chd

const (
	// CodecNone indicates uncompressed data.
	CodecNone uint32 = 0x00000000

	// CodecZlib is the standard zlib codec ("zlib").
	CodecZlib uint32 = 0x7a6c6962

	// CodecLZMA is the LZMA codec ("lzma").
	CodecLZMA uint32 = 0x6c7a6d61

	// CodecHuff is the CHD Huffman codec ("huff").
	CodecHuff uint32 = 0x68756666

	// CodecFLAC is the FLAC audio codec ("flac").
	CodecFLAC uint32 = 0x666c6163

	// CodecZstd is the Zstandard codec ("zstd").
	CodecZstd uint32 = 0x7a737464

	// CodecCDZlib is the CD zlib codec ("cdzl").
	// Compresses CD data sectors with zlib, subchannel with zlib.
	CodecCDZlib uint32 = 0x63647a6c

	// CodecCDLZMA is the CD LZMA codec ("cdlz").
	// Compresses CD data sectors with LZMA, subchannel with zlib.
	CodecCDLZMA uint32 = 0x63646c7a

	// CodecCDFLAC is the CD FLAC codec ("cdfl").
	// Compresses CD audio sectors with FLAC, subchannel with zlib.
	CodecCDFLAC uint32 = 0x6364666c

	// CodecCDZstd is the CD Zstandard codec ("cdzs").
	// Compresses CD data sectors with Zstandard, subchannel with zlib.
	CodecCDZstd uint32 = 0x63647a73
)

const (
	// MaxCompMapLen is the maximum compressed map size (100MB).
	MaxCompMapLen = 100 * 1024 * 1024

	// MaxNumHunks is the maximum number of hunks (10M = ~200GB uncompressed).
	MaxNumHunks = 10_000_000

	// MaxMetadataLen is the maximum metadata entry size (16MB, matches 24-bit limit).
	MaxMetadataLen = 16 * 1024 * 1024

	// MaxNumTracks is the maximum number of tracks (200, generous for any disc).
	MaxNumTracks = 200

	// MaxMetadataEntries is the maximum metadata chain entries (prevents loops).
	MaxMetadataEntries = 1000
)

const (
	HunkCompTypeCodec0   = 0  // Compressed with compressor 0
	HunkCompTypeCodec1   = 1  // Compressed with compressor 1
	HunkCompTypeCodec2   = 2  // Compressed with compressor 2
	HunkCompTypeCodec3   = 3  // Compressed with compressor 3
	HunkCompTypeNone     = 4  // Uncompressed
	HunkCompTypeSelf     = 5  // Reference to another hunk in this CHD
	HunkCompTypeParent   = 6  // Reference to parent CHD
	HunkCompTypeRLESmall = 7  // RLE: repeat last compression type (small count)
	HunkCompTypeRLELarge = 8  // RLE: repeat last compression type (large count)
	HunkCompTypeSelf0    = 9  // Self reference to same hunk as last
	HunkCompTypeSelf1    = 10 // Self reference to last+1
	HunkCompTypeParSelf  = 11 // Parent reference to self
	HunkCompTypePar0     = 12 // Parent reference same as last
	HunkCompTypePar1     = 13 // Parent reference last+1
)

const (
	// MetaTagCHT2 is the CD Track v2 metadata tag ("CHT2")
	MetaTagCHT2 = 0x43485432

	// MetaTagCHCD is the CD metadata tag ("CHCD")
	MetaTagCHCD = 0x43484344

	// MetaTagCHTR is the CD Track v1 metadata tag ("CHTR")
	MetaTagCHTR = 0x43485452

	// MetaTagGDTR is the GD-ROM track metadata tag ("CHGD")
	MetaTagGDTR = 0x43484744
)