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

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

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

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

// MatrixCommandCallback is a function that gets called when the bot is issued a command over Matrix
type MatrixCommandCallback func(ctx context.Context, evt *event.Event, args []string) string

// MatrixCommand stores information about a matrix chat command
type MatrixCommand struct {
	cmd         string
	callback    MatrixCommandCallback
	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 MatrixCommandCallback) {
	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)
	client.Syncer.(mautrix.ExtensibleSyncer).OnSync(client.DontProcessOldEvents)
	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 {
			prefixes := []string{"!", configuration.matrix.username + " "}
			for _, prefix := range prefixes {
				if strings.HasPrefix(evt.Content.AsMessage().Body, prefix) {
					msg := evt.Content.AsMessage().Body
					cmd := strings.TrimPrefix(strings.Split(msg, " ")[0], prefix)
					found_command := false
					for _, command := range Chatcommands {
						if command.cmd == cmd {
							found_command = true
							out := command.callback(ctx, evt, strings.Split(strings.TrimPrefix(msg, prefix+cmd), " "))
							content := format.RenderMarkdown(out, true, false)
							content.SetReply(evt)
							client.SendMessageEvent(ctx, evt.RoomID, event.EventMessage, content)
						}
					}
					if !found_command {
						client.SendText(ctx, evt.RoomID, "🔴 Command not found")
					}
					break
				}
			}
		}
	})

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

	registerChatCommand("sites", "Display all available sites", func(ctx context.Context, evt *event.Event, args []string) string {
		text := "⚪️ Getting sites...\n"
		sites, err := getAllSites()
		if err.code != 0 {
			return text + "🔴 Failed to get sites!"
		}
		for _, site := range sites {
			text = fmt.Sprintf("%s- %s\n", text, site.name)
		}
		if len(sites) == 0 {
			text = text + "*No sites found*"
		}
		return text
	})

	registerChatCommand("restart", "Restart a site.", func(ctx context.Context, evt *event.Event, args []string) string {
		if len(args) < 2 {
			return "🔴 Invalid site."
		}
		site, found, err := getSite(args[1])
		if err != nil {
			return "🔴 Failed to get site " + args[2] + "!"
		} else if !found {
			return "🔴 Invalid site."
		}
		text := "⚪️ Restarting server..."
		derr := site.Restart()
		if derr.code != 0 {
			derr.SendOverMatrix()
			return text + "\n🔴 Failed to restart site!"
		}
		return text + "\n🟢 Successfully restarted site."
	})

	go func() {
		for range time.Tick(time.Second * 6) {
			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{}
		}
	}()

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