// Display (Crystalfontz CFA-635 USB LCD)
//
// Douglas Thrift
//
// $Id$

#include <foreach.hpp>
#include <scopes.hpp>

#include <iomanip>
#include <iostream>

#include <fcntl.h>
#include <termios.h>

#include "Display.hpp"

extern bool debug;

static uint16_t GetCRC(uint8_t *buffer, size_t length)
{
	static const uint16_t table[256] = {
		0x00000, 0x01189, 0x02312, 0x0329b, 0x04624, 0x057ad, 0x06536, 0x074bf,
		0x08C48, 0x09DC1, 0x0AF5A, 0x0BED3, 0x0CA6C, 0x0DBE5, 0x0E97E, 0x0F8F7,
		0x01081, 0x00108, 0x03393, 0x0221a, 0x056a5, 0x0472c, 0x075b7, 0x0643e,
		0x09CC9, 0x08D40, 0x0BFDB, 0x0AE52, 0x0DAED, 0x0CB64, 0x0F9FF, 0x0E876,
		0x02102, 0x0308b, 0x00210, 0x01399, 0x06726, 0x076af, 0x04434, 0x055bd,
		0x0AD4A, 0x0BCC3, 0x08E58, 0x09FD1, 0x0EB6E, 0x0FAE7, 0x0C87C, 0x0D9F5,
		0x03183, 0x0200a, 0x01291, 0x00318, 0x077a7, 0x0662e, 0x054b5, 0x0453c,
		0x0BDCB, 0x0AC42, 0x09ED9, 0x08F50, 0x0FBEF, 0x0EA66, 0x0D8FD, 0x0C974,
		0x04204, 0x0538d, 0x06116, 0x0709f, 0x00420, 0x015a9, 0x02732, 0x036bb,
		0x0ce4c, 0x0dfc5, 0x0ed5e, 0x0fcd7, 0x08868, 0x099e1, 0x0ab7a, 0x0baf3,
		0x05285, 0x0430c, 0x07197, 0x0601e, 0x014a1, 0x00528, 0x037b3, 0x0263a,
		0x0decd, 0x0cf44, 0x0fddf, 0x0ec56, 0x098e9, 0x08960, 0x0bbfb, 0x0aa72,
		0x06306, 0x0728f, 0x04014, 0x0519d, 0x02522, 0x034ab, 0x00630, 0x017b9,
		0x0EF4E, 0x0FEC7, 0x0CC5C, 0x0DDD5, 0x0A96A, 0x0B8E3, 0x08A78, 0x09BF1,
		0x07387, 0x0620e, 0x05095, 0x0411c, 0x035a3, 0x0242a, 0x016b1, 0x00738,
		0x0FFCF, 0x0EE46, 0x0DCDD, 0x0CD54, 0x0B9EB, 0x0A862, 0x09AF9, 0x08B70,
		0x08408, 0x09581, 0x0a71a, 0x0b693, 0x0c22c, 0x0d3a5, 0x0e13e, 0x0f0b7,
		0x00840, 0x019c9, 0x02b52, 0x03adb, 0x04e64, 0x05fed, 0x06d76, 0x07cff,
		0x09489, 0x08500, 0x0b79b, 0x0a612, 0x0d2ad, 0x0c324, 0x0f1bf, 0x0e036,
		0x018c1, 0x00948, 0x03bd3, 0x02a5a, 0x05ee5, 0x04f6c, 0x07df7, 0x06c7e,
		0x0a50a, 0x0b483, 0x08618, 0x09791, 0x0e32e, 0x0f2a7, 0x0c03c, 0x0d1b5,
		0x02942, 0x038cb, 0x00a50, 0x01bd9, 0x06f66, 0x07eef, 0x04c74, 0x05dfd,
		0x0b58b, 0x0a402, 0x09699, 0x08710, 0x0f3af, 0x0e226, 0x0d0bd, 0x0c134,
		0x039C3, 0x0284A, 0x01AD1, 0x00B58, 0x07FE7, 0x06E6E, 0x05CF5, 0x04D7C,
		0x0c60c, 0x0d785, 0x0e51e, 0x0f497, 0x08028, 0x091a1, 0x0a33a, 0x0b2b3,
		0x04a44, 0x05bcd, 0x06956, 0x078df, 0x00c60, 0x01de9, 0x02f72, 0x03efb,
		0x0d68d, 0x0c704, 0x0f59f, 0x0e416, 0x090a9, 0x08120, 0x0b3bb, 0x0a232,
		0x05AC5, 0x04B4C, 0x079D7, 0x0685E, 0x01CE1, 0x00D68, 0x03FF3, 0x02E7A,
		0x0e70e, 0x0f687, 0x0c41c, 0x0d595, 0x0a12a, 0x0b0a3, 0x08238, 0x093b1,
		0x06b46, 0x07acf, 0x04854, 0x059dd, 0x02d62, 0x03ceb, 0x00e70, 0x01ff9,
		0x0f78f, 0x0e606, 0x0d49d, 0x0c514, 0x0b1ab, 0x0a022, 0x092b9, 0x08330,
		0x07BC7, 0x06A4E, 0x058D5, 0x0495C, 0x03DE3, 0x02C6A, 0x01EF1, 0x00F78,
	};
	register uint16_t crc(0xffff);

	while (length--)
		crc = (crc >> 8) ^ table[(crc ^ *buffer++) & 0xff];

	return ~crc;
}

Display::Packet::Packet(Display::Packet::Command command, uint8_t length, const uint8_t *data) : command(command), length(length)
{
	if (length > sizeof (this->data))
		throw;

