package com.xtremelabs.robolectric.shadows;

import java.util.concurrent.TimeUnit;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import android.os.AsyncTask;

import com.xtremelabs.robolectric.Robolectric;
import com.xtremelabs.robolectric.WithTestDefaultsRunner;
import com.xtremelabs.robolectric.util.Join;
import com.xtremelabs.robolectric.util.Transcript;

import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.*;

@RunWith(WithTestDefaultsRunner.class)
public class AsyncTaskTest {
    private Transcript transcript;

    @Before public void setUp() throws Exception {
        transcript = new Transcript();
        Robolectric.getBackgroundScheduler().pause();
        Robolectric.getUiThreadScheduler().pause();
    }

    @Test
    public void testNormalFlow() throws Exception {
        AsyncTask<String, String, String> asyncTask = new MyAsyncTask();

        asyncTask.execute("a", "b");
        transcript.assertEventsSoFar("onPreExecute");

        Robolectric.runBackgroundTasks();
        transcript.assertEventsSoFar("doInBackground a, b");
        assertEquals("Result should get stored in the AsyncTask", "c", asyncTask.get(100, TimeUnit.MILLISECONDS));

        Robolectric.runUiThreadTasks();
        transcript.assertEventsSoFar("onPostExecute c");
    }

    @Test
    public void testCancelBeforeBackground() throws Exception {
        AsyncTask<String, String, String> asyncTask = new MyAsyncTask();

        asyncTask.execute("a", "b");
        transcript.assertEventsSoFar("onPreExecute");

        assertTrue(asyncTask.cancel(true));
        assertTrue(asyncTask.isCancelled());

        Robolectric.runBackgroundTasks();
        transcript.assertNoEventsSoFar();

        Robolectric.runUiThreadTasks();
        transcript.assertEventsSoFar("onCancelled");
    }

    @Test
    public void testCancelBeforePostExecute() throws Exception {
        AsyncTask<String, String, String> asyncTask = new MyAsyncTask();

        asyncTask.execute("a", "b");
        transcript.assertEventsSoFar("onPreExecute");

        Robolectric.runBackgroundTasks();
        transcript.assertEventsSoFar("doInBackground a, b");
        assertEquals("Result should get stored in the AsyncTask", "c", asyncTask.get(100, TimeUnit.MILLISECONDS));

        assertFalse(asyncTask.cancel(true));
        assertFalse(asyncTask.isCancelled());

        Robolectric.runUiThreadTasks();
        transcript.assertEventsSoFar("onPostExecute c");
    }

    @Test
    public void progressUpdatesAreQueuedUntilBackgroundThreadFinishes() throws Exception {
        AsyncTask<String, String, String> asyncTask = new MyAsyncTask() {
            @Override protected String doInBackground(String... strings) {
                publishProgress("33%");
                publishProgress("66%");
                publishProgress("99%");
                return "done";
            }
        };

        asyncTask.execute("a", "b");
        transcript.assertEventsSoFar("onPreExecute");

        Robolectric.runBackgroundTasks();
        transcript.assertNoEventsSoFar();
        assertEquals("Result should get stored in the AsyncTask", "done", asyncTask.get(100, TimeUnit.MILLISECONDS));

        Robolectric.runUiThreadTasks();
        transcript.assertEventsSoFar(
                "onProgressUpdate 33%",
                "onProgressUpdate 66%",
                "onProgressUpdate 99%",
                "onPostExecute done");
    }

    @Test
    public void executeReturnsAsyncTask() throws Exception {
        Robolectric.getBackgroundScheduler().unPause();
        AsyncTask<String, String, String> asyncTask = new MyAsyncTask();
        assertThat(asyncTask.execute("a", "b").get(), equalTo("c"));
    }

    @Test
    public void shouldGetStatusForAsyncTask() throws Exception {
        AsyncTask<String, String, String> asyncTask = new MyAsyncTask();
        assertThat(asyncTask.getStatus(), is(AsyncTask.Status.PENDING));
        asyncTask.execute("a");
        assertThat(asyncTask.getStatus(), is(AsyncTask.Status.RUNNING));
        Robolectric.getBackgroundScheduler().unPause();
        assertThat(asyncTask.getStatus(), is(AsyncTask.Status.FINISHED));
    }

    private class MyAsyncTask extends AsyncTask<String, String, String> {
        @Override protected void onPreExecute() {
            transcript.add("onPreExecute");
        }

        @Override protected String doInBackground(String... strings) {
            transcript.add("doInBackground " + Join.join(", ", (Object[]) strings));
            return "c";
        }

        @Override protected void onProgressUpdate(String... values) {
            transcript.add("onProgressUpdate " + Join.join(", ", (Object[]) values));
        }

        @Override protected void onPostExecute(String s) {
            transcript.add("onPostExecute " + s);
        }

        @Override protected void onCancelled() {
        	transcript.add("onCancelled");
        }
    }
}