Add support for mixcloud

Makefile

@@ -1,6 +1,6 @@
 all: mumbledj
 
-mumbledj: main.go commands.go parseconfig.go strings.go service.go youtube_dl.go service_youtube.go service_soundcloud.go songqueue.go cache.go
+mumbledj: main.go commands.go parseconfig.go strings.go service.go youtube_dl.go service_youtube.go service_soundcloud.go service_mixcloud.go songqueue.go cache.go
 	go get github.com/karmakaze/goop
 	rm -rf Goopfile.lock
 	goop install

main.go

@@ -243,6 +243,7 @@ func main() {
 
 	dj.defaultChannel = strings.Split(channel, "/")
 
+	services = append(services, Mixcloud{})
 	CheckAPIKeys()
 
 	dj.client.Attach(gumbleutil.Listener{

service_mixcloud.go

@@ -0,0 +1,109 @@
+/*
+ * MumbleDJ
+ * By Matthieu Grieger
+ * service_mixcloud.go
+ * Copyright (c) 2016 Benjmain Klettbach (MIT License)
+ */
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/jmoiron/jsonq"
+	"github.com/layeh/gumble/gumble"
+)
+
+// Regular expressions for mixcloud urls
+var mixcloudSongPattern = `https?:\/\/(www\.)?mixcloud\.com\/([\w-]+)\/([\w-]+)(#t=\n\n?(:\n\n)*)?`
+
+// Mixcloud implements the Service interface
+type Mixcloud struct{}
+
+// ------------------
+//  MIXCLOUD SERVICE
+// ------------------
+
+// ServiceName is the human readable version of the service name
+func (mc Mixcloud) ServiceName() string {
+	return "Mixcloud"
+}
+
+// TrackName is the human readable version of the service name
+func (mc Mixcloud) TrackName() string {
+	return "Song"
+}
+
+// URLRegex checks to see if service will accept URL
+func (mc Mixcloud) URLRegex(url string) bool {
+	return RegexpFromURL(url, []string{mixcloudSongPattern}) != nil
+}
+
+// NewRequest creates the requested song and adds to the queue
+func (mc Mixcloud) NewRequest(user *gumble.User, url string) ([]Song, error) {
+	var apiResponse *jsonq.JsonQuery
+	var songArray []Song
+	var err error
+	timesplit := strings.Split(url, "#t=")
+	url = strings.Replace(timesplit[0], "www", "api", 1)
+	if apiResponse, err = PerformGetRequest(url); err != nil {
+		return nil, errors.New(INVALID_URL_MSG)
+	}
+
+	if strings.Contains(url, "playlists") {
+		// PLAYLIST
+		// Playlists from Mixcloud are not supported, because they do not provide an API for them.
+		return nil, errors.New(fmt.Sprintf(NO_PLAYLISTS_SUPPORTED_MSG, mc.ServiceName()))
+	} else {
+		// SONG
+		// Calculate offset
+		offset := 0
+		if len(timesplit) == 2 {
+			timesplit = strings.Split(timesplit[1], ":")
+			multiplier := 1
+			for i := len(timesplit) - 1; i >= 0; i-- {
+				time, _ := strconv.Atoi(timesplit[i])
+				offset += time * multiplier
+				multiplier *= 60
+			}
+		}
+
+		// Add the track
+		if song, err := mc.NewSong(user, apiResponse, offset); err == nil {
+			return append(songArray, song), err
+		}
+		return nil, err
+	}
+}
+
+// NewSong creates a track and adds to the queue
+func (mc Mixcloud) NewSong(user *gumble.User, trackData *jsonq.JsonQuery, offset int) (Song, error) {
+	title, _ := trackData.String("name")
+	id, _ := trackData.String("slug")
+	duration, _ := trackData.Int("audio_length")
+	url, _ := trackData.String("url")
+	thumbnail, err := trackData.String("pictures", "large")
+	if err != nil {
+		// Song has no artwork, using profile avatar instead
+		userObj, _ := trackData.Object("user")
+		thumbnail, _ = jsonq.NewQuery(userObj).String("pictures", "thumbnail")
+	}
+
+	song := &AudioTrack{
+		id:        id,
+		title:     title,
+		url:       url,
+		thumbnail: thumbnail,
+		submitter: user,
+		duration:  duration,
+		offset:    offset,
+		format:    "best",
+		skippers:  make([]string, 0),
+		dontSkip:  false,
+		service:   mc,
+	}
+	return song, nil
+}

strings.go

@@ -41,6 +41,9 @@ const NO_MUSIC_PLAYING_MSG = "There is no music playing at the moment."
 // Message shown to users when they attempt to skip a playlist when there is no playlist playing.
 const NO_PLAYLIST_PLAYING_MSG = "There is no playlist playing at the moment."
 
+// Message shown to users when they try to play a playlist from a source which doesn't support playlists.
+const NO_PLAYLISTS_SUPPORTED_MSG = "Playlists from %s are not supported."
+
 // Message shown to users when they attempt to use the nextsong command when there is no song coming up.
 const NO_SONG_NEXT_MSG = "There are no songs queued at the moment."