/*
 * scribiu -- read notebooks and voice memos from Livescribe pens
 * Copyright (C) 2015 Javier S. Pedro <javier@javispedro.com>
 *
 * This file contains parts of:
 * libsmartpen -- library for communicating with the Livescribe Pulse Smartpen
 * Copyright (C) 2010 Steven Walter
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <QtCore/QDebug>
#include <QtCore/QFile>

#include "stfreader.h"

#define TABLE_v(i, ...) static qint8 tab_ ## i [] = { __VA_ARGS__ }
#define TABLE static CodeTable table[] = {
#define TABLE_i(i) {i, sizeof(tab_ ## i), tab_ ## i},
#define END_TABLE }; static int table_size = sizeof(table) / sizeof(CodeTable);

StfReader::StfReader()
: handler(0)
{
}

StfReader::~StfReader()
{
}

StfReader::StrokeHandler::~StrokeHandler()
{
}

bool StfReader::parseV1(BitReader& br)
{
	quint64 cur_time = 0;

	while (!br.atEnd()) {
		syncV1(br);
		quint8 header = br.readBits(8);
		quint64 time;
		QPoint p0, pa;
		int f0;

		switch (header) {
		case 0x80: /* End of file. */
			return true;
			break;
		case 0:
			time = br.readBits(8);
			break;
		case 0x08:
			time = br.readBits(16);
			break;
		case 0x10:
			time = br.readBits(32);
			break;
		case 0x18:
			time = br.readBits(64);
			break;
		default:
			qWarning("Unknown header 0x%x", header);
			return false;
		}

		/* Start of a stroke. */
		cur_time += time;
		p0.setX(br.readBits(16));
		p0.setY(br.readBits(16));
		f0 = readForce(br);

		quint64 stroke_time = cur_time;

		if (handler) {
			bool res = handler->startStroke(p0, f0, cur_time);
			if (!res) return false;
		}

		while (!br.atEnd()) {
			header = readHeader(br);
			if (header == 0 || header == 1) {
				time = readTime(br);
			} else {
				int header2 = readHeader2(br);
				switch (header2) {
				case 0:
					time = br.readBits(8);
					break;
				case 1:
					time = br.readBits(16);
					break;
				case 2:
					time = br.readBits(32);
					break;
				default:
					qWarning("Unknown stroke time header %d", header2);
					return false;
				}
			}

			if (time == 0) {
				if (handler) {
					bool res = handler->endStroke(stroke_time);
					if (!res) return false;
				}
				break;
			}

			bool do_delta;
			QPoint delta;
			qint8 deltaf;

			if (header > 0) {
				bool have_len = br.readBits(1);
				if (have_len) {
					do_delta = false;
					QPoint p1;
					p1.setX(br.readBits(16));
					p1.setY(br.readBits(16));
					pa = p1 - p0;
				} else {
					do_delta = true;
					delta.setX(br.readSignedBits(8));
					delta.setY(br.readSignedBits(8));
				}
			} else {
				do_delta = true;
				delta.setX(readDeltaX(br));
				delta.setY(readDeltaY(br));
			}

			deltaf = readDeltaF(br);

			if (do_delta) {
				pa = delta + (pa * static_cast<int>(time)) / 256;
			}

			p0 += pa;
			pa *= 256 / static_cast<int>(time);
			f0 += deltaf;

			stroke_time += time;

			if (handler) {
				bool res = handler->strokePoint(p0, f0, stroke_time);
				if (!res) return false;
			}
		}
	}

	return false;
}

void StfReader::syncV1(BitReader &br)
{
	br.skipUntilNextByte();
	while (!br.atEnd() && (br.peekBits(8) & ~(0x80|0x10|0x08))) {
		br.readBits(8);
	}
}

qint8 StfReader::decodeV1(BitReader& br, CodeTable* tab, int tab_size)
{
	int got_bits = 0;
	int codeacc = 0;
	int stream = 0;

	for (int i = 0; i < tab_size; i++) {
		int get_bits = tab[i].bits - got_bits;
		codeacc <<= get_bits;
		codeacc += tab[i].size;

