:] == '\n\n':
		t = t[:-1]
	typecheck(t, str)
	return t

# Indent text with indent.
def Indent(text, indent):
	typecheck(text, str)
	typecheck(indent, str)
	t = ''
	for line in text.split('\n'):
		t += indent + line + '\n'
	typecheck(t, str)
	return t

# Return the first line of l
def line1(text):
	typecheck(text, str)
	return text.split('\n')[0]

_change_prolog = """# Change list.
# Lines beginning with # are ignored.
# Multi-line values should be indented.
"""

#######################################################################
# Mercurial helper functions

# Get effective change nodes taking into account applied MQ patches
def effective_revpair(repo):
    try:
	return cmdutil.revpair(repo, ['qparent'])
    except:
	return cmdutil.revpair(repo, None)

# Return list of changed files in repository that match pats.
# Warn about patterns that did not match.
def matchpats(ui, repo, pats, opts):
	matcher = cmdutil.match(repo, pats, opts)
	node1, node2 = effective_revpair(repo)
	modified, added, removed, deleted, unknown, ignored, clean = repo.status(node1, node2, matcher, ignored=True, clean=True, unknown=True)
	return (modified, added, removed, deleted, unknown, ignored, clean)

# Return list of changed files in repository that match pats.
# The patterns came from the command line, so we warn
# if they have no effect or cannot be understood.
def ChangedFiles(ui, repo, pats, opts, taken=None):
	taken = taken or {}
	# Run each pattern separately so that we can warn about
	# patterns that didn't do anything useful.
	for p in pats:
		modified, added, removed, deleted, unknown, ignored, clean = matchpats(ui, repo, [p], opts)
		redo = False
		for f in unknown:
			promptadd(ui, repo, f)
			redo = True
		for f in deleted:
			promptremove(ui, repo, f)
			redo = True
		if redo:
			modified, added, removed, deleted, unknown, ignored, clean = matchpats(ui, repo, [p], opts)
		for f in modified + added + removed:
			if f in taken:
				ui.warn("warning: %s already in CL %s\n" % (f, taken[f].name))
		if not modified and not added and not removed:
			ui.warn("warning: %s did not match any modified files\n" % (p,))

	# Again, all at once (eliminates duplicates)
	modified, added, removed = matchpats(ui, repo, pats, opts)[:3]
	l = modified + added + removed
	l.sort()
	if taken:
		l = Sub(l, taken.keys())
	return l

# Return list of changed files in repository that match pats and still exist.
def ChangedExistingFiles(ui, repo, pats, opts):
	modified, added = matchpats(ui, repo, pats, opts)[:2]
	l = modified + added
	l.sort()
	return l

# Return list of files claimed by existing CLs
def Taken(ui, repo):
	all = LoadAllCL(ui, repo, web=False)
	taken = {}
	for _, cl in all.items():
		for f in cl.files:
			taken[f] = cl
	return taken

# Return list of changed files that are not claimed by other CLs
def DefaultFiles(ui, repo, pats, opts):
	return ChangedFiles(ui, repo, pats, opts, taken=Taken(ui, repo))

def Sub(l1, l2):
	return [l for l in l1 if l not in l2]

def Add(l1, l2):
	l = l1 + Sub(l2, l1)
	l.sort()
	return l

def Intersect(l1, l2):
	return [l for l in l1 if l in l2]

def getremote(ui, repo, opts):
	# save $http_proxy; creating the HTTP repo object will
	# delete it in an attempt to "help"
	proxy = os.environ.get('http_proxy')
	source = hg.parseurl(ui.expandpath("default"), None)[0]
	try:
		remoteui = hg.remoteui # hg 1.6
	except:
		remoteui = cmdutil.remoteui
	other = hg.repository(remoteui(repo, opts), source)
	if proxy is not None:
		os.environ['http_proxy'] = proxy
	return other

def Incoming(ui, repo, opts):
	_, incoming, _ = findcommonincoming(repo, getremote(ui, repo, opts))
	return incoming

desc_re = '^(.+: |(tag )?(release|weekly)\.|fix build)'

desc_msg = '''Your CL description appears not to use the standard form.

The first line of your change description is conventionally a
one-line summary of the change, prefixed by the primary affected package,
and is used as the subject for code review mail; the rest of the description
elaborates.

Examples:

	encoding/rot13: new package

	math: add IsInf, IsNaN
	
	net: fix cname in LookupHost

	unicode: update to Unicode 5.0.2

'''

	
def promptremove(ui, repo, f):
	if promptyesno(ui, "hg remove %s (y/n)?" % (f,)):
		if commands.remove(ui, repo, 'path:'+f) != 0:
			ui.warn("error removing %s" % (f,))

def promptadd(ui, repo, f):
	if promptyesno(ui, "hg add %s (y/n)?" % (f,)):
		if commands.add(ui, repo, 'path:'+f) != 0:
			ui.warn("error adding %s" % (f,))

def EditCL(ui, repo, cl):
	set_status(None)	# do not show status
	s = cl.EditorText()
	while True:
		s = ui.edit(s, ui.username())
		clx, line, err = ParseCL(s, cl.name)
		if err != '':
			if not promptyesno(ui, "error parsing change list: line %d: %s\nre-edit (y/n)?" % (line, err)):
				return "change list not modified"
			continue
		
		# Check description.
		if clx.desc == '':
			if promptyesno(ui, "change list should have a description\nre-edit (y/n)?"):
				continue
		elif not re.match(desc_re, clx.desc.split('\n')[0]):
			if promptyesno(ui, desc_msg + "re-edit (y/n)?"):
				continue

		# Check file list for files that need to be hg added or hg removed
		# or simply aren't understood.
		pats = ['path:'+f for f in clx.files]
		modified, added, removed, deleted, unknown, ignored, clean = matchpats(ui, repo, pats, {})
		files = []
		for f in clx.files:
			if f in modified or f in added or f in removed:
				files.append(f)
				continue
			if f in deleted:
				promptremove(ui, repo, f)
				files.append(f)
				continue
			if f in unknown:
				promptadd(ui, repo, f)
				files.append(f)
				continue
			if f in ignored:
				ui.warn("error: %s is excluded by .hgignore; omitting\n" % (f,))
				continue
			if f in clean:
				ui.warn("warning: %s is listed in the CL but unchanged\n" % (f,))
				files.append(f)
				continue
			p = repo.root + '/' + f
			if os.path.isfile(p):
				ui.warn("warning: %s is a file but not known to hg\n" % (f,))
				files.append(f)
				continue
			if os.path.isdir(p):
				ui.warn("error: %s is a directory, not a file; omitting\n" % (f,))
				continue
			ui.warn("error: %s does not exist; omitting\n" % (f,))
		clx.files = files

		cl.desc = clx.desc
		cl.reviewer = clx.reviewer
		cl.cc = clx.cc
		cl.files = clx.files
		break
	return ""

# For use by submit, etc. (NOT by change)
# Get change list number or list of files from command line.
# If files are given, make a new change list.
def CommandLineCL(ui, repo, pats, opts, defaultcc=None):
	if len(pats) > 0 and GoodCLName(pats[0]):
		if len(pats) != 1:
			return None, "cannot specify change number and file names"
		if opts.get('message'):
			return None, "cannot use -m with existing CL"
		cl, err = LoadCL(ui, repo, pats[0], web=True)
		if err != "":
			return None, err
	else:
		cl = CL("new")
		cl.local = True
		cl.files = ChangedFiles(ui, repo, pats, opts, taken=Taken(ui, repo))
		if not cl.files:
			return None, "no files changed"
	if opts.get('reviewer'):
		cl.reviewer = Add(cl.reviewer, SplitCommaSpace(opts.get('reviewer')))
	if opts.get('cc'):
		cl.cc = Add(cl.cc, SplitCommaSpace(opts.get('cc')))
	if defaultcc:
		cl.cc = Add(cl.cc, defaultcc)
	if cl.name == "new":
		if opts.get('message'):
			cl.desc = opts.get('message')
		else:
			err = EditCL(ui, repo, cl)
			if err != '':
				return None, err
	return cl, ""

# reposetup replaces cmdutil.match with this wrapper,
# which expands the syntax @clnumber to mean the files
# in that CL.
original_match = None
def ReplacementForCmdutilMatch(repo, pats=None, opts=None, globbed=False, default='relpath'):
	taken = []
	files = []
	pats = pats or []
	opts = opts or {}
	for p in pats:
		if p.startswith('@'):
			taken.append(p)
			clname = p[1:]
			if not GoodCLName(clname):
				raise util.Abort("invalid CL name " + clname)
			cl, err = LoadCL(repo.ui, repo, clname, web=False)
			if err != '':
				raise util.Abort("loading CL " + clname + ": " + err)
			if not cl.files:
				raise util.Abort("no files in CL " + clname)
			files = Add(files, cl.files)
	pats = Sub(pats, taken) + ['path:'+f for f in files]
	return original_match(repo, pats=pats, opts=opts, globbed=globbed, default=default)

def RelativePath(path, cwd):
	n = len(cwd)
	if path.startswith(cwd) and path[n] == '/':
		return path[n+1:]
	return path

def CheckFormat(ui, repo, files, just_warn=False):
	set_status("running gofmt")
	CheckGofmt(ui, repo, files, just_warn)
	CheckTabfmt(ui, repo, files, just_warn)

