package main

import (
	"log"
	"strings"
	"time"

	"net/url"

	"github.com/mvdan/xurls"
	"github.com/thoj/go-ircevent"
	"gopkg.in/alecthomas/kingpin.v2"

	"github.com/icedream/irc-medialink/manager"
	"github.com/icedream/irc-medialink/parsers/soundcloud"
	"github.com/icedream/irc-medialink/parsers/web"
	"github.com/icedream/irc-medialink/parsers/wikipedia"
	"github.com/icedream/irc-medialink/parsers/youtube"
)

func must(err error) {
	if err == nil {
		return
	}

	log.Fatal(err)
}

func main() {
	var youtubeApiKey string

	var soundcloudClientId string
	var soundcloudClientSecret string

	var debug bool
	var useTLS bool
	var server string
	var password string
	var timeout time.Duration
	var pingFreq time.Duration

	nickname := "YouTubeBot"
	ident := "youtube"
	var nickservPw string
	channels := []string{}

	// IRC config
	kingpin.Flag("nick", "The nickname.").Short('n').StringVar(&nickname)
	kingpin.Flag("ident", "The ident.").Short('i').StringVar(&ident)
	kingpin.Flag("debug", "Enables debug mode.").Short('d').BoolVar(&debug)
	kingpin.Flag("tls", "Use TLS.").BoolVar(&useTLS)
	kingpin.Flag("server", "The server to connect to.").Short('s').StringVar(&server)
	kingpin.Flag("password", "The password to use for logging into the IRC server.").Short('p').StringVar(&password)
	kingpin.Flag("timeout", "The timeout on the connection.").Short('t').DurationVar(&timeout)
	kingpin.Flag("pingfreq", "The ping frequency.").DurationVar(&pingFreq)
	kingpin.Flag("nickserv-pw", "NickServ password.").StringVar(&nickservPw)
	kingpin.Flag("channels", "Channels to join.").Short('c').StringsVar(&channels)

	// Youtube config
	kingpin.Flag("youtube-key", "The API key to use to access the YouTube API.").StringVar(&youtubeApiKey)
	kingpin.Flag("soundcloud-id", "The SoundCloud ID.").StringVar(&soundcloudClientId)
	kingpin.Flag("soundcloud-secret", "The SoundCloud secret.").StringVar(&soundcloudClientSecret)

	kingpin.Parse()

	if len(nickname) == 0 {
		log.Fatal("Nickname must be longer than 0 chars.")
	}
	if len(ident) == 0 {
		log.Fatal("Ident must be longer than 0 chars.")
	}

	// Manager
	m := manager.NewManager()

	// Load youtube parser
	youtubeParser := &youtube.Parser{
		Config: &youtube.Config{ApiKey: youtubeApiKey},
	}
	must(m.RegisterParser(youtubeParser))

	// Load soundcloud parser
	soundcloudParser := &soundcloud.Parser{
		Config: &soundcloud.Config{
			ClientId:     soundcloudClientId,
			ClientSecret: soundcloudClientSecret,
		},
	}
	must(m.RegisterParser(soundcloudParser))

	// Load wikipedia parser
	must(m.RegisterParser(new(wikipedia.Parser)))

	// Load web parser
	must(m.RegisterParser(new(web.Parser)))

	// IRC
	conn := m.AntifloodIrcConn(irc.IRC(nickname, ident))
	conn.Debug = debug
	conn.VerboseCallbackHandler = conn.Debug
	conn.UseTLS = useTLS
	conn.Password = password
	if timeout > time.Duration(0) {
		conn.Timeout = timeout
	}
	if pingFreq > time.Duration(0) {
		conn.PingFreq = pingFreq
	}

	joinChan := make(chan string)
	inviteChan := make(chan string)

	// register callbacks
	conn.AddCallback("001", func(e *irc.Event) { // handle RPL_WELCOME
		// nickserv login
		if len(nickservPw) > 0 {
			conn.Privmsg("NickServ", "IDENTIFY "+nickservPw)
			log.Print("Sent NickServ login request.")
		}

		// I am a bot! (+B user mode)
		conn.Mode(conn.GetNick(), "+B-iw")

