// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package path

import (
	"os"
	"testing"
)

type CleanTest struct {
	path, clean string
}

var cleantests = []CleanTest{
	// Already clean
	CleanTest{"", "."},
	CleanTest{"abc", "abc"},
	CleanTest{"abc/def", "abc/def"},
	CleanTest{"a/b/c", "a/b/c"},
	CleanTest{".", "."},
	CleanTest{"..", ".."},
	CleanTest{"../..", "../.."},
	CleanTest{"../../abc", "../../abc"},
	CleanTest{"/abc", "/abc"},
	CleanTest{"/", "/"},

	// Remove trailing slash
	CleanTest{"abc/", "abc"},
	CleanTest{"abc/def/", "abc/def"},
	CleanTest{"a/b/c/", "a/b/c"},
	CleanTest{"./", "."},
	CleanTest{"../", ".."},
	CleanTest{"../../", "../.."},
	CleanTest{"/abc/", "/abc"},

	// Remove doubled slash
	CleanTest{"abc//def//ghi", "abc/def/ghi"},
	CleanTest{"//abc", "/abc"},
	CleanTest{"///abc", "/abc"},
	CleanTest{"//abc//", "/abc"},
	CleanTest{"abc//", "abc"},

	// Remove . elements
	CleanTest{"abc/./def", "abc/def"},
	CleanTest{"/./abc/def", "/abc/def"},
	CleanTest{"abc/.", "abc"},

	// Remove .. elements
	CleanTest{"abc/def/ghi/../jkl", "abc/def/jkl"},
	CleanTest{"abc/def/../ghi/../jkl", "abc/jkl"},
	CleanTest{"abc/def/..", "abc"},
	CleanTest{"abc/def/../..", "."},
	CleanTest{"/abc/def/../..", "/"},
	CleanTest{"abc/def/../../..", ".."},
	CleanTest{"/abc/def/../../..", "/"},
	CleanTest{"abc/def/../../../ghi/jkl/../../../mno", "../../mno"},

	// Combinations
	CleanTest{"abc/./../def", "def"},
	CleanTest{"abc//./../def", "def"},
	CleanTest{"abc/../../././../def", "../../def"},
}

func TestClean(t *testing.T) {
	for _, test := range cleantests {
		if s := Clean(test.path); s != test.clean {
			t.Errorf("Clean(%q) = %q, want %q", test.path, s, test.clean)
		}
	}
}

type SplitTest struct {
	path, dir, file string
}

var splittests = []SplitTest{
	SplitTest{"a/b", "a/", "b"},
	SplitTest{"a/b/", "a/b/", ""},
	SplitTest{"a/", "a/", ""},
	SplitTest{"a", "", "a"},
	SplitTest{"/", "/", ""},
}

func TestSplit(t *testing.T) {
	for _, test := range splittests {
		if d, f := Split(test.path); d != test.dir || f != test.file {
			t.Errorf("Split(%q) = %q, %q, want %q, %q", test.path, d, f, test.dir, test.file)
		}
	}
}

type JoinTest struct {
	elem []string
	path string
}

var jointests = []JoinTest{
	// zero parameters
	JoinTest{[]string{}, ""},

	// one parameter
	JoinTest{[]string{""}, ""},
	JoinTest{[]string{"a"}, "a"},

	// two parameters
	JoinTest{[]string{"a", "b"}, "a/b"},
	JoinTest{[]string{"a", ""}, "a"},
	JoinTest{[]string{"", "b"}, "b"},
	JoinTest{[]string{"/", "a"}, "/a"},
	JoinTest{[]string{"/", ""}, "/"},
	JoinTest{[]string{"a/", "b"}, "a/b"},
	JoinTest{[]string{"a/", ""}, "a"},
	JoinTest{[]string{"", ""}, ""},
}

