package main

import (
	"flag"
	"log"
	"net"
	"net/http"
	"net/http/fcgi"
	"os"
	"os/signal"
	"syscall"

	"marisa.chaotic.ninja/marisa"
)

type templatedata struct {
	Links   []string
	Size    string
	Maxsize string
}

type metadata struct {
	Filename string
	Size     int64
	Expiry   int64
}

var conf struct {
	user     string
	group    string
	chroot   string
	listen   string
	baseuri  string
	rootdir  string
	tmplpath string
	filepath string
	metapath string
	filectx  string
	maxsize  int64
	expiry   int64
}

var verbose bool

func main() {
	var err error
	var configfile string
	var listener net.Listener

	/* default values */
	conf.listen = "127.0.0.1:8080"
	conf.baseuri = "http://127.0.0.1:8080"
	conf.rootdir = "static"
	conf.tmplpath = "templates"
	conf.filepath = "files"
	conf.metapath = "meta"
	conf.filectx = "/f/"
	conf.maxsize = 34359738368
	conf.expiry = 86400

	flag.StringVar(&configfile, "f", "", "Configuration file")
	flag.BoolVar(&verbose, "v", false, "Verbose logging")
	flag.Parse()

	if configfile != "" {
		if verbose {
			log.Printf("Reading configuration %s", configfile)
		}
		parseconfig(configfile)
	}

	if conf.chroot != "" {
		if verbose {
			log.Printf("Changing root to %s", conf.chroot)
		}
		syscall.Chroot(conf.chroot)
	}

	if conf.listen[0] == '/' {
		/* Remove any stale socket */
		os.Remove(conf.listen)
		if listener, err = net.Listen("unix", conf.listen); err != nil {
			log.Fatal(err)
		}
		defer listener.Close()

		/*
		 * Ensure unix socket is removed on exit.
		 * Note: this might not work when dropping privileges…
		 */
		defer os.Remove(conf.listen)
		sigs := make(chan os.Signal, 1)
		signal.Notify(sigs, os.Interrupt, os.Kill, syscall.SIGTERM)
		go func() {
			_ = <-sigs
			listener.Close()
			if err = os.Remove(conf.listen); err != nil {
				log.Fatal(err)
			}
			os.Exit(0)
		}()
	} else {
		if listener, err = net.Listen("tcp", conf.listen); err != nil {
			log.Fatal(err)
		}
		defer listener.Close()
	}

	if conf.user != "" {
		if verbose {
			log.Printf("Dropping privileges to %s", conf.user)
		}
		uid, gid, err := usergroupids(conf.user, conf.group)
		if err != nil {
			log.Fatal(err)
		}

		if listener.Addr().Network() == "unix" {
			os.Chown(conf.listen, uid, gid)
		}

		syscall.Setuid(uid)
		syscall.Setgid(gid)
	}

	http.HandleFunc("/", uploader)
	http.Handle(conf.filectx, http.StripPrefix(conf.filectx, http.FileServer(http.Dir(conf.filepath))))

	if verbose {
		log.Printf("Starting marisa %v\n", marisa.FullVersion())
		log.Printf("Listening on %s", conf.listen)
	}

	if listener.Addr().Network() == "unix" {
		err = fcgi.Serve(listener, nil)
		log.Fatal(err) /* NOTREACHED */
	}

	err = http.Serve(listener, nil)
	log.Fatal(err) /* NOTREACHED */
}