/*
 * Copyright (C) 2012 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.gallery3d.filtershow.cache;

import android.content.ContentResolver;
import android.content.Context;
import android.content.res.Resources;
import android.database.Cursor;
import android.database.sqlite.SQLiteException;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapRegionDecoder;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.media.ExifInterface;
import android.net.Uri;
import android.provider.MediaStore;
import android.util.Log;

import com.adobe.xmp.XMPException;
import com.adobe.xmp.XMPMeta;

import com.android.gallery3d.R;
import com.android.gallery3d.common.Utils;
import com.android.gallery3d.exif.ExifInvalidFormatException;
import com.android.gallery3d.exif.ExifParser;
import com.android.gallery3d.exif.ExifTag;
import com.android.gallery3d.filtershow.FilterShowActivity;
import com.android.gallery3d.filtershow.HistoryAdapter;
import com.android.gallery3d.filtershow.imageshow.ImageCrop;
import com.android.gallery3d.filtershow.imageshow.ImageShow;
import com.android.gallery3d.filtershow.presets.ImagePreset;
import com.android.gallery3d.filtershow.tools.SaveCopyTask;
import com.android.gallery3d.util.XmpUtilHelper;

import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Vector;
import java.util.concurrent.locks.ReentrantLock;

public class ImageLoader {

    private static final String LOGTAG = "ImageLoader";
    private final Vector<ImageShow> mListeners = new Vector<ImageShow>();
    private Bitmap mOriginalBitmapSmall = null;
    private Bitmap mOriginalBitmapLarge = null;
    private Bitmap mBackgroundBitmap = null;

    private Cache mCache = null;
    private Cache mHiresCache = null;
    private final ZoomCache mZoomCache = new ZoomCache();

    private int mOrientation = 0;
    private HistoryAdapter mAdapter = null;

    private FilterShowActivity mActivity = null;

    public static final int ORI_NORMAL     = ExifInterface.ORIENTATION_NORMAL;
    public static final int ORI_ROTATE_90  = ExifInterface.ORIENTATION_ROTATE_90;
    public static final int ORI_ROTATE_180 = ExifInterface.ORIENTATION_ROTATE_180;
    public static final int ORI_ROTATE_270 = ExifInterface.ORIENTATION_ROTATE_270;
    public static final int ORI_FLIP_HOR   = ExifInterface.ORIENTATION_FLIP_HORIZONTAL;
    public static final int ORI_FLIP_VERT  = ExifInterface.ORIENTATION_FLIP_VERTICAL;
    public static final int ORI_TRANSPOSE  = ExifInterface.ORIENTATION_TRANSPOSE;
    public static final int ORI_TRANSVERSE = ExifInterface.ORIENTATION_TRANSVERSE;

    private Context mContext = null;
    private Uri mUri = null;

    private Rect mOriginalBounds = null;
    private static int mZoomOrientation = ORI_NORMAL;

    private ReentrantLock mLoadingLock = new ReentrantLock();

    public ImageLoader(FilterShowActivity activity, Context context) {
        mActivity = activity;
        mContext = context;
        mCache = new DelayedPresetCache(this, 30);
        mHiresCache = new DelayedPresetCache(this, 3);
    }

    public static int getZoomOrientation() {
        return mZoomOrientation;
    }

    public FilterShowActivity getActivity() {
        return mActivity;
    }

    public void loadBitmap(Uri uri,int size) {
        mLoadingLock.lock();
        mUri = uri;
        mOrientation = getOrientation(mContext, uri);
        mOriginalBitmapSmall = loadScaledBitmap(uri, 160);
        if (mOriginalBitmapSmall == null) {
            // Couldn't read the bitmap, let's exit
            mActivity.cannotLoadImage();
        }
        mOriginalBitmapLarge = loadScaledBitmap(uri, size);
        updateBitmaps();
        mLoadingLock.unlock();
    }

    public Uri getUri() {
        return mUri;
    }

    public Rect getOriginalBounds() {
        return mOriginalBounds;
    }

    public static int getOrientation(Context context, Uri uri) {
        if (ContentResolver.SCHEME_FILE.equals(uri.getScheme())) {
            return getOrientationFromPath(uri.getPath());
        }

        Cursor cursor = null;
        try {
            cursor = context.getContentResolver().query(uri,
                    new String[] {
                        MediaStore.Images.ImageColumns.ORIENTATION
                    },
                    null, null, null);
            if (cursor.moveToNext()){
              int ori =   cursor.getInt(0);

              switch (ori){
                  case 0:   return ORI_NORMAL;
                  case 90:  return ORI_ROTATE_90;
                  case 270: return ORI_ROTATE_270;
                  case 180: return ORI_ROTATE_180;
                  default:
                      return -1;
              }
            } else{
                return -1;
            }
        } catch (SQLiteException e){
            return ExifInterface.ORIENTATION_UNDEFINED;
        } finally {
            Utils.closeSilently(cursor);
        }
    }

