package xmpp

import (
	"time"
	//"os"
	"strings"
	"fmt"
	"crypto/tls"

	log "github.com/sirupsen/logrus"
	gxmpp "github.com/mattn/go-xmpp"

	. "git.deuxfleurs.fr/Deuxfleurs/easybridge/connector"
)

// User id format: username@server (= JID)
// OR: nickname@room_name@muc_server

// Room id format: room_name@muc_server (= MUC ID)

type XMPP struct {
	handler Handler

	connectorLoopNum int
	connected bool
	timeout int

	server string
	port int
	ssl bool
	jid string
	jid_localpart string
	password string
	nickname string

	conn *gxmpp.Client

	isMUC map[string]bool
}

func (xm *XMPP) SetHandler(h Handler) {
	xm.handler = h
}

func(xm *XMPP) Protocol() string {
	return "xmpp"
}

func (xm *XMPP) Configure(c Configuration) error {
	if xm.conn != nil {
		xm.Close()
	}

	// Parse and validate configuration
	var err error

	xm.server, err = c.GetString("server")
	if err != nil {
		return err
	}

	xm.port, err = c.GetInt("port", 5222)
	if err != nil {
		return err
	}

	xm.ssl, err = c.GetBool("ssl", true)
	if err != nil {
		return err
	}

	xm.jid, err = c.GetString("jid")
	if err != nil {
		return err
	}
	jid_parts := strings.Split(xm.jid, "@")
	if len(jid_parts) != 2 {
		return fmt.Errorf("Invalid JID: %s", xm.jid)
	}
	if jid_parts[1] != xm.server {
		return fmt.Errorf("JID %s not on server %s", xm.jid, xm.server)
	}
	xm.jid_localpart = jid_parts[0]
	xm.nickname = xm.jid_localpart

	xm.password, err = c.GetString("password")
	if err != nil {
		return err
	}

	// Try to connect
	if xm.isMUC == nil {
		xm.isMUC = make(map[string]bool)
	}

	xm.connectorLoopNum += 1
	go xm.connectLoop(xm.connectorLoopNum)

	for i := 0; i < 42; i++ {
		time.Sleep(time.Duration(1)*time.Second)
		if xm.connected {
			return nil
		}
	}
	return fmt.Errorf("Failed to connect after 42s attempting")
}

func (xm *XMPP) connectLoop(num int) {
	xm.timeout = 10
	for {
		if xm.connectorLoopNum != num {
			return
		}
		tc := &tls.Config{
			ServerName:         strings.Split(xm.jid, "@")[1],
			InsecureSkipVerify: true,
		}
		options := gxmpp.Options{
			Host: xm.server,
			User: xm.jid,
			Password: xm.password,
			NoTLS: true,
			StartTLS: xm.ssl,
			Session: true,
			TLSConfig: tc,
		}
		var err error
		xm.conn, err = options.NewClient()
		if err != nil {
			xm.connected = false
			fmt.Printf("XMPP failed to connect / disconnected: %s\n", err)
			fmt.Printf("Retrying in %ds\n", xm.timeout)
			time.Sleep(time.Duration(xm.timeout) * time.Second)
			xm.timeout *= 2
			if xm.timeout > 600 {
				xm.timeout = 600
			}
		} else {
			xm.connected = true
			xm.timeout = 10
			err = xm.handleXMPP()
			if err != nil {
				xm.connected = false
				fmt.Printf("XMPP disconnected: %s\n", err)
				fmt.Printf("Reconnecting.\n")
			}
		}
	}
}

func (xm *XMPP) xmppKeepAlive() chan bool {
	done := make(chan bool)
	go func() {
		ticker := time.NewTicker(90 * time.Second)
		defer ticker.Stop()
		for {
			select {
			case <-ticker.C:
				if err := xm.conn.PingC2S("", ""); err != nil {
					log.Printf("PING failed %#v\n", err)
				}
			case <-done:
				return
			}
		}
	}()
	return done
}