# Check that gofmt run on the list of files does not change them
def CheckGofmt(ui, repo, files, just_warn):
	files = [f for f in files if (f.startswith('src/') or f.startswith('test/bench/')) and f.endswith('.go')]
	if not files:
		return
	cwd = os.getcwd()
	files = [RelativePath(repo.root + '/' + f, cwd) for f in files]
	files = [f for f in files if os.access(f, 0)]
	if not files:
		return
	try:
		cmd = subprocess.Popen(["gofmt", "-l"] + files, shell=False, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=sys.platform != "win32")
		cmd.stdin.close()
	except:
		raise util.Abort("gofmt: " + ExceptionDetail())
	data = cmd.stdout.read()
	errors = cmd.stderr.read()
	cmd.wait()
	set_status("done with gofmt")
	if len(errors) > 0:
		ui.warn("gofmt errors:\n" + errors.rstrip() + "\n")
		return
	if len(data) > 0:
		msg = "gofmt needs to format these files (run hg gofmt):\n" + Indent(data, "\t").rstrip()
		if just_warn:
			ui.warn("warning: " + msg + "\n")
		else:
			raise util.Abort(msg)
	return

# Check that *.[chys] files indent using tabs.
def CheckTabfmt(ui, repo, files, just_warn):
	files = [f for f in files if f.startswith('src/') and re.search(r"\.[chys]$", f)]
	if not files:
		return
	cwd = os.getcwd()
	files = [RelativePath(repo.root + '/' + f, cwd) for f in files]
	files = [f for f in files if os.access(f, 0)]
	badfiles = []
	for f in files:
		try:
			for line in open(f, 'r'):
				if line.startswith('    '):
					badfiles.append(f)
					break
		except:
			# ignore cannot open file, etc.
			pass
	if len(badfiles) > 0:
		msg = "these files use spaces for indentation (use tabs instead):\n\t" + "\n\t".join(badfiles)
		if just_warn:
			ui.warn("warning: " + msg + "\n")
		else:
			raise util.Abort(msg)
	return

#######################################################################
# Mercurial commands

# every command must take a ui and and repo as arguments.
# opts is a dict where you can find other command line flags
#
# Other parameters are taken in order from items on the command line that
# don't start with a dash.  If no default value is given in the parameter list,
# they are required.
#

def change(ui, repo, *pats, **opts):
	"""create, edit or delete a change list

	Create, edit or delete a change list.
	A change list is a group of files to be reviewed and submitted together,
	plus a textual description of the change.
	Change lists are referred to by simple alphanumeric names.

	Changes must be reviewed before they can be submitted.

	In the absence of options, the change command opens the
	change list for editing in the default editor.

	Deleting a change with the -d or -D flag does not affect
	the contents of the files listed in that change.  To revert
	the files listed in a change, use

		hg revert @123456

	before running hg change -d 123456.
	"""

	if missing_codereview:
		return missing_codereview

	dirty = {}
	if len(pats) > 0 and GoodCLName(pats[0]):
		name = pats[0]
		if len(pats) != 1:
			return "cannot specify CL name and file patterns"
		pats = pats[1:]
		cl, err = LoadCL(ui, repo, name, web=True)
		if err != '':
			return err
		if not cl.local and (opts["stdin"] or not opts["stdout"]):
			return "cannot change non-local CL " + name
	else:
		name = "new"
		cl = CL("new")
		dirty[cl] = True
		files = ChangedFiles(ui, repo, pats, opts, taken=Taken(ui, repo))

	if opts["delete"] or opts["deletelocal"]:
		if opts["delete"] and opts["deletelocal"]:
			return "cannot use -d and -D together"
		flag = "-d"
		if opts["deletelocal"]:
			flag = "-D"
		if name == "new":
			return "cannot use "+flag+" with file patterns"
		if opts["stdin"] or opts["stdout"]:
			return "cannot use "+flag+" with -i or -o"
		if not cl.local:
			return "cannot change non-local CL " + name
		if opts["delete"]:
			if cl.copied_from:
				return "original author must delete CL; hg change -D will remove locally"
			PostMessage(ui, cl.name, "*** Abandoned ***", send_mail=cl.mailed)
			EditDesc(cl.name, closed="checked")
		cl.Delete(ui, repo)
		return

	if opts["stdin"]:
		s = sys.stdin.read()
		clx, line, err = ParseCL(s, name)
		if err != '':
			return "error parsing change list: line %d: %s" % (line, err)
		if clx.desc is not None:
			cl.desc = clx.desc;
			dirty[cl] = True
		if clx.reviewer is not None:
			cl.reviewer = clx.reviewer
			dirty[cl] = True
		if clx.cc is not None:
			cl.cc = clx.cc
			dirty[cl] = True
		if clx.files is not None:
			cl.files = clx.files
			dirty[cl] = True

	if not opts["stdin"] and not opts["stdout"]:
		if name == "new":
			cl.files = files
		err = EditCL(ui, repo, cl)
		if err != "":
			return err
		dirty[cl] = True

	for d, _ in dirty.items():
		name = d.name
		d.Flush(ui, repo)
		if name == "new":
			d.Upload(ui, repo, quiet=True)

	if opts["stdout"]:
		ui.write(cl.EditorText())
	elif name == "new":
		if ui.quiet:
			ui.write(cl.name)
		else:
			ui.write("CL created: " + cl.url + "\n")
	return

def code_login(ui, repo, **opts):
	"""log in to code review server

	Logs in to the code review server, saving a cookie in
	a file in your home directory.
	"""
	if missing_codereview:
		return missing_codereview

	MySend(None)

def clpatch(ui, repo, clname, **opts):
	"""import a patch from the code review server

	Imports a patch from the code review server into the local client.
	If the local client has already modified any of the files that the
	patch modifies, this command will refuse to apply the patch.

	Submitting an imported patch will keep the original author's
	name as the Author: line but add your own name to a Committer: line.
	"""
	if missing_codereview:
		return missing_codereview

	cl, patch, err = DownloadCL(ui, repo, clname)
	if err != "":
		return err
	if patch == emptydiff:
		return "codereview issue %s has no diff" % clname

	argv = ["hgpatch"]
	if opts["no_incoming"]:
		argv += ["--checksync=false"]
	try:
		cmd = subprocess.Popen(argv, shell=False, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=None, close_fds=sys.platform != "win32")
	except:
		return "hgpatch: " + ExceptionDetail()

	out, err = cmd.communicate(patch)
	if cmd.returncode != 0 and not opts["ignore_hgpatch_failure"]:
		return "hgpatch failed"
	cl.local = True
	cl.files = out.strip().split()
	if not cl.files:
		return "codereview issue %s has no diff" % clname
	files = ChangedFiles(ui, repo, [], opts)
	extra = Sub(cl.files, files)
	if extra:
		ui.warn("warning: these files were listed in the patch but not changed:\n\t" + "\n\t".join(extra) + "\n")
	cl.Flush(ui, repo)
	ui.write(cl.PendingText() + "\n")

def download(ui, repo, clname, **opts):
	"""download a change from the code review server

	Download prints a description of the given change list
	followed by its diff, downloaded from the code review server.
	"""
	if missing_codereview:
		return missing_codereview

	cl, patch, err = DownloadCL(ui, repo, clname)
	if err != "":
		return err
	ui.write(cl.EditorText() + "\n")
	ui.write(patch + "\n")
	return

def file(ui, repo, clname, pat, *pats, **opts):
	"""assign files to or remove files from a change list

	Assign files to or (with -d) remove files from a change list.

	The -d option only removes files from the change list.
	It does not edit them or remove them from the repository.
	"""
	if missing_codereview:
		return missing_codereview

	pats = tuple([pat] + list(pats))
	if not GoodCLName(clname):
		return "invalid CL name " + clname

	dirty = {}
	cl, err = LoadCL(ui, repo, clname, web=False)
	if err != '':
		return err
	if not cl.local:
		return "cannot change non-local CL " + clname

	files = ChangedFiles(ui, repo, pats, opts)

	if opts["delete"]:
		oldfiles = Intersect(files, cl.files)
		if oldfiles:
			if not ui.quiet:
				ui.status("# Removing files from CL.  To undo:\n")
				ui.status("#	cd %s\n" % (repo.root))
				for f in oldfiles:
					ui.status("#	hg file %s %s\n" % (cl.name, f))
			cl.files = Sub(cl.files, oldfiles)
			cl.Flush(ui, repo)
		else:
			ui.status("no such files in CL")
		return

	if not files:
		return "no such modified files"

	files = Sub(files, cl.files)
	taken = Taken(ui, repo)
	warned = False
	for f in files:
		if f in taken:
			if not warned and not ui.quiet:
				ui.status("# Taking files from other CLs.  To undo:\n")
				ui.status("#	cd %s\n" % (repo.root))
				warned = True
			ocl = taken[f]
			if not ui.quiet:
				ui.status("#	hg file %s %s\n" % (ocl.name, f))
			if ocl not in dirty:
				ocl.files = Sub(ocl.files, files)
				dirty[ocl] = True
	cl.files = Add(cl.files, files)
	dirty[cl] = True
	for d, _ in dirty.items():
		d.Flush(ui, repo)
	return

