/*
 * 				Firetweet - Twitter client for Android
 * 
 *  Copyright (C) 2012-2014 Mariotaku Lee <mariotaku.lee@gmail.com>
 * 
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 * 
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.getlantern.firetweet.nyan;

import android.content.Context;
import android.graphics.Canvas;
import android.view.SurfaceHolder;

public final class NyanSurfaceHelper implements SurfaceHolder.Callback {

    private SurfaceHolder mHolder;
    private DrawingThread mThread;
    private final NyanDrawingHelper mNyanDrawingHelper;

    public NyanSurfaceHelper(final Context context) {
        mNyanDrawingHelper = new NyanDrawingHelper(context);
    }

    public SurfaceHolder getHolder() {
        return mHolder;
    }

    public void setScale(final float scale) {
        mNyanDrawingHelper.setScale(scale);
    }

    public void setSkipDrawing(final boolean skipDrawing) {
        if (mThread != null) {
            mThread.setSkipDrawing(skipDrawing);
        }
    }

    public void start() {
        if (mThread != null) return;
        mThread = new DrawingThread(this, mNyanDrawingHelper);
        mThread.start();
    }

    public void stop() {
        if (mThread != null) {
            mThread.cancel();
        }
        mThread = null;
    }

    @Override
    public void surfaceChanged(final SurfaceHolder holder, final int format, final int width, final int height) {
        mNyanDrawingHelper.dispatchSizeChanged(width, height);
    }

    @Override
    public void surfaceCreated(final SurfaceHolder holder) {
        mHolder = holder;
        start();
    }

    @Override
    public void surfaceDestroyed(final SurfaceHolder holder) {
        stop();
        mHolder = null;
    }

    private static class DrawingThread extends Thread {

        private final NyanSurfaceHelper mSurfaceHelper;
        private final NyanDrawingHelper mDrawingHelper;
        private boolean mCancelled;
        private boolean mSkipDrawing;

        DrawingThread(final NyanSurfaceHelper surfaceHelper, final NyanDrawingHelper drawingHelper) {
            mSurfaceHelper = surfaceHelper;
            mDrawingHelper = drawingHelper;
        }

        public void cancel() {
            mCancelled = true;
        }

        @Override
        public void run() {
            while (!mCancelled) {
                final long startTime = System.currentTimeMillis();
                drawFrame();
                final long endTime = System.currentTimeMillis();
                try {
                    Thread.sleep(Math.max(0, 66 - (endTime - startTime)));
                } catch (final InterruptedException ignored) {

                }
            }
        }

        public void setSkipDrawing(final boolean skipDrawing) {
            mSkipDrawing = skipDrawing;
        }

        private void drawFrame() {
            final SurfaceHolder holder = mSurfaceHelper.getHolder();
            if (mSkipDrawing || holder == null || holder.isCreating()) return;
            final Canvas c = holder.lockCanvas();
            if (c == null) return;
            if (mDrawingHelper != null) {
                mDrawingHelper.dispatchDraw(c);
            }
            holder.unlockCanvasAndPost(c);
        }

    }
}