package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"path"
	"strings"
	"syscall"
	"time"

	"srs.epita.fr/fic-server/settings"
)

func main() {
	bind := "127.0.0.1:8080"
	prefix := "/"
	teamsDir := "./TEAMS/"
	settings.SettingsDir = "./SETTINGSDIST"

	// Read paremeters from environment
	if v, exists := os.LookupEnv("FIC_BASEURL"); exists {
		prefix = v
	}
	if v, exists := os.LookupEnv("FIC_RECEIVER_BIND"); exists {
		bind = v
	}
	if v, exists := os.LookupEnv("FIC_SETTINGSDIST"); exists {
		settings.SettingsDir = v
	}
	if v, exists := os.LookupEnv("FIC_STARTED_FILE"); exists {
		startedFile = v
	}
	if v, exists := os.LookupEnv("FIC_SUBMISSIONS_DIRECTORY"); exists {
		SubmissionDir = v
	}
	if v, exists := os.LookupEnv("FIC_TEAMS_DIRECTORY"); exists {
		teamsDir = v
	}

	flag.StringVar(&bind, "bind", bind, "Bind port/socket")
	flag.StringVar(&prefix, "prefix", prefix, "Request path prefix to strip (from proxy)")
	flag.StringVar(&teamsDir, "teams", teamsDir, "Base directory where find existing teams")
	flag.StringVar(&settings.SettingsDir, "settings", settings.SettingsDir, "Base directory where read settings")
	flag.StringVar(&startedFile, "startedFile", startedFile, "Path to the file to create/remove whether or not the challenge is running")
	flag.StringVar(&SubmissionDir, "submission", SubmissionDir, "Base directory where save submissions")
	var simulator = flag.String("simulator", "", "Team to simulate (for development only)")
	flag.StringVar(&staticDir, "static", staticDir, "Set to serve pages as well (for development only, use with -simulator)")
	flag.Parse()

	log.SetPrefix("[receiver] ")

	startedFile = path.Clean(startedFile)
	SubmissionDir = path.Clean(SubmissionDir)
	TmpSubmissionDir = path.Join(SubmissionDir, ".tmp")

	log.Println("Creating submission directory...")
	if _, err := os.Stat(TmpSubmissionDir); os.IsNotExist(err) {
		if err = os.MkdirAll(TmpSubmissionDir, 0700); err != nil {
			log.Fatal("Unable to create submission directory:", err)
		}
	}

	prefix = strings.TrimRight(prefix, "/")

	// Load configuration
	settings.LoadAndWatchSettings(path.Join(settings.SettingsDir, settings.SettingsFile), reloadSettings)

	// Register handlers
	http.Handle(fmt.Sprintf("%s/chname", prefix), http.StripPrefix(fmt.Sprintf("%s/chname", prefix), submissionTeamChecker{"name change", ChNameHandler, teamsDir, *simulator}))
	http.Handle(fmt.Sprintf("%s/issue", prefix), http.StripPrefix(fmt.Sprintf("%s/issue", prefix), submissionTeamChecker{"issue", IssueHandler, teamsDir, *simulator}))
	http.Handle(fmt.Sprintf("%s/openhint/", prefix), http.StripPrefix(fmt.Sprintf("%s/openhint/", prefix), submissionTeamChecker{"opening hint", HintHandler, teamsDir, *simulator}))
	http.Handle(fmt.Sprintf("%s/wantchoices/", prefix), http.StripPrefix(fmt.Sprintf("%s/wantchoices/", prefix), submissionTeamChecker{"wantint choices", WantChoicesHandler, teamsDir, *simulator}))
	http.Handle(fmt.Sprintf("%s/registration", prefix), http.StripPrefix(fmt.Sprintf("%s/registration", prefix), submissionChecker{"registration", RegistrationHandler}))
	http.Handle(fmt.Sprintf("%s/resolution/", prefix), http.StripPrefix(fmt.Sprintf("%s/resolution/", prefix), ResolutionHandler{}))
	http.Handle(fmt.Sprintf("%s/reset_progress", prefix), http.StripPrefix(fmt.Sprintf("%s/reset_progress", prefix), submissionTeamChecker{"reset_progress", ResetProgressHandler, teamsDir, *simulator}))
	http.Handle(fmt.Sprintf("%s/submission/", prefix), http.StripPrefix(fmt.Sprintf("%s/submission/", prefix), submissionTeamChecker{"submission", SubmissionHandler, teamsDir, *simulator}))

