/*
	Aseba - an event-based framework for distributed robot control
	Created by Stéphane Magnenat <stephane at magnenat dot net> (http://stephane.magnenat.net)
	with contributions from the community.
	Copyright (C) 2007--2018 the authors, see authors.txt for details.

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published
	by the Free Software Foundation, version 3 of the License.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

#include "HexFile.h"
#include <istream>
#include <ostream>
#include <fstream>
#include <iostream>
#include <iomanip>
#include <cassert>
#include <algorithm>
#include <valarray>
#include <iterator>

namespace Aseba
{
	const char* HexFile::Error::what() const noexcept
	{
		return toString().c_str();
	}

	std::string HexFile::EarlyEOF::toString() const
	{
		return FormatableString("Early end of file after %0 lines").arg(line);
	}

	std::string HexFile::InvalidRecord::toString() const
	{
		return FormatableString("Invalid record at line %0").arg(line);
	}

	std::string HexFile::WrongCheckSum::toString() const
	{
		return FormatableString("Wrong checksum (%0 instead of %1) at line %2").arg(computedCheckSum, 0, 16).arg(recordCheckSum, 0, 16).arg(line);
	}

	std::string HexFile::UnknownRecordType::toString() const
	{
		return FormatableString("Unknown record type (%1) at line %0").arg(line).arg(recordType, 0, 16);
	}

	std::string HexFile::FileOpeningError::toString() const
	{
		return FormatableString("Can't open file %0").arg(fileName);
	}

	unsigned HexFile::getUint4(std::istream &stream)
	{
		int c = stream.get();
		if (c <= '9')
			return c - '0';
		else if (c <= 'F')
			return c - 'A' + 10;
		else
			return c - 'a' + 10;
	}

	unsigned HexFile::getUint8(std::istream &stream)
	{
		return (getUint4(stream) << 4) | getUint4(stream);
	}

	unsigned HexFile::getUint16(std::istream &stream)
	{
		return (getUint8(stream) << 8) | getUint8(stream);
	}

	void HexFile::read(const std::string &fileName)
	{
		std::ifstream ifs(fileName.c_str());

		if (ifs.bad())
			throw FileOpeningError(fileName);

		int lineCounter = 0;
		uint32_t baseAddress = 0;

		while (ifs.good())
		{
			// leading ":" character
			char c;
			ifs >> c;
			if (c != ':')
				throw InvalidRecord(lineCounter);

			uint8_t computedCheckSum = 0;

			// record data length
			uint8_t dataLength = getUint8(ifs);
			computedCheckSum += dataLength;

			// short address
			uint16_t lowAddress = getUint16(ifs);
			computedCheckSum += lowAddress;
			computedCheckSum += lowAddress >> 8;

			// record type
			uint8_t recordType = getUint8(ifs);
			computedCheckSum += recordType;

			switch (recordType)
			{
				case 0:
				// data record
				{
					// read data
					std::vector<uint8_t> recordData;
					for (int i = 0; i != dataLength; i++)
					{
						uint8_t d = getUint8(ifs);
						computedCheckSum += d;
						recordData.push_back(d);
						//std::cout << "data " << std::hex << (unsigned)d << "\n";
					}

					// verify checksum
					uint8_t checkSum = getUint8(ifs);
					computedCheckSum = 1 + ~computedCheckSum;
					if (checkSum != computedCheckSum)
						throw WrongCheckSum(lineCounter, checkSum, computedCheckSum);

					// compute address
					uint32_t address = lowAddress;
					address += baseAddress;
					//std::cout << "data record at address 0x" << std::hex << address << "\n";

					// is some place to add
					bool found = false;
					for (auto & it : data)
					{
						size_t chunkSize = it.second.size();
						if (address == it.first + chunkSize)
						{
							// copy new
							std::copy(recordData.begin(), recordData.end(), std::back_inserter(it.second));
							found = true;
							//std::cout << "tail fusable chunk found\n";
							break;
						}
						else if (address + recordData.size() == it.first)
						{
							// resize
							it.second.resize(chunkSize + recordData.size());
							// move
							std::copy_backward(it.second.begin(), it.second.begin() + chunkSize, it.second.end());
							// copy new
							std::copy(recordData.begin(), recordData.end(), it.second.begin());
							found = true;
							//std::cout << "head fusable chunk found\n";
							break;
						}
					}
					if (!found)
						data[address] = recordData;
				}
				break;

				case 1:
				// end of file record
				for (auto it = data.begin(); it != data.end(); ++it)
				{
					//std::cout << "End of file found. Address " << it->first << " size " << it->second.size() << "\n";
				}
				ifs.close();
				return;
				break;

				case 2:
				// extended segment address record
				{
					if (dataLength != 2)
						throw InvalidRecord(lineCounter);

					// read data
					uint16_t highAddress = getUint16(ifs);
					computedCheckSum += highAddress;
					computedCheckSum += highAddress >> 8;
					baseAddress = highAddress;
					baseAddress <<= 4;
					//std::cout << "Extended segment address record (?!): 0x" << std::hex << baseAddress << "\n";

					// verify checksum
					uint8_t checkSum = getUint8(ifs);
					computedCheckSum = 1 + ~computedCheckSum;
					if (checkSum != computedCheckSum)
						throw WrongCheckSum(lineCounter, checkSum, computedCheckSum);
				}
				break;

				case 4:
				// extended linear address record
				{
					if (dataLength != 2)
						throw InvalidRecord(lineCounter);

					// read data
					uint16_t highAddress = getUint16(ifs);
					computedCheckSum += highAddress;
					computedCheckSum += highAddress >> 8;
					baseAddress = highAddress;
					baseAddress <<= 16;
					//std::cout << "Linear address record: 0x" << std::hex << baseAddress << "\n";

					// verify checksum
					uint8_t checkSum = getUint8(ifs);
					computedCheckSum = 1 + ~computedCheckSum;
					if (checkSum != computedCheckSum)
						throw WrongCheckSum(lineCounter, checkSum, computedCheckSum);
				}
				break;

				case 5: // start linear address record
				{
					// Start linear address record are not used by the Aseba
					// bootloader protocol so we can ignore them.

