#include <string>
#include <cstdio>
#include <iostream>
#include <utility> // std::pair, std::makr_pair
#include <memory> // std::shared_ptr
#include <stdexcept> // std::runtime_error
#include <opencv2/opencv.hpp> // all opencv header
#include <libraw/libraw.h>
#include <exiv2/exiv2.hpp> // exiv2
#include "hdrplus/bayer_image.h"
#include "hdrplus/utility.h" // box_filter_kxk
namespace hdrplus
{

	bayer_image::bayer_image(const std::string& bayer_image_path)
	{
		libraw_processor = std::make_shared<LibRaw>();

		// Open RAW image file
		int return_code;
		if ((return_code = libraw_processor->open_file(bayer_image_path.c_str())) != LIBRAW_SUCCESS)
		{
			libraw_processor->recycle();
#ifdef __ANDROID__
			return;
#else
			throw std::runtime_error("Error opening file " + bayer_image_path + " " + libraw_strerror(return_code));
#endif
		}

		// Unpack the raw image
		if ((return_code = libraw_processor->unpack()) != LIBRAW_SUCCESS)
		{
#ifdef __ANDROID__
			return;
#else
			throw std::runtime_error("Error unpack file " + bayer_image_path + " " + libraw_strerror(return_code));
#endif
		}

		// Get image basic info
		width = int(libraw_processor->imgdata.rawdata.sizes.raw_width);
		height = int(libraw_processor->imgdata.rawdata.sizes.raw_height);

		// Read exif tags
		Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(bayer_image_path);
		assert(image.get() != 0);
		image->readMetadata();
		Exiv2::ExifData &exifData = image->exifData();
		if (exifData.empty()) {
			std::string error(bayer_image_path);
			error += ": No Exif data found in the file";
			std::cout << error << std::endl;
		}

		white_level = exifData["Exif.Image.WhiteLevel"].toLong();
		black_level_per_channel.resize(4);
		black_level_per_channel.at(0) = exifData["Exif.Image.BlackLevel"].toLong(0);
		black_level_per_channel.at(1) = exifData["Exif.Image.BlackLevel"].toLong(1);
		black_level_per_channel.at(2) = exifData["Exif.Image.BlackLevel"].toLong(2);
		black_level_per_channel.at(3) = exifData["Exif.Image.BlackLevel"].toLong(3);
		iso = exifData["Exif.Image.ISOSpeedRatings"].toLong();

		// Create CV mat
		// https://answers.opencv.org/question/105972/de-bayering-a-cr2-image/
		// https://www.libraw.org/node/2141
		raw_image = cv::Mat(height, width, CV_16U, libraw_processor->imgdata.rawdata.raw_image).clone(); // changed the order of width and height

		// 2x2 box filter
		grayscale_image = box_filter_kxk<uint16_t, 2>(raw_image);

#ifndef NDEBUG
		printf("%s::%s read bayer image %s with\n width %zu\n height %zu\n iso %.3f\n white level %d\n black level %d %d %d %d\n", \
			__FILE__, __func__, bayer_image_path.c_str(), width, height, iso, white_level, \
			black_level_per_channel[0], black_level_per_channel[1], black_level_per_channel[2], black_level_per_channel[3]);
		fflush(stdout);
#endif
	}

	bayer_image::bayer_image(const std::vector<uint8_t>& bayer_image_content)
	{
		libraw_processor = std::make_shared<LibRaw>();

		// Open RAW image file
		int return_code;
		if ((return_code = libraw_processor->open_buffer((void *)(&bayer_image_content[0]), bayer_image_content.size())) != LIBRAW_SUCCESS)
		{
			libraw_processor->recycle();
#ifdef __ANDROID__ || _WIN32
			return;
#else
			// throw std::runtime_error("Error opening file " + bayer_image_path + " " + libraw_strerror( return_code ));
			return;
#endif
		}

		// Unpack the raw image
		if ((return_code = libraw_processor->unpack()) != LIBRAW_SUCCESS)
		{
#ifdef __ANDROID__ || _WIN32
			return;
#else
			// throw std::runtime_error("Error unpack file " + bayer_image_path + " " + libraw_strerror( return_code ));
			return;
#endif
		}

		// Get image basic info
		width = int(libraw_processor->imgdata.rawdata.sizes.raw_width);
		height = int(libraw_processor->imgdata.rawdata.sizes.raw_height);

		// Read exif tags
		Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(&bayer_image_content[0], bayer_image_content.size());
		assert(image.get() != 0);
		image->readMetadata();
		Exiv2::ExifData &exifData = image->exifData();
		if (exifData.empty()) {
			std::string error = "No Exif data found in the file";
			std::cout << error << std::endl;
		}

		white_level = exifData["Exif.Image.WhiteLevel"].toLong();
		black_level_per_channel.resize(4);
		black_level_per_channel.at(0) = exifData["Exif.Image.BlackLevel"].toLong(0);
		black_level_per_channel.at(1) = exifData["Exif.Image.BlackLevel"].toLong(1);
		black_level_per_channel.at(2) = exifData["Exif.Image.BlackLevel"].toLong(2);
		black_level_per_channel.at(3) = exifData["Exif.Image.BlackLevel"].toLong(3);
		iso = exifData["Exif.Image.ISOSpeedRatings"].toLong();

