Download app archive to temporary file.

app/src/main/java/de/ccc/events/badge/card10/hatchery/AppDetailFragment.kt

@@ -22,6 +22,7 @@
 
 package de.ccc.events.badge.card10.hatchery
 
+import android.os.AsyncTask
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
@@ -29,7 +30,7 @@ import android.view.ViewGroup
 import androidx.fragment.app.Fragment
 import de.ccc.events.badge.card10.R
 import kotlinx.android.synthetic.main.app_detail_fragment.*
-import java.lang.IllegalStateException
+import java.io.File
 
 class AppDetailFragment : Fragment() {
 
@@ -51,5 +52,30 @@ class AppDetailFragment : Fragment() {
         label_content_size.text = getString(R.string.app_detail_content_size, app.size_of_content)
 
         label_description.text = app.description
+
+        button_download.setOnClickListener {
+            ReleaseDownload(app).execute()
+        }
+    }
+
+    private class ReleaseDownload(private val app: App) : AsyncTask<Void, Void, String?>() {
+
+        override fun doInBackground(vararg p0: Void?): String? {
+            return try {
+                val inputStream = HatcheryClient().openDownloadStream(app)
+                val file = File.createTempFile(app.slug, ".tar.gz")
+                val outputStream = file.outputStream()
+
+                inputStream.copyTo(outputStream)
+
+                file.absolutePath
+            } catch (e: Exception) {
+                null
+            }
+        }
+
+        override fun onPostExecute(result: String?) {
+            // TODO: Handle result
+        }
     }
 }

app/src/main/java/de/ccc/events/badge/card10/hatchery/HatcheryClient.kt

@@ -29,6 +29,8 @@ import okhttp3.Request
 import okhttp3.Response
 import org.json.JSONArray
 import org.json.JSONException
+import org.json.JSONObject
+import java.io.InputStream
 
 private const val TAG = "HatcheryClient"
 
@@ -81,4 +83,57 @@ class HatcheryClient {
 
         return resultList
     }
+
+    fun getReleaseUrl(app: App): String {
+        val client = OkHttpClient()
+        val request = Request.Builder()
+            .url("$HATCHERY_BASE_URL/eggs/get/${app.slug}/json")
+            .build()
+
+        val response: Response
+        try {
+            response = client.newCall(request).execute()
+        } catch (e: Exception) {
+            throw HatcheryClientException(0)
+        }
+
+        if (response.code != 200) {
+            throw HatcheryClientException(response.code)
+        }
+
+        val body = response.body?.string() ?: ""
+
+        try {
+            val responseJson = JSONObject(body)
+            val version = responseJson.getJSONObject("info").getString("version")
+            return responseJson.getJSONObject("releases")
+                .getJSONArray(version).getJSONObject(0).getString("url")
+
+        } catch (e: JSONException) {
+            Log.e(TAG, "Error parsing JSON: ${e.message}")
+            throw HatcheryClientException(0)
+        }
+    }
+
+    fun openDownloadStream(app: App): InputStream {
+        val releaseUrl = getReleaseUrl(app)
+
+        val client = OkHttpClient()
+        val request = Request.Builder()
+            .url(releaseUrl)
+            .build()
+
+        val response: Response
+        try {
+            response = client.newCall(request).execute()
+        } catch (e: Exception) {
+            throw HatcheryClientException(0)
+        }
+
+        if (response.code != 200) {
+            throw HatcheryClientException(response.code)
+        }
+
+        return response.body?.byteStream() ?: throw HatcheryClientException(0)
+    }
 }

app/src/main/res/layout/app_detail_fragment.xml

@@ -35,8 +35,7 @@
                 app:layout_constraintRight_toRightOf="parent"
                 app:layout_constraintTop_toTopOf="parent"
                 android:id="@+id/button_download"
-                android:text="@string/app_detail_button_download"
-                android:enabled="false"/>
+                android:text="@string/app_detail_button_download"/>
 
     </androidx.constraintlayout.widget.ConstraintLayout>