/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dumprendertree2;

import android.app.Service;
import android.content.Intent;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.util.Log;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

/**
 * A service that handles managing the results of tests, informing of crashes, generating
 * summaries, etc.
 */
public class ManagerService extends Service {

    private static final String LOG_TAG = "ManagerService";

    private static final int MSG_CRASH_TIMEOUT_EXPIRED = 0;
    private static final int MSG_SUMMARIZER_DONE = 1;

    private static final int CRASH_TIMEOUT_MS = 20 * 1000;

    /** TODO: make it a setting */
    static final String RESULTS_ROOT_DIR_PATH =
            Environment.getExternalStorageDirectory() + File.separator + "layout-test-results";

    /** TODO: Make it a setting */
    private static final List<String> EXPECTED_RESULT_LOCATION_RELATIVE_DIR_PREFIXES =
            new ArrayList<String>(3);
    {
        EXPECTED_RESULT_LOCATION_RELATIVE_DIR_PREFIXES.add("platform" + File.separator +
                "android-v8" + File.separator);
        EXPECTED_RESULT_LOCATION_RELATIVE_DIR_PREFIXES.add("platform" + File.separator +
                "android" + File.separator);
        EXPECTED_RESULT_LOCATION_RELATIVE_DIR_PREFIXES.add("");
    }

    /** TODO: Make these settings */
    private static final String TEXT_RESULT_EXTENSION = "txt";
    private static final String IMAGE_RESULT_EXTENSION = "png";

    static final int MSG_PROCESS_ACTUAL_RESULTS = 0;
    static final int MSG_ALL_TESTS_FINISHED = 1;
    static final int MSG_FIRST_TEST = 2;
    static final int MSG_CURRENT_TEST_CRASHED = 3;
    static final int MSG_RESET = 4;

    /**
     * This handler is purely for IPC. It is used to create mMessenger
     * that generates a binder returned in onBind method.
     */
    private Handler mIncomingHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_RESET:
                    mSummarizer.reset();
                    break;

                case MSG_FIRST_TEST:
                    Bundle bundle = msg.getData();
                    ensureNextTestSetup(bundle.getString("firstTest"), bundle.getInt("index"));
                    break;

                case MSG_PROCESS_ACTUAL_RESULTS:
                    Log.d(LOG_TAG,"mIncomingHandler: " + msg.getData().getString("relativePath"));
                    onActualResultsObtained(msg.getData());
                    break;

                case MSG_CURRENT_TEST_CRASHED:
                    mInternalMessagesHandler.removeMessages(MSG_CRASH_TIMEOUT_EXPIRED);
                    onTestCrashed();
                    break;

                case MSG_ALL_TESTS_FINISHED:
                    /** We run it in a separate thread to avoid ANR */
                    new Thread() {
                        @Override
                        public void run() {
                            mSummarizer.setTestsRelativePath(mAllTestsRelativePath);
                            Message msg = Message.obtain(mInternalMessagesHandler,
                                    MSG_SUMMARIZER_DONE);
                            mSummarizer.summarize(msg);
                        }
                    }.start();
            }
        }
    };

    private Messenger mMessenger = new Messenger(mIncomingHandler);

    private Handler mInternalMessagesHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_CRASH_TIMEOUT_EXPIRED:
                    onTestCrashed();
                    break;

                case MSG_SUMMARIZER_DONE:
                    Intent intent = new Intent(ManagerService.this, TestsListActivity.class);
                    intent.setAction(Intent.ACTION_SHUTDOWN);
                    /** This flag is needed because we send the intent from the service */
                    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    startActivity(intent);
                    break;
            }
        }
    };

    private Summarizer mSummarizer;

    private String mCurrentlyRunningTest;
    private int mCurrentlyRunningTestIndex;

    /**
     * These are implementation details of getExpectedResultPath() used to reduce the number
     * of requests required to the host server.
     */
    private String mLastExpectedResultPathRequested;
    private String mLastExpectedResultPathFetched;

    private String mAllTestsRelativePath;

    @Override
    public void onCreate() {
        super.onCreate();

        mSummarizer = new Summarizer(RESULTS_ROOT_DIR_PATH, getApplicationContext());
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        mAllTestsRelativePath = intent.getStringExtra("path");
        assert mAllTestsRelativePath != null;
        return START_STICKY;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return mMessenger.getBinder();
    }

    private void onActualResultsObtained(Bundle bundle) {
        mInternalMessagesHandler.removeMessages(MSG_CRASH_TIMEOUT_EXPIRED);
        ensureNextTestSetup(bundle.getString("nextTest"), bundle.getInt("testIndex") + 1);

        AbstractResult results =
                AbstractResult.TestType.valueOf(bundle.getString("type")).createResult(bundle);