    static int getOrientationFromPath(String path) {
        int orientation = -1;
        InputStream is = null;
        try {
            is = new FileInputStream(path);
            ExifParser parser = ExifParser.parse(is, ExifParser.OPTION_IFD_0);
            int event = parser.next();
            while (event != ExifParser.EVENT_END) {
                if (event == ExifParser.EVENT_NEW_TAG) {
                    ExifTag tag = parser.getTag();
                    if (tag.getTagId() == ExifTag.TAG_ORIENTATION) {
                        orientation = (int) tag.getValueAt(0);
                        break;
                    }
                }
                event = parser.next();
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ExifInvalidFormatException e) {
            e.printStackTrace();
        } finally {
            Utils.closeSilently(is);
        }
        return orientation;
    }

    private void updateBitmaps() {
        if (mOrientation > 1) {
            mOriginalBitmapSmall = rotateToPortrait(mOriginalBitmapSmall, mOrientation);
            mOriginalBitmapLarge = rotateToPortrait(mOriginalBitmapLarge, mOrientation);
        }
        mZoomOrientation = mOrientation;
        mCache.setOriginalBitmap(mOriginalBitmapSmall);
        mHiresCache.setOriginalBitmap(mOriginalBitmapLarge);
        warnListeners();
    }

    public static Bitmap rotateToPortrait(Bitmap bitmap,int ori) {
           Matrix matrix = new Matrix();
           int w = bitmap.getWidth();
           int h = bitmap.getHeight();
           if (ori == ORI_ROTATE_90 ||
                   ori == ORI_ROTATE_270 ||
                   ori == ORI_TRANSPOSE||
                   ori == ORI_TRANSVERSE) {
               int tmp = w;
               w = h;
               h = tmp;
           }
           switch(ori){
               case ORI_ROTATE_90:
                   matrix.setRotate(90,w/2f,h/2f);
                   break;
               case ORI_ROTATE_180:
                   matrix.setRotate(180,w/2f,h/2f);
                   break;
               case ORI_ROTATE_270:
                   matrix.setRotate(270,w/2f,h/2f);
                   break;
               case ORI_FLIP_HOR:
                   matrix.preScale(-1, 1);
                   break;
              case ORI_FLIP_VERT:
                   matrix.preScale(1, -1);
                   break;
               case ORI_TRANSPOSE:
                   matrix.setRotate(90,w/2f,h/2f);
                   matrix.preScale(1, -1);
                   break;
               case ORI_TRANSVERSE:
                   matrix.setRotate(270,w/2f,h/2f);
                   matrix.preScale(1, -1);
                   break;
               case ORI_NORMAL:
               default:
                   return bitmap;
            }

        return Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),
                bitmap.getHeight(), matrix, true);
    }

    private void closeStream(Closeable stream) {
        if (stream != null) {
            try {
                stream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    private Bitmap loadRegionBitmap(Uri uri, Rect bounds) {
        InputStream is = null;
        try {
            is = mContext.getContentResolver().openInputStream(uri);
            BitmapRegionDecoder decoder = BitmapRegionDecoder.newInstance(is, false);
            return decoder.decodeRegion(bounds, null);
        } catch (FileNotFoundException e) {
            Log.e(LOGTAG, "FileNotFoundException: " + uri);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            closeStream(is);
        }
        return null;
    }

    static final int MAX_BITMAP_DIM = 2048;
    private Bitmap loadScaledBitmap(Uri uri, int size) {
        InputStream is = null;
        try {
            is = mContext.getContentResolver().openInputStream(uri);
            Log.v(LOGTAG, "loading uri " + uri.getPath() + " input stream: "
                    + is);
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(is, null, o);

            int width_tmp = o.outWidth;
            int height_tmp = o.outHeight;

            mOriginalBounds = new Rect(0, 0, width_tmp, height_tmp);

            int scale = 1;
            while (true) {
                if (width_tmp <= MAX_BITMAP_DIM && height_tmp <= MAX_BITMAP_DIM) {
                    if (width_tmp / 2 < size || height_tmp / 2 < size) {
                        break;
                    }
                }
                width_tmp /= 2;
                height_tmp /= 2;
                scale *= 2;
            }

            // decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;

            closeStream(is);
            is = mContext.getContentResolver().openInputStream(uri);
            return BitmapFactory.decodeStream(is, null, o2);
        } catch (FileNotFoundException e) {
            Log.e(LOGTAG, "FileNotFoundException: " + uri);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            closeStream(is);
        }
        return null;
    }

    public Bitmap getBackgroundBitmap(Resources resources) {
        if (mBackgroundBitmap == null) {
            mBackgroundBitmap = BitmapFactory.decodeResource(resources,
                    R.drawable.filtershow_background);
        }
        return mBackgroundBitmap;

