#include <stdio.h>
#include "JpegImageCollection.h"


namespace Image {

JpegImageCollection::JpegImageCollection(const std::vector<JpegImage>& images) :
	m_width(0),
	m_height(0),
	m_strideX(0),
	m_strideY(0)
{
	if (images.size() == 0)
		return;

	m_width = images[0].Width();
	m_strideX = images[0].StrideX();
	m_strideY = images[0].StrideY();

	size_t height = images[0].Height();
	m_height = height * images.size();
	m_imageData.resize(m_strideY * m_height);

	std::vector<char>::iterator outIterator = m_imageData.begin();
	for (std::vector<JpegImage>::const_iterator it = images.begin(); it != images.end(); ++it)
		outIterator = std::copy(it->Data().begin(), it->Data().end(), outIterator);
}

void JpegImageCollection::Save(const std::string& fileName)
{
	if (m_width == 0 || m_height == 0 || m_strideX == 0 || m_strideY == 0)
		return;

	struct jpeg_compress_struct cinfo;
	struct jpeg_error_mgr jerr;

	FILE* outFile = fopen(fileName.c_str(), "wb");

	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_compress(&cinfo);
	jpeg_stdio_dest(&cinfo, outFile);

	cinfo.image_width = m_width;
	cinfo.image_height = m_height;
	cinfo.input_components = m_strideX;
	cinfo.in_color_space = JCS_RGB;

	jpeg_set_defaults( &cinfo );
	cinfo.num_components = 3;
	cinfo.dct_method = JDCT_FLOAT;
	jpeg_set_quality(&cinfo, 80, TRUE);

	jpeg_start_compress( &cinfo, TRUE );

	JSAMPROW scanlines[1];
	while (cinfo.next_scanline < cinfo.image_height)
	{
		scanlines[0] = reinterpret_cast<JSAMPROW>(&m_imageData[cinfo.next_scanline * m_strideY]);
		jpeg_write_scanlines(&cinfo, scanlines, 1);
	}

	jpeg_finish_compress(&cinfo);
	jpeg_destroy_compress(&cinfo);
	fclose(outFile);
}

} // namespace Image