/*
  TinyEXIF.h -- A simple ISO C++ library to parse basic EXIF and XMP
                information from a JPEG file.

  Copyright (c) 2015-2025 Seacave
  cdc.seacave@gmail.com
  MIT License
*/

#ifndef __TINYEXIF_H__
#define __TINYEXIF_H__

#include <cstdint>
#include <string>
#include <vector>

#define TINYEXIF_MAJOR_VERSION 1
#define TINYEXIF_MINOR_VERSION 0
#define TINYEXIF_PATCH_VERSION 3

#ifdef _MSC_VER
#   ifdef TINYEXIF_EXPORT
#       define TINYEXIF_LIB __declspec(dllexport)
#   elif defined(TINYEXIF_IMPORT)
#       define TINYEXIF_LIB __declspec(dllimport)
#   else
#       define TINYEXIF_LIB
#   endif
#elif __GNUC__ >= 4
#   define TINYEXIF_LIB __attribute__((visibility("default")))
#else
#   define TINYEXIF_LIB
#endif

namespace TinyEXIF {

enum ErrorCode {
	PARSE_SUCCESS           = 0, // Parse EXIF and/or XMP was successful
	PARSE_INVALID_JPEG      = 1, // No JPEG markers found in buffer, possibly invalid JPEG file
	PARSE_UNKNOWN_BYTEALIGN = 2, // Byte alignment specified in EXIF file was unknown (neither Motorola nor Intel)
	PARSE_ABSENT_DATA       = 3, // No EXIF and/or XMP data found in JPEG file
	PARSE_CORRUPT_DATA      = 4, // EXIF and/or XMP header was found, but data was corrupted
};

enum FieldCode {
	FIELD_NA                 = 0, // No EXIF or XMP data
	FIELD_EXIF               = (1 << 0), // EXIF data available
	FIELD_XMP                = (1 << 1), // XMP data available
	FIELD_ALL                = FIELD_EXIF|FIELD_XMP
};

class EntryParser;

//
// Interface class responsible for fetching stream data to be parsed
//
class TINYEXIF_LIB EXIFStream {
public:
	virtual ~EXIFStream() {}

	// Check the state of the stream.
	virtual bool IsValid() const = 0;

	// Return the pointer to the beginning of the desired size buffer
	// following current buffer position.
	virtual const uint8_t* GetBuffer(unsigned desiredLength) = 0;

	// Advance current buffer position with the desired size;
	// return false if stream ends in less than the desired size.
	virtual bool SkipBuffer(unsigned desiredLength) = 0;
};

//
// Class responsible for storing and parsing EXIF & XMP metadata from a JPEG stream
//
class TINYEXIF_LIB EXIFInfo {
public:
	EXIFInfo();
	EXIFInfo(EXIFStream& stream);
	EXIFInfo(std::istream& stream); // NB: the stream must have been opened in binary mode
	EXIFInfo(const uint8_t* data, unsigned length);

	// Parsing function for an entire JPEG image stream.
	//
	// PARAM 'stream': Interface to fetch JPEG image stream.
	// PARAM 'data': A pointer to a JPEG image.
	// PARAM 'length': The length of the JPEG image.
	// RETURN:  PARSE_SUCCESS (0) on success with 'result' filled out
	//          error code otherwise, as defined by the PARSE_* macros
	int parseFrom(EXIFStream& stream);
	int parseFrom(std::istream& stream); // NB: the stream must have been opened in binary mode
	int parseFrom(const uint8_t* data, unsigned length);

	// Parsing function for an EXIF segment. This is used internally by parseFrom()
	// but can be called for special cases where only the EXIF section is 
	// available (i.e., a blob starting with the bytes "Exif\0\0").
	int parseFromEXIFSegment(const uint8_t* buf, unsigned len);

#ifndef TINYEXIF_NO_XMP_SUPPORT
	// Parsing function for an XMP segment. This is used internally by parseFrom()
	// but can be called for special cases where only the XMP section is 
	// available (i.e., a blob starting with the bytes "http://ns.adobe.com/xap/1.0/\0").
	int parseFromXMPSegment(const uint8_t* buf, unsigned len);
	int parseFromXMPSegmentXML(const char* szXML, unsigned len);
#endif // TINYEXIF_NO_XMP_SUPPORT

