Unshuffle kind of working (#15)

Author: devgianlu

common/src/main/java/xyz/gianlu/librespot/common/Utils.java

@@ -4,6 +4,7 @@
 import org.apache.log4j.Logger;
 import org.jetbrains.annotations.NotNull;
 import xyz.gianlu.librespot.common.proto.Metadata;
+import xyz.gianlu.librespot.common.proto.Spirc;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -33,6 +34,18 @@ public static String toBase64(@NotNull ByteString bytes) {
         return Base64.getEncoder().encodeToString(bytes.toByteArray());
     }
 
+    public static int indexOf(@NotNull List<Spirc.TrackRef> list, @NotNull Spirc.TrackRef ref) {
+        for (int i = 0; i < list.size(); i++) {
+            Spirc.TrackRef item = list.get(i);
+            if (item.hasGid() && ref.hasGid() && item.getGid().equals(ref.getGid()))
+                return i;
+            else if (item.hasUri() && ref.hasUri() && item.getUri().equals(ref.getUri()))
+                return i;
+        }
+
+        return -1;
+    }
+
     @NotNull
     public static String readLine(@NotNull InputStream in) throws IOException {
         ByteArrayOutputStream buffer = new ByteArrayOutputStream();

core/src/main/java/xyz/gianlu/librespot/mercury/JsonMercuryRequest.java

@@ -0,0 +1,32 @@
+package xyz.gianlu.librespot.mercury;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParser;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.InputStreamReader;
+import java.lang.reflect.InvocationTargetException;
+
+/**
+ * @author Gianlu
+ */
+public class JsonMercuryRequest<W extends JsonWrapper> {
+    private static final JsonParser PARSER = new JsonParser();
+    final RawMercuryRequest request;
+    private final Class<W> wrapperClass;
+
+    JsonMercuryRequest(@NotNull RawMercuryRequest request, @NotNull Class<W> wrapperClass) {
+        this.request = request;
+        this.wrapperClass = wrapperClass;
+    }
+
+    @NotNull
+    public W instantiate(@NotNull MercuryClient.Response resp) {
+        try {
+            JsonElement elm = PARSER.parse(new InputStreamReader(resp.payload.stream()));
+            return wrapperClass.getConstructor(JsonElement.class).newInstance(elm);
+        } catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+}

core/src/main/java/xyz/gianlu/librespot/mercury/JsonWrapper.java

@@ -0,0 +1,27 @@
+package xyz.gianlu.librespot.mercury;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author Gianlu
+ */
+public abstract class JsonWrapper {
+    private final JsonElement elm;
+
+    public JsonWrapper(@NotNull JsonElement elm) {
+        this.elm = elm;
+    }
+
+    @NotNull
+    public final JsonObject obj() {
+        return elm.getAsJsonObject();
+    }
+
+    @NotNull
+    public final JsonArray array() {
+        return elm.getAsJsonArray();
+    }
+}

core/src/main/java/xyz/gianlu/librespot/mercury/MercuryClient.java

@@ -70,6 +70,13 @@ public Response sendSync(@NotNull RawMercuryRequest request) throws IOException
         return Utils.wait(reference);
     }
 
+    @NotNull
+    public <W extends JsonWrapper> W sendSync(@NotNull JsonMercuryRequest<W> request) throws IOException, MercuryException {
+        Response resp = sendSync(request.request);
+        if (resp.statusCode >= 200 && resp.statusCode < 300) return request.instantiate(resp);
+        else throw new MercuryException(resp);
+    }
+
     @NotNull
     public <P extends AbstractMessageLite> P sendSync(@NotNull ProtobufMercuryRequest<P> request) throws IOException, MercuryException {
         Response resp = sendSync(request.request);