def gofmt(ui, repo, *pats, **opts):
	"""apply gofmt to modified files

	Applies gofmt to the modified files in the repository that match
	the given patterns.
	"""
	if missing_codereview:
		return missing_codereview

	files = ChangedExistingFiles(ui, repo, pats, opts)
	files = [f for f in files if f.endswith(".go")]
	if not files:
		return "no modified go files"
	cwd = os.getcwd()
	files = [RelativePath(repo.root + '/' + f, cwd) for f in files]
	try:
		cmd = ["gofmt", "-l"]
		if not opts["list"]:
			cmd += ["-w"]
		if os.spawnvp(os.P_WAIT, "gofmt", cmd + files) != 0:
			raise util.Abort("gofmt did not exit cleanly")
	except error.Abort, e:
		raise
	except:
		raise util.Abort("gofmt: " + ExceptionDetail())
	return

def mail(ui, repo, *pats, **opts):
	"""mail a change for review

	Uploads a patch to the code review server and then sends mail
	to the reviewer and CC list asking for a review.
	"""
	if missing_codereview:
		return missing_codereview

	cl, err = CommandLineCL(ui, repo, pats, opts, defaultcc=defaultcc)
	if err != "":
		return err
	cl.Upload(ui, repo, gofmt_just_warn=True)
	if not cl.reviewer:
		# If no reviewer is listed, assign the review to defaultcc.
		# This makes sure that it appears in the 
		# codereview.appspot.com/user/defaultcc
		# page, so that it doesn't get dropped on the floor.
		if not defaultcc:
			return "no reviewers listed in CL"
		cl.cc = Sub(cl.cc, defaultcc)
		cl.reviewer = defaultcc
		cl.Flush(ui, repo)

	if cl.files == []:
		return "no changed files, not sending mail"

	cl.Mail(ui, repo)		

def nocommit(ui, repo, *pats, **opts):
	"""(disabled when using this extension)"""
	return "The codereview extension is enabled; do not use commit."

def pending(ui, repo, *pats, **opts):
	"""show pending changes

	Lists pending changes followed by a list of unassigned but modified files.
	"""
	if missing_codereview:
		return missing_codereview

	m = LoadAllCL(ui, repo, web=True)
	names = m.keys()
	names.sort()
	for name in names:
		cl = m[name]
		ui.write(cl.PendingText() + "\n")

	files = DefaultFiles(ui, repo, [], opts)
	if len(files) > 0:
		s = "Changed files not in any CL:\n"
		for f in files:
			s += "\t" + f + "\n"
		ui.write(s)

def reposetup(ui, repo):
	global original_match
	if original_match is None:
		start_status_thread()
		original_match = cmdutil.match
		cmdutil.match = ReplacementForCmdutilMatch
		RietveldSetup(ui, repo)

def CheckContributor(ui, repo, user=None):
	set_status("checking CONTRIBUTORS file")
	if not user:
		user = ui.config("ui", "username")
		if not user:
			raise util.Abort("[ui] username is not configured in .hgrc")
	_, userline = FindContributor(ui, repo, user, warn=False)
	if not userline:
		raise util.Abort("cannot find %s in CONTRIBUTORS" % (user,))
	return userline

def FindContributor(ui, repo, user, warn=True):
	user = user.lower()
	m = re.match(r".*<(.*)>", user)
	if m:
		user = m.group(1)

	if user not in contributors:
		if warn:
			ui.warn("warning: cannot find %s in CONTRIBUTORS\n" % (user,))
		return None, None
	
	user, email = contributors[user]
	return email, "%s <%s>" % (user, email)

def submit(ui, repo, *pats, **opts):
	"""submit change to remote repository

	Submits change to remote repository.
	Bails out if the local repository is not in sync with the remote one.
	"""
	if missing_codereview:
		return missing_codereview

	# We already called this on startup but sometimes Mercurial forgets.
	set_mercurial_encoding_to_utf8()

	repo.ui.quiet = True
	if not opts["no_incoming"] and Incoming(ui, repo, opts):
		return "local repository out of date; must sync before submit"

	cl, err = CommandLineCL(ui, repo, pats, opts, defaultcc=defaultcc)
	if err != "":
		return err

	user = None
	if cl.copied_from:
		user = cl.copied_from
	userline = CheckContributor(ui, repo, user)
	typecheck(userline, str)

	about = ""
	if cl.reviewer:
		about += "R=" + JoinComma([CutDomain(s) for s in cl.reviewer]) + "\n"
	if opts.get('tbr'):
		tbr = SplitCommaSpace(opts.get('tbr'))
		cl.reviewer = Add(cl.reviewer, tbr)
		about += "TBR=" + JoinComma([CutDomain(s) for s in tbr]) + "\n"
	if cl.cc:
		about += "CC=" + JoinComma([CutDomain(s) for s in cl.cc]) + "\n"

	if not cl.reviewer:
		return "no reviewers listed in CL"

	if not cl.local:
		return "cannot submit non-local CL"

	# upload, to sync current patch and also get change number if CL is new.
	if not cl.copied_from:
		cl.Upload(ui, repo, gofmt_just_warn=True)

	# check gofmt for real; allowed upload to warn in order to save CL.
	cl.Flush(ui, repo)
	CheckFormat(ui, repo, cl.files)

	about += "%s%s\n" % (server_url_base, cl.name)

	if cl.copied_from:
		about += "\nCommitter: " + CheckContributor(ui, repo, None) + "\n"
	typecheck(about, str)

	if not cl.mailed and not cl.copied_from:		# in case this is TBR
		cl.Mail(ui, repo)

	# submit changes locally
	date = opts.get('date')
	if date:
		opts['date'] = util.parsedate(date)
		typecheck(opts['date'], str)
	opts['message'] = cl.desc.rstrip() + "\n\n" + about
	typecheck(opts['message'], str)

	if opts['dryrun']:
		print "NOT SUBMITTING:"
		print "User: ", userline
		print "Message:"
		print Indent(opts['message'], "\t")
		print "Files:"
		print Indent('\n'.join(cl.files), "\t")
		return "dry run; not submitted"

	m = match.exact(repo.root, repo.getcwd(), cl.files)
	node = repo.commit(ustr(opts['message']), ustr(userline), opts.get('date'), m)
	if not node:
		return "nothing changed"

	# push to remote; if it fails for any reason, roll back
	try:
		log = repo.changelog
		rev = log.rev(node)
		parents = log.parentrevs(rev)
		if (rev-1 not in parents and
				(parents == (nullrev, nullrev) or
				len(log.heads(log.node(parents[0]))) > 1 and
				(parents[1] == nullrev or len(log.heads(log.node(parents[1]))) > 1))):
			# created new head
			raise util.Abort("local repository out of date; must sync before submit")

		# push changes to remote.
		# if it works, we're committed.
		# if not, roll back
		other = getremote(ui, repo, opts)
		r = repo.push(other, False, None)
		if r == 0:
			raise util.Abort("local repository out of date; must sync before submit")
	except:
		repo.rollback()
		raise

	# we're committed. upload final patch, close review, add commit message
	changeURL = short(node)
	url = other.url()
	m = re.match("^https?://([^@/]+@)?([^.]+)\.googlecode\.com/hg/", url)
	if m:
		changeURL = "http://code.google.com/p/%s/source/detail?r=%s" % (m.group(2), changeURL)
	else:
		print >>sys.stderr, "URL: ", url
	pmsg = "*** Submitted as " + changeURL + " ***\n\n" + opts['message']

	# When posting, move reviewers to CC line,
	# so that the issue stops showing up in their "My Issues" page.
	PostMessage(ui, cl.name, pmsg, reviewers="", cc=JoinComma(cl.reviewer+cl.cc))

	if not cl.copied_from:
		EditDesc(cl.name, closed="checked")
	cl.Delete(ui, repo)

def sync(ui, repo, **opts):
	"""synchronize with remote repository

	Incorporates recent changes from the remote repository
	into the local repository.
	"""
	if missing_codereview:
		return missing_codereview

	if not opts["local"]:
		ui.status = sync_note
		ui.note = sync_note
		other = getremote(ui, repo, opts)
		modheads = repo.pull(other)
		err = commands.postincoming(ui, repo, modheads, True, "tip")
		if err:
			return err
	commands.update(ui, repo)
	sync_changes(ui, repo)

def sync_note(msg):
	# we run sync (pull -u) in verbose mode to get the
	# list of files being updated, but that drags along
	# a bunch of messages we don't care about.
	# omit them.
	if msg == 'resolving manifests\n':
		return
	if msg == 'searching for changes\n':
		return
	if msg == "couldn't find merge tool hgmerge\n":
		return
	sys.stdout.write(msg)

def sync_changes(ui, repo):
	# Look through recent change log descriptions to find
	# potential references to http://.*/our-CL-number.
	# Double-check them by looking at the Rietveld log.
	def Rev(rev):
		desc = repo[rev].description().strip()
		for clname in re.findall('(?m)^http://(?:[^\n]+)/([0-9]+)$', desc):
			if IsLocalCL(ui, repo, clname) and IsRietveldSubmitted(ui, clname, repo[rev].hex()):
				ui.warn("CL %s submitted as %s; closing\n" % (clname, repo[rev]))
				cl, err = LoadCL(ui, repo, clname, web=False)
				if err != "":
					ui.warn("loading CL %s: %s\n" % (clname, err))
					continue
				if not cl.copied_from:
					EditDesc(cl.name, closed="checked")
				cl.Delete(ui, repo)

	if hgversion < '1.4':
		get = util.cachefunc(lambda r: repo[r].changeset())
		changeiter, matchfn = cmdutil.walkchangerevs(ui, repo, [], get, {'rev': None})
		n = 0
		for st, rev, fns in changeiter:
			if st != 'iter':
				continue
			n += 1
			if n > 100:
				break
			Rev(rev)
	else:
		matchfn = cmdutil.match(repo, [], {'rev': None})
		def prep(ctx, fns):
			pass
		for ctx in cmdutil.walkchangerevs(repo, matchfn, {'rev': None}, prep):
			Rev(ctx.rev())

