// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.

package config

import (
	"io/ioutil"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/stretchr/testify/require"
)

func TestWatcherInvalidDirectory(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping watcher test in short mode")
	}

	callback := func() {}
	_, err := newWatcher("/does/not/exist", callback)
	require.Error(t, err, "should have failed to watch a non-existent directory")
}

func TestWatcher(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping watcher test in short mode")
	}

	tempDir, err := ioutil.TempDir("", "TestWatcher")
	require.NoError(t, err)
	defer os.RemoveAll(tempDir)

	f, err := ioutil.TempFile(tempDir, "TestWatcher")
	require.NoError(t, err)
	defer f.Close()
	defer os.Remove(f.Name())

	called := make(chan bool)
	callback := func() {
		called <- true
	}
	watcher, err := newWatcher(f.Name(), callback)
	require.NoError(t, err)
	defer watcher.Close()

	// Write to a different file
	ioutil.WriteFile(filepath.Join(tempDir, "unrelated"), []byte("data"), 0644)
	select {
	case <-called:
		require.Fail(t, "callback should not have been called for unrelated file")
	case <-time.After(1 * time.Second):
	}

	// Write to the watched file
	ioutil.WriteFile(f.Name(), []byte("data"), 0644)
	select {
	case <-called:
	case <-time.After(5 * time.Second):
		require.Fail(t, "callback should have been called when file written")
	}
}