#ifndef DNGINFO_TIFF_H
#define DNGINFO_TIFF_H

#include <string>
#include <memory>
#include <cstdint>
#include <vector>
#include <map>
#include <variant>

constexpr int16_t TIFF_MAGIC = 42;

enum ByteOrder: uint16_t {
	LE = 0x4949,
	BE = 0x4d4d
};

enum FieldType: uint16_t {
	BYTE        = 1,
	ASCII       = 2,
	SHORT       = 3,
	LONG        = 4,
	RATIONAL    = 5,
	SBYTE       = 6,
	UNDEFINED   = 7,
	SSHORT      = 8,
	SLONG       = 9,
	SRATIONAL   = 10,
	FLOAT       = 11,
	DOUBLE      = 12
};

enum TiffTag: uint16_t {
	NEW_SUBFILE_TYPE = 0xFE,
	IMAGE_WIDTH = 0x100,
	IMAGE_LENGTH = 0x101,
	BITS_PER_SAMPLE = 0x102,
	COMPRESSION = 0x103,
	PHOTOMETRIC_INTERPRETATION = 0x106,
	IMAGE_DESCRIPTION = 0x10E,
	MANUFACTURER = 0x10F,
	MODEL = 0x110,
	STRIP_OFFSETS = 0x111,
	ORIENTATION = 0x112,
	SAMPLES_PER_PIXEL = 0x115,
	ROWS_PER_STRIP = 0x116,
	STRIP_BYTE_COUNTS = 0x117,
	X_RESOLUTION = 0x11A,
	Y_RESOLUTION = 0x11B,
	PLANAR_CONFIGURATION = 0x11C,
	RESOLUTION_UNIT = 0x128,
	SOFTWARE = 0x131,
	DATE_TIME = 0x132,
	XML_PACKET = 0x2BC,
    CFA_REPEAT_PATTERN_DIM = 0x828D,
    CFA_PATTERN = 0x828E,
    EXPOSURE_TIME = 0x829A,
    F_NUMBER = 0x829D,
    EXIF_IFD = 0x8769,
    ISO_SPEED_RATINGS = 0x8827,
    DATE_TIME_ORIGINAL = 0x9003,
    FOCAL_LENGTH = 0x920A,
    TIFF_EP_STANDARD_ID = 0x9216

};

enum PhotometricInterpretation: uint16_t {
	WHITE_IS_ZERO = 0,
	BLACK_IS_ZERO = 1,
	RGB = 2,
	PALETTE_COLOR = 3,
	TRANSPARENCY_MASK = 4,
	YCBCR = 6,
	COLOR_FILTER_ARRAY = 32803,
	LINEAR_RAW = 34892
};

enum Compression: uint16_t {
	NO_COMPRESSION = 1,
	HUFFMAN = 2,
	PACK_BITS = 32773
};

enum ResolutionUnit: uint16_t {
	NO_UNIT = 1,
	INCH = 2,
	CENTIMETER = 3
};

enum Orientation: uint16_t {
	NORMAL = 1,
	FLIP_HORIZONTAL = 2,
	FLIP_BOTH = 3,
	FLIP_VERTICAL = 4,
	NORMAL_ROTATED = 5,
	FLIP_HORIZONTAL_ROTATED = 6,
	FLIP_BOTH_ROTATED = 7,
	FLIP_VERTICAL_ROTATED = 8
};

enum PlanarConfiguration : uint16_t {
	CHUNKY = 1,
	PLANAR = 2
};

struct TIFFHeader {
	ByteOrder byteOrder;
	uint16_t magic;
	uint32_t firstIfdOffset;
};

struct IfdEntry {
	TiffTag tag;
	FieldType type;
	uint32_t numberOfValues;
	uint32_t valueOrOffset;
};

template <typename T>
struct RationalType {
	T numerator;
	T denominator;
};

using Rational = RationalType<uint32_t>;
using SRational = RationalType<int32_t>;

enum CFAPatternDim: uint16_t {};
enum CFAPattern: uint8_t {
    RED = 0,
    GREEN = 1,
    BLUE = 2,
    CYAN = 3,
    MAGENTA = 4,
    YELLOW = 5,
    WHITE = 6
};

std::ostream& operator<<(std::ostream& stream, Compression compression);
std::ostream& operator<<(std::ostream& stream, PhotometricInterpretation pr);
template<typename T> std::ostream& operator<<(std::ostream& stream, const RationalType<T>& rational);
std::ostream& operator<<(std::ostream& stream, ResolutionUnit unit);
std::ostream& operator<<(std::ostream& stream, Orientation orientation);
std::ostream& operator<<(std::ostream& stream, PlanarConfiguration conf);
template<typename T> std::ostream& operator<<(std::ostream& stream, const std::vector<T>& vector);

class ImageFileDirectory {
public:
    using EntryValueType = std::variant<uint8_t, uint16_t, uint32_t, Rational, int8_t, int16_t, int32_t, SRational, float, double, std::string,
            Compression, PhotometricInterpretation, std::vector<Compression>, std::vector<PhotometricInterpretation>,
            ResolutionUnit, std::vector<ResolutionUnit>, Orientation, std::vector<Orientation>,
            PlanarConfiguration, std::vector<PlanarConfiguration>,
            CFAPatternDim, std::vector<CFAPatternDim>,
            CFAPattern, std::vector<CFAPattern>,
            std::vector<uint8_t>, std::vector<uint16_t>, std::vector<uint32_t>, std::vector<Rational>,
            std::vector<int8_t>, std::vector<int16_t>, std::vector<int32_t>, std::vector<SRational>,
            std::vector<float>, std::vector<double>>;

public:
	explicit ImageFileDirectory(char* ptr, char* filePtr);
	uint32_t nextOffset() const;
	std::optional<EntryValueType> operator[](TiffTag tag) const;
	void dumpInfo() const;

private:
    size_t sizeOfType(FieldType type) const;
    template<typename T> void parseValue(char* filePtr, IfdEntry* entry);
    template<typename T> void parseValueImpl(char* filePtr, IfdEntry* entry);

private:
	uint16_t _entriesCount;
	IfdEntry* _entries;
	uint32_t _nextIfdOffset;
	std::map<TiffTag, EntryValueType> _entriesMap;
};

class TIFF {
public:
	explicit TIFF(std::string fileName);
	std::vector<ImageFileDirectory> ifds() const;

private:
	std::unique_ptr<char[]> _data;
	std::vector<ImageFileDirectory> _ifds;
};

#endif //DNGINFO_TIFF_H