	if *simulator != "" {
		if _, err := os.Stat(path.Join(teamsDir, *simulator)); os.IsNotExist(err) {
			log.Printf("WARNING: Team '%s' doesn't exist yet in %s.", *simulator, teamsDir)
		}

		// Serve team files
		http.Handle(fmt.Sprintf("%s/wait.json", prefix), http.StripPrefix(prefix, http.FileServer(http.Dir(path.Join(teamsDir, *simulator)))))
		http.Handle(fmt.Sprintf("%s/my.json", prefix), http.StripPrefix(prefix, TeamMyServer{path.Join(teamsDir, *simulator)}))

		// Serve generated content
		http.Handle(fmt.Sprintf("%s/teams.json", prefix), http.StripPrefix(prefix, http.FileServer(http.Dir(teamsDir))))
		http.Handle(fmt.Sprintf("%s/themes.json", prefix), http.StripPrefix(prefix, http.FileServer(http.Dir(teamsDir))))
		http.Handle(fmt.Sprintf("%s/stats.json", prefix), http.StripPrefix(prefix, http.FileServer(http.Dir(teamsDir))))
		http.Handle(fmt.Sprintf("%s/settings.json", prefix), http.StripPrefix(prefix, http.FileServer(http.Dir(settings.SettingsDir))))

		// Serve static assets
		http.Handle(fmt.Sprintf("%s/css/", prefix), http.StripPrefix(prefix, http.FileServer(http.Dir(staticDir))))
		http.Handle(fmt.Sprintf("%s/js/", prefix), http.StripPrefix(prefix, http.FileServer(http.Dir(staticDir))))

		http.Handle(fmt.Sprintf("%s/files/", prefix), http.StripPrefix(prefix, http.FileServer(http.Dir("FILES"))))

		// Serve index
		http.HandleFunc(fmt.Sprintf("%s/edit", prefix), serveIndex)
		http.HandleFunc(fmt.Sprintf("%s/rank", prefix), serveIndex)
		http.HandleFunc(fmt.Sprintf("%s/register", prefix), serveIndex)
		http.HandleFunc(fmt.Sprintf("%s/rules", prefix), serveIndex)
		http.HandleFunc(fmt.Sprintf("%s/videos", prefix), serveIndex)
	}

	// Prepare graceful shutdown
	interrupt := make(chan os.Signal, 1)
	signal.Notify(interrupt, os.Interrupt, syscall.SIGTERM)

	srv := &http.Server{
		Addr:              bind,
		ReadHeaderTimeout: 15 * time.Second,
		ReadTimeout:       15 * time.Second,
		WriteTimeout:      10 * time.Second,
		IdleTimeout:       30 * time.Second,
	}

	// Serve pages
	go func() {
		log.Fatal(srv.ListenAndServe())
	}()
	log.Println(fmt.Sprintf("Ready, listening on %s", bind))

	// Wait shutdown signal and touch timestamp
	ticker := time.NewTicker(time.Second)
	defer ticker.Stop()

loop:
	for {
		select {
		case <-interrupt:
			break loop
		case <-ticker.C:
			now := time.Now()
			os.Chtimes(SubmissionDir, now, now)
		}
	}

	log.Print("The service is shutting down...")
	srv.Shutdown(context.Background())
	log.Println("done")
}