package main

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

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 ReturnPicFilename(w http.ResponseWriter, req *http.Request) {
	var picFilename io.Reader = strings.NewReader(GetRandImg())
	io.Copy(w, picFilename)
}

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 ReturnHTML(w http.ResponseWriter, req *http.Request) {
	htmlOpen, err := template.ParseFiles("dist/index.html")
	if err != nil {
		log.Println(err.Error())
		return
	}
	image := GetRandImg()
	fmt.Println(image)
	htmlOpen.Execute(w, image)
}

func main() {
	log.Println("Server Start")
	imagesDir := http.FileServer(http.Dir("images"))
	staticDir := http.FileServer(http.Dir("dist/assets"))
	http.Handle("/images/", http.StripPrefix("/images/", imagesDir))
	http.Handle("/assets/", http.StripPrefix("/assets/", staticDir))

	http.HandleFunc("/rand", ReturnPicFilename)
	http.HandleFunc("/", ReturnHTML)
	http.ListenAndServe(":3666", nil)
}