    }

    public Bitmap getOriginalBitmapSmall() {
        return mOriginalBitmapSmall;
    }

    public Bitmap getOriginalBitmapLarge() {
        return mOriginalBitmapLarge;
    }

    public void addListener(ImageShow imageShow) {
        mLoadingLock.lock();
        if (!mListeners.contains(imageShow)) {
            mListeners.add(imageShow);
        }
        mHiresCache.addObserver(imageShow);
        mLoadingLock.unlock();
    }

    private void warnListeners() {
        mActivity.runOnUiThread(mWarnListenersRunnable);
    }

    private Runnable mWarnListenersRunnable = new Runnable() {

        @Override
        public void run() {
            for (int i = 0; i < mListeners.size(); i++) {
                ImageShow imageShow = mListeners.elementAt(i);
                imageShow.imageLoaded();
            }
        }
    };

    // TODO: this currently does the loading + filtering on the UI thread -- need to
    // move this to a background thread.
    public Bitmap getScaleOneImageForPreset(ImageShow caller, ImagePreset imagePreset, Rect bounds,
            boolean force) {
        mLoadingLock.lock();
        Bitmap bmp = mZoomCache.getImage(imagePreset, bounds);
        if (force || bmp == null) {
            bmp = loadRegionBitmap(mUri, bounds);
            if (bmp != null) {
                // TODO: this workaround for RS might not be needed ultimately
                Bitmap bmp2 = bmp.copy(Bitmap.Config.ARGB_8888, true);
                float scaleFactor = imagePreset.getScaleFactor();
                imagePreset.setScaleFactor(1.0f);
                bmp2 = imagePreset.apply(bmp2);
                imagePreset.setScaleFactor(scaleFactor);
                mZoomCache.setImage(imagePreset, bounds, bmp2);
                return bmp2;
            }
        }
        mLoadingLock.unlock();
        return bmp;
    }

    // Caching method
    public Bitmap getImageForPreset(ImageShow caller, ImagePreset imagePreset,
            boolean hiRes) {
        mLoadingLock.lock();
        if (mOriginalBitmapSmall == null) {
            return null;
        }
        if (mOriginalBitmapLarge == null) {
            return null;
        }

        Bitmap filteredImage = null;

        if (hiRes) {
            filteredImage = mHiresCache.get(imagePreset);
        } else {
            filteredImage = mCache.get(imagePreset);
        }

        if (filteredImage == null) {
            if (hiRes) {
                mHiresCache.prepare(imagePreset);
                mHiresCache.addObserver(caller);
            } else {
                mCache.prepare(imagePreset);
                mCache.addObserver(caller);
            }
        }
        mLoadingLock.unlock();
        return filteredImage;
    }

    public void resetImageForPreset(ImagePreset imagePreset, ImageShow caller) {
        mLoadingLock.lock();
        mHiresCache.reset(imagePreset);
        mCache.reset(imagePreset);
        mZoomCache.reset(imagePreset);
        mLoadingLock.unlock();
    }

    public void saveImage(ImagePreset preset, final FilterShowActivity filterShowActivity,
            File destination) {
        preset.setIsHighQuality(true);
        preset.setScaleFactor(1.0f);
        new SaveCopyTask(mContext, mUri, destination, new SaveCopyTask.Callback() {

            @Override
            public void onComplete(Uri result) {
                filterShowActivity.completeSaveImage(result);
            }

        }).execute(preset);
    }

    public void setAdapter(HistoryAdapter adapter) {
        mAdapter = adapter;
    }

    public HistoryAdapter getHistory() {
        return mAdapter;
    }

    public XMPMeta getXmpObject() {
        try {
            InputStream is = mContext.getContentResolver().openInputStream(getUri());
            return XmpUtilHelper.extractXMPMeta(is);
        } catch (FileNotFoundException e) {
            return null;
        }
    }

    /**
     * Determine if this is a light cycle 360 image
     *
     * @return true if it is a light Cycle image that is full 360
     */
    public boolean queryLightCycle360() {
        try {
            InputStream is = mContext.getContentResolver().openInputStream(getUri());
            XMPMeta meta = XmpUtilHelper.extractXMPMeta(is);
            if (meta == null) {
                return false;
            }
            String name = meta.getPacketHeader();
            try {
                String namespace = "http://ns.google.com/photos/1.0/panorama/";
                String cropWidthName = "GPano:CroppedAreaImageWidthPixels";
                String fullWidthName = "GPano:FullPanoWidthPixels";

                if (!meta.doesPropertyExist(namespace, cropWidthName)) {
                    return false;
                }
                if (!meta.doesPropertyExist(namespace, fullWidthName)) {
                    return false;
                }

                Integer cropValue = meta.getPropertyInteger(namespace, cropWidthName);
                Integer fullValue = meta.getPropertyInteger(namespace, fullWidthName);

                // Definition of a 360:
                // GFullPanoWidthPixels == CroppedAreaImageWidthPixels
                if (cropValue != null && fullValue != null) {
                    return cropValue.equals(fullValue);
                }

                return false;
            } catch (XMPException e) {
                return false;
            }
        } catch (FileNotFoundException e) {
            return false;
        }
    }

}