Added basic Subsonic interface

app/src/main/java/com/cappielloantonio/play/subsonic/Subsonic.java

@@ -0,0 +1,51 @@
+package com.cappielloantonio.play.subsonic;
+
+import com.cappielloantonio.play.subsonic.base.Version;
+
+import java.util.List;
+import java.util.Map;
+
+public class Subsonic {
+    private final SubsonicPreferences preferences;
+
+    private static final Version API_MIN_VERSION = Version.of("1.13.0");
+    private static final Version API_MAX_VERSION = Version.of("1.15.0");
+
+    private Version apiVersion = API_MAX_VERSION;
+
+    public Subsonic(SubsonicPreferences preferences) {
+        this.preferences = preferences;
+    }
+
+    public SubsonicPreferences getPreferences() {
+        return preferences;
+    }
+
+    public static Version getApiMinVersion() {
+        return API_MIN_VERSION;
+    }
+
+    public static Version getApiMaxVersion() {
+        return API_MAX_VERSION;
+    }
+
+    public Version getApiVersion() {
+        return apiVersion;
+    }
+
+    public String createUrl(String path, Map<String, List<String>> params) {
+        final StringBuilder sb = new StringBuilder(preferences.getServerUrl());
+
+        sb.append("/rest/").append(path);
+        sb.append("?u=").append(preferences.getUsername());
+        sb.append("&s=").append(preferences.getAuthentication().getSalt());
+        sb.append("&t=").append(preferences.getAuthentication().getToken());
+        sb.append("&v=").append(getApiVersion().getVersionString());
+        sb.append("&c=").append(preferences.getClientName());
+        sb.append("&f=").append("xml");
+
+        params.keySet().forEach(k -> params.get(k).forEach(v -> sb.append("&").append(k).append("=").append(v)));
+
+        return sb.toString().replace("//rest", "/rest");
+    }
+}