Add Profile (following/followers) Endpoint to API (#241)

* Add Profile Endpoint

* Add ability to query followers of profiles
* Add GeneralJson wrapper for generic json responses
* Add statusCode field to MercuryException
* Update README.md

* Fixed request method + using GenericJson for tokens + refactored

Co-authored-by: Gianlu <[email protected]>

Author: markuspi

api/README.md

@@ -34,6 +34,10 @@ All the endpoints will respond with `200` if successful or:
 ### Tokens
 - `POST /token/{scope}` Request an access token for a specific scope (or a comma separated list of scopes).
 
+### Profile
+- `GET /profile/{user_id}/followers` Retrieve a list of profiles that are followers of the specified user
+- `GET /profile/{user_id}/following` Retrieve a list of profiles that the specified user is following
+
 ### Events
 You can subscribe for players events by creating a WebSocket connection to `/events`.
 The currently available events are:

api/src/main/java/xyz/gianlu/librespot/api/ApiServer.java

@@ -28,6 +28,7 @@ public ApiServer(@NotNull ApiConfiguration conf, @NotNull SessionWrapper wrapper
                 .post("/metadata/{uri}", new MetadataHandler(wrapper, false))
                 .post("/search/{query}", new SearchHandler(wrapper))
                 .post("/token/{scope}", new TokensHandler(wrapper))
+                .post("/profile/{user_id}/{action}", new ProfileHandler(wrapper))
                 .get("/events", events));
     }
 

api/src/main/java/xyz/gianlu/librespot/api/handlers/ProfileHandler.java

@@ -0,0 +1,68 @@
+package xyz.gianlu.librespot.api.handlers;
+
+import io.undertow.server.HttpServerExchange;
+import io.undertow.util.Headers;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.jetbrains.annotations.NotNull;
+import xyz.gianlu.librespot.api.SessionWrapper;
+import xyz.gianlu.librespot.api.Utils;
+import xyz.gianlu.librespot.core.Session;
+import xyz.gianlu.librespot.mercury.MercuryClient;
+import xyz.gianlu.librespot.mercury.MercuryRequests;
+
+import java.io.IOException;
+import java.util.Deque;
+import java.util.Map;
+
+public final class ProfileHandler extends AbsSessionHandler {
+    private static final Logger LOGGER = LogManager.getLogger(ProfileHandler.class);
+
+    public ProfileHandler(@NotNull SessionWrapper wrapper) {
+        super(wrapper);
+    }
+
+    private static void profileAction(@NotNull HttpServerExchange exchange, @NotNull Session session, @NotNull String userId, @NotNull String action) throws IOException {
+        String uri = String.format("hm://user-profile-view/v2/desktop/profile/%s/%s", userId, action);
+
+        try {
+            MercuryRequests.GenericJson resp = session.mercury().sendSync(MercuryRequests.getGenericJson(uri));
+            exchange.getResponseHeaders().put(Headers.CONTENT_TYPE, "application/json");
+            exchange.getResponseSender().send(resp.toString());
+        } catch (MercuryClient.MercuryException ex) {
+            Utils.internalError(exchange, ex);
+            LOGGER.error("Failed handling api request. {uri: {}}", uri, ex);
+        }
+    }
+
+    @Override
+    protected void handleRequest(@NotNull HttpServerExchange exchange, @NotNull Session session) throws Exception {
+        exchange.startBlocking();
+        if (exchange.isInIoThread()) {
+            exchange.dispatch(this);
+            return;
+        }
+
+        Map<String, Deque<String>> params = Utils.readParameters(exchange);
+        String userId = Utils.getFirstString(params, "user_id");
+        if (userId == null) {
+            Utils.invalidParameter(exchange, "user_id");
+            return;
+        }
+
+        String action = Utils.getFirstString(params, "action");
+        if (action == null) {
+            Utils.invalidParameter(exchange, "action");
+            return;
+        }
+
+        switch (action) {
+            case "followers":
+            case "following":
+                profileAction(exchange, session, userId, action);
+                break;
+            default:
+                Utils.invalidParameter(exchange, "action");
+        }
+    }
+}

core/src/main/java/xyz/gianlu/librespot/core/TokenProvider.java

@@ -1,6 +1,7 @@
 package xyz.gianlu.librespot.core;
 
 import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.jetbrains.annotations.NotNull;
@@ -48,8 +49,8 @@ public synchronized StoredToken getToken(@NotNull String... scopes) throws IOExc
         }
 