func (xm *XMPP) handleXMPP() error {
	done := xm.xmppKeepAlive()
	defer close(done)

	for {
		m, err := xm.conn.Recv()
		if err != nil {
			return err
		}

		fmt.Printf("XMPP: %#v\n", m)

		switch v := m.(type) {
		case gxmpp.Chat:
			log.Printf("== Receiving %#v\n", v)

			if v.Text == "" && v.Type == "groupchat" && !strings.Contains(v.Remote, "/") {
				// Empty message when we joined group chat
				xm.handler.Joined(RoomID(v.Remote))
				if v.Subject != "" {
					xm.handler.RoomInfoUpdated(RoomID(v.Remote), &RoomInfo{
						Description: v.Subject,
					})
				}
				continue
			}

			if v.Text == "" || v.Remote == xm.jid {
				continue
			}

			event := &Event{
				Type: EVENT_MESSAGE,
				Text: v.Text,
			}
			log.Printf("Remote: %s\n", v.Remote)

			if strings.HasPrefix(event.Text, "/me ") {
				event.Type = EVENT_ACTION
				event.Text = strings.Replace(event.Text, "/me ", "", 1)
			}

			if v.Type == "chat" {
				remote_jid := strings.Split(v.Remote, "/")[0]
				event.Author = UserID(remote_jid)
				xm.handler.Event(event)
			}
			if v.Type == "groupchat" {
				remote := strings.Split(v.Remote, "/")
				if len(remote) != 2 {
					log.Printf("Invalid remote: %s\n", v.Remote)
					continue
				}
				event.Room = RoomID(remote[0])
				event.Author = UserID(remote[1] + "@" + remote[0])

				if strings.Contains(v.Text, "has set the subject to:") {
					// TODO
					continue
				}

				xm.handler.Event(event)
			}
		case gxmpp.Presence:
			remote := strings.Split(v.From, "/")
			if muc, ok := xm.isMUC[remote[0]]; ok && muc && len(remote) == 2 {
				event := &Event{
					Type: EVENT_JOIN,
					Room: RoomID(remote[0]),
					Author: UserID(remote[1] + "@" + remote[0]),
				}
				if v.Type == "unavailable" {
					event.Type = EVENT_LEAVE
				}
				xm.handler.Event(event)
			}
			// Do nothing.
		}
	}
}

func (xm *XMPP) User() UserID {
	return UserID(xm.jid)
}

func (xm *XMPP) SetUserInfo(info *UserInfo) error {
	//TODO
	return fmt.Errorf("Not implemented")
}

func (xm *XMPP) SetRoomInfo(roomId RoomID, info *RoomInfo) error {
	// TODO
	return fmt.Errorf("Not implemented")
}

func (xm *XMPP) Join(roomId RoomID) error {
	xm.isMUC[string(roomId)] = true

	fmt.Printf("Join %s with nick %s\n", roomId, xm.nickname)
	_, err := xm.conn.JoinMUCNoHistory(string(roomId), xm.nickname)
	return err
}

func (xm *XMPP) Invite(userId UserID, roomId RoomID) error {
	// TODO
	return fmt.Errorf("Not implemented")
}

func (xm *XMPP) Leave(roomId RoomID) {
	// TODO
}

func (xm *XMPP) Send(event *Event) error {
	if len(event.Recipient) > 0 {
		xm.conn.Send(gxmpp.Chat{
			Type: "chat",
			Remote: string(event.Recipient),
			Text: event.Text,
		})
		return nil
	} else if len(event.Room) > 0 {
		xm.conn.Send(gxmpp.Chat{
			Type: "groupchat",
			Remote: string(event.Room),
			Text: event.Text,
		})
		return nil
	} else {
		return fmt.Errorf("Invalid event")
	}
}

func (xm *XMPP) Close() {
	xm.conn.Close()
	xm.conn = nil
	xm.connectorLoopNum += 1
}