	// Set all data members to default values.
	// Should be called before parsing a new stream.
	void clear();

private:
	// Parse tag as Image IFD.
	void parseIFDImage(EntryParser&, unsigned&, unsigned&);
	// Parse tag as Exif IFD.
	void parseIFDExif(EntryParser&);
	// Parse tag as GPS IFD.
	void parseIFDGPS(EntryParser&);
	// Parse tag as MakerNote IFD.
	void parseIFDMakerNote(EntryParser&);

public:
	// Data fields
	uint32_t Fields;                    // Store if EXIF and/or XMP data fields are available
	uint32_t ImageWidth;                // Image width reported in EXIF data
	uint32_t ImageHeight;               // Image height reported in EXIF data
	uint32_t RelatedImageWidth;         // Original image width reported in EXIF data
	uint32_t RelatedImageHeight;        // Original image height reported in EXIF data
	std::string ImageDescription;       // Image description
	std::string Make;                   // Camera manufacturer's name
	std::string Model;                  // Camera model
	std::string SerialNumber;           // Serial number of the body of the camera
	uint16_t Orientation;               // Image orientation, start of data corresponds to
									    // 0: unspecified in EXIF data
									    // 1: upper left of image
									    // 3: lower right of image
									    // 6: upper right of image
									    // 8: lower left of image
									    // 9: undefined
	double XResolution;                 // Number of pixels per ResolutionUnit in the ImageWidth direction
	double YResolution;                 // Number of pixels per ResolutionUnit in the ImageLength direction
	uint16_t ResolutionUnit;            // Unit of measurement for XResolution and YResolution
									    // 1: no absolute unit of measurement. Used for images that may have a non-square aspect ratio, but no meaningful absolute dimensions
									    // 2: inch
									    // 3: centimeter
	uint16_t BitsPerSample;             // Number of bits per component
	std::string Software;               // Software used
	std::string DateTime;               // File change date and time
	std::string DateTimeOriginal;       // Original file date and time (may not exist)
	std::string DateTimeDigitized;      // Digitization date and time (may not exist)
	std::string SubSecTimeOriginal;     // Sub-second time that original picture was taken
	std::string Copyright;              // File copyright information
	double ExposureTime;                // Exposure time in seconds
	double FNumber;                     // F/stop
	uint16_t ExposureProgram;           // Exposure program
	                                    // 0: not defined
	                                    // 1: manual
	                                    // 2: normal program
	                                    // 3: aperture priority
	                                    // 4: shutter priority
	                                    // 5: creative program
	                                    // 6: action program
	                                    // 7: portrait mode
	                                    // 8: landscape mode
	uint16_t ISOSpeedRatings;           // ISO speed
	double ShutterSpeedValue;           // Shutter speed (reciprocal of exposure time)
	double ApertureValue;               // The lens aperture
	double BrightnessValue;             // The value of brightness
	double ExposureBiasValue;           // Exposure bias value in EV
	double SubjectDistance;             // Distance to focus point in meters
	double FocalLength;                 // Focal length of lens in millimeters
	uint16_t Flash;                     // Flash info
	                                    // Flash used (Flash&1)
	                                    // 0: no flash, >0: flash used
	                                    // Flash returned light status ((Flash & 6) >> 1)
	                                    // 0: no strobe return detection function
	                                    // 1: reserved
	                                    // 2: strobe return light not detected
	                                    // 3: strobe return light detected
	                                    // Flash mode ((Flash & 24) >> 3)
	                                    // 0: unknown
	                                    // 1: compulsory flash firing
	                                    // 2: compulsory flash suppression
	                                    // 3: auto mode
	                                    // Flash function ((Flash & 32) >> 5)
	                                    // 0: flash function present, >0: no flash function
	                                    // Flash red-eye ((Flash & 64) >> 6)
	                                    // 0: no red-eye reduction mode or unknown, >0: red-eye reduction supported
	uint16_t MeteringMode;              // Metering mode
	                                    // 0: unknown
	                                    // 1: average
	                                    // 2: center weighted average
	                                    // 3: spot
	                                    // 4: multi-spot
	                                    // 5: pattern
	                                    // 6: partial
	uint16_t LightSource;               // Kind of light source
	                                    // 0: unknown
	                                    // 1: daylight
	                                    // 2: fluorescent
	                                    // 3: tungsten (incandescent light)
	                                    // 4: flash
	                                    // 9: fine weather
	                                    // 10: cloudy weather
	                                    // 11: shade
	                                    // 12: daylight fluorescent (D 5700 - 7100K)
	                                    // 13: day white fluorescent (N 4600 - 5400K)
	                                    // 14: cool white fluorescent (W 3900 - 4500K)
	                                    // 15: white fluorescent (WW 3200 - 3700K)
	                                    // 17: standard light A
	                                    // 18: standard light B
	                                    // 19: standard light C
										// 20: D55
