// fetchTitle attempts to retrieve the title element for a given url.
func fetchTitle(c *proto.Client, m *proto.Message, url string) {
	resp, err := http.Get(url)
	if err != nil {
		return
	}

	body, err := ioutil.ReadAll(resp.Body)
	resp.Body.Close()

	if err != nil {
		return
	}

	body = bytes.ToLower(body)
	s := bytes.Index(body, []byte("<title>"))
	if s == -1 {
		return
	}

	body = body[s+7:]

	e := bytes.Index(body, []byte("</title>"))
	if e == -1 {
		e = len(body) - 1
	}

	body = bytes.TrimSpace(body[:e])

	c.PrivMsg(m.Receiver, "%s's link shows: %s",
		m.SenderName, html.UnescapeString(string(body)))
}

// Init initializes the plugin. it loads configuration data and binds
// commands and protocol handlers.
func (p *Plugin) Load(c *proto.Client) (err error) {
	err = p.Base.Load(c)
	if err != nil {
		return
	}

	c.Bind(proto.CmdPrivMsg, func(c *proto.Client, m *proto.Message) {
		p.parseURL(c, m)
	})

	ini := p.LoadConfig()
	if ini == nil {
		return
	}

	s := ini.Section("exclude")
	list := s.List("url")
	p.exclude = make([]*regexp.Regexp, len(list))

	for i := range list {
		p.exclude[i], err = regexp.Compile(list[i])

		if err != nil {
			return
		}
	}

	return
}

// ctcpVersion handles a CTCP version request.
func ctcpVersion(c *proto.Client, m *proto.Message) bool {
	if m.Data != "\x01VERSION\x01" {
		return false
	}

	c.PrivMsg(m.SenderName, "%s %d.%d", AppName, AppVersionMajor, AppVersionMinor)
	return true
}

// ctcpPing handles a CTCP ping request.
func ctcpPing(c *proto.Client, m *proto.Message) bool {
	if !strings.HasPrefix(m.Data, "\x01PING ") {
		return false
	}

	c.PrivMsg(m.SenderName, "\x01PONG %s\x01", m.Data[6:])
	return true
}

// bind binds protocol message handlers.
func bind(c *proto.Client) {
	c.Bind(proto.Unknown, onAny)
	c.Bind(proto.CmdPing, onPing)
	c.Bind(proto.EndOfMOTD, onJoinChannels)
	c.Bind(proto.ErrNoMOTD, onJoinChannels)
	c.Bind(proto.ErrNicknameInUse, onNickInUse)
	c.Bind(proto.CmdPrivMsg, onPrivMsg)
}

// shutdown cleans up our mess.
func shutdown(conn *net.Conn, client *proto.Client) {
	plugin.Unload(client)

	log.Printf("Shutting down.")
	client.Quit(config.QuitMessage)
	client.Close()
	conn.Close()
}

// onNickInUse is called whenever we receive a notification that our
// nickname is already in use. We will attempt to re-acquire it by
// identifying with our password. Otherwise we will pick a new name.
func onNickInUse(c *proto.Client, m *proto.Message) {
	if len(config.NickservPassword) > 0 {
		c.Recover(config.Nickname, config.NickservPassword)
		return
	}

	config.SetNickname(config.Nickname + "_")
	c.Nick(config.Nickname, "")
}

// fetchTweet attempts to retrieve the tweet associated with a given url.
func fetchTweet(c *proto.Client, m *proto.Message, url string) {
	id, err := strconv.ParseInt(twitterUrlRegex.FindStringSubmatch(url)[2], 10, 64)
	if err != nil {
		c.PrivMsg(m.Receiver, "error parsing tweet :(")
		log.Print("error parsing tweet for %s: %v", url, err)
		fetchTitle(c, m, url)
		return
	}
	tweet, err := api.GetTweet(id, nil)
	if err != nil {
		log.Print("error parsing tweet for %s: %v", url, err)
		fetchTitle(c, m, url)
		return
	}
	c.PrivMsg(m.Receiver, "%s's tweet shows: %s",
		m.SenderName, html.UnescapeString(tweet.Text))
}

func (p *Plugin) Load(c *proto.Client) (err error) {
	err = p.Base.Load(c)
	if err != nil {
		return
	}