         LOGGER.debug("Token expired or not suitable, requesting again. {scopes: {}, oldToken: {}}", Arrays.asList(scopes), token);
-        MercuryRequests.KeymasterToken resp = session.mercury().sendSync(MercuryRequests.requestToken(session.deviceId(), String.join(",", scopes)));
-        token = new StoredToken(resp);
+        MercuryRequests.GenericJson resp = session.mercury().sendSync(MercuryRequests.requestToken(session.deviceId(), String.join(",", scopes)));
+        token = new StoredToken(resp.obj);
 
         LOGGER.debug("Updated token successfully! {scopes: {}, newToken: {}}", Arrays.asList(scopes), token);
         tokens.add(token);
@@ -68,12 +69,12 @@ public static class StoredToken {
         public final String[] scopes;
         public final long timestamp;
 
-        private StoredToken(@NotNull MercuryRequests.KeymasterToken token) {
+        private StoredToken(@NotNull JsonObject obj) {
             timestamp = TimeProvider.currentTimeMillis();
-            expiresIn = token.obj.get("expiresIn").getAsInt();
-            accessToken = token.obj.get("accessToken").getAsString();
+            expiresIn = obj.get("expiresIn").getAsInt();
+            accessToken = obj.get("accessToken").getAsString();
 
-            JsonArray scopesArray = token.obj.getAsJsonArray("scope");
+            JsonArray scopesArray = obj.getAsJsonArray("scope");
             scopes = new String[scopesArray.size()];
             for (int i = 0; i < scopesArray.size(); i++)
                 scopes[i] = scopesArray.get(i).getAsString();

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

@@ -352,7 +352,7 @@ void dispatch(@NotNull Response resp) {
     }
 
     public static class MercuryException extends Exception {
-        private MercuryException(Response response) {
+        private MercuryException(@NotNull Response response) {
             super(String.format("status: %d", response.statusCode));
         }
     }

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

@@ -98,8 +98,13 @@ public static JsonMercuryRequest<ResolvedContextWrapper> resolveContext(@NotNull
     }
 
     @NotNull
-    public static JsonMercuryRequest<KeymasterToken> requestToken(@NotNull String deviceId, @NotNull String scope) {
-        return new JsonMercuryRequest<>(RawMercuryRequest.get(String.format("hm://keymaster/token/authenticated?scope=%s&client_id=%s&device_id=%s", scope, KEYMASTER_CLIENT_ID, deviceId)), KeymasterToken.class);
+    public static JsonMercuryRequest<GenericJson> requestToken(@NotNull String deviceId, @NotNull String scope) {
+        return new JsonMercuryRequest<>(RawMercuryRequest.get(String.format("hm://keymaster/token/authenticated?scope=%s&client_id=%s&device_id=%s", scope, KEYMASTER_CLIENT_ID, deviceId)), GenericJson.class);
+    }
+
+    @NotNull
+    public static JsonMercuryRequest<GenericJson> getGenericJson(@NotNull String uri) {
+        return new JsonMercuryRequest<>(RawMercuryRequest.get(uri), GenericJson.class);
     }
 
     @NotNull
@@ -159,4 +164,11 @@ public KeymasterToken(@NotNull JsonObject obj) {
             super(obj);
         }
     }
+
+    public static final class GenericJson extends JsonWrapper {
+
+        public GenericJson(@NotNull JsonObject obj) {
+            super(obj);
+        }
+    }
 }