/*
 * Copyright (C) 2009 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 jp.co.techfirm.patom.util;

import java.io.FileDescriptor;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;

import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteException;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.net.Uri;
import android.os.ParcelFileDescriptor;
import android.provider.BaseColumns;
import android.provider.MediaStore;
import android.provider.MediaStore.Images;
import android.provider.MediaStore.MediaColumns;
import android.provider.MediaStore.Images.Thumbnails;
import android.util.Log;

/**
 * Thumbnail generation routines for media provider. This class should only be
 * used internaly. {@hide} THIS IS NOT FOR PUBLIC API.
 */

public class ThumbnailUtil {
	private static final String TAG = "ThumbnailUtil";
	// Whether we should recycle the input (unless the output is the input).
	public static final boolean RECYCLE_INPUT = true;
	public static final boolean NO_RECYCLE_INPUT = false;
	public static final boolean ROTATE_AS_NEEDED = true;
	public static final boolean NO_ROTATE = false;
	public static final boolean USE_NATIVE = true;
	public static final boolean NO_NATIVE = false;

	public static final int THUMBNAIL_TARGET_SIZE = 320;
	public static final int MINI_THUMB_TARGET_SIZE = 96;
	public static final int THUMBNAIL_MAX_NUM_PIXELS = 512 * 384;
	public static final int MINI_THUMB_MAX_NUM_PIXELS = 128 * 128;
	public static final int UNCONSTRAINED = -1;
	private static final String[] PROJECTION = new String[] {
			MediaStore.Images.Thumbnails._ID, MediaColumns.DATA };

	/**
	 * Make a bitmap from a given Uri.
	 * 
	 * @param uri
	 */
	public static Bitmap makeBitmap(int minSideLength, int maxNumOfPixels,
			Uri uri, ContentResolver cr) {
		return makeBitmap(minSideLength, maxNumOfPixels, uri, cr, NO_NATIVE);
	}

	/*
	 * Compute the sample size as a function of minSideLength and
	 * maxNumOfPixels. minSideLength is used to specify that minimal width or
	 * height of a bitmap. maxNumOfPixels is used to specify the maximal size in
	 * pixels that is tolerable in terms of memory usage.
	 * 
	 * The function returns a sample size based on the constraints. Both size
	 * and minSideLength can be passed in as IImage.UNCONSTRAINED, which
	 * indicates no care of the corresponding constraint. The functions prefers
	 * returning a sample size that generates a smaller bitmap, unless
	 * minSideLength = IImage.UNCONSTRAINED.
	 * 
	 * Also, the function rounds up the sample size to a power of 2 or multiple
	 * of 8 because BitmapFactory only honors sample size this way. For example,
	 * BitmapFactory downsamples an image by 2 even though the request is 3. So
	 * we round up the sample size to avoid OOM.
	 */
	public static int computeSampleSize(BitmapFactory.Options options,
			int minSideLength, int maxNumOfPixels) {
		int initialSize = computeInitialSampleSize(options, minSideLength,
				maxNumOfPixels);

		int roundedSize;
		if (initialSize <= 8) {
			roundedSize = 1;
			while (roundedSize < initialSize) {
				roundedSize <<= 1;
			}
		} else {
			roundedSize = (initialSize + 7) / 8 * 8;
		}

		return roundedSize;
	}

	private static int computeInitialSampleSize(BitmapFactory.Options options,
			int minSideLength, int maxNumOfPixels) {
		double w = options.outWidth;
		double h = options.outHeight;

		int lowerBound = (maxNumOfPixels == UNCONSTRAINED) ? 1 : (int) Math
				.ceil(Math.sqrt(w * h / maxNumOfPixels));
		int upperBound = (minSideLength == UNCONSTRAINED) ? 128 : (int) Math
				.min(Math.floor(w / minSideLength), Math.floor(h
						/ minSideLength));

		if (upperBound < lowerBound) {
			// return the larger one when there is no overlapping zone.
			return lowerBound;
		}