// join takes a []string and passes it to Join.
func join(elem []string, args ...string) string {
	args = elem
	return Join(args)
}

func TestJoin(t *testing.T) {
	for _, test := range jointests {
		if p := join(test.elem); p != test.path {
			t.Errorf("join(%q) = %q, want %q", test.elem, p, test.path)
		}
	}
}

type ExtTest struct {
	path, ext string
}

var exttests = []ExtTest{
	ExtTest{"path.go", ".go"},
	ExtTest{"path.pb.go", ".go"},
	ExtTest{"a.dir/b", ""},
	ExtTest{"a.dir/b.go", ".go"},
	ExtTest{"a.dir/", ""},
}

func TestExt(t *testing.T) {
	for _, test := range exttests {
		if x := Ext(test.path); x != test.ext {
			t.Errorf("Ext(%q) = %q, want %q", test.path, x, test.ext)
		}
	}
}

type Node struct {
	name    string
	entries []*Node // nil if the entry is a file
	mark    int
}

var tree = &Node{
	"testdata",
	[]*Node{
		&Node{"a", nil, 0},
		&Node{"b", []*Node{}, 0},
		&Node{"c", nil, 0},
		&Node{
			"d",
			[]*Node{
				&Node{"x", nil, 0},
				&Node{"y", []*Node{}, 0},
				&Node{
					"z",
					[]*Node{
						&Node{"u", nil, 0},
						&Node{"v", nil, 0},
					},
					0,
				},
			},
			0,
		},
	},
	0,
}

func walkTree(n *Node, path string, f func(path string, n *Node)) {
	f(path, n)
	for _, e := range n.entries {
		walkTree(e, Join(path, e.name), f)
	}
}

func makeTree(t *testing.T) {
	walkTree(tree, tree.name, func(path string, n *Node) {
		if n.entries == nil {
			fd, err := os.Open(path, os.O_CREAT, 0660)
			if err != nil {
				t.Errorf("makeTree: %v", err)
			}
			fd.Close()
		} else {
			os.Mkdir(path, 0770)
		}
	})
}

func markTree(n *Node) { walkTree(n, "", func(path string, n *Node) { n.mark++ }) }

func checkMarks(t *testing.T) {
	walkTree(tree, tree.name, func(path string, n *Node) {
		if n.mark != 1 {
			t.Errorf("node %s mark = %d; expected 1", path, n.mark)
		}
		n.mark = 0
	})
}

// Assumes that each node name is unique. Good enough for a test.
func mark(name string) {
	walkTree(tree, tree.name, func(path string, n *Node) {
		if n.name == name {
			n.mark++
		}
	})
}

type TestVisitor struct{}

func (v *TestVisitor) VisitDir(path string, d *os.Dir) bool {
	mark(d.Name)
	return true
}

func (v *TestVisitor) VisitFile(path string, d *os.Dir) {
	mark(d.Name)
}

func TestWalk(t *testing.T) {
	makeTree(t)

	// 1) ignore error handling, expect none
	v := &TestVisitor{}
	Walk(tree.name, v, nil)
	checkMarks(t)

	// 2) handle errors, expect none
	errors := make(chan os.Error, 64)
	Walk(tree.name, v, errors)
	if err, ok := <-errors; ok {
		t.Errorf("no error expected, found: s", err)
	}
	checkMarks(t)

	if os.Getuid() != 0 {
		// introduce 2 errors: chmod top-level directories to 0
		os.Chmod(Join(tree.name, tree.entries[1].name), 0)
		os.Chmod(Join(tree.name, tree.entries[3].name), 0)
		// mark respective subtrees manually
		markTree(tree.entries[1])
		markTree(tree.entries[3])
		// correct double-marking of directory itself
		tree.entries[1].mark--
		tree.entries[3].mark--

		// 3) handle errors, expect two
		errors = make(chan os.Error, 64)
		os.Chmod(Join(tree.name, tree.entries[1].name), 0)
		Walk(tree.name, v, errors)
		for i := 1; i <= 2; i++ {
			if _, ok := <-errors; !ok {
				t.Errorf("%d. error expected, none found", i)
				break
			}
		}
		if err, ok := <-errors; ok {
			t.Errorf("only two errors expected, found 3rd: %v", err)
		}
		// the inaccessible subtrees were marked manually
		checkMarks(t)
	}

	// cleanup
	os.Chmod(Join(tree.name, tree.entries[1].name), 0770)
	os.Chmod(Join(tree.name, tree.entries[3].name), 0770)
	if err := os.RemoveAll(tree.name); err != nil {
		t.Errorf("removeTree: %v", err)
	}
}