/*
 * Copyright (C) 2013 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.testingcamera2.v1;

import android.content.Context;
import android.hardware.camera2.CaptureRequest;
import android.util.Size;
import android.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaFormat;
import android.media.MediaMuxer;
import android.media.MediaRecorder;
import android.media.MediaScannerConnection;
import android.os.Environment;
import android.util.Log;
import android.util.Size;
import android.view.Surface;

import java.io.File;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

/**
 * Camera video recording class. It takes frames produced by camera and encoded
 * with either MediaCodec or MediaRecorder. MediaRecorder path is not
 * implemented yet.
 */
public class CameraRecordingStream {
    private static final String TAG = "CameraRecordingStream";
    private static final boolean VERBOSE = Log.isLoggable(TAG, Log.VERBOSE);
    private static final int STREAM_STATE_IDLE = 0;
    private static final int STREAM_STATE_CONFIGURED = 1;
    private static final int STREAM_STATE_RECORDING = 2;
    private static final int FRAME_RATE = 30; // 30fps
    private static final int IFRAME_INTERVAL = 1; // 1 seconds between I-frames
    private static final int TIMEOUT_USEC = 10000; // Timeout value 10ms.
    // Sync object to protect stream state access from multiple threads.
    private final Object mStateLock = new Object();

    private int mStreamState = STREAM_STATE_IDLE;
    private MediaCodec mEncoder;
    private Surface mRecordingSurface;
    private int mEncBitRate;
    private int mOrientation;
    private MediaCodec.BufferInfo mBufferInfo;
    private MediaMuxer mMuxer;
    private int mTrackIndex = -1;
    private boolean mMuxerStarted;
    private boolean mUseMediaCodec = false;
    private Size mStreamSize = new Size(-1, -1);
    private int mOutputFormat = MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4;
    private Thread mRecordingThread;
    private MediaRecorder mMediaRecorder;
    private String mOutputFile;

    public CameraRecordingStream() {
    }

    /**
     * Configure stream with a size and encoder mode.
     *
     * @param ctx Application context.
     * @param size Size of recording stream.
     * @param useMediaCodec The encoder for this stream to use, either MediaCodec
     * or MediaRecorder.
     * @param bitRate Bit rate the encoder takes.
     * @param orientation Recording orientation in degree (0,90,180,270)
     * @param outputFormat Output file format as listed in {@link MediaMuxer.OutputFormat}
     */
    public synchronized void configure(
            Context ctx, Size size, boolean useMediaCodec, int bitRate, int orientation,
            int outputFormat) {
        if (getStreamState() == STREAM_STATE_RECORDING) {
            throw new IllegalStateException(
                    "Stream can only be configured when stream is in IDLE state");
        }

        boolean isConfigChanged =
                (!mStreamSize.equals(size)) ||
                (mUseMediaCodec != useMediaCodec) ||
                (mEncBitRate != bitRate) ||
                (mOrientation != orientation);

        mStreamSize = size;
        mUseMediaCodec = useMediaCodec;
        mEncBitRate = bitRate;
        mOrientation = orientation;
        mOutputFormat = outputFormat;

        if (mUseMediaCodec) {
            if (getStreamState() == STREAM_STATE_CONFIGURED) {
                /**
                 * Stream is already configured, need release encoder and muxer
                 * first, then reconfigure only if configuration is changed.
                 */
                if (!isConfigChanged) {
                    /**
                     * TODO: this is only the skeleton, it is tricky to
                     * implement because muxer need reconfigure always. But
                     * muxer is closely coupled with MediaCodec for now because
                     * muxer can only be started once format change callback is
                     * sent from mediacodec. We need decouple MediaCodec and
                     * Muxer for future.
                     */
                }
                releaseEncoder();
                releaseMuxer(ctx);
                configureMediaCodecEncoder();
            } else {
                configureMediaCodecEncoder();
            }
        } else {
            configureMediaRecorder();
        }

        setStreamState(STREAM_STATE_CONFIGURED);
    }

    /**
     * Add the stream output surface to the target output surface list.
     *
     * @param outputSurfaces The output surface list where the stream can
     * add/remove its output surface.
     * @param detach Detach the recording surface from the outputSurfaces.
     */
    public synchronized void onConfiguringOutputs(List<Surface> outputSurfaces,
            boolean detach) {
        if (detach) {
            // Can detach the surface in CONFIGURED and RECORDING state
            if (getStreamState() != STREAM_STATE_IDLE) {
                outputSurfaces.remove(mRecordingSurface);
            } else {
                Log.w(TAG, "Can not detach surface when recording stream is in IDLE state");
            }
        } else {
            // Can add surface only in CONFIGURED state.
            if (getStreamState() == STREAM_STATE_CONFIGURED) {
                outputSurfaces.add(mRecordingSurface);
            } else {
                Log.w(TAG, "Can only add surface when recording stream is in CONFIGURED state");
            }
        }
    }