	# Remove files that are not modified from the CLs in which they appear.
	all = LoadAllCL(ui, repo, web=False)
	changed = ChangedFiles(ui, repo, [], {})
	for _, cl in all.items():
		extra = Sub(cl.files, changed)
		if extra:
			ui.warn("Removing unmodified files from CL %s:\n" % (cl.name,))
			for f in extra:
				ui.warn("\t%s\n" % (f,))
			cl.files = Sub(cl.files, extra)
			cl.Flush(ui, repo)
		if not cl.files:
			if not cl.copied_from:
				ui.warn("CL %s has no files; delete with hg change -d %s\n" % (cl.name, cl.name))
			else:
				ui.warn("CL %s has no files; delete locally with hg change -D %s\n" % (cl.name, cl.name))
	return

def upload(ui, repo, name, **opts):
	"""upload diffs to the code review server

	Uploads the current modifications for a given change to the server.
	"""
	if missing_codereview:
		return missing_codereview

	repo.ui.quiet = True
	cl, err = LoadCL(ui, repo, name, web=True)
	if err != "":
		return err
	if not cl.local:
		return "cannot upload non-local change"
	cl.Upload(ui, repo)
	print "%s%s\n" % (server_url_base, cl.name)
	return

review_opts = [
	('r', 'reviewer', '', 'add reviewer'),
	('', 'cc', '', 'add cc'),
	('', 'tbr', '', 'add future reviewer'),
	('m', 'message', '', 'change description (for new change)'),
]

cmdtable = {
	# The ^ means to show this command in the help text that
	# is printed when running hg with no arguments.
	"^change": (
		change,
		[
			('d', 'delete', None, 'delete existing change list'),
			('D', 'deletelocal', None, 'delete locally, but do not change CL on server'),
			('i', 'stdin', None, 'read change list from standard input'),
			('o', 'stdout', None, 'print change list to standard output'),
		],
		"[-d | -D] [-i] [-o] change# or FILE ..."
	),
	"^clpatch": (
		clpatch,
		[
			('', 'ignore_hgpatch_failure', None, 'create CL metadata even if hgpatch fails'),
			('', 'no_incoming', None, 'disable check for incoming changes'),
		],
		"change#"
	),
	# Would prefer to call this codereview-login, but then
	# hg help codereview prints the help for this command
	# instead of the help for the extension.
	"code-login": (
		code_login,
		[],
		"",
	),
	"^download": (
		download,
		[],
		"change#"
	),
	"^file": (
		file,
		[
			('d', 'delete', None, 'delete files from change list (but not repository)'),
		],
		"[-d] change# FILE ..."
	),
	"^gofmt": (
		gofmt,
		[
			('l', 'list', None, 'list files that would change, but do not edit them'),
		],
		"FILE ..."
	),
	"^pending|p": (
		pending,
		[],
		"[FILE ...]"
	),
	"^mail": (
		mail,
		review_opts + [
		] + commands.walkopts,
		"[-r reviewer] [--cc cc] [change# | file ...]"
	),
	"^submit": (
		submit,
		review_opts + [
			('', 'no_incoming', None, 'disable initial incoming check (for testing)'),
			('n', 'dryrun', None, 'make change only locally (for testing)'),
		] + commands.walkopts + commands.commitopts + commands.commitopts2,
		"[-r reviewer] [--cc cc] [change# | file ...]"
	),
	"^sync": (
		sync,
		[
			('', 'local', None, 'do not pull changes from remote repository')
		],
		"[--local]",
	),
	"^upload": (
		upload,
		[],
		"change#"
	),
}


#######################################################################
# Wrappers around upload.py for interacting with Rietveld

# HTML form parser
class FormParser(HTMLParser):
	def __init__(self):
		self.map = {}
		self.curtag = None
		self.curdata = None
		HTMLParser.__init__(self)
	def handle_starttag(self, tag, attrs):
		if tag == "input":
			key = None
			value = ''
			for a in attrs:
				if a[0] == 'name':
					key = a[1]
				if a[0] == 'value':
					value = a[1]
			if key is not None:
				self.map[key] = value
		if tag == "textarea":
			key = None
			for a in attrs:
				if a[0] == 'name':
					key = a[1]
			if key is not None:
				self.curtag = key
				self.curdata = ''
	def handle_endtag(self, tag):
		if tag == "textarea" and self.curtag is not None:
			self.map[self.curtag] = self.curdata
			self.curtag = None
			self.curdata = None
	def handle_charref(self, name):
		self.handle_data(unichr(int(name)))
	def handle_entityref(self, name):
		import htmlentitydefs
		if name in htmlentitydefs.entitydefs:
			self.handle_data(htmlentitydefs.entitydefs[name])
		else:
			self.handle_data("&" + name + ";")
	def handle_data(self, data):
		if self.curdata is not None:
			self.curdata += data

# XML parser
def XMLGet(ui, path):
	try:
		data = MySend(path, force_auth=False);
	except:
		ui.warn("XMLGet %s: %s\n" % (path, ExceptionDetail()))
		return None
	return ET.XML(data)

def IsRietveldSubmitted(ui, clname, hex):
	feed = XMLGet(ui, "/rss/issue/" + clname)
	if feed is None:
		return False
	for sum in feed.findall("{http://www.w3.org/2005/Atom}entry/{http://www.w3.org/2005/Atom}summary"):
		text = sum.text.strip()
		m = re.match('\*\*\* Submitted as [^*]*?([0-9a-f]+) \*\*\*', text)
		if m is not None and len(m.group(1)) >= 8 and hex.startswith(m.group(1)):
			return True
	return False

def DownloadCL(ui, repo, clname):
	set_status("downloading CL " + clname)
	cl, err = LoadCL(ui, repo, clname)
	if err != "":
		return None, None, "error loading CL %s: %s" % (clname, ExceptionDetail())

	# Grab RSS feed to learn about CL
	feed = XMLGet(ui, "/rss/issue/" + clname)
	if feed is None:
		return None, None, "cannot download CL"

	# Find most recent diff
	diff = None
	prefix = 'http://' + server + '/'
	for link in feed.findall("{http://www.w3.org/2005/Atom}entry/{http://www.w3.org/2005/Atom}link"):
		if link.get('rel') != 'alternate':
			continue
		text = link.get('href')
		if not text.startswith(prefix) or not text.endswith('.diff'):
			continue
		diff = text[len(prefix)-1:]
	if diff is None:
		return None, None, "CL has no diff"
	diffdata = MySend(diff, force_auth=False)

	# Find author - first entry will be author who created CL.
	nick = None
	for author in feed.findall("{http://www.w3.org/2005/Atom}entry/{http://www.w3.org/2005/Atom}author/{http://www.w3.org/2005/Atom}name"):
		nick = author.text.strip()
		break
	if not nick:
		return None, None, "CL has no author"

	# The author is just a nickname: get the real email address.
	try:
		# want URL-encoded nick, but without a=, and rietveld rejects + for %20.
		url = "/user_popup/" + urllib.urlencode({"a": nick})[2:].replace("+", "%20")
		data = MySend(url, force_auth=False)
	except:
		ui.warn("error looking up %s: %s\n" % (nick, ExceptionDetail()))
		cl.copied_from = nick+"@needtofix"
		return cl, diffdata, ""
	match = re.match(r"<b>(.*) \((.*)\)</b>", data)
	if not match:
		return None, None, "error looking up %s: cannot parse result %s" % (nick, repr(data))
	if match.group(1) != nick and match.group(2) != nick:
		return None, None, "error looking up %s: got info for %s, %s" % (nick, match.group(1), match.group(2))
	email = match.group(1)

	# Print warning if email is not in CONTRIBUTORS file.
	FindContributor(ui, repo, email)
	cl.copied_from = email

	return cl, diffdata, ""

def MySend(request_path, payload=None,
		content_type="application/octet-stream",
		timeout=None, force_auth=True,
		**kwargs):
	"""Run MySend1 maybe twice, because Rietveld is unreliable."""
	try:
		return MySend1(request_path, payload, content_type, timeout, force_auth, **kwargs)
	except Exception, e:
		if type(e) == urllib2.HTTPError and e.code == 403:	# forbidden, it happens
			raise
		print >>sys.stderr, "Loading "+request_path+": "+ExceptionDetail()+"; trying again in 2 seconds."
		time.sleep(2)
		return MySend1(request_path, payload, content_type, timeout, force_auth, **kwargs)

# Like upload.py Send but only authenticates when the
# redirect is to www.google.com/accounts.  This keeps
# unnecessary redirects from happening during testing.
def MySend1(request_path, payload=None,
				content_type="application/octet-stream",
				timeout=None, force_auth=True,
				**kwargs):
	"""Sends an RPC and returns the response.