	w := new(cmd.Command)
	w.Name = "define"
	w.Description = "Fetch the definition for the given term"
	w.Restricted = false
	w.Params = []cmd.Param{
		{Name: "term", Description: "Word to find definition for", Pattern: cmd.RegAny},
	}
	w.Execute = func(cmd *cmd.Command, c *proto.Client, m *proto.Message) {
		dict, err := Dial("tcp", "dict.org:2628")
		if err != nil {
			log.Printf("[dict] %s", err)
			c.PrivMsg(m.Receiver, "%s, No definition found for '%s'",
				m.SenderName, cmd.Params[0].Value)
			return
		}

		def, err := dict.Define("wn", cmd.Params[0].Value)
		if err != nil {
			log.Printf("[dict] %s", err)
			c.PrivMsg(m.Receiver, "%s, No definition found for '%s'",
				m.SenderName, cmd.Params[0].Value)
			return
		}

		if len(def) == 0 {
			c.PrivMsg(m.Receiver, "%s, No definition found for '%s'",
				m.SenderName, cmd.Params[0].Value)
			return
		}

		space := []byte{' '}
		mspace := []byte{' ', ' '}
		line := bytes.Replace(def[0].Text, []byte{'\n'}, space, -1)

		// Strip all multi-space indents.
		for bytes.Index(line, mspace) > -1 {
			line = bytes.Replace(line, mspace, space, -1)
		}

		c.PrivMsg(m.Receiver, "%s: %s", m.SenderName, line)
	}

	cmd.Register(w)

	return
}

// Parse reads incoming message data and tries to parse it into
// a command structure and then execute it.
func Parse(prefix string, c *proto.Client, m *proto.Message) bool {
	prefixlen := len(prefix)

	if prefixlen == 0 || !strings.HasPrefix(m.Data, prefix) {
		return false
	}

	// Split the data into a name and list of parameters.
	name, params := parseCommand(m.Data[prefixlen:])
	if len(name) == 0 {
		return false
	}

	// Ensure the given command exists.
	new, ok := commands[name]
	if !ok {
		c.PrivMsg(m.SenderName, "Unknown command %q", name)
		return false
	}

	// Create a new command instance.
	cmd := new()
	pc := cmd.RequiredParamCount()
	lp := len(params)

	// Make sure we received enough parameters.
	if pc > lp {
		c.PrivMsg(m.SenderName, "Missing parameters for command %q", name)
		return false
	}

	// Copy over parameter values and ensure they are of the right format.
	for i := 0; i < pc && i < lp; i++ {
		cmd.Params[i].Value = params[i]

		if !cmd.Params[i].Valid() {
			c.PrivMsg(m.SenderName, "Invalid parameter value %q for command %q",
				params[i], name)
			return false
		}
	}

	// Execute the command.
	if cmd.Execute == nil {
		c.PrivMsg(m.SenderName, "Command %q is not implemented", name)
		return false
	}

	go cmd.Execute(cmd, c, m)
	return true
}

// Init initializes the plugin. it loads configuration data and binds
// commands and protocol handlers.
func Init(profile string, c *proto.Client) {
	log.Println("Initializing: url")

	ini := ini.New()
	err := ini.Load(plugin.ConfigPath(profile, "url"))

	if err != nil {
		log.Fatal(err)
	}

	s := ini.Section("exclude")
	list := s.List("url")
	exclude = make([]*regexp.Regexp, len(list))

	for i := range list {
		exclude[i], err = regexp.Compile(list[i])
		if err != nil {
			log.Fatalf("- Invalid pattern: %s", list[i])
		}
	}

	c.Bind(proto.CmdPrivMsg, parseURL)
}

// Parse reads incoming message data and tries to parse it into
// a command structure and then execute it.
func Parse(prefix string, c *proto.Client, m *proto.Message) bool {
	prefixlen := len(prefix)

	if prefixlen == 0 || !strings.HasPrefix(m.Data, prefix) {
		return false
	}

	// Split the data into a name and list of parameters.
	name, params := parseCommand(m.Data[prefixlen:])
	if len(name) == 0 {
		return false
	}

	// Ensure the given command exists.
	cmd := findCommand(name)
	if cmd == nil {
		return false
	}

	cmd.Data = strings.TrimSpace(m.Data[prefixlen+len(name):])

