/*
 * 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 com.android.camera;

import com.android.gallery.R;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.ContentResolver;
import android.content.DialogInterface;
import android.content.Intent;
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.Handler;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.Animation;
import android.view.animation.TranslateAnimation;

import com.android.camera.gallery.IImage;

import java.io.Closeable;
import java.io.FileDescriptor;
import java.io.IOException;

/**
 * Collection of utility functions used in this package.
 */
public class Util {
    private static final String TAG = "Util";
    public static final int DIRECTION_LEFT = 0;
    public static final int DIRECTION_RIGHT = 1;
    public static final int DIRECTION_UP = 2;
    public static final int DIRECTION_DOWN = 3;

    private static OnClickListener sNullOnClickListener;

    private Util() {
    }

    // 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;
    }

    /*
     * 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 == IImage.UNCONSTRAINED) ? 1 :
                (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
        int upperBound = (minSideLength == IImage.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 == IImage.UNCONSTRAINED) &&
                (minSideLength == IImage.UNCONSTRAINED)) {
            return 1;
        } else if (minSideLength == IImage.UNCONSTRAINED) {
            return lowerBound;
        } else {
            return upperBound;
        }
    }

    // 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 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;
    }

    public static <T>  int indexOf(T [] array, T s) {
        for (int i = 0; i < array.length; i++) {
            if (array[i].equals(s)) {
                return i;
            }
        }
        return -1;
    }

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

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

    /**
     * Make a bitmap from a given Uri.
     *
     * @param uri
     */
    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;
            if (useNative) {
                options = createNativeAllocOptions();
            }
            return makeBitmap(minSideLength, maxNumOfPixels, uri, cr, input,
                    options);
        } catch (IOException ex) {
            return null;
        } finally {
            closeSilently(input);
        }
    }

    public static Bitmap makeBitmap(int minSideLength, int maxNumOfPixels,
            ParcelFileDescriptor pfd, boolean useNative) {
        BitmapFactory.Options options = null;
        if (useNative) {
            options = createNativeAllocOptions();
        }
        return makeBitmap(minSideLength, maxNumOfPixels, null, null, pfd,
                options);
    }

    public static Bitmap makeBitmap(int minSideLength, int maxNumOfPixels,
            Uri uri, ContentResolver cr, ParcelFileDescriptor pfd,
            BitmapFactory.Options options) {
        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.inJustDecodeBounds = true;
            BitmapManager.instance().decodeFileDescriptor(fd, 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;
            return BitmapManager.instance().decodeFileDescriptor(fd, options);
        } catch (OutOfMemoryError ex) {
            Log.e(TAG, "Got oom exception ", ex);
            return null;
        } finally {
            closeSilently(pfd);
        }
    }

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

    public static synchronized OnClickListener getNullOnClickListener() {
        if (sNullOnClickListener == null) {
            sNullOnClickListener = new OnClickListener() {
                public void onClick(View v) {
                }
            };
        }
        return sNullOnClickListener;
    }

    public static void Assert(boolean cond) {
        if (!cond) {
            throw new AssertionError();
        }
    }

    public static boolean equals(String a, String b) {
        // return true if both string are null or the content equals
        return a == b || a.equals(b);
    }

    private static class BackgroundJob
            extends MonitoredActivity.LifeCycleAdapter implements Runnable {

        private final MonitoredActivity mActivity;
        private final ProgressDialog mDialog;
        private final Runnable mJob;
        private final Handler mHandler;
        private final Runnable mCleanupRunner = new Runnable() {
            public void run() {
                mActivity.removeLifeCycleListener(BackgroundJob.this);
                if (mDialog.getWindow() != null) mDialog.dismiss();
            }
        };

        public BackgroundJob(MonitoredActivity activity, Runnable job,
                ProgressDialog dialog, Handler handler) {
            mActivity = activity;
            mDialog = dialog;
            mJob = job;
            mActivity.addLifeCycleListener(this);
            mHandler = handler;
        }

        public void run() {
            try {
                mJob.run();
            } finally {
                mHandler.post(mCleanupRunner);
            }
        }


        @Override
        public void onActivityDestroyed(MonitoredActivity activity) {
            // We get here only when the onDestroyed being called before
            // the mCleanupRunner. So, run it now and remove it from the queue
            mCleanupRunner.run();
            mHandler.removeCallbacks(mCleanupRunner);
        }

        @Override
        public void onActivityStopped(MonitoredActivity activity) {
            mDialog.hide();
        }

        @Override
        public void onActivityStarted(MonitoredActivity activity) {
            mDialog.show();
        }
    }

    public static void startBackgroundJob(MonitoredActivity activity,
            String title, String message, Runnable job, Handler handler) {
        // Make the progress dialog uncancelable, so that we can gurantee
        // the thread will be done before the activity getting destroyed.
        ProgressDialog dialog = ProgressDialog.show(
                activity, title, message, true, false);
        new Thread(new BackgroundJob(activity, job, dialog, handler)).start();
    }

    // Returns an intent which is used for "set as" menu items.
    public static Intent createSetAsIntent(IImage image) {
        Uri u = image.fullSizeImageUri();
        Intent intent = new Intent(Intent.ACTION_ATTACH_DATA);
        intent.setDataAndType(u, image.getMimeType());
        intent.putExtra("mimeType", image.getMimeType());
        return intent;
    }

    // Returns Options that set the puregeable flag for Bitmap decode.
    public static BitmapFactory.Options createNativeAllocOptions() {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inNativeAlloc = true;
        return options;
    }
}