		if ((maxNumOfPixels == UNCONSTRAINED)
				&& (minSideLength == UNCONSTRAINED)) {
			return 1;
		} else if (minSideLength == UNCONSTRAINED) {
			return lowerBound;
		} else {
			return upperBound;
		}
	}

	public static Bitmap makeBitmap(int minSideLength, int maxNumOfPixels,
			Uri uri, ContentResolver cr, boolean useNative) {
		ParcelFileDescriptor input = null;
		try {
			input = cr.openFileDescriptor(uri, "r");
			BitmapFactory.Options options = null;
			return makeBitmap(minSideLength, maxNumOfPixels, uri, cr, input,
					options);
		} catch (IOException ex) {
			Log.e(TAG, "", ex);
			return null;
		} finally {
			closeSilently(input);
		}
	}

	// Rotates the bitmap by the specified degree.
	// If a new bitmap is created, the original bitmap is recycled.
	public static Bitmap rotate(Bitmap b, int degrees) {
		if (degrees != 0 && b != null) {
			Matrix m = new Matrix();
			m.setRotate(degrees, (float) b.getWidth() / 2, (float) b
					.getHeight() / 2);
			try {
				Bitmap b2 = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b
						.getHeight(), m, true);
				if (b != b2) {
					b.recycle();
					b = b2;
				}
			} catch (OutOfMemoryError ex) {
				// We have no memory to rotate. Return the original bitmap.
			}
		}
		return b;
	}

	private static void closeSilently(ParcelFileDescriptor c) {
		if (c == null)
			return;
		try {
			c.close();
		} catch (Throwable t) {
			// do nothing
		}
	}

	private static ParcelFileDescriptor makeInputStream(Uri uri,
			ContentResolver cr) {
		try {
			return cr.openFileDescriptor(uri, "r");
		} catch (IOException ex) {
			return null;
		}
	}

	public static Bitmap makeBitmap(int minSideLength, int maxNumOfPixels,
			Uri uri, ContentResolver cr, ParcelFileDescriptor pfd,
			BitmapFactory.Options options) {
		Bitmap b = null;
		try {
			if (pfd == null)
				pfd = makeInputStream(uri, cr);
			if (pfd == null)
				return null;
			if (options == null)
				options = new BitmapFactory.Options();

			FileDescriptor fd = pfd.getFileDescriptor();
			options.inSampleSize = 1;
			options.inJustDecodeBounds = true;
			BitmapFactory.decodeFileDescriptor(fd, null, options);
			if (options.mCancel || options.outWidth == -1
					|| options.outHeight == -1) {
				return null;
			}
			options.inSampleSize = computeSampleSize(options, minSideLength,
					maxNumOfPixels);
			options.inJustDecodeBounds = false;

			options.inDither = false;
			options.inPreferredConfig = Bitmap.Config.ARGB_8888;
			b = BitmapFactory.decodeFileDescriptor(fd, null, options);
		} catch (OutOfMemoryError ex) {
			Log.e(TAG, "Got oom exception ", ex);
			return null;
		} finally {
			closeSilently(pfd);
		}
		return b;
	}

	/**
	 * Creates a centered bitmap of the desired size.
	 * 
	 * @param source
	 * @param recycle
	 *            whether we want to recycle the input
	 */
	public static Bitmap extractMiniThumb(Bitmap source, int width, int height,
			boolean recycle) {
		if (source == null) {
			return null;
		}

		float scale;
		if (source.getWidth() < source.getHeight()) {
			scale = width / (float) source.getWidth();
		} else {
			scale = height / (float) source.getHeight();
		}
		Matrix matrix = new Matrix();
		matrix.setScale(scale, scale);
		Bitmap miniThumbnail = transform(matrix, source, width, height, true,
				recycle);
		return miniThumbnail;
	}

