package main

import (
	"encoding/json"
	"io"
	"log"
	"net/http"
	"os"
)

func init() {
	log.SetFlags(log.Lmicroseconds | log.Lshortfile)
	logFile, err := os.Create("main.log")
	if err != nil {
		log.Printf("Error creating log file: %v", err)
		os.Exit(1)
	}
	logger := io.MultiWriter(os.Stdout, logFile)
	log.SetOutput(logger)
}

const DOWNLOAD_WORKERS = 10

var downloadQueue = make(chan *DownloadTask, 100)

func enableCORS(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type")

		if r.Method == http.MethodOptions {
			w.WriteHeader(http.StatusOK)
			return
		}
		next.ServeHTTP(w, r)
	})
}

func handleDownload(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Invalid request method", http.StatusMethodNotAllowed)
		return
	}

	var req DownloadRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		log.Printf("Error parsing JSON: %v", err)
		http.Error(w, "Error parsing JSON", http.StatusBadRequest)
		return
	}

	downloadQueue <- &DownloadTask{Url: req.Link}
	w.WriteHeader(http.StatusOK)
}

func main() {
	for i := 0; i < DOWNLOAD_WORKERS; i++ {
		worker := &DownloadWorker{id: i, input: downloadQueue}
		go worker.Run()
	}

	mux := http.NewServeMux()
	mux.Handle("/download", enableCORS(http.HandlerFunc(handleDownload)))
	log.Println("Server starting on :5000")
	err := http.ListenAndServe(":5000", mux)
	if err != nil {
		log.Println("Error starting server:", err)
	}
}