package irc

import (
	"fmt"
	"io"
	"net"
	"strings"
	"sync"
	"time"

	"github.com/sorcix/irc"
)

// Client represents an IRC Client connection to the server
type Client struct {
	*irc.Conn
	conn     net.Conn
	Nickname string
	Name     string
	Host     string
	Username string
	RealName string

	Prefix *irc.Prefix

	Server     *Server
	authorized bool

	idleTimer *time.Timer
	quitTimer *time.Timer

	AwayMessage string

	channels     map[string]*Channel
	channelMutex sync.Mutex

	*UserModeSet
}

func (s *Server) newClient(ircConn *irc.Conn, conn net.Conn) *Client {
	client := &Client{Conn: ircConn, conn: conn, Server: s}
	client.authorized = len(s.Config.Password) == 0
	client.idleTimer = time.AfterFunc(time.Minute, client.idle)
	client.channels = map[string]*Channel{}
	client.UserModeSet = NewUserModeSet()
	return client
}

// Close cleans up the IRC client and closes the connection
func (c *Client) Close() error {
	c.Server.RemoveClient(c)
	c.Server.RemoveClientNick(c)

	return c.Conn.Close()
}

// Ping sends an IRC PING command to a client
func (c *Client) Ping() {
	m := irc.Message{Command: irc.PING, Trailing: c.Server.Config.Name}
	c.Encode(&m)
}

// Pong sends an IRC PONG command to the client
func (c *Client) Pong() {
	m := irc.Message{Command: irc.PONG, Trailing: c.Server.Config.Name}
	c.Encode(&m)
}

func (c *Client) handleIncoming() {
	c.Server.AddClient(c)
	for {
		message, err := c.Decode()
		if err != nil {

			_, closedError := err.(*net.OpError)
			if err == io.EOF || err == io.ErrClosedPipe || closedError || strings.Contains(err.Error(), "use of closed network connection") {
				return
			}

			continue
		}
		if message == nil || message.Len() == 0 {
			continue
		}

		c.idleTimer.Stop()
		c.idleTimer = time.AfterFunc(time.Minute, c.idle)
		if c.quitTimer != nil {
			c.quitTimer.Stop()
			c.quitTimer = nil
		}

		c.Server.CommandsMux.ServeIRC(message, c)

	}

}

func (c *Client) idle() {
	c.Ping()
	c.quitTimer = time.AfterFunc(time.Minute, c.quit)
}

func (c *Client) quit() {
	// Have client leave/part each channel
	for _, channel := range c.GetChannels() {
		channel.Quit(c, "Disconnected")
	}
	c.Quit()
}

// Quit sends the IRC Quit command and closes the connection
func (c *Client) Quit() {
	m := irc.Message{Prefix: &irc.Prefix{Name: c.Server.Config.Name}, Command: irc.QUIT,
		Params: []string{c.Nickname}}

	c.Encode(&m)
	c.Close()
}

// Welcome handles initial client connection IRC protocols for a client.
// Welcome procedure includes IRC WELCOME, Host Info, and MOTD
func (c *Client) Welcome() {

	// Have all client info now
	c.Prefix = &irc.Prefix{Name: c.Nickname, User: c.Name, Host: c.Host}

	m := irc.Message{Prefix: c.Server.Prefix, Command: irc.RPL_WELCOME,
		Params: []string{c.Nickname, "Welcome to the Internet Relay Network", c.Prefix.String()}}

	err := c.Encode(&m)
	if err != nil {
		return
	}

	m = irc.Message{Prefix: c.Server.Prefix, Command: irc.RPL_YOURHOST,
		Params: []string{c.Nickname, fmt.Sprintf("Your host is %s, running version %s", c.Server.Config.Name, c.Server.Config.Version)}}

	err = c.Encode(&m)
	if err != nil {
		return
	}

	m = irc.Message{Prefix: c.Server.Prefix, Command: irc.RPL_CREATED,
		Params: []string{c.Nickname, fmt.Sprintf("This server was created %s", c.Server.created)}}

	err = c.Encode(&m)
	if err != nil {
		return
	}

	m = irc.Message{Prefix: c.Server.Prefix, Command: irc.RPL_MYINFO,
		Params: []string{c.Nickname, fmt.Sprintf("%s  - Golang IRC server", c.Server.Config.Name)}}

	err = c.Encode(&m)
	if err != nil {
		return
	}

	// Send MOTD
	c.MOTD()

}

// MOTD returns the Message of the Day of the server to the client
func (c *Client) MOTD() {

	if len(c.Server.Config.MOTD) == 0 {
		m := irc.Message{Prefix: c.Server.Prefix, Command: irc.ERR_NOMOTD, Params: []string{c.Nickname}, Trailing: "MOTD File is missing"}
		c.Encode(&m)
	}

	m := irc.Message{Prefix: c.Server.Prefix, Command: irc.RPL_MOTDSTART,
		Params: []string{c.Nickname, fmt.Sprintf("%s  - Message of the day", c.Server.Config.Name)}}

	err := c.Encode(&m)
	if err != nil {
		return
	}

	m = irc.Message{Prefix: c.Server.Prefix, Command: irc.RPL_MOTD,
		Params: []string{c.Nickname, c.Server.Config.MOTD}}

	err = c.Encode(&m)
	if err != nil {
		return
	}

	m = irc.Message{Prefix: c.Server.Prefix, Command: irc.RPL_ENDOFMOTD,
		Params: []string{c.Nickname, "End of MOTD"}}

	err = c.Encode(&m)
	if err != nil {
		return
	}
}

// AddChannel adds a channel to the client's active list
func (c *Client) AddChannel(channel *Channel) {
	c.channelMutex.Lock()
	defer c.channelMutex.Unlock()
	c.channels[channel.Name] = channel
}

// RemoveChannel removes a channel to the client's active list
func (c *Client) RemoveChannel(channel *Channel) {
	c.channelMutex.Lock()
	defer c.channelMutex.Unlock()
	delete(c.channels, channel.Name)
}

// GetChannels gets a list of channels this client is joined to
func (c *Client) GetChannels() map[string]*Channel {
	return c.channels
}