package com.hw.photomovie.util.stackblur;

import android.graphics.Bitmap;

import java.util.ArrayList;
import java.util.concurrent.Callable;

/**
 * Blur using Java code.
 *
 * This is a compromise between Gaussian Blur and Box blur
 * It creates much better looking blurs than Box Blur, but is
 * 7x faster than my Gaussian Blur implementation.

 * I called it Stack Blur because this describes best how this
 * filter works internally: it creates a kind of moving stack
 * of colors whilst scanning through the image. Thereby it
 * just has to add one new block of color to the right side
 * of the stack and remove the leftmost color. The remaining
 * colors on the topmost layer of the stack are either added on
 * or reduced by one, depending on if they are on the right or
 * on the left side of the stack.
 *
 * @author Enrique López Mañas <eenriquelopez@gmail.com>
 * http://www.neo-tech.es
 *
 * Author of the original algorithm: Mario Klingemann <mario.quasimondo.com>
 *
 * Based heavily on http://vitiy.info/Code/stackblur.cpp
 * See http://vitiy.info/stackblur-algorithm-multi-threaded-blur-for-cpp/
 *
 * @copyright: Enrique López Mañas
 * @license: Apache License 2.0
 */
class JavaBlurProcess implements BlurProcess {

	private static final short[] stackblur_mul = {
			512, 512, 456, 512, 328, 456, 335, 512, 405, 328, 271, 456, 388, 335, 292, 512,
			454, 405, 364, 328, 298, 271, 496, 456, 420, 388, 360, 335, 312, 292, 273, 512,
			482, 454, 428, 405, 383, 364, 345, 328, 312, 298, 284, 271, 259, 496, 475, 456,
			437, 420, 404, 388, 374, 360, 347, 335, 323, 312, 302, 292, 282, 273, 265, 512,
			497, 482, 468, 454, 441, 428, 417, 405, 394, 383, 373, 364, 354, 345, 337, 328,
			320, 312, 305, 298, 291, 284, 278, 271, 265, 259, 507, 496, 485, 475, 465, 456,
			446, 437, 428, 420, 412, 404, 396, 388, 381, 374, 367, 360, 354, 347, 341, 335,
			329, 323, 318, 312, 307, 302, 297, 292, 287, 282, 278, 273, 269, 265, 261, 512,
			505, 497, 489, 482, 475, 468, 461, 454, 447, 441, 435, 428, 422, 417, 411, 405,
			399, 394, 389, 383, 378, 373, 368, 364, 359, 354, 350, 345, 341, 337, 332, 328,
			324, 320, 316, 312, 309, 305, 301, 298, 294, 291, 287, 284, 281, 278, 274, 271,
			268, 265, 262, 259, 257, 507, 501, 496, 491, 485, 480, 475, 470, 465, 460, 456,
			451, 446, 442, 437, 433, 428, 424, 420, 416, 412, 408, 404, 400, 396, 392, 388,
			385, 381, 377, 374, 370, 367, 363, 360, 357, 354, 350, 347, 344, 341, 338, 335,
			332, 329, 326, 323, 320, 318, 315, 312, 310, 307, 304, 302, 299, 297, 294, 292,
			289, 287, 285, 282, 280, 278, 275, 273, 271, 269, 267, 265, 263, 261, 259
	};

	private static final byte[] stackblur_shr = {
			9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17,
			17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19,
			19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,
			20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,
			21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
			21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22,
			22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
			22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23,
			23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
			23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
			23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
			23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
			24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
			24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
			24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
			24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24
	};

	@Override
	public Bitmap blur(Bitmap original, float radius) {
		int w = original.getWidth();
		int h = original.getHeight();
		int[] currentPixels = new int[w * h];
		original.getPixels(currentPixels, 0, w, 0, 0, w, h);
		int cores = StackBlurManager.EXECUTOR_THREADS;

