/*
 *  This file is part of RawTherapee.
 *
 *  RawTherapee 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.
 * 
 *  RawTherapee 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 RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  © 2010 Emil Martinec <ejmartin@uchicago.edu>
 *    
 */

#include <cstddef>
#include <cmath>
#include "curves.h"
#include "labimage.h"
#include "improcfun.h"
#include "rawimagesource.h"
#include "rt_math.h"

#ifdef _OPENMP
#include <omp.h>
#endif

#define CLIPC(a) ((a)>-32000?((a)<32000?(a):32000):-32000)

#define DIRWT(i1,j1,i,j) (rangefn[abs((int)data_fine->L[i1][j1]-data_fine->L[i][j])+abs((int)data_fine->a[i1][j1]-data_fine->a[i][j])+abs((int)data_fine->b[i1][j1]-data_fine->b[i][j])] )

namespace rtengine {
	
	static const int maxlevel = 4;
	
	//sequence of scales
	static const int scales[8] = {1,2,4,8,16,32,64,128};
	//sequence of pitches
	static const int pitches[8] = {1,1,1,1,1,1,1,1};
	
	//sequence of scales
	//static const int scales[8] = {1,1,1,1,1,1,1,1};
	//sequence of pitches
	//static const int pitches[8] = {2,2,2,2,2,2,2,2};
	
	//sequence of scales
	//static const int scales[8] = {1,3,6,10,15,21,28,36};
	//sequence of pitches
	//static const int pitches[8] = {1,1,1,1,1,1,1,1};
	
	//sequence of scales
	//static const int scales[8] = {1,1,2,4,8,16,32,64};
	//sequence of pitches
	//static const int pitches[8] = {2,1,1,1,1,1,1,1};
	
	//pitch is spacing of subsampling
	//scale is spacing of directional averaging weights
	//example 1: no subsampling at any level -- pitch=1, scale=2^n
	//example 2: subsampling by 2 every level -- pitch=2, scale=1 at each level
	//example 3: no subsampling at first level, subsampling by 2 thereafter -- 
	//	pitch =1, scale=1 at first level; pitch=2, scale=2 thereafter
	
	
	
	
	void ImProcFunctions :: dirpyrLab_equalizer(LabImage * src, LabImage * dst, /*float luma, float chroma, float gamma*/ const double * mult )
	{
		
		//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
		
		LUTf rangefn(0x20000);
								
		
		//set up weights		
		float noise = 1500;
		
		
		//set up range functions
		
		for (int i=0; i<0x20000; i++) 
			rangefn[i] = (int)((noise/((double)i + noise)));

		
		//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
		
		
		
		int level;
		int ** buffer[3];
		
		
		LabImage * dirpyrLablo[maxlevel]; 
		
		int w = src->W;
		int h = src->H;
		
		buffer[0] = allocArray<int> (w+128, h+128);
		buffer[1] = allocArray<int> (w+128, h+128);
		buffer[2] = allocArray<int> (w+128, h+128);
		
		for (int i=0; i<h+128; i++)
			for (int j=0; j<w+128; j++) {
				for (int c=0; c<3; c++) 
					buffer[c][i][j]=0;
			}
		
		w = (int)((w-1)/pitches[0])+1;
		h = (int)((h-1)/pitches[0])+1;
		
		dirpyrLablo[0] = new LabImage(w, h);
		
		for (level=1; level<maxlevel; level++) {
			w = (int)((w-1)/pitches[level])+1;
			h = (int)((h-1)/pitches[level])+1;
			dirpyrLablo[level] = new LabImage(w, h);
		};
		
		//////////////////////////////////////////////////////////////////////////////
		
		
		// c[0] = luma = noise_L
		// c[1] = chroma = noise_ab
		// c[2] decrease of noise var with scale
		// c[3] radius of domain blur at each level
		// c[4] shadow smoothing
		// c[5] edge preservation
		
		level = 0;
		
		int scale = scales[level];
		int pitch = pitches[level];
		//int thresh = 10 * c[8];
		//impulse_nr (src, src, m_w1, m_h1, thresh, noisevar);
		
		dirpyr_eq(src, dirpyrLablo[0], rangefn, 0, pitch, scale, mult );
		
		level = 1;
		int totalpitch = pitches[0];
		
		while(level < maxlevel)
		{
			scale = scales[level];
			pitch = pitches[level];
			
			dirpyr_eq(dirpyrLablo[level-1], dirpyrLablo[level], rangefn, level, pitch, scale, mult );
			
			level ++;
			totalpitch *= pitch;
		}
		
		//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
		//initiate buffer for final image
		for(int i = 0, i1=0; i < src->H; i+=totalpitch, i1++)
			for(int j = 0, j1=0; j < src->W; j+=totalpitch, j1++) {
				