    /**
     * Update capture request with configuration required for recording stream.
     *
     * @param requestBuilder Capture request builder that needs to be updated
     * for recording specific camera settings.
     * @param detach Detach the recording surface from the capture request.
     */
    public synchronized void onConfiguringRequest(CaptureRequest.Builder requestBuilder,
            boolean detach) {
        if (detach) {
            // Can detach the surface in CONFIGURED and RECORDING state
            if (getStreamState() != STREAM_STATE_IDLE) {
                requestBuilder.removeTarget(mRecordingSurface);
            } else {
                Log.w(TAG, "Can not detach surface when recording stream is in IDLE state");
            }
        } else {
            // Can add surface only in CONFIGURED state.
            if (getStreamState() == STREAM_STATE_CONFIGURED) {
                requestBuilder.addTarget(mRecordingSurface);
            } else {
                Log.w(TAG, "Can only add surface when recording stream is in CONFIGURED state");
            }
        }
    }

    /**
     * Start recording stream. Calling start on an already started stream has no
     * effect.
     */
    public synchronized void start() {
        if (getStreamState() == STREAM_STATE_RECORDING) {
            Log.w(TAG, "Recording stream is already started");
            return;
        }

        if (getStreamState() != STREAM_STATE_CONFIGURED) {
            throw new IllegalStateException("Recording stream is not configured yet");
        }

        setStreamState(STREAM_STATE_RECORDING);
        if (mUseMediaCodec) {
            startMediaCodecRecording();
        } else {
            mMediaRecorder.start();
        }
    }

    /**
     * <p>
     * Stop recording stream. Calling stop on an already stopped stream has no
     * effect. Producer(in this case, CameraDevice) should stop before this call
     * to avoid sending buffers to a stopped encoder.
     * </p>
     * <p>
     * TODO: We have to release encoder and muxer for MediaCodec mode because
     * encoder is closely coupled with muxer, and muxser can not be reused
     * across different recording session(by design, you can not reset/restart
     * it). To save the subsequent start recording time, we need avoid releasing
     * encoder for future.
     * </p>
     * @param ctx Application context.
     */
    public synchronized void stop(Context ctx) {
        if (getStreamState() != STREAM_STATE_RECORDING) {
            Log.w(TAG, "Recording stream is not started yet");
            return;
        }

        setStreamState(STREAM_STATE_IDLE);
        Log.e(TAG, "setting camera to idle");
        if (mUseMediaCodec) {
            // Wait until recording thread stop
            try {
                mRecordingThread.join();
            } catch (InterruptedException e) {
                throw new RuntimeException("Stop recording failed", e);
            }
            // Drain encoder
            doMediaCodecEncoding(/* notifyEndOfStream */true);
            releaseEncoder();
            releaseMuxer(ctx);
        } else {
            try {
                mMediaRecorder.stop();
            } catch (RuntimeException e) {
                // this can happen if there were no frames received by recorder
                Log.e(TAG, "Could not create output file");
            }
            releaseMediaRecorder();
        }
    }

    /**
     * Starts MediaCodec mode recording.
     */
    private void startMediaCodecRecording() {
        /**
         * Start video recording asynchronously. we need a loop to handle output
         * data for each frame.
         */
        mRecordingThread = new Thread() {
            @Override
            public void run() {
                if (VERBOSE) {
                    Log.v(TAG, "Recording thread starts");
                }

                while (getStreamState() == STREAM_STATE_RECORDING) {
                    // Feed encoder output into the muxer until recording stops.
                    doMediaCodecEncoding(/* notifyEndOfStream */false);
                }
                if (VERBOSE) {
                    Log.v(TAG, "Recording thread completes");
                }
                return;
            }
        };
        mRecordingThread.start();
    }

    // Thread-safe access to the stream state.
    private synchronized void setStreamState(int state) {
        synchronized (mStateLock) {
            if (state < STREAM_STATE_IDLE) {
                throw new IllegalStateException("try to set an invalid state");
            }
            mStreamState = state;
        }
    }

