#include "Globals.h"
#include "ChunkSource.h"
#include <QThread>
#include "src/Generating/BioGen.h"
#include "src/StringCompression.h"
#include "src/WorldStorage/FastNBT.h"
#include "inifile/iniFile.h"





/** Map for converting biome values to colors. Initialized from biomeColors[]. */
static uchar biomeToColor[256 * 4];

/** Map for converting biome values to colors. Used to initialize biomeToColor[].*/
static struct
{
	EMCSBiome m_Biome;
	uchar m_Color[3];
} biomeColors[] =
{
	{ biOcean,                { 0x00, 0x00, 0x70 }, },
	{ biPlains,               { 0x8d, 0xb3, 0x60 }, },
	{ biDesert,               { 0xfa, 0x94, 0x18 }, },
	{ biExtremeHills,         { 0x60, 0x60, 0x60 }, },
	{ biForest,               { 0x05, 0x66, 0x21 }, },
	{ biTaiga,                { 0x0b, 0x66, 0x59 }, },
	{ biSwampland,            { 0x2f, 0xff, 0xda }, },
	{ biRiver,                { 0x30, 0x30, 0xaf }, },
	{ biHell,                 { 0x7f, 0x00, 0x00 }, },
	{ biSky,                  { 0x00, 0x7f, 0xff }, },
	{ biFrozenOcean,          { 0xa0, 0xa0, 0xdf }, },
	{ biFrozenRiver,          { 0xa0, 0xa0, 0xff }, },
	{ biIcePlains,            { 0xff, 0xff, 0xff }, },
	{ biIceMountains,         { 0xa0, 0xa0, 0xa0 }, },
	{ biMushroomIsland,       { 0xff, 0x00, 0xff }, },
	{ biMushroomShore,        { 0xa0, 0x00, 0xff }, },
	{ biBeach,                { 0xfa, 0xde, 0x55 }, },
	{ biDesertHills,          { 0xd2, 0x5f, 0x12 }, },
	{ biForestHills,          { 0x22, 0x55, 0x1c }, },
	{ biTaigaHills,           { 0x16, 0x39, 0x33 }, },
	{ biExtremeHillsEdge,     { 0x7f, 0x8f, 0x7f }, },
	{ biJungle,               { 0x53, 0x7b, 0x09 }, },
	{ biJungleHills,          { 0x2c, 0x42, 0x05 }, },

	{ biJungleEdge,           { 0x62, 0x8b, 0x17 }, },
	{ biDeepOcean,            { 0x00, 0x00, 0x30 },	},
	{ biStoneBeach,           { 0xa2, 0xa2, 0x84 },	},
	{ biColdBeach,            { 0xfa, 0xf0, 0xc0 },	},
	{ biBirchForest,          { 0x30, 0x74, 0x44 },	},
	{ biBirchForestHills,     { 0x1f, 0x5f, 0x32 },	},
	{ biRoofedForest,         { 0x40, 0x51, 0x1a },	},
	{ biColdTaiga,            { 0x31, 0x55, 0x4a },	},
	{ biColdTaigaHills,       { 0x59, 0x7d, 0x72 },	},
	{ biMegaTaiga,            { 0x59, 0x66, 0x51 },	},
	{ biMegaTaigaHills,       { 0x59, 0x66, 0x59 },	},
	{ biExtremeHillsPlus,     { 0x50, 0x70, 0x50 },	},
	{ biSavanna,              { 0xbd, 0xb2, 0x5f },	},
	{ biSavannaPlateau,       { 0xa7, 0x9d, 0x64 },	},
	{ biMesa,                 { 0xd9, 0x45, 0x15 },	},
	{ biMesaPlateauF,         { 0xb0, 0x97, 0x65 },	},
	{ biMesaPlateau,          { 0xca, 0x8c, 0x65 },	},