				//copy pixels
				buffer[0][i][j] = dirpyrLablo[maxlevel-1]->L[i1][j1];
				buffer[1][i][j] = dirpyrLablo[maxlevel-1]->a[i1][j1];
				buffer[2][i][j] = dirpyrLablo[maxlevel-1]->b[i1][j1];
				
			}
		
		//if we are not subsampling, this is lots faster but does the typecasting work???
		//memcpy(buffer[0],dirpyrLablo[maxlevel-1]->L,sizeof(buffer[0]));
		//memcpy(buffer[1],dirpyrLablo[maxlevel-1]->a,sizeof(buffer[1]));
		//memcpy(buffer[2],dirpyrLablo[maxlevel-1]->b,sizeof(buffer[2]));
		
		//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
		
		
		
		for(int level = maxlevel - 1; level > 0; level--)
		{
			
			//int scale = scales[level];
			int pitch = pitches[level];
			
			totalpitch /= pitch;
			
			idirpyr_eq(dirpyrLablo[level], dirpyrLablo[level-1], buffer, level, pitch, totalpitch, mult );
			
		}
		
		
		scale = scales[0];
		pitch = pitches[0];
		totalpitch /= pitch;
		
		idirpyr_eq(dirpyrLablo[0], dst, buffer, 0, pitch, totalpitch, mult );
		
		
		//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
		
		
		for (int i=0; i<dst->H; i++) 
			for (int j=0; j<dst->W; j++) {
				
                // TODO: Is integer cast necessary here?
				dst->L[i][j] = CLIP((int)(  buffer[0][i][j]  ));
				dst->a[i][j] = CLIPC((int)( buffer[1][i][j]  ));
				dst->b[i][j] = CLIPC((int)( buffer[2][i][j]  ));
				
			}
		
		//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
		
		
		for(int i = 0; i < maxlevel; i++)
		{
			delete dirpyrLablo[i];
		}
		
		for (int c=0;c<3;c++)
			freeArray<int>(buffer[c], h+128);
		
		
		//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	}
	
	void ImProcFunctions::dirpyr_eq(LabImage* data_fine, LabImage* data_coarse, LUTf & rangefn, int level, int pitch, int scale, const double * mult  )
	{
		
		//pitch is spacing of subsampling
		//scale is spacing of directional averaging weights
		//example 1: no subsampling at any level -- pitch=1, scale=2^n
		//example 2: subsampling by 2 every level -- pitch=2, scale=1 at each level
		//example 3: no subsampling at first level, subsampling by 2 thereafter -- 
		//	pitch =1, scale=1 at first level; pitch=2, scale=2 thereafter
		
		
		//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
		// calculate weights, compute directionally weighted average
		
		int width = data_fine->W;
		int height = data_fine->H;
		

		
		//generate domain kernel 
		int halfwin = 1;//min(ceil(2*sig),3);
		int scalewin = halfwin*scale;
		

#ifdef _OPENMP
#pragma omp parallel for
#endif
		for(int i = 0; i < height; i+=pitch) { int i1=i/pitch;
			for(int j = 0, j1=0; j < width; j+=pitch, j1++)
			{				
				float Lout, aout, bout;
				float norm;
				norm = 0;//if we do want to include the input pixel in the sum
				Lout = 0;
				aout = 0;
				bout = 0;
				
				for(int inbr=max(0,i-scalewin); inbr<=min(height-1,i+scalewin); inbr+=scale) {
					for (int jnbr=max(0,j-scalewin); jnbr<=min(width-1,j+scalewin); jnbr+=scale) {
						float dirwt = DIRWT(inbr, jnbr, i, j);
						Lout += dirwt*data_fine->L[inbr][jnbr];
						aout += dirwt*data_fine->a[inbr][jnbr];
						bout += dirwt*data_fine->b[inbr][jnbr];
						norm += dirwt;
					}
				}
				data_coarse->L[i1][j1]=Lout/norm;//low pass filter
				data_coarse->a[i1][j1]=aout/norm;
				data_coarse->b[i1][j1]=bout/norm;
			}
		}
		
		
		
		
	}
	
	//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	
	void ImProcFunctions::idirpyr_eq(LabImage* data_coarse, LabImage* data_fine, int *** buffer, int level, int pitch, int scale, const double * mult )
	{
		
		int width = data_fine->W;
		int height = data_fine->H;
		
		float lumamult[4], chromamult[4];
		for (int i=0; i<4; i++) {
			lumamult[i] = mult[i];
			chromamult[i] = mult[i+4];
		}
		
		float wtdsum[6], norm, dirwt;
		float hipass[3];
		int i1, j1;	
		