    // Thread-safe access to the stream state.
    private int getStreamState() {
        synchronized(mStateLock) {
            return mStreamState;
        }
    }

    private void releaseEncoder() {
        // Release encoder
        if (VERBOSE) {
            Log.v(TAG, "releasing encoder");
        }
        if (mEncoder != null) {
            mEncoder.stop();
            mEncoder.release();
            if (mRecordingSurface != null) {
                mRecordingSurface.release();
            }
            mEncoder = null;
        }
    }

    private void releaseMuxer(Context ctx) {
        if (VERBOSE) {
            Log.v(TAG, "releasing muxer");
        }

        if (mMuxer != null) {
            mMuxer.stop();
            mMuxer.release();
            mMuxer = null;
            MediaScannerConnection.scanFile(ctx, new String [] { mOutputFile }, null, null);
        }
    }

    private void releaseMediaRecorder() {
        if (VERBOSE) {
            Log.v(TAG, "releasing media recorder");
        }

        if (mMediaRecorder != null) {
            mMediaRecorder.release();
            mMediaRecorder = null;
        }

        if (mRecordingSurface != null) {
            mRecordingSurface.release();
            mRecordingSurface = null;
        }
    }

    private String getOutputMime() {
        switch (mOutputFormat) {
            case MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4:
                return "video/avc";

            case MediaMuxer.OutputFormat.MUXER_OUTPUT_WEBM:
                return "video/x-vnd.on2.vp8";

            default:
                throw new IllegalStateException("Configure with unrecognized format.");
        }
    }

    private String getOutputExtension() {
        switch (mOutputFormat) {
            case MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4:
                return ".mp4";

            case MediaMuxer.OutputFormat.MUXER_OUTPUT_WEBM:
                return ".webm";

            default:
                throw new IllegalStateException("Configure with unrecognized format.");
        }
    }

    private String getOutputMediaFileName() {
        String state = Environment.getExternalStorageState();
        // Check if external storage is mounted
        if (!Environment.MEDIA_MOUNTED.equals(state)) {
            Log.e(TAG, "External storage is not mounted!");
            return null;
        }

        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_DCIM), "TestingCamera2");
        // Create the storage directory if it does not exist
        if (!mediaStorageDir.exists()) {
            if (!mediaStorageDir.mkdirs()) {
                Log.e(TAG, "Failed to create directory " + mediaStorageDir.getPath()
                        + " for pictures/video!");
                return null;
            }
        }

        // Create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String mediaFileName = mediaStorageDir.getPath() + File.separator +
                "VID_" + timeStamp + getOutputExtension();

        Log.v(TAG, "Recording file name: " + mediaFileName);
        return mediaFileName;
    }

    /**
     * Configures encoder and muxer state, and prepares the input Surface.
     * Initializes mEncoder, mMuxer, mRecordingSurface, mBufferInfo,
     * mTrackIndex, and mMuxerStarted.
     */
    private void configureMediaCodecEncoder() {
        mBufferInfo = new MediaCodec.BufferInfo();
        MediaFormat format =
                MediaFormat.createVideoFormat(getOutputMime(),
                        mStreamSize.getWidth(), mStreamSize.getHeight());
        /**
         * Set encoding properties. Failing to specify some of these can cause
         * the MediaCodec configure() call to throw an exception.
         */
        format.setInteger(MediaFormat.KEY_COLOR_FORMAT,
                MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
        format.setInteger(MediaFormat.KEY_BIT_RATE, mEncBitRate);
        format.setInteger(MediaFormat.KEY_FRAME_RATE, FRAME_RATE);
        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, IFRAME_INTERVAL);
        Log.i(TAG, "configure video encoding format: " + format);

        // Create/configure a MediaCodec encoder.
        try {
            mEncoder = MediaCodec.createEncoderByType(getOutputMime());
        } catch (IOException ioe) {
            throw new IllegalStateException(
                    "failed to create " + getOutputMime() + " encoder", ioe);
        }
        mEncoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
        mRecordingSurface = mEncoder.createInputSurface();
        mEncoder.start();

        String outputFileName = getOutputMediaFileName();
        if (outputFileName == null) {
            throw new IllegalStateException("Failed to get video output file");
        }

        /**
         * Create a MediaMuxer. We can't add the video track and start() the
         * muxer until the encoder starts and notifies the new media format.
         */
        try {
            mOutputFile = outputFileName;
            mMuxer = new MediaMuxer(mOutputFile, mOutputFormat);
            mMuxer.setOrientationHint(mOrientation);
        } catch (IOException ioe) {
            throw new IllegalStateException("MediaMuxer creation failed", ioe);
        }
        mMuxerStarted = false;
    }