	// Ensure the current user us allowed to execute the command.
	if cmd.Restricted && !isWhitelisted(m.SenderMask) {
		c.PrivMsg(m.SenderName, "Access to %q denied.", name)
		return false
	}

	// Make sure we received enough parameters.
	pc := cmd.RequiredParamCount()
	lp := len(params)

	if pc > lp {
		c.PrivMsg(m.SenderName, "Missing parameters for command %q", name)
		return false
	}

	// Copy over parameter values and ensure they are of the right format.
	for i := 0; i < lp && i < len(cmd.Params); i++ {
		cmd.Params[i].Value = params[i]

		if !cmd.Params[i].Valid() {
			c.PrivMsg(m.SenderName, "Invalid parameter value %q for command %q",
				params[i], name)
			return false
		}
	}

	// Execute the command.
	if cmd.Execute != nil {
		go cmd.Execute(cmd, c, m)
	}

	return true
}

func (p *Plugin) Load(c *proto.Client) (err error) {
	err = p.Base.Load(c)
	if err != nil {
		return
	}

	comm := new(cmd.Command)
	comm.Name = "quit"
	comm.Description = "Unconditionally quit the bot program"
	comm.Restricted = true
	comm.Execute = func(cmd *cmd.Command, c *proto.Client, m *proto.Message) {
		c.Quit("")
	}
	cmd.Register(comm)

	comm = new(cmd.Command)
	comm.Name = "join"
	comm.Description = "Join the given channel"
	comm.Restricted = true
	comm.Params = []cmd.Param{
		{Name: "channel", Optional: false, Pattern: cmd.RegChannel},
		{Name: "key", Optional: true, Pattern: cmd.RegAny},
		{Name: "chanservpass", Optional: true, Pattern: cmd.RegAny},
	}
	comm.Execute = func(cmd *cmd.Command, c *proto.Client, m *proto.Message) {
		var ch irc.Channel
		ch.Name = cmd.Params[0].Value

		if len(cmd.Params) > 1 {
			ch.Key = cmd.Params[1].Value
		}

		if len(cmd.Params) > 2 {
			ch.ChanservPassword = cmd.Params[2].Value
		}

		c.Join(&ch)
	}
	cmd.Register(comm)

	comm = new(cmd.Command)
	comm.Name = "leave"
	comm.Description = "Leave the given channel"
	comm.Restricted = true
	comm.Params = []cmd.Param{
		{Name: "channel", Optional: true, Pattern: cmd.RegChannel},
	}
	comm.Execute = func(cmd *cmd.Command, c *proto.Client, m *proto.Message) {
		var ch irc.Channel

		if len(cmd.Params) > 0 {
			ch.Name = cmd.Params[0].Value
		} else {
			if !m.FromChannel() {
				return
			}
			ch.Name = m.Receiver
		}

		c.Part(&ch)
	}
	cmd.Register(comm)

	return
}

// onJoinChannels is used to complete the login procedure.
// We have just received the server's MOTD and now is a good time to
// start joining channels.
func onJoinChannels(c *proto.Client, m *proto.Message) {
	c.Join(config.Channels)
}

// onPing handles PING messages.
func onPing(c *proto.Client, m *proto.Message) {
	c.Pong(m.Data)
}

func (p *Plugin) Load(c *proto.Client) (err error) {
	err = p.Base.Load(c)
	if err != nil {
		return
	}

	ini := p.LoadConfig()
	if ini == nil {
		log.Fatalf("[weather] No API key found.")
		return
	}

	key := ini.Section("api").S("key", "")
	if len(key) == 0 {
		log.Fatalf("[weather] No API key found.")
		return
	}

	w := new(cmd.Command)
	w.Name = "weather"
	w.Description = "Fetch the current weather for a given location"
	w.Restricted = false
	w.Params = []cmd.Param{
		{Name: "location", Description: "Name of the city/town for the forecast", Pattern: cmd.RegAny},
	}

	w.Execute = func(cmd *cmd.Command, c *proto.Client, m *proto.Message) {
		location := url.QueryEscape(cmd.Params[0].Value)
		resp, err := http.Get(fmt.Sprintf(_url, location, key))
		if err != nil {
			return
		}