	Args:
		request_path: The path to send the request to, eg /api/appversion/create.
		payload: The body of the request, or None to send an empty request.
		content_type: The Content-Type header to use.
		timeout: timeout in seconds; default None i.e. no timeout.
			(Note: for large requests on OS X, the timeout doesn't work right.)
		kwargs: Any keyword arguments are converted into query string parameters.

	Returns:
		The response body, as a string.
	"""
	# TODO: Don't require authentication.  Let the server say
	# whether it is necessary.
	global rpc
	if rpc == None:
		rpc = GetRpcServer(upload_options)
	self = rpc
	if not self.authenticated and force_auth:
		self._Authenticate()
	if request_path is None:
		return

	old_timeout = socket.getdefaulttimeout()
	socket.setdefaulttimeout(timeout)
	try:
		tries = 0
		while True:
			tries += 1
			args = dict(kwargs)
			url = "http://%s%s" % (self.host, request_path)
			if args:
				url += "?" + urllib.urlencode(args)
			req = self._CreateRequest(url=url, data=payload)
			req.add_header("Content-Type", content_type)
			try:
				f = self.opener.open(req)
				response = f.read()
				f.close()
				# Translate \r\n into \n, because Rietveld doesn't.
				response = response.replace('\r\n', '\n')
				# who knows what urllib will give us
				if type(response) == unicode:
					response = response.encode("utf-8")
				typecheck(response, str)
				return response
			except urllib2.HTTPError, e:
				if tries > 3:
					raise
				elif e.code == 401:
					self._Authenticate()
				elif e.code == 302:
					loc = e.info()["location"]
					if not loc.startswith('https://www.google.com/a') or loc.find('/ServiceLogin') < 0:
						return ''
					self._Authenticate()
				else:
					raise
	finally:
		socket.setdefaulttimeout(old_timeout)

def GetForm(url):
	f = FormParser()
	f.feed(ustr(MySend(url)))	# f.feed wants unicode
	f.close()
	# convert back to utf-8 to restore sanity
	m = {}
	for k,v in f.map.items():
		m[k.encode("utf-8")] = v.replace("\r\n", "\n").encode("utf-8")
	return m

# Fetch the settings for the CL, like reviewer and CC list, by
# scraping the Rietveld editing forms.
def GetSettings(issue):
	set_status("getting issue metadata from web")
	# The /issue/edit page has everything but only the
	# CL owner is allowed to fetch it (and submit it).
	f = None
	try:
		f = GetForm("/" + issue + "/edit")
	except:
		pass
	if not f or 'reviewers' not in f:
		# Maybe we're not the CL owner.  Fall back to the
		# /publish page, which has the reviewer and CC lists,
		# and then fetch the description separately.
		f = GetForm("/" + issue + "/publish")
		f['description'] = MySend("/"+issue+"/description", force_auth=False)
	return f

def EditDesc(issue, subject=None, desc=None, reviewers=None, cc=None, closed=None):
	set_status("uploading change to description")
	form_fields = GetForm("/" + issue + "/edit")
	if subject is not None:
		form_fields['subject'] = subject
	if desc is not None:
		form_fields['description'] = desc
	if reviewers is not None:
		form_fields['reviewers'] = reviewers
	if cc is not None:
		form_fields['cc'] = cc
	if closed is not None:
		form_fields['closed'] = closed
	ctype, body = EncodeMultipartFormData(form_fields.items(), [])
	response = MySend("/" + issue + "/edit", body, content_type=ctype)
	if response != "":
		print >>sys.stderr, "Error editing description:\n" + "Sent form: \n", form_fields, "\n", response
		sys.exit(2)

def PostMessage(ui, issue, message, reviewers=None, cc=None, send_mail=True, subject=None):
	set_status("uploading message")
	form_fields = GetForm("/" + issue + "/publish")
	if reviewers is not None:
		form_fields['reviewers'] = reviewers
	if cc is not None:
		form_fields['cc'] = cc
	if send_mail:
		form_fields['send_mail'] = "checked"
	else:
		del form_fields['send_mail']
	if subject is not None:
		form_fields['subject'] = subject
	form_fields['message'] = message
	
	form_fields['message_only'] = '1'	# Don't include draft comments
	if reviewers is not None or cc is not None:
		form_fields['message_only'] = ''	# Must set '' in order to override cc/reviewer
	ctype = "applications/x-www-form-urlencoded"
	body = urllib.urlencode(form_fields)
	response = MySend("/" + issue + "/publish", body, content_type=ctype)
	if response != "":
		print response
		sys.exit(2)

class opt(object):
	pass

def disabled(*opts, **kwopts):
	raise util.Abort("commit is disabled when codereview is in use")

def RietveldSetup(ui, repo):
	global defaultcc, upload_options, rpc, server, server_url_base, force_google_account, verbosity, contributors
	global missing_codereview

	repo_config_path = ''
	# Read repository-specific options from lib/codereview/codereview.cfg
	try:
		repo_config_path = repo.root + '/lib/codereview/codereview.cfg'
		f = open(repo_config_path)
		for line in f:
			if line.startswith('defaultcc: '):
				defaultcc = SplitCommaSpace(line[10:])
	except:
		# If there are no options, chances are good this is not
		# a code review repository; stop now before we foul
		# things up even worse.  Might also be that repo doesn't
		# even have a root.  See issue 959.
		if repo_config_path == '':
			missing_codereview = 'codereview disabled: repository has no root'
		else:
			missing_codereview = 'codereview disabled: cannot open ' + repo_config_path
		return

	# Should only modify repository with hg submit.
	# Disable the built-in Mercurial commands that might
	# trip things up.
	cmdutil.commit = disabled

	try:
		f = open(repo.root + '/CONTRIBUTORS', 'r')
	except:
		raise util.Abort("cannot open %s: %s" % (repo.root+'/CONTRIBUTORS', ExceptionDetail()))
	for line in f:
		# CONTRIBUTORS is a list of lines like:
		#	Person <email>
		#	Person <email> <alt-email>
		# The first email address is the one used in commit logs.
		if line.startswith('#'):
			continue
		m = re.match(r"([^<>]+\S)\s+(<[^<>\s]+>)((\s+<[^<>\s]+>)*)\s*$", line)
		if m:
			name = m.group(1)
			email = m.group(2)[1:-1]
			contributors[email.lower()] = (name, email)
			for extra in m.group(3).split():
				contributors[extra[1:-1].lower()] = (name, email)

	if not ui.verbose:
		verbosity = 0

	# Config options.
	x = ui.config("codereview", "server")
	if x is not None:
		server = x

	# TODO(rsc): Take from ui.username?
	email = None
	x = ui.config("codereview", "email")
	if x is not None:
		email = x

	server_url_base = "http://" + server + "/"

	testing = ui.config("codereview", "testing")
	force_google_account = ui.configbool("codereview", "force_google_account", False)

	upload_options = opt()
	upload_options.email = email
	upload_options.host = None
	upload_options.verbose = 0
	upload_options.description = None
	upload_options.description_file = None
	upload_options.reviewers = None
	upload_options.cc = None
	upload_options.message = None
	upload_options.issue = None
	upload_options.download_base = False
	upload_options.revision = None
	upload_options.send_mail = False
	upload_options.vcs = None
	upload_options.server = server
	upload_options.save_cookies = True

	if testing:
		upload_options.save_cookies = False
		upload_options.email = "test@example.com"

	rpc = None

#######################################################################
# http://codereview.appspot.com/static/upload.py, heavily edited.

#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#	http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Tool for uploading diffs from a version control system to the codereview app.

Usage summary: upload.py [options] [-- diff_options]

Diff options are passed to the diff command of the underlying system.

Supported version control systems:
	Git
	Mercurial
	Subversion

It is important for Git/Mercurial users to specify a tree/node/branch to diff
against by using the '--rev' option.
"""
# This code is derived from appcfg.py in the App Engine SDK (open source),
# and from ASPN recipe #146306.

import cookielib
import getpass
import logging
import mimetypes
import optparse
import os
import re
import socket
import subprocess
import sys
import urllib
import urllib2
import urlparse

# The md5 module was deprecated in Python 2.5.
try:
	from hashlib import md5
except ImportError:
	from md5 import md5

try:
	import readline
except ImportError:
	pass

# The logging verbosity:
#  0: Errors only.
#  1: Status messages.
#  2: Info logs.
#  3: Debug logs.
verbosity = 1

# Max size of patch or base file.
MAX_UPLOAD_SIZE = 900 * 1024

# whitelist for non-binary filetypes which do not start with "text/"
# .mm (Objective-C) shows up as application/x-freemind on my Linux box.
TEXT_MIMETYPES = [
	'application/javascript',
	'application/x-javascript',
	'application/x-freemind'
]

def GetEmail(prompt):
	"""Prompts the user for their email address and returns it.

