package main

import (
	"fmt"
	"io"
	"log"
	"math/rand"
	"net/http"
	"os"
)

func GetPicsArray() []string {
	files, err := os.ReadDir("images")
	if err != nil {
		panic(err)
	}
	if len(files) == 0 {
		return []string{"no images"}
	}
	var filesNames = make([]string, len(files))
	for i, file := range files {
		filesNames[i] = string(file.Name())
	}
	return filesNames
}

func GetRandImg() string {
	picsArray := GetPicsArray()
	return picsArray[rand.Intn(len(picsArray))]
}

func ReturnPic(w http.ResponseWriter, req *http.Request) {
	picture, _ := os.Open(fmt.Sprintf("images/%v", GetRandImg()))
	var pictureReader io.Reader = picture
	io.Copy(w, pictureReader)
	log.Println("Картинка отдана")
}

func main() {
	log.Println("Server Start")
	http.HandleFunc("/", ReturnPic)
	http.ListenAndServe(":3666", nil)
}