	// M variants:
	{ biSunflowerPlains,      { 0xb5, 0xdb, 0x88 }, },
	{ biDesertM,              { 0xff, 0xbc, 0x40 }, },
	{ biExtremeHillsM,        { 0x88, 0x88, 0x88 }, },
	{ biFlowerForest,         { 0x2d, 0x8e, 0x49 }, },
	{ biTaigaM,               { 0x33, 0x8e, 0x81 }, },
	{ biSwamplandM,           { 0x07, 0xf9, 0xb2 }, },
	{ biIcePlainsSpikes,      { 0xb4, 0xdc, 0xdc }, },
	{ biJungleM,              { 0x7b, 0xa3, 0x31 }, },
	{ biJungleEdgeM,          { 0x62, 0x8b, 0x17 }, },
	{ biBirchForestM,         { 0x58, 0x9c, 0x6c }, },
	{ biBirchForestHillsM,    { 0x47, 0x87, 0x5a }, },
	{ biRoofedForestM,        { 0x68, 0x79, 0x42 }, },
	{ biColdTaigaM,           { 0x24, 0x3f, 0x36 }, },
	{ biMegaSpruceTaiga,      { 0x45, 0x4f, 0x3e }, },
	{ biMegaSpruceTaigaHills, { 0x45, 0x4f, 0x4e }, },
	{ biExtremeHillsPlusM,    { 0x78, 0x98, 0x78 }, },
	{ biSavannaM,             { 0xe5, 0xda, 0x87 }, },
	{ biSavannaPlateauM,      { 0xa7, 0x9d, 0x74 }, },
	{ biMesaBryce,            { 0xff, 0x6d, 0x3d }, },
	{ biMesaPlateauFM,        { 0xd8, 0xbf, 0x8d }, },
	{ biMesaPlateauM,         { 0xf2, 0xb4, 0x8d }, },
} ;





static class BiomeColorsInitializer
{
public:
	BiomeColorsInitializer(void)
	{
		// Reset all colors to gray:
		for (size_t i = 0; i < ARRAYCOUNT(biomeToColor); i++)
		{
			biomeToColor[i] = 0x7f;
		}

		// Set known biomes to their colors:
		for (size_t i = 0; i < ARRAYCOUNT(biomeColors); i++)
		{
			uchar * color = &biomeToColor[4 * biomeColors[i].m_Biome];
			color[0] = biomeColors[i].m_Color[2];
			color[1] = biomeColors[i].m_Color[1];
			color[2] = biomeColors[i].m_Color[0];
			color[3] = 0xff;
		}
	}
} biomeColorInitializer;





/** Converts biomes in an array into the chunk image data. */
static void biomesToImage(cChunkDef::BiomeMap & a_Biomes, Chunk::Image & a_Image)
{
	// Make sure the two arrays are of the same size, compile-time.
	// Note that a_Image is actually 4 items per pixel, so the array is 4 times bigger:
	static const char Check1[4 * ARRAYCOUNT(a_Biomes) - ARRAYCOUNT(a_Image)      + 1] = {};
	static const char Check2[ARRAYCOUNT(a_Image)      - 4 * ARRAYCOUNT(a_Biomes) + 1] = {};

	// Convert the biomes into color:
	for (size_t i = 0; i < ARRAYCOUNT(a_Biomes); i++)
	{
		a_Image[4 * i + 0] = biomeToColor[4 * a_Biomes[i] + 0];
		a_Image[4 * i + 1] = biomeToColor[4 * a_Biomes[i] + 1];
		a_Image[4 * i + 2] = biomeToColor[4 * a_Biomes[i] + 2];
		a_Image[4 * i + 3] = biomeToColor[4 * a_Biomes[i] + 3];
	}
}





////////////////////////////////////////////////////////////////////////////////
// BioGenSource:

