package main

import (
	"bufio"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"
	"path"
	"time"
)

const startedFile = "started"

var TeamsDir string
var SubmissionDir string

func touchStartedFile(startSub time.Duration) {
	time.Sleep(startSub)
	if fd, err := os.Create(path.Join(TeamsDir, startedFile)); err == nil {
		log.Println("Started! Go, Go, Go!!")
		fd.Close()
	} else {
		log.Println("Unable to start challenge:", err)
	}
}

func main() {
	var bind = flag.String("bind", "0.0.0.0:8080", "Bind port/socket")
	var prefix = flag.String("prefix", "", "Request path prefix to strip (from proxy)")
	var start = flag.Int64("start", 0, fmt.Sprintf("Challenge start timestamp (in 2 minutes: %d)", time.Now().Unix() / 60 * 60 + 120))
	var duration = flag.Duration("duration", 180 * time.Minute, "Challenge duration")
	flag.StringVar(&TeamsDir, "teams", "../TEAMS", "Base directory where save teams JSON files")
	flag.StringVar(&SubmissionDir, "submission", "./submissions/", "Base directory where save submissions")
	flag.Parse()

	log.Println("Creating submission directory...")
	if _, err := os.Stat(SubmissionDir); os.IsNotExist(err) {
		if err := os.MkdirAll(SubmissionDir, 0777); err != nil {
			log.Fatal("Unable to create submission directory: ", err)
		}
	}

	startTime := time.Unix(*start, 0)
	startSub := startTime.Sub(time.Now())
	end := startTime.Add(*duration).Add(time.Duration(1 * time.Second))

	log.Println("Challenge ends on", end)
	if startSub > 0 {
		log.Println("Challenge starts at", startTime, "in", startSub)

		fmt.Printf("PRESS ENTER TO LAUNCH THE COUNTDOWN ")
		bufio.NewReader(os.Stdin).ReadLine()

		if _, err := os.Stat(path.Join(TeamsDir, startedFile)); !os.IsNotExist(err) {
			os.Remove(path.Join(TeamsDir, startedFile))
		}

		go touchStartedFile(startTime.Sub(time.Now().Add(time.Duration(1 * time.Second))))
	} else {
		log.Println("Challenge started at", startTime, "since", -startSub)
		go touchStartedFile(time.Duration(0))
	}

	log.Println("Registering handlers...")
	http.Handle(fmt.Sprintf("%s/time.json", *prefix), http.StripPrefix(*prefix, TimeHandler{startTime, *duration}))
	http.Handle(fmt.Sprintf("%s/", *prefix), http.StripPrefix(*prefix, SubmissionHandler{end}))

	log.Println(fmt.Sprintf("Ready, listening on %s", *bind))
	if err := http.ListenAndServe(*bind, nil); err != nil {
		log.Fatal("Unable to listen and serve: ", err)
	}
}