		
		// for coarsest level, take non-subsampled lopass image and subtract from lopass_fine to generate hipass image
		
		// denoise hipass image, add back into lopass_fine to generate denoised image at fine scale
		
		// now iterate:
		// (1) take denoised image at level n, expand and smooth using gradient weights from lopass image at level n-1
		//     the result is the smoothed image at level n-1
		// (2) subtract smoothed image at level n-1 from lopass image at level n-1 to make hipass image at level n-1
		// (3) denoise the hipass image at level n-1
		// (4) add the denoised image at level n-1 to the smoothed image at level n-1 to make the denoised image at level n-1
		
		// note that the coarsest level amounts to skipping step (1) and doing (2,3,4).
		// in other words, skip step one if pitch=1
		
		
		
		if (pitch==1) {
			// step (1-2-3-4) 
#ifdef _OPENMP
#pragma omp parallel for
#endif
			for(int i = 0; i < height; i++)
				for(int j = 0; j < width; j++) {
					
					//luma
					float hipass0 = (float)data_fine->L[i][j]-data_coarse->L[i][j];
					buffer[0][i*scale][j*scale] += hipass0 * lumamult[level];//*luma;
					
					//chroma
					float hipass1 = data_fine->a[i][j]-data_coarse->a[i][j];
					float hipass2 = data_fine->b[i][j]-data_coarse->b[i][j];
					buffer[1][i*scale][j*scale] += hipass1 * chromamult[level]; //*chroma;
					buffer[2][i*scale][j*scale] += hipass2 * chromamult[level]; //*chroma;
				}
			
		} else {
			
			// step (1)
			//if (pitch>1), pitch=2; expand coarse image, fill in missing data
			
			LabImage* smooth;
			smooth = new LabImage(width, height);
#ifdef _OPENMP
#pragma	omp parallel
#endif

{
#ifdef _OPENMP
#pragma omp for
#endif
			for(int i = 0; i < height; i+=pitch){ int i2=i/pitch;
				for(int j = 0, j2=0; j < width; j+=pitch, j2++) {
					
					//copy common pixels
					smooth->L[i][j] = data_coarse->L[i2][j2];
					smooth->a[i][j] = data_coarse->a[i2][j2];
					smooth->b[i][j] = data_coarse->b[i2][j2];
				}
			}
						
#ifdef _OPENMP
#pragma omp for
#endif
			for(int i = 0; i < height-1; i+=2)
				for(int j = 0; j < width-1; j+=2) {
					//do midpoint first
					norm=dirwt=0;
					wtdsum[0]=wtdsum[1]=wtdsum[2]=wtdsum[3]=wtdsum[4]=wtdsum[5]=0.0;
					for(i1=i; i1<min(height,i+3); i1+=2)
						for (j1=j; j1<min(width,j+3); j1+=2) {
							dirwt = 1;//IDIRWT(i1, j1, i, j);
							wtdsum[0] += dirwt*smooth->L[i1][j1];
							wtdsum[1] += dirwt*smooth->a[i1][j1];
							wtdsum[2] += dirwt*smooth->b[i1][j1];
							wtdsum[3] += dirwt*buffer[0][i1*scale][j1*scale];// not completely right if j1*scale or i1*scale is out of bounds of original image ???
							wtdsum[4] += dirwt*buffer[1][i1*scale][j1*scale];// also should we use directional average?
							wtdsum[5] += dirwt*buffer[2][i1*scale][j1*scale];
							norm+=dirwt;
						}
					norm = 1/norm;
					smooth->L[i+1][j+1]=wtdsum[0]*norm;
					smooth->a[i+1][j+1]=wtdsum[1]*norm;
					smooth->b[i+1][j+1]=wtdsum[2]*norm;
					buffer[0][(i+1)*scale][(j+1)*scale]=wtdsum[3]*norm;
					buffer[1][(i+1)*scale][(j+1)*scale]=wtdsum[4]*norm;
					buffer[2][(i+1)*scale][(j+1)*scale]=wtdsum[5]*norm;
				}
#ifdef _OPENMP
#pragma omp for
#endif
			for(int i = 0; i < height-1; i+=2)
				for(int j = 0; j < width-1; j+=2) {
					//now right neighbor
					if (j+1==width) continue;
					norm=dirwt=0;
					wtdsum[0]=wtdsum[1]=wtdsum[2]=wtdsum[3]=wtdsum[4]=wtdsum[5]=0.0;
					for (j1=j; j1<min(width,j+3); j1+=2) {
						dirwt = 1;//IDIRWT(i, j1, i, j);
						wtdsum[0] += dirwt*smooth->L[i][j1];
						wtdsum[1] += dirwt*smooth->a[i][j1];
						wtdsum[2] += dirwt*smooth->b[i][j1];
						wtdsum[3] += dirwt*buffer[0][i*scale][j1*scale];
						wtdsum[4] += dirwt*buffer[1][i*scale][j1*scale];
						wtdsum[5] += dirwt*buffer[2][i*scale][j1*scale];
						norm+=dirwt;
					}
					for (i1=max(0,i-1); i1<min(height,i+2); i1+=2) {
						dirwt = 1;//IDIRWT(i1, j+1, i, j);
						wtdsum[0] += dirwt*smooth->L[i1][j+1];
						wtdsum[1] += dirwt*smooth->a[i1][j+1];
						wtdsum[2] += dirwt*smooth->b[i1][j+1];
						wtdsum[3] += dirwt*buffer[0][i1*scale][(j+1)*scale];
						wtdsum[4] += dirwt*buffer[1][i1*scale][(j+1)*scale];
						wtdsum[5] += dirwt*buffer[2][i1*scale][(j+1)*scale];
						norm+=dirwt;
					}
					norm = 1/norm;
					smooth->L[i][j+1]=wtdsum[0]*norm;
					smooth->a[i][j+1]=wtdsum[1]*norm;
					smooth->b[i][j+1]=wtdsum[2]*norm;
					buffer[0][i][(j+1)*scale]=wtdsum[3]*norm;
					buffer[1][i][(j+1)*scale]=wtdsum[4]*norm;
					buffer[2][i][(j+1)*scale]=wtdsum[5]*norm;
					
