Add SoundCloud service (#15)

Add SoundCloud service

services/soundcloud/SoundcloudPlaylistUrlIdHandler.java

@@ -0,0 +1,75 @@
+package org.schabi.newpipe.extractor.services.soundcloud;
+
+import org.json.JSONObject;
+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+import org.jsoup.nodes.Element;
+import org.schabi.newpipe.extractor.Downloader;
+import org.schabi.newpipe.extractor.NewPipe;
+import org.schabi.newpipe.extractor.UrlIdHandler;
+import org.schabi.newpipe.extractor.exceptions.ParsingException;
+import org.schabi.newpipe.extractor.utils.Parser;
+
+public class SoundcloudPlaylistUrlIdHandler implements UrlIdHandler {
+
+    private static final SoundcloudPlaylistUrlIdHandler instance = new SoundcloudPlaylistUrlIdHandler();
+
+    public static SoundcloudPlaylistUrlIdHandler getInstance() {
+        return instance;
+    }
+
+    @Override
+    public String getUrl(String listId) throws ParsingException {
+        try {
+            Downloader dl = NewPipe.getDownloader();
+
+            String response = dl.download("https://api-v2.soundcloud.com/playlists/" + listId
+                    + "?client_id=" + SoundcloudParsingHelper.clientId());
+            JSONObject responseObject = new JSONObject(response);
+
+            return responseObject.getString("permalink_url");
+        } catch (Exception e) {
+            throw new ParsingException(e.getMessage(), e);
+        }
+    }
+
+    @Override
+    public String getId(String url) throws ParsingException {
+        try {
+            Downloader dl = NewPipe.getDownloader();
+
+            String response = dl.download(url);
+            Document doc = Jsoup.parse(response);
+
+            Element androidElement = doc.select("meta[property=al:android:url]").first();
+            String id = androidElement.attr("content").substring(23);
+
+            return id;
+        } catch (Exception e) {
+            throw new ParsingException(e.getMessage(), e);
+        }
+    }
+
+    @Override
+    public String cleanUrl(String complexUrl) throws ParsingException {
+        try {
+            Downloader dl = NewPipe.getDownloader();
+
+            String response = dl.download(complexUrl);
+            Document doc = Jsoup.parse(response);
+
+            Element ogElement = doc.select("meta[property=og:url]").first();
+            String url = ogElement.attr("content");
+
+            return url;
+        } catch (Exception e) {
+            throw new ParsingException(e.getMessage(), e);
+        }
+    }
+
+    @Override
+    public boolean acceptUrl(String videoUrl) {
+        String regex = "^https?://(www\\.)?soundcloud.com/[0-9a-z_-]+/sets/[0-9a-z_-]+/?([#?].*)?$";
+        return Parser.isMatch(regex, videoUrl.toLowerCase());
+    }
+}