// Copyright (C) 2024 Leah Neukirchen
//
// based on mautrix-go example code:
//
// Copyright (C) 2017 Tulir Asokan
// Copyright (C) 2018-2020 Luca Weiss
// Copyright (C) 2023 Tulir Asokan
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

package main

import (
	"context"
	"errors"
	"flag"
	"os"
	"os/signal"
	"strings"
	"time"

	"k8s.io/klog"
	"maunium.net/go/mautrix"
	"maunium.net/go/mautrix/id"
)

var (
	flagMatrixHomeserver   = "matrix.org"
	flagMatrixUsername     = "@fafomo:matrix.org"
	flagMatrixPasswordFile = "password.txt"

	flagPresenceMatrixRoom string
	flagPresenceBackendURL string

	flagStreamMatrixRoom string
)

func main() {
	flag.StringVar(&flagMatrixHomeserver, "matrix_homeserver", flagMatrixHomeserver, "Address of Matrix homeserver")
	flag.StringVar(&flagMatrixUsername, "matrix_username", flagMatrixUsername, "Matrix login username")
	flag.StringVar(&flagMatrixPasswordFile, "matrix_password_file", flagMatrixPasswordFile, "Path to file containing matrix login password")
	flag.StringVar(&flagPresenceMatrixRoom, "presence_matrix_room", flagPresenceMatrixRoom, "Matrix room MXID")
	flag.StringVar(&flagPresenceBackendURL, "presence_backend_url", flagPresenceBackendURL, "Checkinator (backend) addresss")
	flag.StringVar(&flagStreamMatrixRoom, "stream_matrix_room", flagStreamMatrixRoom, "Matrix room MXID")
	flag.Parse()

	for _, s := range []struct {
		value string
		name  string
	}{
		{flagMatrixHomeserver, "matrix_homeserver"},
		{flagMatrixUsername, "matrix_username"},
		{flagMatrixPasswordFile, "matrix_password_file"},
	} {
		if s.value == "" {
			klog.Exitf("-%s must be set", s.name)
		}
	}

	startCtx, startCtxC := context.WithTimeout(context.Background(), 20*time.Second)
	defer startCtxC()

	client, err := mautrix.NewClient(flagMatrixHomeserver, id.UserID(flagMatrixUsername), "")
	if err != nil {
		klog.Exitf("NewClient failed: %v", err)
	}

	passwordBytes, err := os.ReadFile(flagMatrixPasswordFile)
	if err != nil {
		klog.Exitf("Could not read password file: %v", err)
	}
	password := strings.TrimSpace(string(passwordBytes))

	klog.Infof("Logging in...")

	login, err := client.Login(startCtx, &mautrix.ReqLogin{
		Type:       mautrix.AuthTypePassword,
		Identifier: mautrix.UserIdentifier{Type: mautrix.IdentifierTypeUser, User: flagMatrixUsername},
		Password:   password,
	})
	if err != nil {
		klog.Exitf("Failed to log in: %v", err)
	}

	client.AccessToken = login.AccessToken

	klog.Infof("Now running...")

	ctx, ctxC := signal.NotifyContext(context.Background(), os.Interrupt)
	defer ctxC()

	// Run Matrix sync process in the background.
	syncDone := make(chan struct{})
	go func() {
		err := client.SyncWithContext(ctx)
		defer close(syncDone)
		if err != nil && !errors.Is(err, ctx.Err()) {
			klog.Exitf("Sync failed: %v", err)
		}
	}()

	if flagPresenceMatrixRoom != "" || flagPresenceBackendURL != "" {
		if flagPresenceMatrixRoom == "" || flagPresenceBackendURL == "" {
			klog.Exitf("If presence_matrix_room is set, presence_backend_url must be set (and vice versa)")
		}
		klog.Infof("Starting presence module.")
		go presence(ctx, client)
	} else {
		klog.Infof("NOT starting presence module.")
	}

	if flagStreamMatrixRoom != "" {
		klog.Infof("Starting streaming module.")
		go streaming(ctx, client)
	} else {
		klog.Infof("NOT starting streaming module.")
	}

	<-ctx.Done()
	klog.Infof("Waiting for graceful sync before exiting...")
	<-syncDone
	klog.Infof("Done.")
}