		// Create CV mat
		// https://answers.opencv.org/question/105972/de-bayering-a-cr2-image/
		// https://www.libraw.org/node/2141
		raw_image = cv::Mat(height, width, CV_16U, libraw_processor->imgdata.rawdata.raw_image).clone(); // changed the order of width and height

		// 2x2 box filter
		grayscale_image = box_filter_kxk<uint16_t, 2>(raw_image);

#ifndef NDEBUG
		printf("%s::%s read bayer image with\n width %zu\n height %zu\n iso %.3f\n white level %d\n black level %d %d %d %d\n", \
			__FILE__, __func__, width, height, iso, white_level, \
			black_level_per_channel[0], black_level_per_channel[1], black_level_per_channel[2], black_level_per_channel[3]);
		fflush(stdout);
#endif
	}

	bayer_image::bayer_image(std::shared_ptr<MemFile> bayer_image_file)
	{
		libraw_processor = std::make_shared<LibRaw>();

		// Open RAW image file
		int return_code;
		{
			std::vector<uint8_t>& fileData = bayer_image_file->content;
			if ((return_code = libraw_processor->open_buffer((void *)(&fileData[0]), fileData.size())) != LIBRAW_SUCCESS)
			{
				libraw_processor->recycle();
#ifdef __ANDROID__
				return;
#else
				return;
				// throw std::runtime_error("Error opening file " + bayer_image_path + " " + libraw_strerror( return_code ));
#endif
			}
		}


		// Unpack the raw image
		if ((return_code = libraw_processor->unpack()) != LIBRAW_SUCCESS)
		{
#ifdef __ANDROID__
			return;
#else
			return;
			// throw std::runtime_error("Error unpack file " + bayer_image_path + " " + libraw_strerror( return_code ));
#endif
		}

		// Get image basic info
		width = int(libraw_processor->imgdata.rawdata.sizes.raw_width);
		height = int(libraw_processor->imgdata.rawdata.sizes.raw_height);

		// Read exif tags
		Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(&bayer_image_file->content[0], bayer_image_file->content.size());
		assert(image.get() != 0);
		image->readMetadata();
		Exiv2::ExifData &exifData = image->exifData();
		if (exifData.empty()) {
			std::string error = "No Exif data found in the file";
			std::cout << error << std::endl;
		}

		white_level = exifData["Exif.Image.WhiteLevel"].toLong();
		black_level_per_channel.resize(4);
		black_level_per_channel.at(0) = exifData["Exif.Image.BlackLevel"].toLong(0);
		black_level_per_channel.at(1) = exifData["Exif.Image.BlackLevel"].toLong(1);
		black_level_per_channel.at(2) = exifData["Exif.Image.BlackLevel"].toLong(2);
		black_level_per_channel.at(3) = exifData["Exif.Image.BlackLevel"].toLong(3);
		iso = exifData["Exif.Image.ISOSpeedRatings"].toLong();

		// Create CV mat
		// https://answers.opencv.org/question/105972/de-bayering-a-cr2-image/
		// https://www.libraw.org/node/2141
		raw_image = cv::Mat(height, width, CV_16U, libraw_processor->imgdata.rawdata.raw_image).clone(); // changed the order of width and height

		// 2x2 box filter
		grayscale_image = box_filter_kxk<uint16_t, 2>(raw_image);

#ifndef NDEBUG
		printf("%s::%s read bayer image with\n width %zu\n height %zu\n iso %.3f\n white level %d\n black level %d %d %d %d\n", \
			__FILE__, __func__, width, height, iso, white_level, \
			black_level_per_channel[0], black_level_per_channel[1], black_level_per_channel[2], black_level_per_channel[3]);
		fflush(stdout);
#endif
	}

	std::pair<double, double> bayer_image::get_noise_params() const
	{
		// Set ISO to 100 if not positive
		double iso_ = iso <= 0 ? 100 : iso;

		// Calculate shot noise and read noise parameters w.r.t ISO 100
		double lambda_shot_p = iso_ / 100.0f * baseline_lambda_shot;
		double lambda_read_p = (iso_ / 100.0f) * (iso_ / 100.0f) * baseline_lambda_read;

		double black_level = (black_level_per_channel[0] + \
			black_level_per_channel[1] + \
			black_level_per_channel[2] + \
			black_level_per_channel[3]) / 4.0;

		// Rescale shot and read noise to normal range
		double lambda_shot = lambda_shot_p * (white_level - black_level);
		double lambda_read = lambda_read_p * (white_level - black_level) * (white_level - black_level);

		// return pair
		return std::make_pair(lambda_shot, lambda_read);
	}

}