package main

import (
	"flag"
	"fmt"
	"log"
	"os"
	"os/exec"
	"time"

	"github.com/vitali-fedulov/images3"
)

var display string
var imagesStore string
var delay int

func main() {
	flag.StringVar(&display, "d", "", "Display")
	flag.StringVar(&imagesStore, "s", "", "Images directory")
	flag.IntVar(&delay, "t", 60, "Delay between checks")
	flag.Parse()

	directory, _ := os.MkdirTemp("", "smart-screensaver")
	images := []string{}
	i := 0

	for {
		image := fmt.Sprintf("%s/%d.jpg", directory, i)
		_, err := exec.Command("import", "-display", display, "-window", "root", image).Output()

		i++

		if err == nil {
			images = append(images, image)
		}

		log.Println("Checking...")

		if len(images) == 2 {
			img1, _ := images3.Open(images[0])
			img2, _ := images3.Open(images[1])

			icon1 := images3.Icon(img1, images[0])
			icon2 := images3.Icon(img2, images[1])

			if images3.Similar(icon1, icon2) {
				log.Println("Starting screensaver...")
				cmd := exec.Command("feh", "-F", "-r", "--on-last-slide", "resume", "-z", "-D", "2", imagesStore)
				cmd.Env = []string{fmt.Sprintf("DISPLAY=%s", display)}
				_, err := cmd.Output()

				if err != nil {
					log.Println(err.Error())
				}
			}

			os.Remove(images[0])

			images = []string{images[1]}
		}

		time.Sleep(time.Duration(delay) * time.Second)
	}
}