		stream <<= get_bits;
		stream |= br.readBits(get_bits);

		got_bits += get_bits;

		int idx = stream - codeacc;
		if (idx < 0) {
			idx = tab[i].size + idx;
			Q_ASSERT(idx >= 0 && idx < tab[i].size);
			return tab[i].data[idx];
		}
	}

	qWarning("Unknown code");
	return 0;
}

qint8 StfReader::readForce(BitReader &br)
{
	TABLE_v(1, 0);
	TABLE_v(6, 1,4,7,9,10,11,13,15,17,20,21,22,23,24,25,26,27,28,30);
	TABLE_v(7, 2,3,5,6,8,12,14,16,18,19,29,31,32,33,34,35,36,49,52);
	TABLE_v(8, 37,45,46,47,48,50,51,53,54);
	TABLE_v(9, 38,39,40,41,44,55,56);
	TABLE_v(10, 43,57,58);
	TABLE_v(11, 42,59,60,61,62,63);
	TABLE
		TABLE_i(1) TABLE_i(6) TABLE_i(7) TABLE_i(8) TABLE_i(9) TABLE_i(10) TABLE_i(11)
	END_TABLE

	return decodeV1(br, table, table_size);
}

qint8 StfReader::readHeader(BitReader &br)
{
	TABLE_v(1, 0);
	TABLE_v(2, 1, 2);
	TABLE
		 TABLE_i(1) TABLE_i(2)
	END_TABLE

	return decodeV1(br, table, table_size);
}

qint8 StfReader::readHeader2(BitReader &br)
{
	TABLE_v(1, 0);
	TABLE_v(2, 1, 3);
	TABLE
		 TABLE_i(1) TABLE_i(2)
	END_TABLE

	return decodeV1(br, table, table_size);
}

qint8 StfReader::readHeader3(BitReader &br)
{
	TABLE_v(1, 0,1);
	TABLE
		 TABLE_i(1)
	END_TABLE

	return decodeV1(br, table, table_size);
}

qint8 StfReader::readTime(BitReader &br)
{
	TABLE_v(1, 1);
	TABLE_v(2, 2);
	TABLE_v(4, 0,3,4);
	TABLE_v(6, 5,6);
	TABLE_v(7, 7,8);
	TABLE_v(8, 9);
	TABLE_v(9, 10,11);
	TABLE_v(10, 12,13,14);
	TABLE_v(11, 15);
	TABLE_v(12, 16,17,18,19,21,22);
	TABLE_v(13, 20,23,24,25,26,27);
	TABLE_v(14, 28,29,30,31,32,35,36,37,40);
	TABLE_v(15, 38,39,41,44,45,48,50,53,59,60,67,73,82,91,98,99,102);
	TABLE_v(16, 33,34,42,43,46,47,49,51,52,54,55,56,57,58,61,62,63,64,65,66,68,69,70,71,72,74,75,76,77,78,79,80,81,83,84,85,86,87,88,89,90,92,93,94,95,96,97,100,101,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127);
	TABLE
		TABLE_i(1) TABLE_i(2) TABLE_i(4) TABLE_i(6) TABLE_i(7) TABLE_i(8)
		TABLE_i(9) TABLE_i(10) TABLE_i(11) TABLE_i(12) TABLE_i(13) TABLE_i(14)
		TABLE_i(15) TABLE_i(16)
	END_TABLE

	return decodeV1(br, table, table_size);
}

qint8 StfReader::readDeltaX(BitReader &br)
{
	TABLE_v(4, 3,4,5);
	TABLE_v(5, 0,1,2,6,7,8,9,-8,-7,-6,-5,-4,-3,-2,-1);
	TABLE_v(6, 10,11,12,13,-13,-12,-11,-10,-9);
	TABLE_v(7, 14,15,16,17,18,19,-18,-17,-16,-15,-14);
	TABLE_v(8, 20,21,22,23,24,26,-25,-24,-23,-22,-21,-20,-19);
	TABLE_v(9, 25,27,28,29,30,31,32,33,34,36,38,-36,-34,-33,-32,-31,-30,-29,-28,-27,-26);
	TABLE_v(10, 35,37,39,40,41,42,43,44,45,46,47,49,55,-57,-50,-47,-46,-44,-43,-42,-41,-40,-39,-38,-37,-35);
	TABLE
		TABLE_i(4) TABLE_i(5) TABLE_i(6) TABLE_i(7) TABLE_i(8) TABLE_i(9) TABLE_i(10)
	END_TABLE

