// Copyright 2010 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.

// +build freebsd openbsd netbsd darwin linux

package fsnotify

import (
	"os"
	"path/filepath"
	"testing"
	"time"
)

func TestFsnotifyAttrib(t *testing.T) {
	// Create an fsnotify watcher instance and initialize it
	watcher, err := NewWatcher()
	if err != nil {
		t.Fatalf("NewWatcher() failed: %s", err)
	}

	const testDir string = "_test"

	// Create directory to watch
	if err := os.Mkdir(testDir, 0777); err != nil {
		t.Fatalf("Failed to create test directory: %s", err)
	}
	defer os.RemoveAll(testDir)

	// Receive errors on the error channel on a separate goroutine
	go func() {
		for err := range watcher.Error {
			t.Fatalf("error received: %s", err)
		}
	}()

	const testFile string = "_test/TestFsnotifyAttrib.testfile"

	// Receive events on the event channel on a separate goroutine
	eventstream := watcher.Event
	var attribReceived counter
	done := make(chan bool)
	go func() {
		for event := range eventstream {
			// Only count relevant events
			if event.Name == filepath.Clean(testDir) || event.Name == filepath.Clean(testFile) {
				if event.IsModify() {
					attribReceived.increment()
				}
				t.Logf("event received: %s", event)
			} else {
				t.Logf("unexpected event received: %s", event)
			}
		}
		done <- true
	}()

	// Create a file
	// This should add at least one event to the fsnotify event queue
	var f *os.File
	f, err = os.OpenFile(testFile, os.O_WRONLY|os.O_CREATE, 0666)
	if err != nil {
		t.Fatalf("creating test file failed: %s", err)
	}
	f.Sync()

	f.WriteString("data")
	f.Sync()
	f.Close()

	// Add a watch for testFile
	err = watcher.Watch(testFile)
	if err != nil {
		t.Fatalf("Watcher.Watch() failed: %s", err)
	}

	os.Chmod(testFile, 0777)
	if err != nil {
		t.Fatalf("chmod failed: %s", err)
	}

	// We expect this event to be received almost immediately, but let's wait 500 ms to be sure
	time.Sleep(500 * time.Millisecond)
	if attribReceived.value() == 0 {
		t.Fatal("fsnotify attribute events have not received after 500 ms")
	}

	// Try closing the fsnotify instance
	t.Log("calling Close()")
	watcher.Close()
	t.Log("waiting for the event channel to become closed...")
	select {
	case <-done:
		t.Log("event channel closed")
	case <-time.After(1e9):
		t.Fatal("event stream was not closed after 1 second")
	}
}