		ArrayList<BlurTask> horizontal = new ArrayList<BlurTask>(cores);
		ArrayList<BlurTask> vertical = new ArrayList<BlurTask>(cores);
		for (int i = 0; i < cores; i++) {
			horizontal.add(new BlurTask(currentPixels, w, h, (int) radius, cores, i, 1));
			vertical.add(new BlurTask(currentPixels, w, h, (int) radius, cores, i, 2));
		}

		try {
			StackBlurManager.EXECUTOR.invokeAll(horizontal);
		} catch (InterruptedException e) {
			return null;
		}

		try {
			StackBlurManager.EXECUTOR.invokeAll(vertical);
		} catch (InterruptedException e) {
			return null;
		}

		return Bitmap.createBitmap(currentPixels, w, h, Bitmap.Config.ARGB_8888);
	}

	private static void blurIteration(int[] src, int w, int h, int radius, int cores, int core, int step) {
		int x, y, xp, yp, i;
		int sp;
		int stack_start;
		int stack_i;

		int src_i;
		int dst_i;

		long sum_r, sum_g, sum_b,
				sum_in_r, sum_in_g, sum_in_b,
				sum_out_r, sum_out_g, sum_out_b;

		int wm = w - 1;
		int hm = h - 1;
		int div = (radius * 2) + 1;
		int mul_sum = stackblur_mul[radius];
		byte shr_sum = stackblur_shr[radius];
		int[] stack = new int[div];

		if (step == 1)
		{
			int minY = core * h / cores;
			int maxY = (core + 1) * h / cores;

			for(y = minY; y < maxY; y++)
			{
				sum_r = sum_g = sum_b =
				sum_in_r = sum_in_g = sum_in_b =
				sum_out_r = sum_out_g = sum_out_b = 0;

				src_i = w * y; // start of line (0,y)

				for(i = 0; i <= radius; i++)
				{
					stack_i    = i;
					stack[stack_i] = src[src_i];
					sum_r += ((src[src_i] >>> 16) & 0xff) * (i + 1);
					sum_g += ((src[src_i] >>> 8) & 0xff) * (i + 1);
					sum_b += (src[src_i] & 0xff) * (i + 1);
					sum_out_r += ((src[src_i] >>> 16) & 0xff);
					sum_out_g += ((src[src_i] >>> 8) & 0xff);
					sum_out_b += (src[src_i] & 0xff);
				}


				for(i = 1; i <= radius; i++)
				{
					if (i <= wm) src_i += 1;
					stack_i = i + radius;
					stack[stack_i] = src[src_i];
					sum_r += ((src[src_i] >>> 16) & 0xff) * (radius + 1 - i);
					sum_g += ((src[src_i] >>> 8) & 0xff) * (radius + 1 - i);
					sum_b += (src[src_i] & 0xff) * (radius + 1 - i);
					sum_in_r += ((src[src_i] >>> 16) & 0xff);
					sum_in_g += ((src[src_i] >>> 8) & 0xff);
					sum_in_b += (src[src_i] & 0xff);
				}


				sp = radius;
				xp = radius;
				if (xp > wm) xp = wm;
				src_i = xp + y * w; //   img.pix_ptr(xp, y);
				dst_i = y * w; // img.pix_ptr(0, y);
				for(x = 0; x < w; x++)
				{
					src[dst_i] = (int)
								((src[dst_i] & 0xff000000) |
								((((sum_r * mul_sum) >>> shr_sum) & 0xff) << 16) |
								((((sum_g * mul_sum) >>> shr_sum) & 0xff) << 8) |
								((((sum_b * mul_sum) >>> shr_sum) & 0xff)));
					dst_i += 1;

					sum_r -= sum_out_r;
					sum_g -= sum_out_g;
					sum_b -= sum_out_b;

					stack_start = sp + div - radius;
					if (stack_start >= div) stack_start -= div;
					stack_i = stack_start;

					sum_out_r -= ((stack[stack_i] >>> 16) & 0xff);
					sum_out_g -= ((stack[stack_i] >>> 8) & 0xff);
					sum_out_b -= (stack[stack_i] & 0xff);

					if(xp < wm)
					{
						src_i += 1;
						++xp;
					}

					stack[stack_i] = src[src_i];

					sum_in_r += ((src[src_i] >>> 16) & 0xff);
					sum_in_g += ((src[src_i] >>> 8) & 0xff);
					sum_in_b += (src[src_i] & 0xff);
					sum_r    += sum_in_r;
					sum_g    += sum_in_g;
					sum_b    += sum_in_b;

					++sp;
					if (sp >= div) sp = 0;
					stack_i = sp;

					sum_out_r += ((stack[stack_i] >>> 16) & 0xff);
					sum_out_g += ((stack[stack_i] >>> 8) & 0xff);
					sum_out_b += (stack[stack_i] & 0xff);
					sum_in_r  -= ((stack[stack_i] >>> 16) & 0xff);
					sum_in_g  -= ((stack[stack_i] >>> 8) & 0xff);
					sum_in_b  -= (stack[stack_i] & 0xff);
				}

