#include <cmath>
#include "resource_bitmap_reader.h"
#include "pe_resource_viewer.h"
#include "pe_structures.h"

namespace pe_bliss
{
using namespace pe_win;

resource_bitmap_reader::resource_bitmap_reader(const pe_resource_viewer& res)
	:res_(res)
{}

//Returns bitmap data by name and index in language directory (instead of language) (minimum checks of format correctness)
const std::string resource_bitmap_reader::get_bitmap_by_name(const std::wstring& name, uint32_t index) const
{
	return create_bitmap(res_.get_resource_data_by_name(pe_resource_viewer::resource_bitmap, name, index).get_data());
}

//Returns bitmap data by name and language (minimum checks of format correctness)
const std::string resource_bitmap_reader::get_bitmap_by_name(uint32_t language, const std::wstring& name) const
{
	return create_bitmap(res_.get_resource_data_by_name(language, pe_resource_viewer::resource_bitmap, name).get_data());
}

//Returns bitmap data by ID and language (minimum checks of format correctness)
const std::string resource_bitmap_reader::get_bitmap_by_id_lang(uint32_t language, uint32_t id) const
{
	return create_bitmap(res_.get_resource_data_by_id(language, pe_resource_viewer::resource_bitmap, id).get_data());
}

//Returns bitmap data by ID and index in language directory (instead of language) (minimum checks of format correctness)
const std::string resource_bitmap_reader::get_bitmap_by_id(uint32_t id, uint32_t index) const
{
	return create_bitmap(res_.get_resource_data_by_id(pe_resource_viewer::resource_bitmap, id, index).get_data());
}

//Helper function of creating bitmap header
const std::string resource_bitmap_reader::create_bitmap(const std::string& resource_data)
{
	//Create bitmap file header
	bitmapfileheader header = {0};
	header.bfType = 0x4d42; //Signature "BM"
	header.bfOffBits = sizeof(bitmapfileheader) + sizeof(bitmapinfoheader); //Offset to bitmap bits
	header.bfSize = static_cast<uint32_t>(sizeof(bitmapfileheader) + resource_data.length()); //Size of bitmap

	//Check size of resource data
	if(resource_data.length() < sizeof(bitmapinfoheader))
		throw pe_exception("Incorrect resource bitmap", pe_exception::resource_incorrect_bitmap);

	{
		//Get bitmap info header
		const bitmapinfoheader* info = reinterpret_cast<const bitmapinfoheader*>(resource_data.data());

		//If color table is present, skip it
		if(info->biClrUsed != 0)
			header.bfOffBits += 4 * info->biClrUsed; //Add this size to offset to bitmap bits
		else if(info->biBitCount <= 8)
			header.bfOffBits += 4 * static_cast<uint32_t>(std::pow(2.f, info->biBitCount)); //Add this size to offset to bitmap bits
	}

	//Return final bitmap data
	return std::string(reinterpret_cast<const char*>(&header), sizeof(bitmapfileheader)) + resource_data;
}
}