					//now down neighbor
					if (i+1==height) continue;
					norm=0;
					wtdsum[0]=wtdsum[1]=wtdsum[2]=wtdsum[3]=wtdsum[4]=wtdsum[5]=0.0;
					for (i1=i; i1<min(height,i+3); i1+=2) {
						dirwt = 1;//IDIRWT(i1, j, i, j);
						wtdsum[0] += dirwt*smooth->L[i1][j];
						wtdsum[1] += dirwt*smooth->a[i1][j];
						wtdsum[2] += dirwt*smooth->b[i1][j];
						wtdsum[3] += dirwt*buffer[0][i1*scale][j*scale];
						wtdsum[4] += dirwt*buffer[1][i1*scale][j*scale];
						wtdsum[5] += dirwt*buffer[2][i1*scale][j*scale];
						norm+=dirwt;
					}
					for (j1=max(0,j-1); j1<min(width,j+2); j1+=2) {
						dirwt = 1;//IDIRWT(i+1, j1, i, j);
						wtdsum[0] += dirwt*smooth->L[i+1][j1];
						wtdsum[1] += dirwt*smooth->a[i+1][j1];
						wtdsum[2] += dirwt*smooth->b[i+1][j1];
						wtdsum[3] += dirwt*buffer[0][(i+1)*scale][j1*scale];
						wtdsum[4] += dirwt*buffer[1][(i+1)*scale][j1*scale];
						wtdsum[5] += dirwt*buffer[2][(i+1)*scale][j1*scale];
						norm+=dirwt;
					}
					norm=1/norm;
					smooth->L[i+1][j]=wtdsum[0]*norm;
					smooth->a[i+1][j]=wtdsum[1]*norm;
					smooth->b[i+1][j]=wtdsum[2]*norm;
					buffer[0][(i+1)*scale][j*scale]=wtdsum[3]*norm;
					buffer[1][(i+1)*scale][j*scale]=wtdsum[4]*norm;
					buffer[2][(i+1)*scale][j*scale]=wtdsum[5]*norm;
					
				}
			
			
			// step (2-3-4) 
#ifdef _OPENMP
#pragma omp for
#endif
			for(int i = 0; i < height; i++)
				for(int j = 0; j < width; j++) {
					
					//luma
					hipass[0] = (float)data_fine->L[i][j]-smooth->L[i][j];
					buffer[0][i*scale][j*scale] += hipass[0] * lumamult[level]; //*luma;
					
					//chroma
					hipass[1] = data_fine->a[i][j]-smooth->a[i][j];
					hipass[2] = data_fine->b[i][j]-smooth->b[i][j];
					buffer[1][i*scale][j*scale] += hipass[1] * chromamult[level]; //*chroma;
					buffer[2][i*scale][j*scale] += hipass[2] * chromamult[level]; //*chroma;
				}
}	// end parallel		
			delete smooth;
			
		}
	}
	
	
#undef DIRWT_L
#undef DIRWT_AB
	
#undef NRWT_L	
#undef NRWT_AB	
	
}