core/src/main/java/xyz/gianlu/librespot/mercury/MercuryRequests.java

@@ -5,7 +5,9 @@
 import com.google.gson.JsonObject;
 import com.google.protobuf.AbstractMessage;
 import com.google.protobuf.ProtocolStringList;
+import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import xyz.gianlu.librespot.common.Utils;
 import xyz.gianlu.librespot.common.proto.Mercury;
 import xyz.gianlu.librespot.common.proto.Metadata;
@@ -262,4 +264,50 @@ public static ProtobufMercuryRequest<Mercury.MercuryMultiGetReply> multiGet(@Not
         request.addProtobufPayload(multi.build());
         return new ProtobufMercuryRequest<>(request.build(), Mercury.MercuryMultiGetReply.parser());
     }
+
+    @NotNull
+    public static JsonMercuryRequest<ResolvedContextWrapper> resolveContext(@NotNull String uri) {
+        return new JsonMercuryRequest<>(RawMercuryRequest.get(String.format("hm://context-resolve/v1/%s", uri)), ResolvedContextWrapper.class);
+    }
+
+    @NotNull
+    private static String getAsString(@NotNull JsonObject obj, @NotNull String key) {
+        JsonElement elm = obj.get(key);
+        if (elm == null) throw new NullPointerException("Unexpected null value for " + key);
+        else return elm.getAsString();
+    }
+
+    @Contract("_, _, !null -> !null")
+    private static String getAsString(@NotNull JsonObject obj, @NotNull String key, @Nullable String fallback) {
+        JsonElement elm = obj.get(key);
+        if (elm == null) return fallback;
+        else return elm.getAsString();
+    }
+
+    public static final class ResolvedContextWrapper extends JsonWrapper {
+
+        public ResolvedContextWrapper(@NotNull JsonElement elm) {
+            super(elm);
+        }
+
+        @NotNull
+        public JsonArray pages() {
+            return obj().getAsJsonArray("pages");
+        }
+
+        @NotNull
+        public JsonObject metadata() {
+            return obj().getAsJsonObject("metadata");
+        }
+
+        @NotNull
+        public String uri() {
+            return getAsString(obj(), "uri");
+        }
+
+        @NotNull
+        public String url() {
+            return getAsString(obj(), "url");
+        }
+    }
 }

core/src/main/java/xyz/gianlu/librespot/mercury/model/TrackId.java

@@ -39,7 +39,13 @@ public static TrackId fromBase62(@NotNull String base62) {
 
     @NotNull
     public static TrackId fromTrackRef(@NotNull Spirc.TrackRef ref) {
-        return new TrackId(Utils.bytesToHex(ref.getGid().toByteArray()));
+        if (ref.hasGid()) {
+            return new TrackId(Utils.bytesToHex(ref.getGid().toByteArray()));
+        } else if (ref.hasUri()) {
+            return fromUri(ref.getUri());
+        } else {
+            throw new IllegalArgumentException("Not enough data to extract the track ID!");
+        }
     }
 
     @NotNull
@@ -56,4 +62,8 @@ public static TrackId fromHex(@NotNull String hex) {
     public @NotNull String toSpotifyUri() {
         return "spotify:track:" + new String(BASE62.encode(new BigInteger(hexId, 16).toByteArray()));
     }
+
+    public byte[] getGid() {
+        return Utils.toByteArray(new BigInteger(hexId, 16));
+    }
 }

core/src/main/java/xyz/gianlu/librespot/player/Player.java

@@ -1,11 +1,17 @@
 package xyz.gianlu.librespot.player;
 
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import com.google.protobuf.ByteString;
 import org.apache.log4j.Logger;
 import org.jetbrains.annotations.NotNull;
 import xyz.gianlu.librespot.common.Utils;
 import xyz.gianlu.librespot.common.proto.Metadata;
 import xyz.gianlu.librespot.common.proto.Spirc;
 import xyz.gianlu.librespot.core.Session;
+import xyz.gianlu.librespot.mercury.MercuryClient;
+import xyz.gianlu.librespot.mercury.MercuryRequests;
+import xyz.gianlu.librespot.mercury.model.TrackId;
 import xyz.gianlu.librespot.spirc.FrameListener;
 import xyz.gianlu.librespot.spirc.SpotifyIrc;
 
@@ -192,8 +198,35 @@ private void shuffleTracks() {
     private void handleShuffle() {
         if (state.getShuffle()) {
             shuffleTracks();
-            stateUpdated();
+        } else {
+            String contextUri = state.getContextUri();
+
+            JsonArray tracks;
+            try {
+                MercuryRequests.ResolvedContextWrapper context = session.mercury().sendSync(MercuryRequests.resolveContext(contextUri));
+                tracks = context.pages().get(0).getAsJsonObject().getAsJsonArray("tracks");
+            } catch (IOException | MercuryClient.MercuryException ex) {
+                LOGGER.fatal("Failed requesting context!", ex);
+                return;
+            }
+
+            int num = Math.min(100, tracks.size());
+            List<Spirc.TrackRef> rebuildState = new ArrayList<>(num);
+            for (int i = 0; i < num; i++) {
+                JsonObject track = tracks.get(i).getAsJsonObject();
+                rebuildState.add(Spirc.TrackRef.newBuilder()
+                        .setGid(ByteString.copyFrom(TrackId.fromUri(track.get("uri").getAsString()).getGid()))
+                        .build());
+            }
+
+            Spirc.TrackRef current = state.getTrack(state.getPlayingTrackIndex());
+
+            state.clearTrack();
+            state.addAllTrack(rebuildState);
+            state.setPlayingTrackIndex(Utils.indexOf(rebuildState, current));
         }
+
+        stateUpdated();
     }
 
     private void handleSeek(int pos) {