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modification, are permitted provided that the following conditions are
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      notice, this list of conditions and the following disclaimer.
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      copyright notice, this list of conditions and the following
      disclaimer in the documentation and/or other materials provided
      with the distribution.
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      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
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MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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 */
package com.android.camera.imageprocessor;

import android.hardware.camera2.CaptureResult;
import android.hardware.camera2.TotalCaptureResult;
import android.media.Image;
import android.util.Log;

import com.android.camera.CaptureModule;
import com.android.camera.util.PersistUtil;
import android.os.SystemProperties;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.NoSuchElementException;

public class ZSLQueue {
    private int mCircularBufferSize;
    private ImageItem[] mBuffer;
    private int mImageHead;
    private int mMetaHead;
    private Object mLock = new Object();
    private CaptureModule mModule;
    private static final boolean DEBUG_QUEUE  =
            (PersistUtil.getCamera2Debug() == PersistUtil.CAMERA2_DEBUG_DUMP_LOG) ||
            (PersistUtil.getCamera2Debug() == PersistUtil.CAMERA2_DEBUG_DUMP_ALL);
    private static final String TAG = "ZSLQueue";

    public ZSLQueue(CaptureModule module) {
        mCircularBufferSize = PersistUtil.getCircularBufferSize();
        synchronized (mLock) {
            mBuffer = new ImageItem[mCircularBufferSize];
            mImageHead = 0;
            mMetaHead = 0;
            mModule = module;
        }
    }

    private int findMeta(long timestamp, int index) {
        int startIndex = index;
        do {
            if(mBuffer[index] != null && mBuffer[index].getMetadata() != null &&
                    mBuffer[index].getMetadata().get(CaptureResult.SENSOR_TIMESTAMP).longValue() == timestamp) {
                return index;
            }
            index = (index + 1) % mBuffer.length;
        } while(index != startIndex);
        return -1;
    }

    private int findImage(long timestamp, int index) {
        int startIndex = index;
        do {
            if(mBuffer[index] != null && mBuffer[index].getImage() != null &&
                    mBuffer[index].getImage().getTimestamp() == timestamp) {
                return index;
            }
            index = (index + 1) % mBuffer.length;
        } while(index != startIndex);
        return -1;
    }

    public void add(Image image, Image rawImage) {
        int lastIndex = -1;
        synchronized (mLock) {
            if(mBuffer == null)
                return;
            if(mBuffer[mImageHead] != null) {
                mBuffer[mImageHead].closeImage();
            } else {
                mBuffer[mImageHead] = new ImageItem();
            }
            if(mBuffer[mImageHead].getMetadata() != null) {
                if((mBuffer[mImageHead].getMetadata().get(CaptureResult.SENSOR_TIMESTAMP)).longValue() == image.getTimestamp()) {
                    mBuffer[mImageHead].setImage(image,rawImage);
                    lastIndex = mImageHead;
                    mImageHead = (mImageHead + 1) % mBuffer.length;
                } else if((mBuffer[mImageHead].getMetadata().get(CaptureResult.SENSOR_TIMESTAMP)).longValue() > image.getTimestamp()) {
                    image.close();
                } else {
                    int i = findMeta(image.getTimestamp(), mImageHead);
                    if(i == -1) {
                        mBuffer[mImageHead].setImage(image, rawImage);
                        mBuffer[mImageHead].setMetadata(null);
                        mImageHead = (mImageHead + 1) % mBuffer.length;
                    } else {
                        lastIndex = mImageHead = i;
                        mBuffer[mImageHead].setImage(image, rawImage);
                        mImageHead = (mImageHead + 1) % mBuffer.length;
                    }
                }
            } else {
                mBuffer[mImageHead].setImage(image, rawImage);
                lastIndex = mImageHead;
                mImageHead = (mImageHead + 1) % mBuffer.length;
            }
        }

        if(DEBUG_QUEUE) Log.d(TAG, "imageIndex: " + lastIndex + " " + image.getTimestamp());
    }

