#include "subdiv.h"
#include "units.h"
#include "trefile.h"


struct MapLevel {
	quint8 level;
	quint8 bits;
	quint16 subdivs;
};

static void unlock(quint8 *dst, const quint8 *src, quint32 size, quint32 key)
{
	static const unsigned char shuf[] = {
		0xb, 0xc, 0xa, 0x0,
		0x8, 0xf, 0x2, 0x1,
		0x6, 0x4, 0x9, 0x3,
		0xd, 0x5, 0x7, 0xe
	};

	int sum = shuf[((key >> 24) + (key >> 16) + (key >> 8) + key) & 0xf];

	for (quint32 i = 0, ringctr = 16; i < size; i++) {
		quint32 upper = src[i] >> 4;
		quint32 lower = src[i];

		upper -= sum;
		upper -= key >> ringctr;
		upper -= shuf[(key >> ringctr) & 0xf];
		ringctr = ringctr ? ringctr - 4 : 16;

		lower -= sum;
		lower -= key >> ringctr;
		lower -= shuf[(key >> ringctr) & 0xf];
		ringctr = ringctr ? ringctr - 4 : 16;

		dst[i] = ((upper << 4) & 0xf0) | (lower & 0xf);
	}
}

TREFile::~TREFile()
{
	SubDivTree::Iterator jt;

	for (QMap<int, SubDivTree*>::iterator it = _subdivs.begin();
	  it != _subdivs.end(); ++it) {
		SubDivTree *tree = *it;
		for (tree->GetFirst(jt); !tree->IsNull(jt); tree->GetNext(jt))
			delete tree->GetAt(jt);
	}

	for (QMap<int, SubDivTree*>::iterator it = _subdivs.begin();
	  it != _subdivs.end(); ++it)
		delete *it;
}

bool TREFile::init()
{
	Handle hdl;

	// Tile bounds
	qint32 north, east, south, west;
	if (!(seek(hdl, 0x15) && readInt24(hdl, north) && readInt24(hdl, east)
	  && readInt24(hdl, south) && readInt24(hdl, west)))
		return false;
	_bounds = RectC(Coordinates(toWGS84(west), toWGS84(north)),
	  Coordinates(toWGS84(east), toWGS84(south)));

	return true;
}

bool TREFile::init2()
{
	Handle hdl;
	quint8 locked;
	quint16 hdrLen;

	if (!(seek(hdl, 0) && readUInt16(hdl, hdrLen)
	  && seek(hdl, 0x0D) && readByte(hdl, locked)))
		return false;

	quint32 levelsOffset, levelsSize, subdivOffset, subdivSize;
	if (!(seek(hdl, 0x21) && readUInt32(hdl, levelsOffset)
	  && readUInt32(hdl, levelsSize) && readUInt32(hdl, subdivOffset)
	  && readUInt32(hdl, subdivSize)))
		return false;

	quint32 extOffset, extSize = 0;
	quint16 extItemSize = 0;
	if (hdrLen > 0x9A) {
		if (!(seek(hdl, 0x7C) && readUInt32(hdl, extOffset)
		  && readUInt32(hdl, extSize) && readUInt16(hdl, extItemSize)))
			return false;
	}

	// Tile levels
	if (levelsSize > 64 || !seek(hdl, levelsOffset))
		return false;
	quint8 levels[64];
	for (quint32 i = 0; i < levelsSize; i++)
		if (!readByte(hdl, levels[i]))
			return false;
	if (locked) {
		quint32 key;
		quint8 unlocked[64];
		if (!seek(hdl, 0xAA) || !readUInt32(hdl, key))
			return false;
		unlock(unlocked, levels, levelsSize, key);
		memcpy(levels, unlocked, levelsSize);
	}

	quint32 levelsCount = levelsSize / 4;
	QVector<MapLevel> ml(levelsCount);
	QMap<int, int> level2bits;

