package bot

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

	"github.com/gissleh/irc"
	"git.aiterp.net/rpdata/logbot3/internal/models"
	"git.aiterp.net/rpdata/logbot3/internal/models/channels"
)

var botKey = "git.aiterp.net/rpdata/logbot.Bot.key"

// The Bot is the IRC client.
type Bot struct {
	client     *irc.Client
	ctx        context.Context
	ctxCancel  context.CancelFunc
	loopCtx    context.Context
	loopCancel context.CancelFunc
	channels   map[string]*Channel
}

// New creates a new Bot.
func New(ctx context.Context, nick string, alternatives []string, user string, realName string) *Bot {
	client := irc.New(ctx, irc.Config{
		Nick:                nick,
		User:                user,
		RealName:            realName,
		Alternatives:        alternatives,
		SendRate:            2,
		SkipSSLVerification: false,
	})

	client.AddHandler(handler)

	bot := &Bot{
		client:   client,
		channels: make(map[string]*Channel),
	}

	client.SetValue(botKey, bot)

	return bot
}

// Connect connects the bot to the IRC server. This will disconnect already
// established connections.
func (bot *Bot) Connect(server string, ssl bool, maxRetries int) (err error) {
	if bot.ctxCancel != nil {
		bot.ctxCancel()
	}
	bot.ctx, bot.ctxCancel = context.WithCancel(bot.client.Context())

	retries := 0
	for maxRetries == 0 || retries < maxRetries {
		err = bot.client.Connect(server, ssl)
		if err != nil {
			log.Println("Connect failed:", err.Error())
			if maxRetries > 0 && retries < maxRetries {
				retries++
				log.Printf("Retrying in 5s (Retry %d/%d)", retries, maxRetries)
			} else {
				log.Println("Retrying in 5s (No retry limit)")
			}

			time.Sleep(time.Second * 10)
			continue
		}

		return nil
	}

	return err
}

func (bot *Bot) addChannel(channelName string) *Channel {
	if bot.channels[channelName] != nil {
		return bot.channels[channelName]
	}

	channel := newChannel(bot, channelName, bot.client)
	go channel.loop()

	bot.channels[channelName] = channel
	return channel
}

func (bot *Bot) handlePost(channelName string, post ChannelPost) {
	channel := bot.channels[channelName]
	if channel == nil {
		channel = bot.addChannel(channelName)
	}
	channel.ch <- post
}

func (bot *Bot) runCommands(commands []string, target irc.Target, replacers map[string]string) {
	if replacers == nil {
		replacers = make(map[string]string)
	}
	replacers["me"] = bot.client.Nick()

	for _, command := range commands {
		for from, to := range replacers {
			command = strings.Replace(command, "%"+from, to, -1)
		}

		bot.client.EmitInput(command, target)
	}
}

func (bot *Bot) loop() {
	bot.loopCtx, bot.loopCancel = context.WithCancel(bot.ctx)

	channelChanges, err := channels.SubscribeLogged(bot.ctx)
	if err != nil {
		log.Println("Failed to get channel changes:", err)
		return
	}

	for {
		select {
		case channel := <-channelChanges:
			{
				channels := []models.Channel{channel}
				deadline := time.After(time.Second * 1)
				buffering := true
				for buffering {
					select {
					case channel := <-channelChanges:
						channels = append(channels, channel)
					case <-deadline:
						buffering = false
					}
				}

				decisions := make(map[string]bool)
				for _, channel := range channels {
					decisions[channel.Name] = channel.Logged
				}
				joins := make([]string, 0, len(decisions))
				parts := make([]string, 0, len(decisions))
				for channelName, logged := range decisions {
					if logged {
						if bot.client.Channel(channelName) != nil {
							continue
						}
						joins = append(joins, channelName)
					} else {
						if bot.client.Channel(channelName) == nil {
							continue
						}
						parts = append(parts, channelName)
					}
				}

				if len(joins) > 0 {
					bot.client.Join(joins...)
				}
				if len(parts) > 0 {
					bot.client.Part(parts...)
				}
			}

		case <-bot.loopCtx.Done():
			{
				log.Println("Spinning down bot loop.")
				return
			}
		}
	}
}

func (bot *Bot) stopLoop() {
	if bot.loopCancel != nil {
		bot.loopCancel()
	}
}