#pragma once
#include "HexViewer.h"
#include <fstream>
#include <iostream>


size_t getFileSize(std::ifstream& f)
{
	size_t currentPos = f.tellg();
	f.seekg(0, std::ios::end);
	size_t size = f.tellg();

	f.seekg(currentPos);
	return size;
}
HexViewer::HexViewer(const char* fileName)
{
	std::ifstream file(fileName, std::ios::binary);
	if (!file.is_open())
	{
		size = 0;
		data = nullptr;
		return;
	}
	size_t bytesCount = getFileSize(file);
	data = new unsigned char[bytesCount];

	file.read((char*)data, bytesCount);
	size = bytesCount;
}

unsigned char convertSymbolToNumber(char symbol)
{
	if (symbol >= '0' && symbol <= '9')
		return symbol - '0';
	else if (symbol >= 'A' && symbol <= 'Z')
		return symbol - 'A' + 10;
	return '\0';
}

size_t getSymbolIndex(char ch)
{
	if ('0' <= ch && ch <= '9')
		return ch - '0';
	else if ('A' <= ch && ch <= 'F')
		return ch - 'A';
	else
		return 0; //error ?
}

unsigned char HexViewergetByte(const char* byteStr)
{
	if (strlen(byteStr) != 2)
		return 0;
	return getSymbolIndex(byteStr[1]) + getSymbolIndex(byteStr[0]) * 16;
}

void resize(unsigned char*& data, size_t& size, size_t newSize)
{
	unsigned char* newDataArr = new unsigned char[newSize];
	
	size_t minSize = std::min(size, newSize);
	for (unsigned i = 0; i < minSize; i++)
		newDataArr[i] = data[i];

	delete[] data;
	data = newDataArr;
	size = newSize;
}

void HexViewer::addByte(const char* byteStr)
{
	if (strlen(byteStr) != 2)
		return;
	unsigned char currentByte = 16*convertSymbolToNumber(byteStr[0]) + convertSymbolToNumber(byteStr[1]);
	resize(data, size, size + 1);
	data[size - 1] = currentByte;
}
void HexViewer::removeLastByte()
{
	if (size == 0)
		return;
	resize(data, size, size - 1);

}
void HexViewer::changeByte(size_t index, const char* byteStr)
{
	if (index >= size || strlen(byteStr) != 2)
		return;

	unsigned char currentByte = convertSymbolToNumber(byteStr[1]) + 16 * convertSymbolToNumber(byteStr[0]);
	data[index] = currentByte;
}

void HexViewer::saveAs(const char* fileName) const
{
	std::ofstream file(fileName, std::ios::binary);

	if (!file.is_open())
		return;
	file.write((const char*)data, size);
}

void convertToHex(unsigned char byte, char* byteHex)
{
	char symbols[] = { '0','1', '2', '3', '4', '5', '6','7',
					  '8','9', 'A', 'B', 'C', 'D', 'E', 'F' };
	byteHex[2] = '\0';
	byteHex[1] = symbols[byte % 16];
	byteHex[0] = symbols[(byte / 16) % 16];
}

bool isLetter(char ch)
{
	return (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z');
}
void HexViewer::print() const
{
	for (unsigned i = 0; i < size; i++)
	{
		char byteHex[3];
		convertToHex(data[i], byteHex);
		std::cout << byteHex << " ";
	}
	std::cout << std::endl;
	for (unsigned i = 0; i < size; i++)
	{
		if (isLetter(data[i]))
			std::cout << data[i];
		else
			std::cout << ".";
		std::cout << "  ";
	}
	std::cout << std::endl;
}
HexViewer::~HexViewer()
{
	delete[] data;
}