	/**
	 * This method first examines if the thumbnail embedded in EXIF is bigger
	 * than our target size. If not, then it'll create a thumbnail from original
	 * image. Due to efficiency consideration, we want to let MediaThumbRequest
	 * avoid calling this method twice for both kinds, so it only requests for
	 * MICRO_KIND and set saveImage to true.
	 * 
	 * This method always returns a "square thumbnail" for MICRO_KIND thumbnail.
	 * 
	 * @param cr
	 *            ContentResolver
	 * @param filePath
	 *            file path needed by EXIF interface
	 * @param uri
	 *            URI of original image
	 * @param origId
	 *            image id
	 * @param kind
	 *            either MINI_KIND or MICRO_KIND
	 * @param saveImage
	 *            Whether to save MINI_KIND thumbnail obtained in this method.
	 * @return Bitmap
	 */
	public static Bitmap createImageThumbnail(ContentResolver cr,
			String filePath, Uri uri, long origId, int kind, boolean saveMini) {
		boolean wantMini = (kind == Images.Thumbnails.MINI_KIND || saveMini);
		int targetSize = wantMini ? ThumbnailUtil.THUMBNAIL_TARGET_SIZE
				: ThumbnailUtil.MINI_THUMB_TARGET_SIZE;
		int maxPixels = wantMini ? ThumbnailUtil.THUMBNAIL_MAX_NUM_PIXELS
				: ThumbnailUtil.MINI_THUMB_MAX_NUM_PIXELS;
		// byte[] thumbData = createThumbnailFromEXIF(filePath, targetSize);
		byte[] thumbData = null;
		Bitmap bitmap = null;

		if (thumbData != null) {
			BitmapFactory.Options options = new BitmapFactory.Options();
			options.inSampleSize = computeSampleSize(options, targetSize,
					maxPixels);
			options.inDither = false;
			options.inPreferredConfig = Bitmap.Config.ARGB_8888;
			options.inJustDecodeBounds = false;
			bitmap = BitmapFactory.decodeByteArray(thumbData, 0,
					thumbData.length, options);
		}

		if (bitmap == null) {
			bitmap = ThumbnailUtil.makeBitmap(targetSize, maxPixels, uri, cr);
		}

		if (bitmap == null) {
			return null;
		}

		if (saveMini) {
			if (thumbData != null) {
				ThumbnailUtil.storeThumbnail(cr, origId, thumbData, bitmap
						.getWidth(), bitmap.getHeight());
			} else {
				ThumbnailUtil.storeThumbnail(cr, origId, bitmap);
			}
		}

		if (kind == Images.Thumbnails.MICRO_KIND) {
			// now we make it a "square thumbnail" for MICRO_KIND thumbnail
			bitmap = ThumbnailUtil.extractMiniThumb(bitmap,
					ThumbnailUtil.MINI_THUMB_TARGET_SIZE,
					ThumbnailUtil.MINI_THUMB_TARGET_SIZE,
					ThumbnailUtil.RECYCLE_INPUT);
		}
		return bitmap;
	}

	public static Bitmap transform(Matrix scaler, Bitmap source,
			int targetWidth, int targetHeight, boolean scaleUp, boolean recycle) {

		int deltaX = source.getWidth() - targetWidth;
		int deltaY = source.getHeight() - targetHeight;
		if (!scaleUp && (deltaX < 0 || deltaY < 0)) {
			/*
			 * In this case the bitmap is smaller, at least in one dimension,
			 * than the target. Transform it by placing as much of the image as
			 * possible into the target and leaving the top/bottom or left/right
			 * (or both) black.
			 */
			Bitmap b2 = Bitmap.createBitmap(targetWidth, targetHeight,
					Bitmap.Config.ARGB_8888);
			Canvas c = new Canvas(b2);

			int deltaXHalf = Math.max(0, deltaX / 2);
			int deltaYHalf = Math.max(0, deltaY / 2);
			Rect src = new Rect(deltaXHalf, deltaYHalf, deltaXHalf
					+ Math.min(targetWidth, source.getWidth()), deltaYHalf
					+ Math.min(targetHeight, source.getHeight()));
			int dstX = (targetWidth - src.width()) / 2;
			int dstY = (targetHeight - src.height()) / 2;
			Rect dst = new Rect(dstX, dstY, targetWidth - dstX, targetHeight
					- dstY);
			c.drawBitmap(source, src, dst, null);
			if (recycle) {
				source.recycle();
			}
			return b2;
		}
		float bitmapWidthF = source.getWidth();
		float bitmapHeightF = source.getHeight();