	The last used email address is saved to a file and offered up as a suggestion
	to the user. If the user presses enter without typing in anything the last
	used email address is used. If the user enters a new address, it is saved
	for next time we prompt.

	"""
	last_email_file_name = os.path.expanduser("~/.last_codereview_email_address")
	last_email = ""
	if os.path.exists(last_email_file_name):
		try:
			last_email_file = open(last_email_file_name, "r")
			last_email = last_email_file.readline().strip("\n")
			last_email_file.close()
			prompt += " [%s]" % last_email
		except IOError, e:
			pass
	email = raw_input(prompt + ": ").strip()
	if email:
		try:
			last_email_file = open(last_email_file_name, "w")
			last_email_file.write(email)
			last_email_file.close()
		except IOError, e:
			pass
	else:
		email = last_email
	return email


def StatusUpdate(msg):
	"""Print a status message to stdout.

	If 'verbosity' is greater than 0, print the message.

	Args:
		msg: The string to print.
	"""
	if verbosity > 0:
		print msg


def ErrorExit(msg):
	"""Print an error message to stderr and exit."""
	print >>sys.stderr, msg
	sys.exit(1)


class ClientLoginError(urllib2.HTTPError):
	"""Raised to indicate there was an error authenticating with ClientLogin."""

	def __init__(self, url, code, msg, headers, args):
		urllib2.HTTPError.__init__(self, url, code, msg, headers, None)
		self.args = args
		self.reason = args["Error"]


class AbstractRpcServer(object):
	"""Provides a common interface for a simple RPC server."""

	def __init__(self, host, auth_function, host_override=None, extra_headers={}, save_cookies=False):
		"""Creates a new HttpRpcServer.

		Args:
			host: The host to send requests to.
			auth_function: A function that takes no arguments and returns an
				(email, password) tuple when called. Will be called if authentication
				is required.
			host_override: The host header to send to the server (defaults to host).
			extra_headers: A dict of extra headers to append to every request.
			save_cookies: If True, save the authentication cookies to local disk.
				If False, use an in-memory cookiejar instead.  Subclasses must
				implement this functionality.  Defaults to False.
		"""
		self.host = host
		self.host_override = host_override
		self.auth_function = auth_function
		self.authenticated = False
		self.extra_headers = extra_headers
		self.save_cookies = save_cookies
		self.opener = self._GetOpener()
		if self.host_override:
			logging.info("Server: %s; Host: %s", self.host, self.host_override)
		else:
			logging.info("Server: %s", self.host)

	def _GetOpener(self):
		"""Returns an OpenerDirector for making HTTP requests.

		Returns:
			A urllib2.OpenerDirector object.
		"""
		raise NotImplementedError()

	def _CreateRequest(self, url, data=None):
		"""Creates a new urllib request."""
		logging.debug("Creating request for: '%s' with payload:\n%s", url, data)
		req = urllib2.Request(url, data=data)
		if self.host_override:
			req.add_header("Host", self.host_override)
		for key, value in self.extra_headers.iteritems():
			req.add_header(key, value)
		return req

	def _GetAuthToken(self, email, password):
		"""Uses ClientLogin to authenticate the user, returning an auth token.

		Args:
			email:    The user's email address
			password: The user's password

		Raises:
			ClientLoginError: If there was an error authenticating with ClientLogin.
			HTTPError: If there was some other form of HTTP error.

		Returns:
			The authentication token returned by ClientLogin.
		"""
		account_type = "GOOGLE"
		if self.host.endswith(".google.com") and not force_google_account:
			# Needed for use inside Google.
			account_type = "HOSTED"
		req = self._CreateRequest(
				url="https://www.google.com/accounts/ClientLogin",
				data=urllib.urlencode({
						"Email": email,
						"Passwd": password,
						"service": "ah",
						"source": "rietveld-codereview-upload",
						"accountType": account_type,
				}),
		)
		try:
			response = self.opener.open(req)
			response_body = response.read()
			response_dict = dict(x.split("=") for x in response_body.split("\n") if x)
			return response_dict["Auth"]
		except urllib2.HTTPError, e:
			if e.code == 403:
				body = e.read()
				response_dict = dict(x.split("=", 1) for x in body.split("\n") if x)
				raise ClientLoginError(req.get_full_url(), e.code, e.msg, e.headers, response_dict)
			else:
				raise

	def _GetAuthCookie(self, auth_token):
		"""Fetches authentication cookies for an authentication token.

		Args:
			auth_token: The authentication token returned by ClientLogin.

		Raises:
			HTTPError: If there was an error fetching the authentication cookies.
		"""
		# This is a dummy value to allow us to identify when we're successful.
		continue_location = "http://localhost/"
		args = {"continue": continue_location, "auth": auth_token}
		req = self._CreateRequest("http://%s/_ah/login?%s" % (self.host, urllib.urlencode(args)))
		try:
			response = self.opener.open(req)
		except urllib2.HTTPError, e:
			response = e
		if (response.code != 302 or
				response.info()["location"] != continue_location):
			raise urllib2.HTTPError(req.get_full_url(), response.code, response.msg, response.headers, response.fp)
		self.authenticated = True

	def _Authenticate(self):
		"""Authenticates the user.

		The authentication process works as follows:
		1) We get a username and password from the user
		2) We use ClientLogin to obtain an AUTH token for the user
				(see http://code.google.com/apis/accounts/AuthForInstalledApps.html).
		3) We pass the auth token to /_ah/login on the server to obtain an
				authentication cookie. If login was successful, it tries to redirect
				us to the URL we provided.

		If we attempt to access the upload API without first obtaining an
		authentication cookie, it returns a 401 response (or a 302) and
		directs us to authenticate ourselves with ClientLogin.
		"""
		for i in range(3):
			credentials = self.auth_function()
			try:
				auth_token = self._GetAuthToken(credentials[0], credentials[1])
			except ClientLoginError, e:
				if e.reason == "BadAuthentication":
					print >>sys.stderr, "Invalid username or password."
					continue
				if e.reason == "CaptchaRequired":
					print >>sys.stderr, (
						"Please go to\n"
						"https://www.google.com/accounts/DisplayUnlockCaptcha\n"
						"and verify you are a human.  Then try again.")
					break
				if e.reason == "NotVerified":
					print >>sys.stderr, "Account not verified."
					break
				if e.reason == "TermsNotAgreed":
					print >>sys.stderr, "User has not agreed to TOS."
					break
				if e.reason == "AccountDeleted":
					print >>sys.stderr, "The user account has been deleted."
					break
				if e.reason == "AccountDisabled":
					print >>sys.stderr, "The user account has been disabled."
					break
				if e.reason == "ServiceDisabled":
					print >>sys.stderr, "The user's access to the service has been disabled."
					break
				if e.reason == "ServiceUnavailable":
					print >>sys.stderr, "The service is not available; try again later."
					break
				raise
			self._GetAuthCookie(auth_token)
			return

	def Send(self, request_path, payload=None,
					content_type="application/octet-stream",
					timeout=None,
					**kwargs):
		"""Sends an RPC and returns the response.

		Args:
			request_path: The path to send the request to, eg /api/appversion/create.
			payload: The body of the request, or None to send an empty request.
			content_type: The Content-Type header to use.
			timeout: timeout in seconds; default None i.e. no timeout.
				(Note: for large requests on OS X, the timeout doesn't work right.)
			kwargs: Any keyword arguments are converted into query string parameters.

		Returns:
			The response body, as a string.
		"""
		# TODO: Don't require authentication.  Let the server say
		# whether it is necessary.
		if not self.authenticated:
			self._Authenticate()

		old_timeout = socket.getdefaulttimeout()
		socket.setdefaulttimeout(timeout)
		try:
			tries = 0
			while True:
				tries += 1
				args = dict(kwargs)
				url = "http://%s%s" % (self.host, request_path)
				if args:
					url += "?" + urllib.urlencode(args)
				req = self._CreateRequest(url=url, data=payload)
				req.add_header("Content-Type", content_type)
				try:
					f = self.opener.open(req)
					response = f.read()
					f.close()
					return response
				except urllib2.HTTPError, e:
					if tries > 3:
						raise
					elif e.code == 401 or e.code == 302:
						self._Authenticate()
					else:
						raise
		finally:
			socket.setdefaulttimeout(old_timeout)


class HttpRpcServer(AbstractRpcServer):
	"""Provides a simplified RPC-style interface for HTTP requests."""

	def _Authenticate(self):
		"""Save the cookie jar after authentication."""
		super(HttpRpcServer, self)._Authenticate()
		if self.save_cookies:
			StatusUpdate("Saving authentication cookies to %s" % self.cookie_file)
			self.cookie_jar.save()

	def _GetOpener(self):
		"""Returns an OpenerDirector that supports cookies and ignores redirects.

