package main

import (
	"fmt"
	"golang.org/x/sys/windows"
	"math/rand"
	"os"
	"strconv"
	"unsafe"
)

func main() {
	fileBytes, err := os.ReadFile("./imgsLocation.txt")
	if err != nil {
		fmt.Printf("Error loading dir info from ./imgsLocation.txt: %v\nPress <enter> to continue...", err)
		fmt.Scanln()
		os.Exit(1)
	}
	files, err := os.ReadDir(string(fileBytes))
	if err != nil {
		fmt.Printf("Error reading images from directory %v: %v\nPress <enter> to continue...", string(fileBytes), err)
		fmt.Scanln()
		os.Exit(1)
	}

	procSystemParamInfo := windows.NewLazyDLL("user32.dll").NewProc("SystemParametersInfoW")
	imagePath, _ := windows.UTF16PtrFromString(string(fileBytes) + `\` + strconv.Itoa(rand.Intn(len(files)-1)+1) + ".jpg")
	procSystemParamInfo.Call(20, 0, uintptr(unsafe.Pointer(imagePath)), 0x001A)
}