		float bitmapAspect = bitmapWidthF / bitmapHeightF;
		float viewAspect = (float) targetWidth / targetHeight;

		if (bitmapAspect > viewAspect) {
			float scale = targetHeight / bitmapHeightF;
			if (scale < .9F || scale > 1F) {
				scaler.setScale(scale, scale);
			} else {
				scaler = null;
			}
		} else {
			float scale = targetWidth / bitmapWidthF;
			if (scale < .9F || scale > 1F) {
				scaler.setScale(scale, scale);
			} else {
				scaler = null;
			}
		}

		Bitmap b1;
		if (scaler != null) {
			// this is used for minithumb and crop, so we want to filter here.
			b1 = Bitmap.createBitmap(source, 0, 0, source.getWidth(), source
					.getHeight(), scaler, true);
		} else {
			b1 = source;
		}

		if (recycle && b1 != source) {
			source.recycle();
		}

		int dx1 = Math.max(0, b1.getWidth() - targetWidth);
		int dy1 = Math.max(0, b1.getHeight() - targetHeight);

		Bitmap b2 = Bitmap.createBitmap(b1, dx1 / 2, dy1 / 2, targetWidth,
				targetHeight);

		if (b2 != b1) {
			if (recycle || b1 != source) {
				b1.recycle();
			}
		}

		return b2;
	}

	private static final String[] THUMB_PROJECTION = new String[] { BaseColumns._ID // 0
	};

	/**
	 * Look up thumbnail uri by given imageId, it will be automatically created
	 * if it's not created yet. Most of the time imageId is identical to
	 * thumbId, but it's not always true.
	 * 
	 * @param req
	 * @param width
	 * @param height
	 * @return Uri Thumbnail uri
	 */
	private static Uri getImageThumbnailUri(ContentResolver cr, long origId,
			int width, int height) {
		Uri thumbUri = Images.Thumbnails.EXTERNAL_CONTENT_URI;
		Cursor c = cr.query(thumbUri, THUMB_PROJECTION, Thumbnails.IMAGE_ID
				+ "=?", new String[] { String.valueOf(origId) }, null);
		try {
			if (c.moveToNext()) {
				return ContentUris.withAppendedId(thumbUri, c.getLong(0));
			}
		} finally {
			if (c != null)
				c.close();
		}

		ContentValues values = new ContentValues(4);
		values.put(Thumbnails.KIND, Thumbnails.MINI_KIND);
		values.put(Thumbnails.IMAGE_ID, origId);
		values.put(Thumbnails.HEIGHT, height);
		values.put(Thumbnails.WIDTH, width);
		try {
			return cr.insert(thumbUri, values);
		} catch (Exception ex) {
			Log.w(TAG, ex);
			return null;
		}
	}

	/**
	 * Store a given thumbnail in the database. (Bitmap)
	 */
	private static boolean storeThumbnail(ContentResolver cr, long origId,
			Bitmap thumb) {
		if (thumb == null)
			return false;
		try {
			Uri uri = getImageThumbnailUri(cr, origId, thumb.getWidth(), thumb
					.getHeight());
			OutputStream thumbOut = cr.openOutputStream(uri);
			thumb.compress(Bitmap.CompressFormat.JPEG, 85, thumbOut);
			thumbOut.close();
			return true;
		} catch (Throwable t) {
			Log.e(TAG, "Unable to store thumbnail", t);
			return false;
		}
	}

	/**
	 * Store a given thumbnail in the database. (byte array)
	 */
	private static boolean storeThumbnail(ContentResolver cr, long origId,
			byte[] jpegThumbnail, int width, int height) {
		if (jpegThumbnail == null)
			return false;

