// 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 net

import (
	"flag"
	"io"
	"regexp"
	"runtime"
	"testing"
	"time"
)

var runErrorTest = flag.Bool("run_error_test", false, "let TestDialError check for dns errors")

type DialErrorTest struct {
	Net     string
	Raddr   string
	Pattern string
}

var dialErrorTests = []DialErrorTest{
	{
		"datakit", "mh/astro/r70",
		"dial datakit mh/astro/r70: unknown network datakit",
	},
	{
		"tcp", "127.0.0.1:☺",
		"dial tcp 127.0.0.1:☺: unknown port tcp/☺",
	},
	{
		"tcp", "no-such-name.google.com.:80",
		"dial tcp no-such-name.google.com.:80: lookup no-such-name.google.com.( on .*)?: no (.*)",
	},
	{
		"tcp", "no-such-name.no-such-top-level-domain.:80",
		"dial tcp no-such-name.no-such-top-level-domain.:80: lookup no-such-name.no-such-top-level-domain.( on .*)?: no (.*)",
	},
	{
		"tcp", "no-such-name:80",
		`dial tcp no-such-name:80: lookup no-such-name\.(.*\.)?( on .*)?: no (.*)`,
	},
	{
		"tcp", "mh/astro/r70:http",
		"dial tcp mh/astro/r70:http: lookup mh/astro/r70: invalid domain name",
	},
	{
		"unix", "/etc/file-not-found",
		"dial unix /etc/file-not-found: no such file or directory",
	},
	{
		"unix", "/etc/",
		"dial unix /etc/: (permission denied|socket operation on non-socket|connection refused)",
	},
	{
		"unixpacket", "/etc/file-not-found",
		"dial unixpacket /etc/file-not-found: no such file or directory",
	},
	{
		"unixpacket", "/etc/",
		"dial unixpacket /etc/: (permission denied|socket operation on non-socket|connection refused)",
	},
}

var duplicateErrorPattern = `dial (.*) dial (.*)`

func TestDialError(t *testing.T) {
	if !*runErrorTest {
		t.Logf("test disabled; use --run_error_test to enable")
		return
	}
	for i, tt := range dialErrorTests {
		c, err := Dial(tt.Net, tt.Raddr)
		if c != nil {
			c.Close()
		}
		if err == nil {
			t.Errorf("#%d: nil error, want match for %#q", i, tt.Pattern)
			continue
		}
		s := err.Error()
		match, _ := regexp.MatchString(tt.Pattern, s)
		if !match {
			t.Errorf("#%d: %q, want match for %#q", i, s, tt.Pattern)
		}
		match, _ = regexp.MatchString(duplicateErrorPattern, s)
		if match {
			t.Errorf("#%d: %q, duplicate error return from Dial", i, s)
		}
	}
}

var revAddrTests = []struct {
	Addr      string
	Reverse   string
	ErrPrefix string
}{
	{"1.2.3.4", "4.3.2.1.in-addr.arpa.", ""},
	{"245.110.36.114", "114.36.110.245.in-addr.arpa.", ""},
	{"::ffff:12.34.56.78", "78.56.34.12.in-addr.arpa.", ""},
	{"::1", "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa.", ""},
	{"1::", "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.0.0.0.ip6.arpa.", ""},
	{"1234:567::89a:bcde", "e.d.c.b.a.9.8.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.7.6.5.0.4.3.2.1.ip6.arpa.", ""},
	{"1234:567:fefe:bcbc:adad:9e4a:89a:bcde", "e.d.c.b.a.9.8.0.a.4.e.9.d.a.d.a.c.b.c.b.e.f.e.f.7.6.5.0.4.3.2.1.ip6.arpa.", ""},
	{"1.2.3", "", "unrecognized address"},
	{"1.2.3.4.5", "", "unrecognized address"},
	{"1234:567:bcbca::89a:bcde", "", "unrecognized address"},
	{"1234:567::bcbc:adad::89a:bcde", "", "unrecognized address"},
}

func TestReverseAddress(t *testing.T) {
	for i, tt := range revAddrTests {
		a, err := reverseaddr(tt.Addr)
		if len(tt.ErrPrefix) > 0 && err == nil {
			t.Errorf("#%d: expected %q, got <nil> (error)", i, tt.ErrPrefix)
			continue
		}
		if len(tt.ErrPrefix) == 0 && err != nil {
			t.Errorf("#%d: expected <nil>, got %q (error)", i, err)
		}
		if err != nil && err.(*DNSError).Err != tt.ErrPrefix {
			t.Errorf("#%d: expected %q, got %q (mismatched error)", i, tt.ErrPrefix, err.(*DNSError).Err)
		}
		if a != tt.Reverse {
			t.Errorf("#%d: expected %q, got %q (reverse address)", i, tt.Reverse, a)
		}
	}
}

func TestShutdown(t *testing.T) {
	if runtime.GOOS == "plan9" {
		return
	}
	l, err := Listen("tcp", "127.0.0.1:0")
	if err != nil {
		if l, err = Listen("tcp6", "[::1]:0"); err != nil {
			t.Fatalf("ListenTCP on :0: %v", err)
		}
	}

	go func() {
		c, err := l.Accept()
		if err != nil {
			t.Fatalf("Accept: %v", err)
		}
		var buf [10]byte
		n, err := c.Read(buf[:])
		if n != 0 || err != io.EOF {
			t.Fatalf("server Read = %d, %v; want 0, io.EOF", n, err)
		}
		c.Write([]byte("response"))
		c.Close()
	}()

	c, err := Dial("tcp", l.Addr().String())
	if err != nil {
		t.Fatalf("Dial: %v", err)
	}
	defer c.Close()

	err = c.(*TCPConn).CloseWrite()
	if err != nil {
		t.Fatalf("CloseWrite: %v", err)
	}
	var buf [10]byte
	n, err := c.Read(buf[:])
	if err != nil {
		t.Fatalf("client Read: %d, %v", n, err)
	}
	got := string(buf[:n])
	if got != "response" {
		t.Errorf("read = %q, want \"response\"", got)
	}
}

func TestTCPListenClose(t *testing.T) {
	l, err := Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("Listen failed: %v", err)
	}

	done := make(chan bool, 1)
	go func() {
		time.Sleep(100 * time.Millisecond)
		l.Close()
	}()
	go func() {
		_, err = l.Accept()
		if err == nil {
			t.Error("Accept succeeded")
		} else {
			t.Logf("Accept timeout error: %s (any error is fine)", err)
		}
		done <- true
	}()
	select {
	case <-done:
	case <-time.After(2 * time.Second):
		t.Fatal("timeout waiting for TCP close")
	}
}

func TestUDPListenClose(t *testing.T) {
	l, err := ListenPacket("udp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("Listen failed: %v", err)
	}

	buf := make([]byte, 1000)
	done := make(chan bool, 1)
	go func() {
		time.Sleep(100 * time.Millisecond)
		l.Close()
	}()
	go func() {
		_, _, err = l.ReadFrom(buf)
		if err == nil {
			t.Error("ReadFrom succeeded")
		} else {
			t.Logf("ReadFrom timeout error: %s (any error is fine)", err)
		}
		done <- true
	}()
	select {
	case <-done:
	case <-time.After(2 * time.Second):
		t.Fatal("timeout waiting for UDP close")
	}
}