					// Skip data
					for (int i = 0; i < 4; i++)
						computedCheckSum += getUint8(ifs);

					computedCheckSum = 1 + ~computedCheckSum;

					uint8_t checkSum = getUint8(ifs);

					if (checkSum != computedCheckSum)
						throw WrongCheckSum(lineCounter, checkSum, computedCheckSum);
				}

				break;


				default:
				throw UnknownRecordType(lineCounter, recordType);
				break;
			}

			lineCounter++;
		}

		throw EarlyEOF(lineCounter);
	}

	void HexFile::writeExtendedLinearAddressRecord(std::ofstream &stream, unsigned addr16)
	{
		assert(addr16 <= 65535);

		uint8_t checkSum = 0;

		stream << ":02000004";
		checkSum += 0x02;
		checkSum += 0x00;
		checkSum += 0x00;
		checkSum += 0x04;

		stream << std::setw(2);
		stream << (addr16 >> 8);
		checkSum += (addr16 >> 8);

		stream << std::setw(2);
		stream << (addr16 & 0xFF);
		checkSum += (addr16 & 0xFF);

		checkSum = (~checkSum) + 1;
		stream << std::setw(2);
		stream << (unsigned)checkSum;

		stream << "\n";
	}

	void HexFile::writeData(std::ofstream &stream, unsigned addr16, unsigned count8, uint8_t *data)
	{
		assert(addr16 <= 65535);
		assert(count8 <= 255);

		uint8_t checkSum = 0;

		stream << ":";

		stream << std::setw(2);
		stream << count8;
		checkSum += count8;

		stream << std::setw(2);
		stream << (addr16 >> 8);
		checkSum += (addr16 >> 8);

		stream << std::setw(2);
		stream << (addr16 & 0xFF);
		checkSum += (addr16 & 0xFF);

		stream << "00";
		checkSum += 0x00;

		for (unsigned i = 0; i < count8; i++)
		{
			stream << std::setw(2);
			stream << (unsigned)data[i];
			checkSum += data[i];
		}

		checkSum = (~checkSum) + 1;
		stream << std::setw(2);
		stream << (unsigned)checkSum;

		stream << "\n";
	}

	void HexFile::strip(unsigned pageSize)
	{
		// Build a page map.
		typedef std::map<uint32_t, std::vector<uint8_t> > PageMap;
		PageMap pageMap;
		for (auto & it : data)
		{
			// get page number
			unsigned chunkAddress = it.first;
			// index inside data chunk
			unsigned chunkDataIndex = 0;
			// size of chunk in bytes
			unsigned chunkSize = it.second.size();

			// copy data from chunk to page
			do
			{
				// get page number
				unsigned pageIndex = (chunkAddress + chunkDataIndex) / pageSize;
				// get address inside page
				unsigned byteIndex = (chunkAddress + chunkDataIndex) % pageSize;

				// if page does not exists, create it
				if (pageMap.find(pageIndex) == pageMap.end())
				{
				//      std::cout << "New page N° " << pageIndex << " for address 0x" << std::hex << chunkAddress << endl;
					pageMap[pageIndex] = std::vector<uint8_t>(pageSize, (uint8_t)0xFF); // New page is created uninitialized
				}
				// copy data
				unsigned amountToCopy = std::min(pageSize - byteIndex, chunkSize - chunkDataIndex);
				copy(it.second.begin() + chunkDataIndex, it.second.begin() + chunkDataIndex + amountToCopy, pageMap[pageIndex].begin() + byteIndex);

				// increment chunk data pointer
				chunkDataIndex += amountToCopy;
			}
			while (chunkDataIndex < chunkSize);
		}

		// Now, for each page, drop it if empty
		data.clear();

		for(auto & it : pageMap)
		{
			int isempty = 1;
			unsigned int i;
			for(i = 0; i < pageSize; i+=4)
				if(it.second[i] != 0xff || it.second[i+1] != 0xff || it.second[i+2] != 0xff) {
					isempty = 0;
					break;
				}
			if(!isempty)
				data[it.first * pageSize] = it.second;
		}


	}

	void HexFile::write(const std::string &fileName) const
	{
		int first = 1;
		unsigned highAddress = 0;
		std::ofstream ofs(fileName.c_str());

		if (ofs.bad())
			throw FileOpeningError(fileName);

		// set format
		ofs.flags(std::ios::hex | std::ios::uppercase);
		ofs.fill('0');

		// for each chunk
		for (const auto & it : data)
		{
			// split address
			unsigned address = it.first;
			unsigned amount = it.second.size();

			for (unsigned count = 0; count < amount;)
			{
				// check if we have changed 64 K boundary, if so, write new high address
				unsigned newHighAddress = (address + count) >> 16;
				if (newHighAddress != highAddress || first)
					writeExtendedLinearAddressRecord(ofs, newHighAddress);
				first = 0;
				highAddress = newHighAddress;

				// write data
				unsigned rowCount = std::min(amount - count, (unsigned)16);
				unsigned lowAddress = (address + count) & 0xFFFF;
				std::valarray<uint8_t> buffer(rowCount);
				std::copy(it.second.begin() + count, it.second.begin() + count + rowCount, &buffer[0]);
				writeData(ofs, lowAddress, rowCount , &buffer[0]);

				// increment counters
				count += rowCount;
			}
		}

		// write EOF
		ofs << ":00000001FF";
	}
}