    public void add(TotalCaptureResult metadata) {
        int lastIndex = -1;
        synchronized (mLock) {
            if(mBuffer == null)
                return;
            long timestamp = -1;
            try {
                timestamp = metadata.get(CaptureResult.SENSOR_TIMESTAMP).longValue();
            } catch(IllegalStateException e) {
                //This happens when corresponding image to this metadata is closed and discarded.
                return;
            }
            if(timestamp == -1) {
                return;
            }
            if(mBuffer[mMetaHead] == null) {
                mBuffer[mMetaHead] = new ImageItem();
            } else {
                mBuffer[mMetaHead].closeMeta();
            }
            if(mBuffer[mMetaHead].getImage() != null) {
                if(mBuffer[mMetaHead].getImage().getTimestamp() == timestamp) {
                    mBuffer[mMetaHead].setMetadata(metadata);
                    lastIndex = mMetaHead;
                    mMetaHead = (mMetaHead + 1) % mBuffer.length;
                } else if(mBuffer[mMetaHead].getImage().getTimestamp() > timestamp) {
                    //Disard
                } else {
                    int i = findImage(timestamp, mMetaHead);
                    if(i == -1) {
                        mBuffer[mMetaHead].setImage(null, null);
                        mBuffer[mMetaHead].setMetadata(metadata);
                        mMetaHead = (mMetaHead + 1) % mBuffer.length;
                    } else {
                        lastIndex = mMetaHead = i;
                        mBuffer[mMetaHead].setMetadata(metadata);
                        mMetaHead = (mMetaHead + 1) % mBuffer.length;
                    }
                }
            } else {
                mBuffer[mMetaHead].setMetadata(metadata);
                lastIndex = mImageHead;
                mMetaHead = (mMetaHead + 1) % mBuffer.length;
            }
        }

        if(DEBUG_QUEUE) Log.d(TAG, "Meta: " + lastIndex + " " + metadata.get(CaptureResult.SENSOR_TIMESTAMP));
    }

    public ImageItem tryToGetMatchingItem() {
        synchronized (mLock) {
            int index = mImageHead;
            ImageItem item;
            do {
                item = mBuffer[index];
                if (item != null && item.isValid() && checkImageRequirement(item.getMetadata())) {
                    mBuffer[index] = null;
                    return item;
                }
                index--;
                if (index < 0) index = mBuffer.length - 1;
            } while (index != mImageHead);
        }
        return null;
    }

    public void onClose() {
        synchronized (mLock) {
            for (int i = 0; i < mBuffer.length; i++) {
                if (mBuffer[i] != null) {
                    mBuffer[i].closeImage();
                    mBuffer[i].closeMeta();
                    mBuffer[i] = null;
                }
            }
            mBuffer = null;
            mImageHead = 0;
            mMetaHead = 0;
        }
    }

    private boolean checkImageRequirement(TotalCaptureResult captureResult) {
        if( (captureResult.get(CaptureResult.LENS_STATE) != null &&
             captureResult.get(CaptureResult.LENS_STATE).intValue() == CaptureResult.LENS_STATE_MOVING)
                ||
            (captureResult.get(CaptureResult.CONTROL_AE_STATE) != null &&
                (captureResult.get(CaptureResult.CONTROL_AE_STATE).intValue() == CaptureResult.CONTROL_AE_STATE_SEARCHING ||
                 captureResult.get(CaptureResult.CONTROL_AE_STATE).intValue() == CaptureResult.CONTROL_AE_STATE_PRECAPTURE))
                ||
            (captureResult.get(CaptureResult.CONTROL_AF_STATE) != null) &&
                (captureResult.get(CaptureResult.CONTROL_AF_STATE) == CaptureResult.CONTROL_AF_STATE_ACTIVE_SCAN ||
                 captureResult.get(CaptureResult.CONTROL_AF_STATE) == CaptureResult.CONTROL_AF_STATE_PASSIVE_SCAN)) {
            return false;
        }

        if( captureResult.get(CaptureResult.CONTROL_AE_STATE) != null &&
            captureResult.get(CaptureResult.FLASH_MODE) != null &&
            captureResult.get(CaptureResult.CONTROL_AE_STATE).intValue() == CaptureResult.CONTROL_AE_STATE_FLASH_REQUIRED &&
            captureResult.get(CaptureResult.FLASH_MODE).intValue() != CaptureResult.FLASH_MODE_OFF) {
            return true;
        }

        if( captureResult.get(CaptureResult.CONTROL_AWB_STATE) != null &&
            captureResult.get(CaptureResult.CONTROL_AWB_STATE).intValue() == CaptureResult.CONTROL_AWB_STATE_SEARCHING ) {
            return false;
        }

        return true;
    }

    static class ImageItem {
        private Image mImage = null;
        private Image mRawImage = null;
        private TotalCaptureResult mMetadata = null;

        public Image getImage() {
            return mImage;
        }

        public Image getRawImage() {return mRawImage;}

        public void setImage(Image image, Image rawImage) {
            if(mImage != null) {
                mImage.close();
            }
            if(mRawImage != null) {
                mRawImage.close();
            }
            mImage = image;
            mRawImage =rawImage;
        }

        public TotalCaptureResult getMetadata() {
            return mMetadata;
        }

        public void setMetadata(TotalCaptureResult metadata) {
            mMetadata = metadata;
        }

        public void closeImage() {
            if(mImage != null) {
                mImage.close();
            }
            if(mRawImage != null) {
                mRawImage.close();
            }
            mImage = null;
        }

        public void closeMeta() {
            mMetadata = null;
        }

        public boolean isValid() {
            if(mImage != null && mMetadata != null) {
                return true;
            }
            return false;
        }
    }
}