/*
 * Copyright 2015 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 android.hardware.camera2.cts;

import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.cts.testcases.Camera2AndroidTestCase;
import android.hardware.camera2.cts.helpers.StaticMetadata;
import android.hardware.camera2.cts.helpers.StaticMetadata.CheckLevel;
import android.util.Log;
import android.os.SystemClock;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.TimeUnit;

import static org.mockito.Mockito.*;

/**
 * <p>Tests for flashlight API.</p>
 */
public class FlashlightTest extends Camera2AndroidTestCase {
    private static final String TAG = "FlashlightTest";
    private static final boolean VERBOSE = Log.isLoggable(TAG, Log.VERBOSE);
    private static final int TORCH_DURATION_MS = 1000;
    private static final int TORCH_TIMEOUT_MS = 3000;
    private static final int NUM_REGISTERS = 10;

    private ArrayList<String> mFlashCameraIdList;

    @Override
    protected void setUp() throws Exception {
        super.setUp();

        // initialize the list of cameras that have a flash unit so it won't interfere with
        // flash tests.
        mFlashCameraIdList = new ArrayList<String>();
        for (String id : mCameraIds) {
            StaticMetadata info =
                    new StaticMetadata(mCameraManager.getCameraCharacteristics(id),
                                       CheckLevel.ASSERT, /*collector*/ null);
            if (info.hasFlash()) {
                mFlashCameraIdList.add(id);
            }
        }
    }

    public void testSetTorchModeOnOff() throws Exception {
        if (mFlashCameraIdList.size() == 0)
            return;

        // reset flash status for all devices with a flash unit
        for (String id : mFlashCameraIdList) {
            resetTorchModeStatus(id);
        }

        // turn on and off torch mode one by one
        for (String id : mFlashCameraIdList) {
            CameraManager.TorchCallback torchListener = mock(CameraManager.TorchCallback.class);
            mCameraManager.registerTorchCallback(torchListener, mHandler); // should get OFF

            mCameraManager.setTorchMode(id, true); // should get ON
            SystemClock.sleep(TORCH_DURATION_MS);
            mCameraManager.setTorchMode(id, false); // should get OFF

            // verify corrected numbers of callbacks
            verify(torchListener, timeout(TORCH_TIMEOUT_MS).
                    times(2)).onTorchModeChanged(id, false);
            verify(torchListener, timeout(TORCH_TIMEOUT_MS).
                    times(mFlashCameraIdList.size() + 1)).
                    onTorchModeChanged(anyString(), eq(false));
            verify(torchListener, timeout(TORCH_TIMEOUT_MS).
                    times(1)).onTorchModeChanged(id, true);
            verify(torchListener, timeout(TORCH_TIMEOUT_MS).
                    times(1)).onTorchModeChanged(anyString(), eq(true));
            verify(torchListener, timeout(TORCH_TIMEOUT_MS).never()).
                    onTorchModeUnavailable(anyString());

            mCameraManager.unregisterTorchCallback(torchListener);
        }

        // turn on all torch modes at once
        if (mFlashCameraIdList.size() >= 2) {
            CameraManager.TorchCallback torchListener = mock(CameraManager.TorchCallback.class);
            mCameraManager.registerTorchCallback(torchListener, mHandler); // should get OFF.

            for (String id : mFlashCameraIdList) {
                // should get ON for this ID.
                // may get OFF for previously-on IDs.
                mCameraManager.setTorchMode(id, true);
            }

            SystemClock.sleep(TORCH_DURATION_MS);

            for (String id : mFlashCameraIdList) {
                // should get OFF if not turned off previously.
                mCameraManager.setTorchMode(id, false);
            }

            verify(torchListener, timeout(TORCH_TIMEOUT_MS).times(mFlashCameraIdList.size())).
                    onTorchModeChanged(anyString(), eq(true));
            // one more off for each id due to callback registeration.
            verify(torchListener, timeout(TORCH_TIMEOUT_MS).
                    times(mFlashCameraIdList.size() * 2)).
                    onTorchModeChanged(anyString(), eq(false));

            mCameraManager.unregisterTorchCallback(torchListener);
        }
    }

    public void testTorchCallback() throws Exception {
        if (mFlashCameraIdList.size() == 0)
            return;

        // reset torch mode status
        for (String id : mFlashCameraIdList) {
            resetTorchModeStatus(id);
        }

