#include <string>
#include <vector>
#include <stdexcept>
#include <fstream>
#include <limits>
#include <cmath>
#include "igs_ifx_common.h" /* igs::image::rgba */
#include "igs_gaussian_blur.h"
#include "igs_gauss_distribution.cpp"

namespace
{
const int diameter_from_radius_(const int radius)
{
	/* テーブルの半径サイズ(=中心位置)からテーブルの大きさを決める */
	return radius * 2 + 1;
}
template <class RT>
void blur_1st_hori_(
	const double **in_plane_with_margin // &(std::vector<double *>).at(0)
	,
	const int height_with_margin, const int width_with_margin, double *brush_sequence // &(std::vector<double *>).at(0)
	,
	const int int_radius, double **out_plane_with_margin // &(std::vector<double *>).at(0)

	/* 参照画像用情報(no margin) */
	,
	const RT *ref /* 求める画像(out)と同じ高さ、幅、チャンネル数 */
	,
	const int ref_mode /* 0=R,1=G,2=B,3=A,4=Luminance,5=Nothing */
	,
	const int ref_channels, const double real_radius, const double sigma)
{
	const int brush_diameter = diameter_from_radius_(int_radius);
	const int width_no_margin = width_with_margin - int_radius * 2;
	const int r_max = std::numeric_limits<RT>::max();
	const RT *ref_vert = ref;
	const RT *ref_hori = ref;
	double before_real_radius = -1.0;

	/* 縦方向 */
	for (int yo = 0; yo < height_with_margin; ++yo) {

		if (ref != 0) {
			if (int_radius < yo && yo < (height_with_margin - int_radius)) {
				ref_vert += width_no_margin * ref_channels;
			}
			ref_hori = ref_vert;
		}

		/* 横方向 */
		for (int xx = 0, xo = int_radius; xx < width_no_margin; ++xx, ++xo) {

			if (ref != 0) {
				const double read_r = real_radius * igs::color::ref_value(
														ref_hori, ref_channels, r_max, ref_mode);
				ref_hori += ref_channels;

				if (read_r != before_real_radius) {
					gauss_distribution_1d_(
						brush_sequence, brush_diameter, igs::gaussian_blur_hv::int_radius(read_r), read_r, sigma);
					before_real_radius = read_r;
				}
			}
			/* ガウス分布で横blur */
			double accum = 0;
			/*
	  for (int xb=0, xi=xx; xb<brush_diameter; ++xb,++xi) {
		accum += in_plane_with_margin[yo][xi] * brush_sequence[xb];
	  }
*/
			const double *bru_seq = brush_sequence;
			int bru_dia = brush_diameter;
			const double *inn_pla = &in_plane_with_margin[yo][xx];
			while (0 < bru_dia--) {
				accum += (*inn_pla++) * (*bru_seq++);
			}
			out_plane_with_margin[yo][xo] = accum;
		}
	}
}
template <class RT>
void blur_2nd_vert_(
	const double **in_plane_with_margin // &(std::vector<double *>).at(0)
	,
	const int height_with_margin, const int width_with_margin, double *brush_sequence // &(std::vector<double *>).at(0)
	,
	const int int_radius, double **out_plane_with_margin // &(std::vector<double *>).at(0)

	/* 参照画像用情報(no margin) */
	,
	const RT *ref /* 求める画像(out)と同じ高さ、幅、チャンネル数 */
	,
	const int ref_mode /* 0=R,1=G,2=B,3=A,4=Luminance,5=Nothing */
	,
	const int ref_channels, const double real_radius, const double sigma)
{
	const int brush_diameter = diameter_from_radius_(int_radius);
	const int height_no_margin = height_with_margin - int_radius * 2;
	const int width_no_margin = width_with_margin - int_radius * 2;
	const int r_max = std::numeric_limits<RT>::max();
	const RT *ref_vert = ref;
	const RT *ref_hori = ref;
	double before_real_radius = -1.0;

	/* 左右マージン部分はもう処理しなくていい */

	/* 横方向 */
	for (int xx = 0, xo = int_radius; xx < width_no_margin; ++xx, ++xo) {

		if (ref != 0) {
			ref_hori += ref_channels;
			ref_vert = ref_hori;
		}

		/* 縦方向 */
		for (int yy = 0, yo = int_radius; yy < height_no_margin; ++yy, ++yo) {

			if (ref != 0) {
				const double read_r = real_radius * igs::color::ref_value(
														ref_vert, ref_channels, r_max, ref_mode);
				ref_vert += width_no_margin * ref_channels;