	::memcpy(this->data, data, length);

	crc = GetCRC(reinterpret_cast<uint8_t *>(this), length + 2);
}

std::ostream &operator<<(std::ostream &output, const Display::Packet &packet)
{
	return output << _B("0x") << std::hex << std::setw(2) << std::setfill('0') << unsigned(packet.command) << _B(" [") << packet.GetData() << ']';
}

void operator<<(int fd, const Display::Packet &packet)
{
	if (packet.length != sizeof (packet.data))
		::memcpy(const_cast<uint8_t *>(packet.data) + packet.length, &packet.crc, 2);

	if (debug)
		std::cerr << _B("<< ") << packet << std::endl;

	Posix::Write(fd, &packet, packet.length + 4);
}

void operator>>(int fd, Display::Packet &packet)
{
	Posix::Read(fd, &packet, 2);
	Posix::Read(fd, packet.data, packet.length);
	Posix::Read(fd, &packet.crc, 2);

	if (debug)
		std::cerr << _B(">> ") << packet << std::endl;
}

void Communicate(Display *display)
{
	display->Communicate_();
}

Display::Display(const std::string &device) : ucom(Posix::Open(device, O_RDWR | O_NOCTTY | O_NONBLOCK)), ucomCondition(ucomLock), running(true), responsesCondition(responsesLock), thread(reinterpret_cast<void *(*)(void *)>(::Communicate), this)
{
	::termios state;

	Posix::CheckError(::tcgetattr(ucom, &state));
	Posix::CheckError(::cfsetospeed(&state, B115200));
	Posix::CheckError(::cfsetispeed(&state, B115200));

	state.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | INPCK | ISTRIP | INLCR | IGNCR | ICRNL | IXON | IXOFF);
	state.c_iflag |= IGNPAR;
	state.c_oflag &= ~(OPOST | ONLCR | ONOCR | ONLRET);
	state.c_cflag &= ~(CSIZE | PARENB | PARODD | HUPCL | CRTSCTS);
	state.c_cflag |= CREAD | CS8 | CSTOPB | CLOCAL;
	state.c_lflag &= ~(ISIG | ICANON | IEXTEN | ECHO);
	state.c_lflag |= NOFLSH;

	Posix::CheckError(::tcsetattr(ucom, TCSANOW, &state));

	_synchronized (ucomLock)
		ucomCondition.Signal();
}

Display::~Display()
{
	running = false;

	thread.Join();

	Posix::Close(ucom);
}

void Display::Communicate_()
{
	_synchronized (ucomLock)
		ucomCondition.Wait();

	while (running)
	{
		Packet response;

		_synchronized (ucomLock)
			try
			{
				ucom >> response;
			}
			catch (const Posix::Error error)
			{
				if (error.what() != _B("Resource temporarily unavailable"))
					throw error;

				goto next;
			}

		if ((response.command & Packet::Error) == Packet::Error);
		else if ((response.command & Packet::Report) == Packet::Report)
			switch (response.command)
			{
			case Packet::KeyActivity:
				_synchronized (keyActivityLock)
					keyActivity.push(response);

				break;
			case Packet::FanSpeedReport:
			case Packet::TemperatureSensorReport:
				break;
			}
		else if ((response.command & Packet::Response) == Packet::Response)
			_synchronized (responsesLock)
			{
				responses.push(response);
				responsesCondition.Signal();
			}

next:	::usleep(500);
	}
}

Display::Packet Display::Communicate_(Display::Packet::Command command, uint8_t length, const uint8_t *data)
{
	Packet packet(command, length, data);

	_synchronized (ucomLock)
		ucom << packet;

	_synchronized (responsesLock)
	{
		while (responses.empty())
			responsesCondition.Wait();

		Packet response(responses.front());

		responses.pop();

		assert ((packet.command | Packet::Response) == response.command);

		return response;
	}

	throw;
}

bool Display::Ping(const std::string &data)
{
	return data == Communicate<const std::string &>(Packet::PingCommand, data).GetData();
}

std::string Display::Version()
{
	return Communicate(Packet::GetHardwareAndFirmwareVersion).GetData();
}

void Display::Set(uint8_t column, uint8_t row, const std::string &data)
{
	Communicate(Packet::SendDataToLCD, column, row, data);
}

Display::KeyActivity Display::GetKeyActivity()
{
	_synchronized (keyActivityLock)
		if (keyActivity.size())
		{
			KeyActivity activity(KeyActivity(*keyActivity.front().data));

			keyActivity.pop();

			return activity;
		}

	return None;
}