			}
		}

		// step 2
		else if (step == 2)
		{
			int minX = core * w / cores;
			int maxX = (core + 1) * w / cores;

			for(x = minX; x < maxX; x++)
			{
				sum_r =    sum_g =    sum_b =
				sum_in_r = sum_in_g = sum_in_b =
				sum_out_r = sum_out_g = sum_out_b = 0;

				src_i = x; // x,0
				for(i = 0; i <= radius; i++)
				{
					stack_i    = i;
					stack[stack_i] = src[src_i];
					sum_r           += ((src[src_i] >>> 16) & 0xff) * (i + 1);
					sum_g           += ((src[src_i] >>> 8) & 0xff) * (i + 1);
					sum_b           += (src[src_i] & 0xff) * (i + 1);
					sum_out_r       += ((src[src_i] >>> 16) & 0xff);
					sum_out_g       += ((src[src_i] >>> 8) & 0xff);
					sum_out_b       += (src[src_i] & 0xff);
				}
				for(i = 1; i <= radius; i++)
				{
					if(i <= hm) src_i += w; // +stride

					stack_i = i + radius;
					stack[stack_i] = src[src_i];
					sum_r += ((src[src_i] >>> 16) & 0xff) * (radius + 1 - i);
					sum_g += ((src[src_i] >>> 8) & 0xff) * (radius + 1 - i);
					sum_b += (src[src_i] & 0xff) * (radius + 1 - i);
					sum_in_r += ((src[src_i] >>> 16) & 0xff);
					sum_in_g += ((src[src_i] >>> 8) & 0xff);
					sum_in_b += (src[src_i] & 0xff);
				}

				sp = radius;
				yp = radius;
				if (yp > hm) yp = hm;
				src_i = x + yp * w; // img.pix_ptr(x, yp);
				dst_i = x;               // img.pix_ptr(x, 0);
				for(y = 0; y < h; y++)
				{
					src[dst_i] = (int)
							((src[dst_i] & 0xff000000) |
							((((sum_r * mul_sum) >>> shr_sum) & 0xff) << 16) |
							((((sum_g * mul_sum) >>> shr_sum) & 0xff) << 8) |
							((((sum_b * mul_sum) >>> shr_sum) & 0xff)));
					dst_i += w;

					sum_r -= sum_out_r;
					sum_g -= sum_out_g;
					sum_b -= sum_out_b;

					stack_start = sp + div - radius;
					if(stack_start >= div) stack_start -= div;
					stack_i = stack_start;

					sum_out_r -= ((stack[stack_i] >>> 16) & 0xff);
					sum_out_g -= ((stack[stack_i] >>> 8) & 0xff);
					sum_out_b -= (stack[stack_i] & 0xff);

					if(yp < hm)
					{
						src_i += w; // stride
						++yp;
					}

					stack[stack_i] = src[src_i];

					sum_in_r += ((src[src_i] >>> 16) & 0xff);
					sum_in_g += ((src[src_i] >>> 8) & 0xff);
					sum_in_b += (src[src_i] & 0xff);
					sum_r    += sum_in_r;
					sum_g    += sum_in_g;
					sum_b    += sum_in_b;

					++sp;
					if (sp >= div) sp = 0;
					stack_i = sp;

					sum_out_r += ((stack[stack_i] >>> 16) & 0xff);
					sum_out_g += ((stack[stack_i] >>> 8) & 0xff);
					sum_out_b += (stack[stack_i] & 0xff);
					sum_in_r  -= ((stack[stack_i] >>> 16) & 0xff);
					sum_in_g  -= ((stack[stack_i] >>> 8) & 0xff);
					sum_in_b  -= (stack[stack_i] & 0xff);
				}
			}
		}

	}

	private static class BlurTask implements Callable<Void> {
		private final int[] _src;
		private final int _w;
		private final int _h;
		private final int _radius;
		private final int _totalCores;
		private final int _coreIndex;
		private final int _round;

		public BlurTask(int[] src, int w, int h, int radius, int totalCores, int coreIndex, int round) {
			_src = src;
			_w = w;
			_h = h;
			_radius = radius;
			_totalCores = totalCores;
			_coreIndex = coreIndex;
			_round = round;
		}

		@Override public Void call() throws Exception {
			blurIteration(_src, _w, _h, _radius, _totalCores, _coreIndex, _round);
			return null;
		}

	}
}