        Log.i(LOG_TAG, "onActualResultObtained: " + results.getRelativePath());
        handleResults(results);
    }

    private void ensureNextTestSetup(String nextTest, int index) {
        if (nextTest == null) {
            Log.w(LOG_TAG, "ensureNextTestSetup(): nextTest=null");
            return;
        }

        mCurrentlyRunningTest = nextTest;
        mCurrentlyRunningTestIndex = index;
        mInternalMessagesHandler.sendEmptyMessageDelayed(MSG_CRASH_TIMEOUT_EXPIRED, CRASH_TIMEOUT_MS);
    }

    /**
     * This sends an intent to TestsListActivity to restart LayoutTestsExecutor.
     * The more detailed description of the flow is in the comment of onNewIntent
     * method in TestsListActivity.
     */
    private void onTestCrashed() {
        handleResults(new CrashedDummyResult(mCurrentlyRunningTest));

        Log.w(LOG_TAG, "onTestCrashed(): " + mCurrentlyRunningTest +
                " (" + mCurrentlyRunningTestIndex + ")");

        Intent intent = new Intent(this, TestsListActivity.class);
        intent.setAction(Intent.ACTION_REBOOT);
        /** This flag is needed because we send the intent from the service */
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.putExtra("crashedTestIndex", mCurrentlyRunningTestIndex);
        startActivity(intent);
    }

    private void handleResults(AbstractResult results) {
        String relativePath = results.getRelativePath();
        results.setExpectedTextResult(getExpectedTextResult(relativePath));
        results.setExpectedTextResultPath(getExpectedTextResultPath(relativePath));
        results.setExpectedImageResult(getExpectedImageResult(relativePath));
        results.setExpectedImageResultPath(getExpectedImageResultPath(relativePath));

        dumpActualTextResult(results);
        dumpActualImageResult(results);

        mSummarizer.appendTest(results);
    }

    private void dumpActualTextResult(AbstractResult result) {
        String testPath = result.getRelativePath();
        String actualTextResult = result.getActualTextResult();
        if (actualTextResult == null) {
            return;
        }

        String resultPath = FileFilter.setPathEnding(testPath, "-actual." + TEXT_RESULT_EXTENSION);
        FsUtils.writeDataToStorage(new File(RESULTS_ROOT_DIR_PATH, resultPath),
                actualTextResult.getBytes(), false);
    }

    private void dumpActualImageResult(AbstractResult result) {
        String testPath = result.getRelativePath();
        byte[] actualImageResult = result.getActualImageResult();
        if (actualImageResult == null) {
            return;
        }

        String resultPath = FileFilter.setPathEnding(testPath,
                "-actual." + IMAGE_RESULT_EXTENSION);
        FsUtils.writeDataToStorage(new File(RESULTS_ROOT_DIR_PATH, resultPath),
                actualImageResult, false);
    }

    public String getExpectedTextResult(String relativePath) {
        byte[] result = getExpectedResult(relativePath, TEXT_RESULT_EXTENSION);
        if (result != null) {
            return new String(result);
        }
        return null;
    }

    public byte[] getExpectedImageResult(String relativePath) {
        return getExpectedResult(relativePath, IMAGE_RESULT_EXTENSION);
    }

    private byte[] getExpectedResult(String relativePath, String extension) {
        String originalRelativePath =
                FileFilter.setPathEnding(relativePath, "-expected." + extension);
        mLastExpectedResultPathRequested = originalRelativePath;

        byte[] bytes = null;
        List<String> locations = EXPECTED_RESULT_LOCATION_RELATIVE_DIR_PREFIXES;

        int size = EXPECTED_RESULT_LOCATION_RELATIVE_DIR_PREFIXES.size();
        for (int i = 0; bytes == null && i < size; i++) {
            relativePath = locations.get(i) + originalRelativePath;
            bytes = FsUtils.readDataFromUrl(FileFilter.getUrl(relativePath, false));
        }

        mLastExpectedResultPathFetched = bytes == null ? null : relativePath;
        return bytes;
    }

    private String getExpectedTextResultPath(String relativePath) {
        return getExpectedResultPath(relativePath, TEXT_RESULT_EXTENSION);
    }

    private String getExpectedImageResultPath(String relativePath) {
        return getExpectedResultPath(relativePath, IMAGE_RESULT_EXTENSION);
    }

    private String getExpectedResultPath(String relativePath, String extension) {
        String originalRelativePath =
            FileFilter.setPathEnding(relativePath, "-expected." + extension);
        if (!originalRelativePath.equals(mLastExpectedResultPathRequested)) {
            getExpectedResult(relativePath, extension);
        }

        return mLastExpectedResultPathFetched;
    }
}