feat: fetch beat metadata from api

app/src/main/java/at/lockstep/player/data/MetadataSyncClient.kt

@@ -1,5 +1,6 @@
 package at.lockstep.player.data
 
+import okhttp3.HttpUrl.Companion.toHttpUrl
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
 import okhttp3.Request
@@ -7,10 +8,56 @@ import okhttp3.RequestBody.Companion.toRequestBody
 import org.json.JSONObject
 import java.io.IOException
 
+sealed class MetadataFetchResult {
+    data class Found(val collection: JSONObject) : MetadataFetchResult()
+
+    data object NotFound : MetadataFetchResult()
+}
+
 class MetadataSyncClient(
     private val httpClient: OkHttpClient,
     private val baseUrl: String,
 ) {
+    @Throws(IOException::class)
+    fun fetchMetadata(
+        accessToken: String,
+        trackId: String,
+        type: String,
+    ): MetadataFetchResult {
+        val url =
+            baseUrl.toHttpUrl()
+                .newBuilder()
+                .addPathSegments("metadata")
+                .addQueryParameter("trackId", trackId)
+                .addQueryParameter("type", type)
+                .build()
+        val request =
+            Request.Builder()
+                .url(url)
+                .addHeader("Authorization", "Bearer $accessToken")
+                .get()
+                .build()
+        httpClient.newCall(request).execute().use { response ->
+            if (response.code == 404) {
+                return MetadataFetchResult.NotFound
+            }
+            val bodyText = response.body?.string().orEmpty()
+            if (!response.isSuccessful) {
+                val message =
+                    runCatching { JSONObject(bodyText).optString("error") }
+                        .getOrNull()
+                        ?.takeIf { it.isNotBlank() }
+                        ?: response.message
+                throw IOException(message)
+            }
+            val collection =
+                runCatching { JSONObject(bodyText).getJSONObject("collection") }
+                    .getOrNull()
+                    ?: throw IOException("Missing collection in response")
+            return MetadataFetchResult.Found(collection)
+        }
+    }
+
     @Throws(IOException::class)
     fun uploadCollection(
         accessToken: String,