package watcher

import (
	"io/fs"
	"math/rand"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"git.velvettear.de/velvettear/loggo"
	"github.com/fsnotify/fsnotify"
)

// the watcher
var watcher *fsnotify.Watcher

// slice of images
var images []string

// initialize the watcher
func Initialize(directory string) {
	timestamp := time.Now().UnixMilli()
	tmp, error := fsnotify.NewWatcher()
	if error != nil {
		loggo.FatalTimed("encountered an error initializing the watcher", timestamp, error.Error())
	}
	watcher = tmp
	loggo.Info("scanning directory for images and subdirectories...", directory)
	filepath.WalkDir(directory, checkDirectory)
	loggo.InfoTimed("found "+strconv.Itoa(len(images))+" images "+strconv.Itoa(len(watcher.WatchList()))+" directories to watch", timestamp)
	go func() {
		for {
			event := <-watcher.Events
			if !isImage(event.Name) {
				continue
			}
			if event.Has(fsnotify.Create) {
				images = append(images, event.Name)
				loggo.Debug("added image to slice of images", event.Name)
			} else if event.Has(fsnotify.Remove) {
				for index, tmp := range images {
					if tmp != event.Name {
						continue
					}
					images = append(images[:index], images[index+1:]...)
					loggo.Debug("removed image from slice of images", event.Name)
				}
			}
		}
	}()
}

// stop the watcher
func Stop() {
	error := watcher.Close()
	if error != nil {
		loggo.Fatal("encountered an error closing the watcher", error.Error())
	}
}

// get a random image
func GetRandomImage() string {
	return images[rand.Intn(len(images))]
}

// add image files to the slice of images and subdirectoies to the watcher
func checkDirectory(path string, dir fs.DirEntry, err error) error {
	if err != nil {
		return err
	}
	if dir.IsDir() {
		watcher.Add(path)
		loggo.Debug("added directory to watcher", path)
		return nil
	}
	if !isImage(path) {
		return nil
	}
	images = append(images, path)
	loggo.Debug("added image to slice of images", path)
	return nil
}

// check if a file is an image
func isImage(file string) bool {
	return strings.HasSuffix(file, ".jpeg") || strings.HasSuffix(file, ".jpg") || strings.HasSuffix(file, ".png")
}