		Returns:
			A urllib2.OpenerDirector object.
		"""
		opener = urllib2.OpenerDirector()
		opener.add_handler(urllib2.ProxyHandler())
		opener.add_handler(urllib2.UnknownHandler())
		opener.add_handler(urllib2.HTTPHandler())
		opener.add_handler(urllib2.HTTPDefaultErrorHandler())
		opener.add_handler(urllib2.HTTPSHandler())
		opener.add_handler(urllib2.HTTPErrorProcessor())
		if self.save_cookies:
			self.cookie_file = os.path.expanduser("~/.codereview_upload_cookies_" + server)
			self.cookie_jar = cookielib.MozillaCookieJar(self.cookie_file)
			if os.path.exists(self.cookie_file):
				try:
					self.cookie_jar.load()
					self.authenticated = True
					StatusUpdate("Loaded authentication cookies from %s" % self.cookie_file)
				except (cookielib.LoadError, IOError):
					# Failed to load cookies - just ignore them.
					pass
			else:
				# Create an empty cookie file with mode 600
				fd = os.open(self.cookie_file, os.O_CREAT, 0600)
				os.close(fd)
			# Always chmod the cookie file
			os.chmod(self.cookie_file, 0600)
		else:
			# Don't save cookies across runs of update.py.
			self.cookie_jar = cookielib.CookieJar()
		opener.add_handler(urllib2.HTTPCookieProcessor(self.cookie_jar))
		return opener


def GetRpcServer(options):
	"""Returns an instance of an AbstractRpcServer.

	Returns:
		A new AbstractRpcServer, on which RPC calls can be made.
	"""

	rpc_server_class = HttpRpcServer

	def GetUserCredentials():
		"""Prompts the user for a username and password."""
		# Disable status prints so they don't obscure the password prompt.
		global global_status
		st = global_status
		global_status = None

		email = options.email
		if email is None:
			email = GetEmail("Email (login for uploading to %s)" % options.server)
		password = getpass.getpass("Password for %s: " % email)

		# Put status back.
		global_status = st
		return (email, password)

	# If this is the dev_appserver, use fake authentication.
	host = (options.host or options.server).lower()
	if host == "localhost" or host.startswith("localhost:"):
		email = options.email
		if email is None:
			email = "test@example.com"
			logging.info("Using debug user %s.  Override with --email" % email)
		server = rpc_server_class(
				options.server,
				lambda: (email, "password"),
				host_override=options.host,
				extra_headers={"Cookie": 'dev_appserver_login="%s:False"' % email},
				save_cookies=options.save_cookies)
		# Don't try to talk to ClientLogin.
		server.authenticated = True
		return server

	return rpc_server_class(options.server, GetUserCredentials,
		host_override=options.host, save_cookies=options.save_cookies)


def EncodeMultipartFormData(fields, files):
	"""Encode form fields for multipart/form-data.

	Args:
		fields: A sequence of (name, value) elements for regular form fields.
		files: A sequence of (name, filename, value) elements for data to be
					uploaded as files.
	Returns:
		(content_type, body) ready for httplib.HTTP instance.

	Source:
		http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/146306
	"""
	BOUNDARY = '-M-A-G-I-C---B-O-U-N-D-A-R-Y-'
	CRLF = '\r\n'
	lines = []
	for (key, value) in fields:
		typecheck(key, str)
		typecheck(value, str)
		lines.append('--' + BOUNDARY)
		lines.append('Content-Disposition: form-data; name="%s"' % key)
		lines.append('')
		lines.append(value)
	for (key, filename, value) in files:
		typecheck(key, str)
		typecheck(filename, str)
		typecheck(value, str)
		lines.append('--' + BOUNDARY)
		lines.append('Content-Disposition: form-data; name="%s"; filename="%s"' % (key, filename))
		lines.append('Content-Type: %s' % GetContentType(filename))
		lines.append('')
		lines.append(value)
	lines.append('--' + BOUNDARY + '--')
	lines.append('')
	body = CRLF.join(lines)
	content_type = 'multipart/form-data; boundary=%s' % BOUNDARY
	return content_type, body


def GetContentType(filename):
	"""Helper to guess the content-type from the filename."""
	return mimetypes.guess_type(filename)[0] or 'application/octet-stream'


# Use a shell for subcommands on Windows to get a PATH search.
use_shell = sys.platform.startswith("win")

def RunShellWithReturnCode(command, print_output=False,
		universal_newlines=True, env=os.environ):
	"""Executes a command and returns the output from stdout and the return code.

	Args:
		command: Command to execute.
		print_output: If True, the output is printed to stdout.
			If False, both stdout and stderr are ignored.
		universal_newlines: Use universal_newlines flag (default: True).

	Returns:
		Tuple (output, return code)
	"""
	logging.info("Running %s", command)
	p = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
		shell=use_shell, universal_newlines=universal_newlines, env=env)
	if print_output:
		output_array = []
		while True:
			line = p.stdout.readline()
			if not line:
				break
			print line.strip("\n")
			output_array.append(line)
		output = "".join(output_array)
	else:
		output = p.stdout.read()
	p.wait()
	errout = p.stderr.read()
	if print_output and errout:
		print >>sys.stderr, errout
	p.stdout.close()
	p.stderr.close()
	return output, p.returncode


def RunShell(command, silent_ok=False, universal_newlines=True,
		print_output=False, env=os.environ):
	data, retcode = RunShellWithReturnCode(command, print_output, universal_newlines, env)
	if retcode:
		ErrorExit("Got error status from %s:\n%s" % (command, data))
	if not silent_ok and not data:
		ErrorExit("No output from %s" % command)
	return data


class VersionControlSystem(object):
	"""Abstract base class providing an interface to the VCS."""

	def __init__(self, options):
		"""Constructor.

		Args:
			options: Command line options.
		"""
		self.options = options

	def GenerateDiff(self, args):
		"""Return the current diff as a string.

		Args:
			args: Extra arguments to pass to the diff command.
		"""
		raise NotImplementedError(
				"abstract method -- subclass %s must override" % self.__class__)

	def GetUnknownFiles(self):
		"""Return a list of files unknown to the VCS."""
		raise NotImplementedError(
				"abstract method -- subclass %s must override" % self.__class__)

	def CheckForUnknownFiles(self):
		"""Show an "are you sure?" prompt if there are unknown files."""
		unknown_files = self.GetUnknownFiles()
		if unknown_files:
			print "The following files are not added to version control:"
			for line in unknown_files:
				print line
			prompt = "Are you sure to continue?(y/N) "
			answer = raw_input(prompt).strip()
			if answer != "y":
				ErrorExit("User aborted")

	def GetBaseFile(self, filename):
		"""Get the content of the upstream version of a file.

		Returns:
			A tuple (base_content, new_content, is_binary, status)
				base_content: The contents of the base file.
				new_content: For text files, this is empty.  For binary files, this is
					the contents of the new file, since the diff output won't contain
					information to reconstruct the current file.
				is_binary: True iff the file is binary.
				status: The status of the file.
		"""

		raise NotImplementedError(
				"abstract method -- subclass %s must override" % self.__class__)


	def GetBaseFiles(self, diff):
		"""Helper that calls GetBase file for each file in the patch.

		Returns:
			A dictionary that maps from filename to GetBaseFile's tuple.  Filenames
			are retrieved based on lines that start with "Index:" or
			"Property changes on:".
		"""
		files = {}
		for line in diff.splitlines(True):
			if line.startswith('Index:') or line.startswith('Property changes on:'):
				unused, filename = line.split(':', 1)
				# On Windows if a file has property changes its filename uses '\'
				# instead of '/'.
				filename = filename.strip().replace('\\', '/')
				files[filename] = self.GetBaseFile(filename)
		return files


	def UploadBaseFiles(self, issue, rpc_server, patch_list, patchset, options,
											files):
		"""Uploads the base files (and if necessary, the current ones as well)."""

		def UploadFile(filename, file_id, content, is_binary, status, is_base):
			"""Uploads a file to the server."""
			set_status("uploading " + filename)
			file_too_large = False
			if is_base:
				type = "base"
			else:
				type = "current"
			if len(content) > MAX_UPLOAD_SIZE:
				print ("Not uploading the %s file for %s because it's too large." %
							(type, filename))
				file_too_large = True
				content = ""
			checksum = md5(content).hexdigest()
			if options.verbose > 0 and not file_too_large:
				print "Uploading %s file for %s" % (type, filename)
			url = "/%d/upload_content/%d/%d" % (int(issue), int(patchset), file_id)
			form_fields = [
				("filename", filename),
				("status", status),
				("checksum", checksum),
				("is_binary", str(is_binary)),
				("is_current", str(not is_base)),
			]
			if file_too_large:
				form_fields.append(("file_too_large", "1"))
			if options.email:
				form_fields.append(("user", options.email))
			ctype, body = EncodeMultipartFormData(form_fields, [("data", filename, content)])
			response_body = rpc_server.Send(url, body, content_type=ctype)
			if not response_body.startswith("OK"):
				StatusUpdate("  --> %s" % response_body)
				sys.exit(1)

