Add method to get final stream url.

Signed-off-by: Yahor Berdnikau <egorr.berd@gmail.com>

subsonic-api/src/integrationTest/kotlin/org/moire/ultrasonic/api/subsonic/GetStreamUrlTest.kt

@@ -0,0 +1,47 @@
+package org.moire.ultrasonic.api.subsonic
+
+import okhttp3.mockwebserver.MockResponse
+import org.amshove.kluent.`should equal to`
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.moire.ultrasonic.api.subsonic.SubsonicAPIVersions.V1_6_0
+import org.moire.ultrasonic.api.subsonic.rules.MockWebServerRule
+
+/**
+ * Integration test for [SubsonicAPIClient.getStreamUrl] method.
+ */
+class GetStreamUrlTest {
+    @JvmField @Rule val mockWebServerRule = MockWebServerRule()
+
+    val id = "boom"
+    private lateinit var client: SubsonicAPIClient
+    private lateinit var expectedUrl: String
+
+    @Before
+    fun setUp() {
+        client = SubsonicAPIClient(mockWebServerRule.mockWebServer.url("/").toString(),
+                USERNAME, PASSWORD, V1_6_0, CLIENT_ID)
+        val baseExpectedUrl = mockWebServerRule.mockWebServer.url("").toString()
+        expectedUrl = "$baseExpectedUrl/rest/stream.view?id=$id&u=$USERNAME" +
+                "&p=${client.passwordHex}&v=${V1_6_0.restApiVersion}&c=$CLIENT_ID&f=json"
+    }
+
+    @Test
+    fun `Should return valid stream url`() {
+        mockWebServerRule.enqueueResponse("ping_ok.json")
+
+        val streamUrl = client.getStreamUrl(id)
+
+        streamUrl `should equal to` expectedUrl
+    }
+
+    @Test
+    fun `Should still return stream url if connection failed`() {
+        mockWebServerRule.mockWebServer.enqueue(MockResponse().setResponseCode(500))
+
+        val streamUrl = client.getStreamUrl(id)
+
+        streamUrl `should equal to` expectedUrl
+    }
+}

subsonic-api/src/main/kotlin/org/moire/ultrasonic/api/subsonic/SubsonicAPIClient.kt

@@ -131,6 +131,22 @@ class SubsonicAPIClient(baseUrl: String,
         }
     }
 
+    /**
+     * Get stream url.
+     *
+     * Calling this method do actual connection to the backend, though not downloading all content.
+     *
+     * Consider do not use this method, but [stream] call.
+     */
+    fun getStreamUrl(id: String): String {
+        val request = api.stream(id).execute()
+        val url = request.raw().request().url().toString()
+        if (request.isSuccessful) {
+            request.body().close()
+        }
+        return url
+    }
+
     private val salt: String by lazy {
         val secureRandom = SecureRandom()
         BigInteger(130, secureRandom).toString(32)
@@ -145,7 +161,7 @@ class SubsonicAPIClient(baseUrl: String,
         }
     }
 
-    private val passwordHex: String by lazy {
+    internal val passwordHex: String by lazy {
         "enc:${password.toHexBytes()}"
     }