		Uri uri = getImageThumbnailUri(cr, origId, width, height);
		if (uri == null) {
			return false;
		}
		try {
			OutputStream thumbOut = cr.openOutputStream(uri);
			thumbOut.write(jpegThumbnail);
			thumbOut.close();
			return true;
		} catch (Throwable t) {
			Log.e(TAG, "Unable to store thumbnail", t);
			return false;
		}
	}

	public static Bitmap getThumbnailBitmap(ContentResolver cr, long origId,
			int kind, BitmapFactory.Options options, Uri baseUri) {
		Bitmap bitmap = null;
		String filePath = null;
		// Log.v(TAG,
		// "getThumbnail: origId="+origId+", kind="+kind+", isVideo="+isVideo);
		// some optimization for MICRO_KIND: if the magic is non-zero, we don't
		// bother
		// querying MediaProvider and simply return thumbnail.
		if (kind == Images.Thumbnails.MICRO_KIND) {
			MiniThumbFile thumbFile = MiniThumbFile.instance(baseUri);
			if (thumbFile.getMagic(origId) != 0) {
				byte[] data = new byte[MiniThumbFile.BYTES_PER_MINTHUMB];
				if (thumbFile.getMiniThumbFromFile(origId, data) != null) {
					bitmap = BitmapFactory
							.decodeByteArray(data, 0, data.length);
					if (bitmap == null) {
						Log.w(TAG, "couldn't decode byte array.");
					}
				}
				return bitmap;
			}
		}

		Cursor c = null;
		try {
			Uri blockingUri = baseUri.buildUpon().appendQueryParameter(
					"blocking", "1").appendQueryParameter("orig_id",
					String.valueOf(origId)).build();
			c = cr.query(blockingUri, PROJECTION, null, null, null);
			// This happens when original image/video doesn't exist.
			if (c == null)
				return null;

			// Assuming thumbnail has been generated, at least original image
			// exists.
			if (kind == Images.Thumbnails.MICRO_KIND) {
				MiniThumbFile thumbFile = MiniThumbFile.instance(baseUri);
				byte[] data = new byte[MiniThumbFile.BYTES_PER_MINTHUMB];
				if (thumbFile.getMiniThumbFromFile(origId, data) != null) {
					bitmap = BitmapFactory
							.decodeByteArray(data, 0, data.length);
					if (bitmap == null) {
						Log.w(TAG, "couldn't decode byte array.");
					}
				}
			} else if (kind == Images.Thumbnails.MINI_KIND) {
				if (c.moveToFirst()) {
					ParcelFileDescriptor pfdInput;
					Uri thumbUri = null;
					try {
						long thumbId = c.getLong(0);
						filePath = c.getString(1);
						thumbUri = ContentUris.withAppendedId(baseUri, thumbId);
						pfdInput = cr.openFileDescriptor(thumbUri, "r");
						bitmap = BitmapFactory.decodeFileDescriptor(pfdInput
								.getFileDescriptor(), null, options);
						pfdInput.close();
					} catch (FileNotFoundException ex) {
						Log.e(TAG, "couldn't open thumbnail " + thumbUri + "; "
								+ ex);
					} catch (IOException ex) {
						Log.e(TAG, "couldn't open thumbnail " + thumbUri + "; "
								+ ex);
					} catch (OutOfMemoryError ex) {
						Log.e(TAG, "failed to allocate memory for thumbnail "
								+ thumbUri + "; " + ex);
					}
				}
			} else {
				throw new IllegalArgumentException("Unsupported kind: " + kind);
			}

			// We probably run out of space, so create the thumbnail in memory.
			if (bitmap == null) {
				Log
						.v(TAG,
								"We probably run out of space, so create the thumbnail in memory.");

				Uri uri = Uri.parse(baseUri.buildUpon().appendPath(
						String.valueOf(origId)).toString().replaceFirst(
						"thumbnails", "media"));
				if (filePath == null) {
					if (c != null)
						c.close();
					c = cr.query(uri, PROJECTION, null, null, null);
					if (c == null || !c.moveToFirst()) {
						return null;
					}
					filePath = c.getString(1);
				}

				bitmap = ThumbnailUtil.createImageThumbnail(cr, filePath, uri,
						origId, kind, false);
			}
		} catch (SQLiteException ex) {
			Log.w(TAG, ex);
		} finally {
			if (c != null)
				c.close();
		}
		return bitmap;
	}
}