	for (quint32 i = 0; i < levelsCount; i++) {
		quint8 *zoom = levels + (i * 4);
		ml[i].level = *zoom;
		ml[i].bits = *(zoom + 1);
		ml[i].subdivs = *(zoom + 2) | (quint16)(*(zoom + 3)) << 8;
		if ((ml[i].level & 0xF) > 15 || ml[i].bits > 24)
			return false;

		level2bits.insert(ml[i].level & 0xF, ml[i].bits);
	}

	// Subdivisions
	if (!seek(hdl, subdivOffset))
		return false;
	SubDiv *s = 0;
	QList<SubDiv*> sl;

	for (int i = 0; i < ml.size(); i++) {
		if (!(ml.at(i).level & 0x80))
			_subdivs.insert(ml.at(i).bits, new SubDivTree());

		for (int j = 0; j < ml.at(i).subdivs; j++) {
			quint32 offset;
			qint32 lon, lat;
			quint8 objects;
			quint16 width, height, nextLevel;

			if (!(readUInt24(hdl, offset) && readByte(hdl, objects)
			  && readInt24(hdl, lon) && readInt24(hdl, lat)
			  && readUInt16(hdl, width) && readUInt16(hdl, height)))
				return false;
			if (i != (int)levelsCount - 1)
				if (!readUInt16(hdl, nextLevel))
					return false;

			if (s)
				s->setEnd(offset);

			if (ml.at(i).level & 0x80) {
				sl.append(0);
				s = 0;
				continue;
			}

			width &= 0x7FFF;
			width <<= (24 - ml.at(i).bits);
			height <<= (24 - ml.at(i).bits);

			s = new SubDiv(offset, lon, lat, ml.at(i).bits, objects);
			sl.append(s);

			double min[2], max[2];
			RectC bounds(Coordinates(toWGS84(lon - width),
			  toWGS84(lat + height + 1)), Coordinates(toWGS84(lon + width + 1),
			  toWGS84(lat - height)));

			min[0] = bounds.left();
			min[1] = bounds.bottom();
			max[0] = bounds.right();
			max[1] = bounds.top();
			_subdivs[ml.at(i).bits]->Insert(min, max, s);
		}
	}

	// objects with extended types (TRE7)
	if (extSize && extItemSize >= 12
	  && (sl.size() - (int)(extSize/extItemSize) + 1 >= 0)) {
		quint32 polygons, lines, points;
		if (!seek(hdl, extOffset))
			return false;

		for (int i = sl.size() - (extSize/extItemSize) + 1; i < sl.size(); i++) {
			if (!(readUInt32(hdl, polygons) && readUInt32(hdl, lines)
			  && readUInt32(hdl, points)))
				return false;
			if (!seek(hdl, hdl.pos + extItemSize - 12))
				return false;
			if (i && sl.at(i-1))
				sl.at(i-1)->setExtEnds(polygons, lines, points);
			if (sl.at(i))
				sl.at(i)->setExtOffsets(polygons, lines, points);
		}
	}

	_levels = _subdivs.keys();

	return true;
}

int TREFile::level(int bits)
{
	if (_levels.isEmpty() && !init2())
		return -1;

	int l = _levels.first();
	for (int i = 0; i < _levels.size(); i++) {
		if (_levels.at(i) > bits)
			break;
		else
			l = _levels.at(i);
	}

	return l;
}

static bool cb(SubDiv *subdiv, void *context)
{
	QList<SubDiv*> *list = (QList<SubDiv*>*)context;
	list->append(subdiv);
	return true;
}

QList<SubDiv*> TREFile::subdivs(const RectC &rect, int bits)
{
	QList<SubDiv*> list;
	SubDivTree *tree = _subdivs.value(level(bits));
	double min[2], max[2];

	min[0] = rect.left();
	min[1] = rect.bottom();
	max[0] = rect.right();
	max[1] = rect.top();

	if (tree)
		tree->Search(min, max, cb, &list);

	return list;
}