    private void configureMediaRecorder() {
        String outputFileName = getOutputMediaFileName();
        if (outputFileName == null) {
            throw new IllegalStateException("Failed to get video output file");
        }
        releaseMediaRecorder();
        mMediaRecorder = new MediaRecorder();
        try {
            if (mOutputFormat == MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4) {
                mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
                mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
                mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
                mMediaRecorder.setOutputFile(outputFileName);
                mMediaRecorder.setVideoEncodingBitRate(mEncBitRate);
                mMediaRecorder.setVideoFrameRate(FRAME_RATE);
                mMediaRecorder.setVideoSize(mStreamSize.getWidth(), mStreamSize.getHeight());
                mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
                mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
                mMediaRecorder.setOrientationHint(mOrientation);
            } else {
                // TODO audio support
                mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
                mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.WEBM);
                mMediaRecorder.setOutputFile(outputFileName);
                mMediaRecorder.setVideoEncodingBitRate(mEncBitRate);
                mMediaRecorder.setVideoFrameRate(FRAME_RATE);
                mMediaRecorder.setVideoSize(mStreamSize.getWidth(), mStreamSize.getHeight());
                mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.VP8);
            }
            mMediaRecorder.prepare();
            mRecordingSurface = mMediaRecorder.getSurface();
        } catch (IllegalStateException e) {
            Log.v(TAG, "MediaRecorder throws IllegalStateException " + e.toString());
        } catch (IOException e) {
            Log.v(TAG, "MediaRecorder throws IOException " + e.toString());
        }
    }

    /**
     * Do encoding by using MediaCodec encoder, then extracts all pending data
     * from the encoder and forwards it to the muxer.
     * <p>
     * If notifyEndOfStream is not set, this returns when there is no more data
     * to output. If it is set, we send EOS to the encoder, and then iterate
     * until we see EOS on the output. Calling this with notifyEndOfStream set
     * should be done once, before stopping the muxer.
     * </p>
     * <p>
     * We're just using the muxer to get a .mp4 file and audio is not included
     * here.
     * </p>
     */
    private void doMediaCodecEncoding(boolean notifyEndOfStream) {
        if (VERBOSE) {
            Log.v(TAG, "doMediaCodecEncoding(" + notifyEndOfStream + ")");
        }

        if (notifyEndOfStream) {
            mEncoder.signalEndOfInputStream();
        }

        ByteBuffer[] encoderOutputBuffers = mEncoder.getOutputBuffers();
        boolean notDone = true;
        while (notDone) {
            int encoderStatus = mEncoder.dequeueOutputBuffer(mBufferInfo, TIMEOUT_USEC);
            if (encoderStatus == MediaCodec.INFO_TRY_AGAIN_LATER) {
                if (!notifyEndOfStream) {
                    /**
                     * Break out of the while loop because the encoder is not
                     * ready to output anything yet.
                     */
                    notDone = false;
                } else {
                    if (VERBOSE) {
                        Log.v(TAG, "no output available, spinning to await EOS");
                    }
                }
            } else if (encoderStatus == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
                // generic case for mediacodec, not likely occurs for encoder.
                encoderOutputBuffers = mEncoder.getOutputBuffers();
            } else if (encoderStatus == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                /**
                 * should happen before receiving buffers, and should only
                 * happen once
                 */
                if (mMuxerStarted) {
                    throw new IllegalStateException("format changed twice");
                }
                MediaFormat newFormat = mEncoder.getOutputFormat();
                if (VERBOSE) {
                    Log.v(TAG, "encoder output format changed: " + newFormat);
                }
                mTrackIndex = mMuxer.addTrack(newFormat);
                mMuxer.start();
                mMuxerStarted = true;
            } else if (encoderStatus < 0) {
                Log.w(TAG, "unexpected result from encoder.dequeueOutputBuffer: " + encoderStatus);
            } else {
                // Normal flow: get output encoded buffer, send to muxer.
                ByteBuffer encodedData = encoderOutputBuffers[encoderStatus];
                if (encodedData == null) {
                    throw new RuntimeException("encoderOutputBuffer " + encoderStatus +
                            " was null");
                }

                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
                    /**
                     * The codec config data was pulled out and fed to the muxer
                     * when we got the INFO_OUTPUT_FORMAT_CHANGED status. Ignore
                     * it.
                     */
                    if (VERBOSE) {
                        Log.v(TAG, "ignoring BUFFER_FLAG_CODEC_CONFIG");
                    }
                    mBufferInfo.size = 0;
                }

                if (mBufferInfo.size != 0) {
                    if (!mMuxerStarted) {
                        throw new RuntimeException("muxer hasn't started");
                    }

                    /**
                     * It's usually necessary to adjust the ByteBuffer values to
                     * match BufferInfo.
                     */
                    encodedData.position(mBufferInfo.offset);
                    encodedData.limit(mBufferInfo.offset + mBufferInfo.size);

                    mMuxer.writeSampleData(mTrackIndex, encodedData, mBufferInfo);
                    if (VERBOSE) {
                        Log.v(TAG, "sent " + mBufferInfo.size + " bytes to muxer");
                    }
                }

                mEncoder.releaseOutputBuffer(encoderStatus, false);

                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                    if (!notifyEndOfStream) {
                        Log.w(TAG, "reached end of stream unexpectedly");
                    } else {
                        if (VERBOSE) {
                            Log.v(TAG, "end of stream reached");
                        }
                    }
                    // Finish encoding.
                    notDone = false;
                }
            }
        } // End of while(notDone)
    }
}