		data, err := ioutil.ReadAll(resp.Body)
		resp.Body.Close()

		if err != nil {
			return
		}

		var wd WeatherData
		err = json.Unmarshal(data, &wd)
		if err != nil {
			return
		}

		if len(wd.Data.Request) == 0 || len(wd.Data.Conditions) == 0 {
			c.PrivMsg(m.Receiver, "%s: No weather data for %q",
				m.SenderName, cmd.Params[0].Value)
			return
		}

		wr := wd.Data.Request[0]
		wc := wd.Data.Conditions[0]

		c.PrivMsg(m.Receiver,
			"%s, weather in %s: %s°C/%s°F/%.2f°K, %s, cloud cover: %s%%, humidity: %s%%, wind: %skph/%smph from %s, pressure: %s mb, visibility: %s km",
			m.SenderName, wr.Query,
			wc.TempC, wc.TempF, wd.TempK(), codeName(wc.WeatherCode),
			wc.CloudCover, wc.Humidity, wc.WindSpeedKmph, wc.WindSpeedMiles,
			wc.WindDir16Point, wc.Pressure, wc.Visibility,
		)
	}

	cmd.Register(w)

	return
}

func (p *Plugin) Load(c *proto.Client) (err error) {
	err = p.Base.Load(c)
	if err != nil {
		return
	}

	ini := p.LoadConfig()
	if ini == nil {
		log.Fatalf("[ipintel] No configuration found.")
		return
	}

	key := ini.Section("api").S("key", "")
	if len(key) == 0 {
		log.Fatalf("[ipintel] No API key found.")
		return
	}

	shared := ini.Section("api").S("shared", "")
	if len(shared) == 0 {
		log.Fatalf("[ipintel] No API shared secret found.")
		return
	}

	drift := ini.Section("api").I64("drift", 0)
	if len(shared) == 0 {
		log.Fatalf("[ipintel] No API shared secret found.")
		return
	}

	w := new(cmd.Command)
	w.Name = "loc"
	w.Description = "Fetch geo-location data for the given IP address."
	w.Restricted = false
	w.Params = []cmd.Param{
		{Name: "ip", Description: "IPv4 address to look up", Pattern: cmd.RegIPv4},
	}
	w.Execute = func(cmd *cmd.Command, c *proto.Client, m *proto.Message) {
		hash := md5.New()
		stamp := fmt.Sprintf("%d", time.Now().UTC().Unix()+drift)
		io.WriteString(hash, key+shared+stamp)

		sig := fmt.Sprintf("%x", hash.Sum(nil))
		target := fmt.Sprintf(url, cmd.Params[0].Value, key, sig)

		resp, err := http.Get(target)
		if err != nil {
			log.Printf("[ipintel]: %v", err)
			return
		}

		body, err := ioutil.ReadAll(resp.Body)
		resp.Body.Close()

		if err != nil {
			log.Printf("[ipintel]: %v", err)
			return
		}

		var data Response
		err = json.Unmarshal(body, &data)
		if err != nil {
			log.Printf("[ipintel]: %v", err)
			return
		}

		inf := data.IPInfo
		mapsURL := fmt.Sprintf("https://maps.google.com/maps?q=%f,%f",
			inf.Location.Latitude, inf.Location.Longitude)

		c.PrivMsg(m.Receiver,
			"%s: %s (%s), Network org.: %s, Carrier: %s, TLD: %s, SLD: %s. "+
				"Location: %s/%s/%s/%s (%f, %f). Postalcode: %s, Timezone: %d, %s",
			m.SenderName,

			inf.IPAddress, inf.IPType,
			inf.Network.Organization,
			inf.Network.Carrier,
			inf.Network.Domain.TLD,
			inf.Network.Domain.SLD,

			inf.Location.Continent,
			inf.Location.CountryData.Name,
			inf.Location.StateData.Name,
			inf.Location.CityData.Name,
			inf.Location.Latitude,
			inf.Location.Longitude,
			inf.Location.CityData.PostalCode,
			inf.Location.CityData.TimeZone,

			mapsURL,
		)
	}

	cmd.Register(w)

	w = new(cmd.Command)
	w.Name = "mibbit"
	w.Description = "Resolve a mibbit address to a real IP address."
	w.Restricted = false
//.........这里部分代码省略.........