/*
 * Copyright 2020 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 androidx.camera.video.internal.workaround;

import android.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaCodecList;
import android.media.MediaFormat;
import android.os.Build;
import android.text.TextUtils;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.annotation.VisibleForTesting;
import androidx.camera.core.Logger;
import androidx.camera.video.internal.DebugUtils;
import androidx.camera.video.internal.compat.quirk.DeviceQuirks;
import androidx.camera.video.internal.compat.quirk.MediaCodecInfoReportIncorrectInfoQuirk;
import androidx.camera.video.internal.compat.quirk.MediaFormatMustNotUseFrameRateToFindEncoderQuirk;
import androidx.camera.video.internal.encoder.InvalidConfigException;
import androidx.core.util.Preconditions;

import java.io.IOException;

/**
 * Workaround to find the suitable encoder.
 *
 * <p>The workaround is to check the quirks to fix the selection of video encoder.
 *
 * @see MediaFormatMustNotUseFrameRateToFindEncoderQuirk
 * @see MediaCodecInfoReportIncorrectInfoQuirk
 */
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
public class EncoderFinder {
    private static final String TAG = "EncoderFinder";

    private final boolean mShouldRemoveKeyFrameRate;

    public EncoderFinder() {
        final MediaFormatMustNotUseFrameRateToFindEncoderQuirk quirk =
                DeviceQuirks.get(MediaFormatMustNotUseFrameRateToFindEncoderQuirk.class);

        mShouldRemoveKeyFrameRate = (quirk != null);
    }

    /**
     * Selects an encoder by a given MediaFormat.
     *
     * <p>The encoder finder might temporarily alter the media format for better compatibility
     * based on OS version. It is not thread safe to use the same media format instance.
     *
     * @param mediaFormat the media format used to find the encoder.
     * @return the MediaCodec suitable for the given media format.
     * @throws InvalidConfigException if it is not able to find a MediaCodec by the given media
     * format.
     */
    @NonNull
    public MediaCodec findEncoder(@NonNull MediaFormat mediaFormat,
            @NonNull MediaCodecList mediaCodecList) throws InvalidConfigException {
        MediaCodec codec;
        String encoderName = findEncoderForFormat(mediaFormat, mediaCodecList);
        try {
            if (TextUtils.isEmpty(encoderName)) {
                String mimeType = mediaFormat.getString(MediaFormat.KEY_MIME);
                codec = MediaCodec.createEncoderByType(mimeType);

                String msg = DebugUtils.dumpCodecCapabilities(mimeType, codec, mediaFormat);
                Logger.w(TAG, String.format("No encoder found that supports requested MediaFormat "
                                + "%s. Create encoder by MIME type. Dump codec info:\n%s",
                        mediaFormat, msg));
            } else {
                codec = MediaCodec.createByCodecName(encoderName);
            }
        } catch (IOException | NullPointerException | IllegalArgumentException e) {
            boolean isMediaFormatInQuirk = shouldCreateCodecByType(mediaFormat);
            String msg = DebugUtils.dumpMediaCodecListForFormat(mediaCodecList, mediaFormat);
            throw new InvalidConfigException(
                    "Encoder cannot created: " + encoderName + ", isMediaFormatInQuirk: "
                            + isMediaFormatInQuirk + "\n" + msg, e);
        }
        return codec;
    }

    @VisibleForTesting
    @Nullable
    String findEncoderForFormat(@NonNull MediaFormat mediaFormat,
            @NonNull MediaCodecList mediaCodecList) {
        Integer tempFrameRate = null;
        Integer tempAacProfile = null;
        try {
            // If the frame rate value is assigned, keep it and restore it later.
            if (mShouldRemoveKeyFrameRate && mediaFormat.containsKey(MediaFormat.KEY_FRAME_RATE)) {
                tempFrameRate = Integer.valueOf(mediaFormat.getInteger(MediaFormat.KEY_FRAME_RATE));
                // Reset frame rate value in API 21.
                mediaFormat.setString(MediaFormat.KEY_FRAME_RATE, null);
            }

            // TODO(b/192129356): Remove KEY_AAC_PROFILE when API <= 23 in order to find an encoder
            //  name or it will get null. This is currently needed for not blocking e2e/MH test.
            //  After the bug has been clarified, the workaround should be removed or a quirk should
            //  be added.
            if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M && mediaFormat.containsKey(
                    MediaFormat.KEY_AAC_PROFILE)) {
                tempAacProfile = Integer.valueOf(
                        mediaFormat.getInteger(MediaFormat.KEY_AAC_PROFILE));
                mediaFormat.setString(MediaFormat.KEY_AAC_PROFILE, null);
            }

            String name = mediaCodecList.findEncoderForFormat(mediaFormat);
            if (name == null) {
                name = findEncoderWithNearestCompatibleBitrate(mediaFormat,
                        mediaCodecList.getCodecInfos());
            }
            return name;
        } finally {
            // Restore the frame rate value.
            if (tempFrameRate != null) {
                mediaFormat.setInteger(MediaFormat.KEY_FRAME_RATE, tempFrameRate.intValue());
            }

            // Restore the aac profile value.
            if (tempAacProfile != null) {
                mediaFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, tempAacProfile.intValue());
            }
        }
    }

    @Nullable
    private String findEncoderWithNearestCompatibleBitrate(@NonNull MediaFormat mediaFormat,
            @NonNull MediaCodecInfo[] codecInfoList) {
        String mime = mediaFormat.getString(MediaFormat.KEY_MIME);
        if (mime == null) {
            Logger.w(TAG, "MediaFormat does not contain mime info.");
            return null;
        }

        for (MediaCodecInfo info : codecInfoList) {
            if (!info.isEncoder()) {
                continue;
            }
            Integer origBitrate = null;
            try {
                MediaCodecInfo.CodecCapabilities caps = info.getCapabilitiesForType(mime);
                Preconditions.checkArgument(caps != null, "MIME type is not supported");

                int newBitrate = -1;
                if (mediaFormat.containsKey(MediaFormat.KEY_BIT_RATE)) {

                    // We only handle video bitrate issues at this moment.
                    MediaCodecInfo.VideoCapabilities videoCaps = caps.getVideoCapabilities();
                    Preconditions.checkArgument(videoCaps != null, "Not video codec");

                    origBitrate = mediaFormat.getInteger(MediaFormat.KEY_BIT_RATE);
                    newBitrate =  videoCaps.getBitrateRange().clamp(origBitrate);
                    mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, newBitrate);
                }
                if (caps.isFormatSupported(mediaFormat)) {
                    Logger.w(TAG, String.format("No encoder found that supports requested bitrate"
                            + ". Adjusting bitrate to nearest supported bitrate [requested: "
                            + "%dbps, nearest: %dbps]", origBitrate, newBitrate));
                    return info.getName();
                }
            } catch (IllegalArgumentException e) {
                // Not supported case.
            } finally {
                if (origBitrate != null) {
                    mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, origBitrate);
                }
            }
        }
        return null;
    }

    private boolean shouldCreateCodecByType(@NonNull MediaFormat mediaFormat) {
        MediaCodecInfoReportIncorrectInfoQuirk quirk =
                DeviceQuirks.get(MediaCodecInfoReportIncorrectInfoQuirk.class);
        if (quirk == null) {
            return false;
        }
        return quirk.isUnSupportMediaCodecInfo(mediaFormat);
    }
}