        CameraManager.TorchCallback torchListener = mock(CameraManager.TorchCallback.class);

        for (int i = 0; i < NUM_REGISTERS; i++) {
            // should get OFF for all cameras with a flash unit.
            mCameraManager.registerTorchCallback(torchListener, mHandler);
            mCameraManager.unregisterTorchCallback(torchListener);
        }

        verify(torchListener, timeout(TORCH_TIMEOUT_MS).
                times(NUM_REGISTERS * mFlashCameraIdList.size())).
                onTorchModeChanged(anyString(), eq(false));
        verify(torchListener, timeout(TORCH_TIMEOUT_MS).never()).
                onTorchModeChanged(anyString(), eq(true));
        verify(torchListener, timeout(TORCH_TIMEOUT_MS).never()).
                onTorchModeUnavailable(anyString());

        // verify passing a null handler will raise IllegalArgumentException
        try {
            mCameraManager.registerTorchCallback(torchListener, null);
            mCameraManager.unregisterTorchCallback(torchListener);
            fail("should get IllegalArgumentException due to no handler");
        } catch (IllegalArgumentException e) {
            // expected exception
        }
    }

    public void testCameraDeviceOpenAfterTorchOn() throws Exception {
        if (mFlashCameraIdList.size() == 0)
            return;

        for (String id : mFlashCameraIdList) {
            for (String idToOpen : mCameraIds) {
                resetTorchModeStatus(id);

                CameraManager.TorchCallback torchListener =
                        mock(CameraManager.TorchCallback.class);

                // this will trigger OFF for each id in mFlashCameraIdList
                mCameraManager.registerTorchCallback(torchListener, mHandler);

                // this will trigger ON for id
                mCameraManager.setTorchMode(id, true);
                SystemClock.sleep(TORCH_DURATION_MS);

                // if id == idToOpen, this will trigger UNAVAILABLE and may trigger OFF.
                // this may trigger UNAVAILABLE for any other id in mFlashCameraIdList
                openDevice(idToOpen);

                // if id == idToOpen, this will trigger OFF.
                // this may trigger OFF for any other id in mFlashCameraIdList.
                closeDevice(idToOpen);

                // this may trigger OFF for id if not received previously.
                mCameraManager.setTorchMode(id, false);

                verify(torchListener, timeout(TORCH_TIMEOUT_MS).times(1)).
                        onTorchModeChanged(id, true);
                verify(torchListener, timeout(TORCH_TIMEOUT_MS).times(1)).
                        onTorchModeChanged(anyString(), eq(true));

                verify(torchListener, timeout(TORCH_TIMEOUT_MS).atLeast(2)).
                        onTorchModeChanged(id, false);
                verify(torchListener, atMost(3)).onTorchModeChanged(id, false);

                verify(torchListener, timeout(TORCH_TIMEOUT_MS).
                        atLeast(mFlashCameraIdList.size())).
                        onTorchModeChanged(anyString(), eq(false));
                verify(torchListener, atMost(mFlashCameraIdList.size() * 2 + 1)).
                        onTorchModeChanged(anyString(), eq(false));

                if (hasFlash(idToOpen)) {
                    verify(torchListener, timeout(TORCH_TIMEOUT_MS).times(1)).
                            onTorchModeUnavailable(idToOpen);
                }
                verify(torchListener, atMost(mFlashCameraIdList.size())).
                            onTorchModeUnavailable(anyString());

                mCameraManager.unregisterTorchCallback(torchListener);
            }
        }
    }

    public void testTorchModeExceptions() throws Exception {
        // cameraIdsToTestTorch = all available camera ID + non-existing camera id +
        //                        non-existing numeric camera id + null
        String[] cameraIdsToTestTorch = new String[mCameraIds.length + 3];
        System.arraycopy(mCameraIds, 0, cameraIdsToTestTorch, 0, mCameraIds.length);
        cameraIdsToTestTorch[mCameraIds.length] = generateNonexistingCameraId();
        cameraIdsToTestTorch[mCameraIds.length + 1] = generateNonexistingNumericCameraId();

        for (String idToOpen : mCameraIds) {
            openDevice(idToOpen);
            try {
                for (String id : cameraIdsToTestTorch) {
                    try {
                        mCameraManager.setTorchMode(id, true);
                        SystemClock.sleep(TORCH_DURATION_MS);
                        mCameraManager.setTorchMode(id, false);
                        if (!hasFlash(id)) {
                            fail("exception should be thrown when turning on torch mode of a " +
                                    "camera without a flash");
                        } else if (id.equals(idToOpen)) {
                            fail("exception should be thrown when turning on torch mode of an " +
                                    "opened camera");
                        }
                    } catch (CameraAccessException e) {
                        if ((hasFlash(id) &&  id.equals(idToOpen) &&
                                    e.getReason() == CameraAccessException.CAMERA_IN_USE) ||
                            (hasFlash(id) && !id.equals(idToOpen) &&
                                    e.getReason() == CameraAccessException.MAX_CAMERAS_IN_USE)) {
                            continue;
                        }
                        fail("(" + id + ") not expecting: " + e.getMessage());
                    } catch (IllegalArgumentException e) {
                        if (hasFlash(id)) {
                            fail("not expecting IllegalArgumentException");
                        }
                    }
                }
            } finally {
                closeDevice(idToOpen);
            }
        }
    }