BioGenSource::BioGenSource(cIniFilePtr a_IniFile) :
	m_IniFile(a_IniFile),
	m_Mtx(QMutex::Recursive)
{
	reload();
}





void BioGenSource::getChunkBiomes(int a_ChunkX, int a_ChunkZ, ChunkPtr a_DestChunk)
{
	cChunkDef::BiomeMap biomes;
	{
		QMutexLocker lock(&m_Mtx);
		m_BiomeGen->GenBiomes(a_ChunkX, a_ChunkZ, biomes);
	}
	Chunk::Image img;
	biomesToImage(biomes, img);
	a_DestChunk->setImage(img);
}





void BioGenSource::reload()
{
	int seed = m_IniFile->GetValueSetI("Generator", "Seed", 0);
	bool unused = false;
	QMutexLocker lock(&m_Mtx);
	m_BiomeGen.reset(cBiomeGen::CreateBiomeGen(*m_IniFile, seed, unused));
}





////////////////////////////////////////////////////////////////////////////////
// AnvilSource::AnvilFile

class AnvilSource::AnvilFile
{
public:
	/** Coordinates of the region file. */
	int m_RegionX, m_RegionZ;

	/** True iff the file contains proper data. */
	bool m_IsValid;



	/** Creates a new instance with the specified region coords. Reads the file header. */
	AnvilFile(int a_RegionX, int a_RegionZ, const AString & a_WorldPath) :
		m_RegionX(a_RegionX),
		m_RegionZ(a_RegionZ),
		m_IsValid(false)
	{
		readFile(Printf("%s/r.%d.%d.mca", a_WorldPath.c_str(), a_RegionX, a_RegionZ));
	}



	/** Returns the compressed data of the specified chunk.
	Returns an empty string when chunk not present. */
	AString getChunkData(int a_ChunkX, int a_ChunkZ)
	{
		if (!m_IsValid)
		{
			return "";
		}

		// Translate to local coords:
		int RelChunkX = a_ChunkX - m_RegionX * 32;
		int RelChunkZ = a_ChunkZ - m_RegionZ * 32;
		ASSERT((RelChunkX >= 0) && (RelChunkX < 32));
		ASSERT((RelChunkZ >= 0) && (RelChunkZ < 32));

		// Get the chunk data location:
		UInt32 chunkOffset = m_Header[RelChunkX + 32 * RelChunkZ] >> 8;
		UInt32 numChunkSectors = m_Header[RelChunkX + 32 * RelChunkZ] & 0xff;
		if ((chunkOffset < 2) || (numChunkSectors == 0))
		{
			return "";
		}

		// Get the real data size:
		const char * chunkData = m_FileData.data() + chunkOffset * 4096;
		UInt32 chunkSize = GetBEInt(chunkData);
		if ((chunkSize < 2) || (chunkSize / 4096 > numChunkSectors))
		{
			// Bad data, bail out
			return "";
		}

		// Check the compression method:
		if (chunkData[4] != 2)
		{
			// Chunk is in an unknown compression
			return "";
		}
		chunkSize--;

		// Read the chunk data:
		return m_FileData.substr(chunkOffset * 4096 + 5, chunkSize);
	}

protected:
	AString m_FileData;
	UInt32 m_Header[2048];


	/** Reads the whole specified file contents and parses the header. */
	void readFile(const AString & a_FileName)
	{
		// Read the entire file:
		m_FileData = cFile::ReadWholeFile(a_FileName);
		if (m_FileData.size() < sizeof(m_Header))
		{
			return;
		}

		// Parse the header - change endianness:
		const char * hdr = m_FileData.data();
		for (size_t i = 0; i < ARRAYCOUNT(m_Header); i++)
		{
			m_Header[i] = GetBEInt(hdr + 4 * i);
		}
		m_IsValid = true;
	}
};





////////////////////////////////////////////////////////////////////////////////
// AnvilSource:

AnvilSource::AnvilSource(QString a_WorldRegionFolder) :
	m_WorldRegionFolder(a_WorldRegionFolder)
{
}





void AnvilSource::getChunkBiomes(int a_ChunkX, int a_ChunkZ, ChunkPtr a_DestChunk)
{
	// Load the compressed data:
	AString compressedChunkData = getCompressedChunkData(a_ChunkX, a_ChunkZ);
	if (compressedChunkData.empty())
	{
		return;
	}

	// Uncompress the chunk data:
	AString uncompressed;
	int res = InflateString(compressedChunkData.data(), compressedChunkData.size(), uncompressed);
	if (res != Z_OK)
	{
		return;
	}

	// Parse the NBT data:
	cParsedNBT nbt(uncompressed.data(), uncompressed.size());
	if (!nbt.IsValid())
	{
		return;
	}

	// Get the biomes out of the NBT:
	int Level = nbt.FindChildByName(0, "Level");
	if (Level < 0)
	{
		return;
	}
	cChunkDef::BiomeMap biomeMap;
	int mcsBiomes = nbt.FindChildByName(Level, "MCSBiomes");
	if ((mcsBiomes >= 0) && (nbt.GetDataLength(mcsBiomes) == sizeof(biomeMap)))
	{
		// Convert the biomes from BigEndian to platform native numbers:
		const char * beBiomes = nbt.GetData(mcsBiomes);
		for (size_t i = 0; i < ARRAYCOUNT(biomeMap); i++)
		{
			biomeMap[i] = (EMCSBiome)GetBEInt(beBiomes + 4 * i);
		}
		// Render the biomes:
		Chunk::Image img;
		biomesToImage(biomeMap, img);
		a_DestChunk->setImage(img);
		return;
	}

	// MCS biomes not found, load Vanilla biomes instead:
	int biomes = nbt.FindChildByName(Level, "Biomes");
	if ((biomes < 0) || (nbt.GetDataLength(biomes) != ARRAYCOUNT(biomeMap)))
	{
		return;
	}
	// Convert the biomes from Vanilla to EMCSBiome:
	const char * vanillaBiomes = nbt.GetData(biomes);
	for (size_t i = 0; i < ARRAYCOUNT(biomeMap); i++)
	{
		biomeMap[i] = EMCSBiome(vanillaBiomes[i]);
	}
	// Render the biomes:
	Chunk::Image img;
	biomesToImage(biomeMap, img);
	a_DestChunk->setImage(img);
}





void AnvilSource::reload()
{
	// Remove all files from the cache:
	QMutexLocker lock(&m_Mtx);
	m_Files.clear();
}





void AnvilSource::chunkToRegion(int a_ChunkX, int a_ChunkZ, int & a_RegionX, int & a_RegionZ)
{
	a_RegionX = a_ChunkX >> 5;
	a_RegionZ = a_ChunkZ >> 5;
}





AString AnvilSource::getCompressedChunkData(int a_ChunkX, int a_ChunkZ)
{
	return getAnvilFile(a_ChunkX, a_ChunkZ)->getChunkData(a_ChunkX, a_ChunkZ);
}





AnvilSource::AnvilFilePtr AnvilSource::getAnvilFile(int a_ChunkX, int a_ChunkZ)
{
	int RegionX, RegionZ;
	chunkToRegion(a_ChunkX, a_ChunkZ, RegionX, RegionZ);

	// Search the cache for the file:
	QMutexLocker lock(&m_Mtx);
	for (auto itr = m_Files.cbegin(), end = m_Files.cend(); itr != end; ++itr)
	{
		if (((*itr)->m_RegionX == RegionX) && ((*itr)->m_RegionZ == RegionZ))
		{
			// Found the file in the cache, move it to front and return it:
			AnvilFilePtr file(*itr);
			m_Files.erase(itr);
			m_Files.push_front(file);
			return file;
		}
	}

	// File not in cache, create it:
	AnvilFilePtr file(new AnvilFile(RegionX, RegionZ, m_WorldRegionFolder.toStdString()));
	m_Files.push_front(file);
	return file;
}