package main

import (
	"context"
	"crypto/rand"
	"encoding/hex"
	"encoding/json"
	"flag"
	"io/ioutil"
	"os"
	"os/signal"
	"syscall"

	log "github.com/sirupsen/logrus"
	"gopkg.in/yaml.v2"

	"git.deuxfleurs.fr/Deuxfleurs/easybridge/mxlib"
)

type ConfigFile struct {
	LogLevel string `json:"log_level"`

	Registration string `json:"registration"`
	ASBindAddr   string `json:"appservice_bind_addr"`
	Server       string `json:"homeserver_url"`
	MatrixDomain string `json:"matrix_domain"`
	NameFormat   string `json:"name_format"`

	WebBindAddr string `json:"web_bind_addr"`
	WebURL      string `json:"web_url"`
	SessionKey  string `json:"web_session_key"`

	DbType string `json:"db_type"`
	DbPath string `json:"db_path"`

	AvatarFile string `json:"easybridge_avatar"`
}

var configFlag = flag.String("config", "./config.json", "Configuration file path")

var config *ConfigFile
var registration *mxlib.Registration

func readConfig() ConfigFile {
	defaultKey := make([]byte, 32)
	rand.Read(defaultKey)

	config_file := ConfigFile{
		LogLevel:     "info",
		ASBindAddr:   "0.0.0.0:8321",
		WebBindAddr:  "0.0.0.0:8281",
		Registration: "./registration.yaml",
		Server:       "http://localhost:8008",
		NameFormat:   "{}_ezbr_",
		DbType:       "sqlite3",
		DbPath:       "easybridge.db",
		AvatarFile:   "./easybridge.jpg",
		SessionKey:   hex.EncodeToString(defaultKey),
	}

	_, err := os.Stat(*configFlag)
	if os.IsNotExist(err) {
		// Generate default config file
		log.Printf("Generating default config file as %s", *configFlag)

		bytes, err := json.MarshalIndent(&config_file, "", "  ")
		if err != nil {
			log.Fatal(err)
		}

		err = ioutil.WriteFile(*configFlag, bytes, 0644)
		if err != nil {
			log.Fatal(err)
		}

		return config_file
	}

	if err != nil {
		log.Fatal(err)
	}

	bytes, err := ioutil.ReadFile(*configFlag)
	if err != nil {
		log.Fatal(err)
	}

	err = json.Unmarshal(bytes, &config_file)
	if err != nil {
		log.Fatal(err)
	}

	return config_file
}

func readRegistration(file string) mxlib.Registration {
	rnd := make([]byte, 64)
	n, err := rand.Read(rnd)
	if err != nil || n != 64 {
		log.Fatal(err)
	}

	reg := mxlib.Registration{
		Id:              "Easybridge",
		Url:             "http://localhost:8321",
		AsToken:         hex.EncodeToString(rnd[:32]),
		HsToken:         hex.EncodeToString(rnd[32:]),
		SenderLocalpart: "_ezbr_",
		RateLimited:     false,
		Namespaces: mxlib.RegistrationNamespaceSet{
			Users: []mxlib.RegistrationNamespace{
				mxlib.RegistrationNamespace{
					Exclusive: true,
					Regex:     "@.*_ezbr_",
				},
			},
			Aliases: []mxlib.RegistrationNamespace{
				mxlib.RegistrationNamespace{
					Exclusive: true,
					Regex:     "#.*_ezbr_",
				},
			},
			Rooms: []mxlib.RegistrationNamespace{},
		},
	}

	_, err = os.Stat(file)
	if os.IsNotExist(err) {
		// Generate default config file
		log.Printf("Generating default registration file as %s", file)

		bytes, err := yaml.Marshal(&reg)
		if err != nil {
			log.Fatal(err)
		}

		err = ioutil.WriteFile(file, bytes, 0644)
		if err != nil {
			log.Fatal(err)
		}

		return reg
	}

	if err != nil {
		log.Fatal(err)
	}

	bytes, err := ioutil.ReadFile(file)
	if err != nil {
		log.Fatal(err)
	}

	err = yaml.Unmarshal(bytes, &reg)
	if err != nil {
		log.Fatal(err)
	}

	return reg
}

func main() {
	flag.Parse()

	// Read configuration
	config_file := readConfig()
	config = &config_file

	log_level, err := log.ParseLevel(config.LogLevel)
	if err != nil {
		log.Fatal(err)
	}
	log.SetLevel(log_level)

	reg_file := readRegistration(config.Registration)
	registration = &reg_file

	// Create context and handlers for errors and signals
	ctx, stop_all := context.WithCancel(context.Background())
	errch := make(chan error)
	sigch := make(chan os.Signal)
	signal.Notify(sigch, os.Interrupt, syscall.SIGTERM)
	defer func() {
		signal.Stop(sigch)
		stop_all()
	}()

	// Start appservice and web server
	_, err = StartAppService(errch, ctx)
	if err != nil {
		log.Fatal(err)
	}

	_ = StartWeb(errch, ctx)

	// Wait for an error somewhere or interrupt signal
	select {
	case err = <-errch:
		log.Error(err)
		stop_all()
	case sig := <-sigch:
		log.Warnf("Got signal: %s", sig.String())
		stop_all()
	case <-ctx.Done():
	}

	log.Info("Closing all account connections...")
	CloseAllAccountsForShutdown()
	log.Info("Exiting.")
}