    private boolean hasFlash(String cameraId) {
        return mFlashCameraIdList.contains(cameraId);
    }

    // make sure the torch status is off.
    private void resetTorchModeStatus(String cameraId) throws Exception {
        TorchCallbackListener torchListener = new TorchCallbackListener(cameraId);

        mCameraManager.registerTorchCallback(torchListener, mHandler);
        mCameraManager.setTorchMode(cameraId, true);
        mCameraManager.setTorchMode(cameraId, false);

        torchListener.waitOnStatusChange(TorchCallbackListener.STATUS_ON);
        torchListener.waitOnStatusChange(TorchCallbackListener.STATUS_OFF);

        mCameraManager.unregisterTorchCallback(torchListener);
    }

    private String generateNonexistingCameraId() {
        String nonExisting = "none_existing_camera";
        for (String id : mCameraIds) {
            if (Arrays.asList(mCameraIds).contains(nonExisting)) {
                nonExisting += id;
            } else {
                break;
            }
        }
        return nonExisting;
    }

    // return a non-existing and non-negative numeric camera id.
    private String generateNonexistingNumericCameraId() {
        int[] numericCameraIds = new int[mCameraIds.length];
        int size = 0;

        for (String cameraId : mCameraIds) {
            try {
                int value = Integer.parseInt(cameraId);
                if (value >= 0) {
                    numericCameraIds[size++] = value;
                }
            } catch (Throwable e) {
                // do nothing if camera id isn't an integer
            }
        }

        if (size == 0) {
            return "0";
        }

        Arrays.sort(numericCameraIds, 0, size);
        if (numericCameraIds[0] != 0) {
            return "0";
        }

        for (int i = 0; i < size - 1; i++) {
            if (numericCameraIds[i] + 1 < numericCameraIds[i + 1]) {
                return String.valueOf(numericCameraIds[i] + 1);
            }
        }

        if (numericCameraIds[size - 1] != Integer.MAX_VALUE) {
            return String.valueOf(numericCameraIds[size - 1] + 1);
        }

        fail("cannot find a non-existing and non-negative numeric camera id");
        return null;
    }

    private final class TorchCallbackListener extends CameraManager.TorchCallback {
        private static final String TAG = "TorchCallbackListener";
        private static final int STATUS_WAIT_TIMEOUT_MS = 3000;
        private static final int QUEUE_CAPACITY = 100;

        private String mCameraId;
        private ArrayBlockingQueue<Integer> mStatusQueue =
                new ArrayBlockingQueue<Integer>(QUEUE_CAPACITY);

        public static final int STATUS_UNAVAILABLE = 0;
        public static final int STATUS_OFF = 1;
        public static final int STATUS_ON = 2;

        public TorchCallbackListener(String cameraId) {
            // only care about events for this camera id.
            mCameraId = cameraId;
        }

        public void waitOnStatusChange(int status) throws Exception {
            while (true) {
                Integer s = mStatusQueue.poll(STATUS_WAIT_TIMEOUT_MS, TimeUnit.MILLISECONDS);
                if (s == null) {
                    fail("waiting for status " + status + " timed out");
                } else if (s.intValue() == status) {
                    return;
                }
            }
        }

        @Override
        public void onTorchModeUnavailable(String cameraId) {
            if (cameraId.equals(mCameraId)) {
                Integer s = new Integer(STATUS_UNAVAILABLE);
                try {
                    mStatusQueue.put(s);
                } catch (Throwable e) {
                    fail(e.getMessage());
                }
            }
        }

        @Override
        public void onTorchModeChanged(String cameraId, boolean enabled) {
            if (cameraId.equals(mCameraId)) {
                Integer s;
                if (enabled) {
                    s = new Integer(STATUS_ON);
                } else {
                    s = new Integer(STATUS_OFF);
                }
                try {
                    mStatusQueue.put(s);
                } catch (Throwable e) {
                    fail(e.getMessage());
                }
            }
        }
    }
}