package main

import (
	"fmt"
	"io"
	"net/http"
	"time"

	"github.com/gorilla/mux"
)

func gameDownloader(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	game := vars["game"]

	Lib.Lock()
	g, ok := Lib.Games[game]
	Lib.Unlock()
	if !ok {
		Logger.Printf("Missing: %s", game)
		http.Error(w, "Game is missing", 404)
		return
	}

	w.Header().Add("Content-type", "application/tar")
	w.Header().Add("Estimated-size", fmt.Sprintf("%d", g.Size))

	Logger.Printf("Client %s is downloading: %s", r.RemoteAddr, game)

	// Invert the writer so we can break up the copy and get progress
	// information in here
	rdr, pwrtr := io.Pipe()
	go func() {
		err := g.Package(pwrtr)
		if err != nil {
			Logger.Println("Error in package writing: ", err)
		}
	}()

	var total int64
	start := time.Now()
	for {
		n, err := io.CopyN(w, rdr, 256*1024*1024)
		if err == io.EOF {
			break
		}
		if err != nil {
			Logger.Printf("Client %s Error Sending game: %s", r.RemoteAddr, err)
			// Headers already sent, don't bother sending an error
			return
		}
		total += n
		mb := float64(total / 1024 / 1024)
		rate := mb / time.Since(start).Seconds()

		Logger.Printf("Client %s is downloading %s: %0.1f%% done %.2f mb/s",
			r.RemoteAddr, game, float64(total)/float64(g.Size)*100, rate)
	}

	Logger.Printf("Client %s finished downloading: %s", r.RemoteAddr, game)
}