		// Join configured channels
		if len(channels) > 0 {
			conn.Join(strings.Join(channels, ","))
		}
	})
	conn.AddCallback("JOIN", func(e *irc.Event) {
		// Is this JOIN not about us?
		if !strings.EqualFold(e.Nick, conn.GetNick()) {
			return
		}

		// Asynchronous notification
		select {
		case joinChan <- e.Arguments[0]:
		default:
		}
	})
	conn.AddCallback("INVITE", func(e *irc.Event) {
		// Is this INVITE not for us?
		if !strings.EqualFold(e.Arguments[0], conn.GetNick()) {
			return
		}

		// Asynchronous notification
		select {
		case inviteChan <- e.Arguments[1]:
		default:
		}

		// We have been invited, autojoin!
		go func(sourceNick string, targetChannel string) {
		joinWaitLoop:
			for {
				select {
				case channel := <-joinChan:
					if strings.EqualFold(channel, targetChannel) {
						// TODO - Thanks message
						time.Sleep(1 * time.Second)
						conn.Privmsgf(targetChannel, "Thanks for inviting me, %s! I am %s, the friendly bot that shows information about links posted in this channel. I hope I can be of great help for everyone here in %s! :)", sourceNick, conn.GetNick(), targetChannel)
						time.Sleep(2 * time.Second)
						conn.Privmsg(targetChannel, "If you ever run into trouble with me (or find any bugs), please use the channel #MediaLink for contact on this IRC.")
						break joinWaitLoop
					}
				case channel := <-inviteChan:
					if strings.EqualFold(channel, targetChannel) {
						break joinWaitLoop
					}
				case <-time.After(time.Minute):
					log.Printf("WARNING: Timed out waiting for us to join %s as we got invited", targetChannel)
					break joinWaitLoop
				}
			}
		}(e.Nick, e.Arguments[1])
		conn.Join(e.Arguments[1])
	})
	conn.AddCallback("PRIVMSG", func(e *irc.Event) {
		go func(event *irc.Event) {
			//sender := event.Nick
			target := event.Arguments[0]
			isChannel := true
			if strings.EqualFold(target, conn.GetNick()) {
				// Private message to us!
				target = event.Nick
				isChannel = false
			}
			if strings.EqualFold(target, conn.GetNick()) {
				// Emergency switch to avoid endless loop,
				// dropping all messages from the bot to the bot!
				log.Printf("BUG - Emergency switch, caught message from bot to bot: %s", event.Arguments)
				return
			}
			msg := stripIrcFormatting(event.Message())

			log.Printf("<%s @ %s> %s", event.Nick, target, msg)

			urlStr := xurls.Relaxed.FindString(msg)

			switch {
			case !isChannel:
				// Explain who we are and what we do
				conn.Privmsgf(target, "Hi, I parse links people post to chat rooms to give some information about them. I also allow people to search for YouTube videos and SoundCloud sounds straight from IRC. If you have questions or got any bug reports, please direct them to Icedream in #MediaLink, thank you!")
			case len(urlStr) > 0: // URL?
				// Parse URL!
				u, err := url.ParseRequestURI(urlStr)
				if err != nil {
					u, err = url.ParseRequestURI("http://" + urlStr)
				}
				if err != nil {
					log.Print(err)
					break
				}

				// Check if this URL has been recently parsed before (antiflood)
				shouldIgnore := m.TrackUrl(target, u)
				if shouldIgnore {
					log.Printf("WARNING: URL antiflood triggered, dropping URL for %s: %s", target, u)
					break
				}

				_, result := m.Parse(u)
				if result.Error != nil {
					log.Print(result.Error)
				}
				if result.UserError != nil {
					if s, err := tplString("error", result.UserError); err != nil {
						log.Print(err)
					} else {
						conn.Privmsg(target, s)
					}
				}
				if result.Error == nil && result.UserError == nil && result.Information != nil {
					for _, i := range result.Information {
						if s, err := tplString("link-info", i); err != nil {
							log.Print(err)
						} else {
							conn.Privmsg(target, s)
						}
					}
				}
			}

		}(e)
	})

	// connect
	must(conn.Connect(server))

	// listen for errors
	log.Print("Now looping.")
	conn.Loop()
}