				if (read_r != before_real_radius) {
					gauss_distribution_1d_(
						brush_sequence, brush_diameter, igs::gaussian_blur_hv::int_radius(read_r), read_r, sigma);
					before_real_radius = read_r;
				}
			}
			/* ガウス分布で横blur */
			double accum = 0;
			/*
	  for (int yb=0,yi=yy; yb<brush_diameter; ++yb,++yi) {
		accum += in_plane_with_margin[yi][xo] * brush_sequence[yb];
	  }
*/
			const double *bru_seq = brush_sequence;
			int bru_dia = brush_diameter;
			const double *inn_pla = &in_plane_with_margin[yy][xo];
			while (0 < bru_dia--) {
				accum += (*inn_pla) * (*bru_seq++);
				inn_pla += width_with_margin;
			}
			out_plane_with_margin[yo][xo] = accum;
		}
	}
}
template <class T>
void get_(
	const T *in, const int height, const int width, const int channels, const int current_ch, double **out // &(std::vector<double *>).at(0)
	)
{
	in += current_ch;
	const double maxi = static_cast<double>(
		std::numeric_limits<T>::max());
	for (int yy = 0; yy < height; ++yy) {
		for (int xx = 0; xx < width; ++xx) {
			out[yy][xx] = static_cast<double>(*in) / maxi;
			in += channels;
		}
	}
}
template <class T>
void put_margin_(
	const double **in_with_margin // &(std::vector<double *>).at(0)
	,
	const int height_with_margin, const int width_with_margin, const int channels, const int current_ch, const int margin, T *out_no_margin)
{
	out_no_margin += current_ch;
	const double maxi = static_cast<double>(
							std::numeric_limits<T>::max()) +
						0.999999;
	for (int yy = margin; yy < (height_with_margin - margin); ++yy) {
		for (int xx = margin; xx < (width_with_margin - margin); ++xx) {
			*out_no_margin = static_cast<T>(in_with_margin[yy][xx] * maxi);
			out_no_margin += channels;
		}
	}
}
template <class T>
bool diff_between_channel_(
	const T *in, const int height, const int width, const int channels, const int ch1, const int ch2)
{
	//if (ch1 == ch2) { return false; }
	//if (channels <= ch1) { return false; }
	//if (channels <= ch2) { return false; }
	for (int yy = 0; yy < height; ++yy) {
		for (int xx = 0; xx < width; ++xx) {
			if (in[ch1] != in[ch2]) {
				return true;
			}
			in += channels;
		}
	}
	return false;
}
template <class IT, class RT>
void convert_hv_(
	const IT *in_with_margin, IT *out_no_margin, const int height_with_margin, const int width_with_margin, const int channels

	,
	double *filter // (double *)(&filter_buf.at(0))
	,
	const int int_radius, double **buffer_inn // &(std::vector<double *>).at(0)
	,
	double **buffer_out // &(std::vector<double *>).at(0)

	/* 参照画像用情報(no margin) */
	,
	const RT *ref /* 求める画像(out)と同じ高さ、幅、チャンネル数 */
	,
	const int ref_mode /* 0=R,1=G,2=B,3=A,4=Luminance,5=Nothing */
	,
	const double real_radius, const double sigma)
{
	bool diff_sw = true; /* 1番目の画像は処理する */
	for (int cc = 0; cc < channels; ++cc) {
		if (0 < cc) { /* 2番目のチャンネル以後 */
			/* 1つ前のチャンネルと違いを調べる */
			diff_sw = diff_between_channel_(
				in_with_margin, height_with_margin, width_with_margin, channels, cc - 1, cc);
		}
		/* 一つ前と同じ画像なら処理せず使い回して高速化する */
		if (diff_sw) {
			get_(
				in_with_margin, height_with_margin, width_with_margin, channels, cc, buffer_inn);
			blur_1st_hori_(
				(const double **)(buffer_inn), height_with_margin, width_with_margin, filter, int_radius, buffer_out

				,
				ref, ref_mode, channels, real_radius, sigma);
			blur_2nd_vert_(
				(const double **)(buffer_out), height_with_margin, width_with_margin, filter, int_radius, buffer_inn

				,
				ref, ref_mode, channels, real_radius, sigma);
		}

		put_margin_(
			(const double **)(buffer_inn), height_with_margin, width_with_margin, channels, cc, int_radius, out_no_margin);
	}
}
}
const int igs::gaussian_blur_hv::int_radius(
	const double real_radius)
{
	/* ぼかしの半径から、pixelサイズ半径(=中心位置=margin)を決める */
	return static_cast<int>(ceil(real_radius));
}
const int igs::gaussian_blur_hv::buffer_bytes(
	const int height_with_margin, const int width_with_margin, const int int_radius)
{
	const int int_diameter = diameter_from_radius_(int_radius);
	return int_diameter * int_diameter * sizeof(double) + height_with_margin * width_with_margin * sizeof(double) + height_with_margin * width_with_margin * sizeof(double);
}
void igs::gaussian_blur_hv::convert(
	/* 入出力画像 */
	const void *in_with_margin, void *out_no_margin