		# Don't want to spawn too many threads, nor do we want to
		# hit Rietveld too hard, or it will start serving 500 errors.
		# When 8 works, it's no better than 4, and sometimes 8 is
		# too many for Rietveld to handle.
		MAX_PARALLEL_UPLOADS = 4

		sema = threading.BoundedSemaphore(MAX_PARALLEL_UPLOADS)
		upload_threads = []
		finished_upload_threads = []
		
		class UploadFileThread(threading.Thread):
			def __init__(self, args):
				threading.Thread.__init__(self)
				self.args = args
			def run(self):
				UploadFile(*self.args)
				finished_upload_threads.append(self)
				sema.release()

		def StartUploadFile(*args):
			sema.acquire()
			while len(finished_upload_threads) > 0:
				t = finished_upload_threads.pop()
				upload_threads.remove(t)
				t.join()
			t = UploadFileThread(args)
			upload_threads.append(t)
			t.start()

		def WaitForUploads():			
			for t in upload_threads:
				t.join()

		patches = dict()
		[patches.setdefault(v, k) for k, v in patch_list]
		for filename in patches.keys():
			base_content, new_content, is_binary, status = files[filename]
			file_id_str = patches.get(filename)
			if file_id_str.find("nobase") != -1:
				base_content = None
				file_id_str = file_id_str[file_id_str.rfind("_") + 1:]
			file_id = int(file_id_str)
			if base_content != None:
				StartUploadFile(filename, file_id, base_content, is_binary, status, True)
			if new_content != None:
				StartUploadFile(filename, file_id, new_content, is_binary, status, False)
		WaitForUploads()

	def IsImage(self, filename):
		"""Returns true if the filename has an image extension."""
		mimetype =  mimetypes.guess_type(filename)[0]
		if not mimetype:
			return False
		return mimetype.startswith("image/")

	def IsBinary(self, filename):
		"""Returns true if the guessed mimetyped isnt't in text group."""
		mimetype = mimetypes.guess_type(filename)[0]
		if not mimetype:
			return False  # e.g. README, "real" binaries usually have an extension
		# special case for text files which don't start with text/
		if mimetype in TEXT_MIMETYPES:
			return False
		return not mimetype.startswith("text/")

class FakeMercurialUI(object):
	def __init__(self):
		self.quiet = True
		self.output = ''
	
	def write(self, *args, **opts):
		self.output += ' '.join(args)

use_hg_shell = False	# set to True to shell out to hg always; slower

class MercurialVCS(VersionControlSystem):
	"""Implementation of the VersionControlSystem interface for Mercurial."""

	def __init__(self, options, ui, repo):
		super(MercurialVCS, self).__init__(options)
		self.ui = ui
		self.repo = repo
		# Absolute path to repository (we can be in a subdir)
		self.repo_dir = os.path.normpath(repo.root)
		# Compute the subdir
		cwd = os.path.normpath(os.getcwd())
		assert cwd.startswith(self.repo_dir)
		self.subdir = cwd[len(self.repo_dir):].lstrip(r"\/")
		if self.options.revision:
			self.base_rev = self.options.revision
		else:
			mqparent, err = RunShellWithReturnCode(['hg', 'log', '--rev', 'qparent', '--template={node}'])
			if not err and mqparent != "":
				self.base_rev = mqparent
			else:
				self.base_rev = RunShell(["hg", "parents", "-q"]).split(':')[1].strip()
	def _GetRelPath(self, filename):
		"""Get relative path of a file according to the current directory,
		given its logical path in the repo."""
		assert filename.startswith(self.subdir), (filename, self.subdir)
		return filename[len(self.subdir):].lstrip(r"\/")

	def GenerateDiff(self, extra_args):
		# If no file specified, restrict to the current subdir
		extra_args = extra_args or ["."]
		cmd = ["hg", "diff", "--git", "-r", self.base_rev] + extra_args
		data = RunShell(cmd, silent_ok=True)
		svndiff = []
		filecount = 0
		for line in data.splitlines():
			m = re.match("diff --git a/(\S+) b/(\S+)", line)
			if m:
				# Modify line to make it look like as it comes from svn diff.
				# With this modification no changes on the server side are required
				# to make upload.py work with Mercurial repos.
				# NOTE: for proper handling of moved/copied files, we have to use
				# the second filename.
				filename = m.group(2)
				svndiff.append("Index: %s" % filename)
				svndiff.append("=" * 67)
				filecount += 1
				logging.info(line)
			else:
				svndiff.append(line)
		if not filecount:
			ErrorExit("No valid patches found in output from hg diff")
		return "\n".join(svndiff) + "\n"

	def GetUnknownFiles(self):
		"""Return a list of files unknown to the VCS."""
		args = []
		status = RunShell(["hg", "status", "--rev", self.base_rev, "-u", "."],
				silent_ok=True)
		unknown_files = []
		for line in status.splitlines():
			st, fn = line.split(" ", 1)
			if st == "?":
				unknown_files.append(fn)
		return unknown_files

	def GetBaseFile(self, filename):
		set_status("inspecting " + filename)
		# "hg status" and "hg cat" both take a path relative to the current subdir
		# rather than to the repo root, but "hg diff" has given us the full path
		# to the repo root.
		base_content = ""
		new_content = None
		is_binary = False
		oldrelpath = relpath = self._GetRelPath(filename)
		# "hg status -C" returns two lines for moved/copied files, one otherwise
		if use_hg_shell:
			out = RunShell(["hg", "status", "-C", "--rev", self.base_rev, relpath])
		else:
			fui = FakeMercurialUI()
			ret = commands.status(fui, self.repo, *[relpath], **{'rev': [self.base_rev], 'copies': True})
			if ret:
				raise util.Abort(ret)
			out = fui.output
		out = out.splitlines()
		# HACK: strip error message about missing file/directory if it isn't in
		# the working copy
		if out[0].startswith('%s: ' % relpath):
			out = out[1:]
		status, what = out[0].split(' ', 1)
		if len(out) > 1 and status == "A" and what == relpath:
			oldrelpath = out[1].strip()
			status = "M"
		if ":" in self.base_rev:
			base_rev = self.base_rev.split(":", 1)[0]
		else:
			base_rev = self.base_rev
		if status != "A":
			if use_hg_shell:
				base_content = RunShell(["hg", "cat", "-r", base_rev, oldrelpath], silent_ok=True)
			else:
				base_content = str(self.repo[base_rev][oldrelpath].data())
			is_binary = "\0" in base_content  # Mercurial's heuristic
		if status != "R":
			new_content = open(relpath, "rb").read()
			is_binary = is_binary or "\0" in new_content
		if is_binary and base_content and use_hg_shell:
			# Fetch again without converting newlines
			base_content = RunShell(["hg", "cat", "-r", base_rev, oldrelpath],
				silent_ok=True, universal_newlines=False)
		if not is_binary or not self.IsImage(relpath):
			new_content = None
		return base_content, new_content, is_binary, status


# NOTE: The SplitPatch function is duplicated in engine.py, keep them in sync.
def SplitPatch(data):
	"""Splits a patch into separate pieces for each file.

	Args:
		data: A string containing the output of svn diff.

	Returns:
		A list of 2-tuple (filename, text) where text is the svn diff output
			pertaining to filename.
	"""
	patches = []
	filename = None
	diff = []
	for line in data.splitlines(True):
		new_filename = None
		if line.startswith('Index:'):
			unused, new_filename = line.split(':', 1)
			new_filename = new_filename.strip()
		elif line.startswith('Property changes on:'):
			unused, temp_filename = line.split(':', 1)
			# When a file is modified, paths use '/' between directories, however
			# when a property is modified '\' is used on Windows.  Make them the same
			# otherwise the file shows up twice.
			temp_filename = temp_filename.strip().replace('\\', '/')
			if temp_filename != filename:
				# File has property changes but no modifications, create a new diff.
				new_filename = temp_filename
		if new_filename:
			if filename and diff:
				patches.append((filename, ''.join(diff)))
			filename = new_filename
			diff = [line]
			continue
		if diff is not None:
			diff.append(line)
	if filename and diff:
		patches.append((filename, ''.join(diff)))
	return patches


def UploadSeparatePatches(issue, rpc_server, patchset, data, options):
	"""Uploads a separate patch for each file in the diff output.

	Returns a list of [patch_key, filename] for each file.
	"""
	patches = SplitPatch(data)
	rv = []
	for patch in patches:
		set_status("uploading patch for " + patch[0])
		if len(patch[1]) > MAX_UPLOAD_SIZE:
			print ("Not uploading the patch for " + patch[0] +
				" because the file is too large.")
			continue
		form_fields = [("filename", patch[0])]
		if not options.download_base:
			form_fields.append(("content_upload", "1"))
		files = [("data", "data.diff", patch[1])]
		ctype, body = EncodeMultipartFormData(form_fields, files)
		url = "/%d/upload_patch/%d" % (int(issue), int(patchset))
		print "Uploading patch for " + patch[0]
		response_body = rpc_server.Send(url, body, content_type=ctype)
		lines = response_body.splitlines()
		if not lines or lines[0] != "OK":
			StatusUpdate("  --> %s" % response_body)
			sys.exit(1)
		rv.append([lines[1], patch[0]])
	return rv