	return decodeV1(br, table, table_size);
}

qint8 StfReader::readDeltaY(BitReader &br)
{
	TABLE_v(5, 0,1,2,3,4,5,6,7,8,-9,-8,-7,-6,-5,-4,-3,-2,-1);
	TABLE_v(6, 9,10,11,12,13,-14,-13,-12,-11,-10);
	TABLE_v(7, 14,15,16,17,18,19,20,-20,-19,-18,-17,-16,-15);
	TABLE_v(8, 21,22,23,24,25,26,27,28,29,30,31,-27,-26,-25,-24,-23,-22,-21);
	TABLE_v(9, 32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,49,-45,-44,-43,-40,-39,-38,-37,-36,-35,-34,-33,-32,-31,-30,-29,-28);
	TABLE_v(10, 47,48,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,66,67,68,69,71,72,73,78,85,-75,-69,-64,-62,-61,-60,-59,-58,-57,-56,-55,-54,-53,-52,-51,-50,-49,-48,-47,-46,-42,-41);

	TABLE
		TABLE_i(5) TABLE_i(6) TABLE_i(7) TABLE_i(8) TABLE_i(9) TABLE_i(10)
	END_TABLE

	return decodeV1(br, table, table_size);
}

qint8 StfReader::readDeltaF(BitReader &br)
{
	TABLE_v(1, 0);
	TABLE_v(3, 1);
	TABLE_v(4, -1);
	TABLE_v(5, 2,-2);
	TABLE_v(6, 3,-3);
	TABLE_v(7, 4,52,53,-4);
	TABLE_v(8, 5,6,49,50,51,54,55,-17,-16,-15,-14,-13,-12,-7,-6,-5);
	TABLE_v(9, 7,8,9,10,11,12,13,30,31,36,37,38,39,40,41,46,48,56,57,-56,-55,-54,-53,-52,-51,-50,-49,-40,-38,-21,-20,-19,-18,-11,-10,-9,-8);
	TABLE_v(10, 14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,32,33,34,35,42,43,44,45,47,58,-57,-48,-47,-46,-45,-44,-43,-42,-41,-39,-37,-36,-35,-34,-33,-32,-31,-29,-28,-27,-26,-25,-24,-23,-22);
	TABLE_v(11, -59,-58,-30);
	TABLE_v(12, 59,-64);
	TABLE_v(13, 60,61,62,63,-63,-62,-61,-60);
	TABLE
		TABLE_i(1) TABLE_i(3) TABLE_i(4) TABLE_i(5) TABLE_i(6) TABLE_i(7)
		TABLE_i(8) TABLE_i(9) TABLE_i(10) TABLE_i(11) TABLE_i(12) TABLE_i(13)
	END_TABLE

	return decodeV1(br, table, table_size);
}

bool StfReader::parse(QIODevice *device)
{
	char magic;
	if (!device->getChar(&magic)) return false;
	if (magic != 0x1) return false;
	if (!device->getChar(&magic)) return false;
	if (magic != 0x0) return false;

	QString version(device->read(14));
	if (version != "Anoto STF v1.0") {
		return false;
	}

	BitReader br(device);

	speed = br.readBits(16);

	return parseV1(br);
}

bool StfReader::parse(const QString &filename)
{
	QFile f(filename);
	if (!f.open(QIODevice::ReadOnly)) {
		qWarning() << "Could not open" << f.fileName();
	}
	return parse(&f);
}

void StfReader::setStrokeHandler(StrokeHandler *newHandler)
{
	Q_ASSERT(newHandler);
	handler = newHandler;
}