	,
	const int height_with_margin, const int width_with_margin, const int channels, const int bits

	/* Pixel毎に効果の強弱 */
	,
	const unsigned char *ref /* 求める画像(out)と同じ高、幅、ch数 */
	,
	const int ref_bits /* refがゼロのときはここもゼロ */
	,
	const int ref_mode /* 0=R,1=G,2=B,3=A,4=Luminance,5=Nothing */

	/* 計算バッファ */
	,
	void *buffer, int buffer_bytes // Must be igs::gaussian_blur_hv::buffer_bytes(-)

	/* Action Geometry */
	,
	const int int_radius // =margin
	,
	const double real_radius, const double sigma //= 0.25
	)
{
	/* 引数チェック */
	if (real_radius <= 0.0) {
		return;
	}

	if ((igs::image::rgba::siz != channels) && (igs::image::rgb::siz != channels) && (1 != channels) /* grayscale */
		) {
		throw std::domain_error("Bad channels,Not rgba/rgb/grayscale");
	}

	/* 変数の設定 */
	const int int_diameter = diameter_from_radius_(int_radius);
	double *double_buffer = static_cast<double *>(buffer);

	/* メモリバッファの設定 */
	std::vector<double> filter_buf(int_diameter);

	std::vector<double *> in_plane_with_margin_dp(
		height_with_margin);
	for (int yy = 0; yy < height_with_margin; ++yy) {
		in_plane_with_margin_dp.at(yy) = double_buffer;
		double_buffer += width_with_margin;
		buffer_bytes -= width_with_margin * sizeof(double);
		if (buffer_bytes <= 0) {
			std::string msg("buffer_inn is empty");
			throw std::domain_error(msg);
		}
	}

	std::vector<double *> out_plane_with_margin_dp(
		height_with_margin);
	for (int yy = 0; yy < height_with_margin; ++yy) {
		out_plane_with_margin_dp.at(yy) = double_buffer;
		double_buffer += width_with_margin;
		buffer_bytes -= width_with_margin * sizeof(double);
		if (buffer_bytes <= 0) {
			std::string msg("buffer_out is empty");
			throw std::domain_error(msg);
		}
	}

	/* filter生成 */
	gauss_distribution_1d_(
		&filter_buf.at(0), int_diameter, int_radius, real_radius, sigma);

	/* 処理 */
	if ((std::numeric_limits<unsigned char>::digits == bits) && ((std::numeric_limits<unsigned char>::digits == ref_bits) || (0 == ref_bits))) {
		convert_hv_(
			static_cast<const unsigned char *>(in_with_margin), static_cast<unsigned char *>(out_no_margin), height_with_margin, width_with_margin, channels, &filter_buf.at(0), int_radius, &in_plane_with_margin_dp.at(0), &out_plane_with_margin_dp.at(0)

																																																								 ,
			ref, ref_mode, real_radius, sigma);
	} else if ((std::numeric_limits<unsigned short>::digits == bits) && ((std::numeric_limits<unsigned char>::digits == ref_bits) || (0 == ref_bits))) {
		convert_hv_(
			static_cast<const unsigned short *>(in_with_margin), static_cast<unsigned short *>(out_no_margin), height_with_margin, width_with_margin, channels, &filter_buf.at(0), int_radius, &in_plane_with_margin_dp.at(0), &out_plane_with_margin_dp.at(0)

																																																								   ,
			ref, ref_mode, real_radius, sigma);
	} else if ((std::numeric_limits<unsigned short>::digits == bits) && (std::numeric_limits<unsigned short>::digits == ref_bits)) {
		convert_hv_(
			static_cast<const unsigned short *>(in_with_margin), static_cast<unsigned short *>(out_no_margin), height_with_margin, width_with_margin, channels, &filter_buf.at(0), int_radius, &in_plane_with_margin_dp.at(0), &out_plane_with_margin_dp.at(0)

																																																								   ,
			reinterpret_cast<const unsigned short *>(ref), ref_mode, real_radius, sigma);
	} else if ((std::numeric_limits<unsigned char>::digits == bits) && (std::numeric_limits<unsigned short>::digits == ref_bits)) {
		convert_hv_(
			static_cast<const unsigned short *>(in_with_margin), static_cast<unsigned short *>(out_no_margin), height_with_margin, width_with_margin, channels, &filter_buf.at(0), int_radius, &in_plane_with_margin_dp.at(0), &out_plane_with_margin_dp.at(0)

																																																								   ,
			reinterpret_cast<const unsigned char *>(ref), ref_mode, real_radius, sigma);
	} else {
		throw std::domain_error("Bad bits,Not uchar/ushort");
	}
}