// package main is the main package for the LapisDeploy program
package main

import (
	"context"
	"log"
	"time"
	"strings"
	"fmt"

	"maunium.net/go/mautrix"
	"maunium.net/go/mautrix/event"
	"maunium.net/go/mautrix/id"
	"maunium.net/go/mautrix/format"
)

// MatrixMessage stores information about a matrix message.
type MatrixMessage struct {
	text string
}

// MatrixCommand stores information about a matrix chat command
type MatrixCommand struct {
	cmd string
	callback func(ctx context.Context, evt *event.Event) string
	description string
}

// Output queue
var MatrixOut []MatrixMessage

// ChatCommands
var Chatcommands []MatrixCommand

// sendMessage sends a message through Matrix
func sendMessage(msg MatrixMessage) {
	MatrixOut = append(MatrixOut, msg)
}

// registerChatCommand
func registerChatCommand(cmd string, description string, callback func(ctx context.Context, evt *event.Event) string) {
	Chatcommands = append(Chatcommands, MatrixCommand{
		cmd: cmd,
		callback: callback,
		description: description,
	})
}

// initMatrix starts a Matrix bot.
func initMatrix() {
	client, err := mautrix.NewClient(configuration.matrix.homeserver, "", "")
	if err != nil {
		log.Fatal(err)
	}
	resp, err := client.Login(context.Background(), &mautrix.ReqLogin{
		Type: "m.login.password",
		Identifier: mautrix.UserIdentifier{Type: mautrix.IdentifierTypeUser, User: configuration.matrix.username},
		Password: configuration.matrix.password,
		StoreCredentials: true,
	})
	if err != nil {
		log.Panic(err)
	}
	log.Printf("[Matrix] Logged in as %s", resp.UserID)

	syncer := client.Syncer.(*mautrix.DefaultSyncer)
	syncer.OnEventType(event.StateMember, func(ctx context.Context, evt *event.Event) {
		if evt.GetStateKey() == client.UserID.String() && evt.Content.AsMember().Membership == event.MembershipInvite {
			if evt.RoomID.String() == configuration.matrix.room_id {
				_, err := client.JoinRoomByID(ctx, evt.RoomID)
				if err == nil {
					log.Printf("[Matrix] Joined room '%s' (Invited by '%s')", evt.RoomID.String(), evt.Sender.String())
				} else {
					log.Printf("[Matrix] Failed to join room '%s' after invite (Invited by '%s')", evt.RoomID.String(), evt.Sender.String())
				}
			} else {
				log.Printf("[Matrix] Rejected invite to room '%s' (Invited by '%s')", evt.RoomID.String(), evt.Sender.String())
			}
		}
	})	
	syncer.OnEventType(event.EventMessage, func(ctx context.Context, evt *event.Event) {
		if evt.RoomID.String() == configuration.matrix.room_id {
			for _, command := range Chatcommands {
				if command.cmd == strings.TrimPrefix(evt.Content.AsMessage().Body, "!") {
					out := command.callback(ctx, evt)
					content := format.RenderMarkdown(out, true, false)
					content.SetReply(evt)
					client.SendMessageEvent(ctx, evt.RoomID, event.EventMessage, content)
				}
			}
		}
	})

	registerChatCommand("help", "Show the help dialouge", func(ctx context.Context, evt *event.Event) string {
		text := ""
		for _,cmd := range Chatcommands {
			text = fmt.Sprintf("%s- %s\n	%s\n", text, cmd.cmd, cmd.description)
		}
		return text
	})

	go func () {
		for range time.Tick(time.Second * 3) {
			log.Printf("Scanning for queued messages...")
			for _, msg := range MatrixOut {
				_, err := client.SendMessageEvent(context.Background(), id.RoomID(configuration.matrix.room_id), event.EventMessage, format.RenderMarkdown(msg.text, true, false))
				if err != nil {
					log.Printf("[Matrix] ERROR : %s", err)
					continue
				}
				log.Print("[Matrix] Sent queued message successfully.")
			}
			MatrixOut = []MatrixMessage{}
		}
	}()

	log.Print("[Matrix] Running!")
	err = client.Sync()
	if err != nil {
		log.Fatal(err)
	}
}