										// 21: D65
										// 22: D75
										// 23: D50
	                                    // 24: ISO studio tungsten
	uint16_t ProjectionType;            // Projection type
									    // 0: unknown projection
									    // 1: perspective projection
									    // 2: equirectangular/spherical projection
	std::vector<uint16_t> SubjectArea;  // Location and area of the main subject in the overall scene expressed in relation to the upper left as origin, prior to rotation
	                                    // 0: unknown
	                                    // 2: location of the main subject as coordinates (first value is the X coordinate and second is the Y coordinate)
	                                    // 3: area of the main subject as a circle (first value is the center X coordinate, second is the center Y coordinate, and third is the diameter)
	                                    // 4: area of the main subject as a rectangle (first value is the center X coordinate, second is the center Y coordinate, third is the width of the area, and fourth is the height of the area)
	struct TINYEXIF_LIB Calibration_t { // Camera calibration information
		double FocalLength;             // Focal length (pixels)
		double OpticalCenterX;          // Principal point X (pixels)
		double OpticalCenterY;          // Principal point Y (pixels)
		bool hasCalibration() const;    // Return true if FocalLength, OpticalCenterX, OpticalCenterY are available (nonzero)
	} Calibration;
	struct TINYEXIF_LIB Distortion_t { // Lens distortion information
		uint32_t DewarpFlag;            // Dewarp flag - indicates whether undistortion has been applied to the image
										// UINT32_MAX: flag missing from EXIF data
										// 0: no dewarp (raw image) - the image is distorted, should also have coefficients
										// 1: dewarp applied (undistorted image)
		double K1;
		double K2;
		double P1;
		double P2;
		double K3;
		bool hasDewarpFlag() const; // Return true if DewarpFlag is available
		bool hasDistortion() const; // Return true if any of K1, K2, P1, P2, K3 are available
	} Distortion;
	struct TINYEXIF_LIB LensInfo_t {    // Lens information
		double FStopMin;                // Min aperture (f-stop)
		double FStopMax;                // Max aperture (f-stop)
		double FocalLengthMin;          // Min focal length (mm)
		double FocalLengthMax;          // Max focal length (mm)
		double DigitalZoomRatio;        // Digital zoom ratio when the image was shot
		double FocalLengthIn35mm;       // Focal length in 35mm film
		double FocalPlaneXResolution;   // Number of pixels in the image width (X) direction per FocalPlaneResolutionUnit on the camera focal plane (may not exist)
		double FocalPlaneYResolution;   // Number of pixels in the image width (Y) direction per FocalPlaneResolutionUnit on the camera focal plane (may not exist)
		uint16_t FocalPlaneResolutionUnit;// Unit for measuring FocalPlaneXResolution and FocalPlaneYResolution (may not exist)
										// 0: unspecified in EXIF data
										// 1: no absolute unit of measurement
										// 2: inch
										// 3: centimeter
		std::string Make;               // Lens manufacturer
		std::string Model;              // Lens model
	} LensInfo;
	struct TINYEXIF_LIB Geolocation_t { // GPS information embedded in file
		double Latitude;                // Image latitude expressed as decimal
		double Longitude;               // Image longitude expressed as decimal
		double Altitude;                // Altitude in meters, relative to sea level
		int8_t AltitudeRef;             // 0: above sea level, -1: below sea level
		double RelativeAltitude;        // Relative altitude in meters
		double RollDegree;              // Flight roll in degrees
		double PitchDegree;             // Flight pitch in degrees
		double YawDegree;               // Flight yaw in degrees
		double SpeedX;                  // Flight speed on X in meters/second
		double SpeedY;                  // Flight speed on Y in meters/second
		double SpeedZ;                  // Flight speed on Z in meters/second
		double AccuracyXY;              // GPS accuracy on XY in meters
		double AccuracyZ;               // GPS accuracy on Z in meters
		double GPSDOP;                  // GPS DOP (data degree of precision)
		uint16_t GPSDifferential;       // Differential correction applied to the GPS receiver (may not exist)
										// 0: measurement without differential correction
										// 1: differential correction applied 
		std::string GPSMapDatum;        // Geodetic survey data (may not exist)
		std::string GPSTimeStamp;       // Time as UTC (Coordinated Universal Time) (may not exist)
		std::string GPSDateStamp;       // A character string recording date and time information relative to UTC (Coordinated Universal Time) YYYY:MM:DD (may not exist)
		struct Coord_t {
			double degrees;
			double minutes;
			double seconds;
			uint8_t direction;
		} LatComponents, LonComponents; // Latitude/Longitude expressed in deg/min/sec
		void parseCoords();             // Convert Latitude/Longitude from deg/min/sec to decimal
		bool hasLatLon() const;         // Return true if (lat,lon) is available
		bool hasAltitude() const;       // Return true if (alt) is available
		bool hasRelativeAltitude()const;// Return true if (rel_alt) is available
		bool hasOrientation() const;    // Return true if (roll,yaw,pitch) is available
		bool hasSpeed() const;          // Return true if (speedX,speedY,speedZ) is available
		bool hasAccuracy() const;       // Return true if (accuracyXY,accuracyZ) is available
	} GeoLocation;
	struct TINYEXIF_LIB GPano_t {       // Spherical metadata. https://developers.google.com/streetview/spherical-metadata
		double PosePitchDegrees;        // Pitch, measured in degrees above the horizon, for the center in the image. Value must be >= -90 and <= 90.
		double PoseRollDegrees;         // Roll, measured in degrees, of the image where level with the horizon is 0. As roll increases, the horizon rotates counterclockwise in the image. Value must be > -180 and <= 180.
		bool hasPosePitchDegrees() const; // Return true if PosePitchDegrees is available
		bool hasPoseRollDegrees() const; // Return true if PoseRollDegrees is available
	} GPano;
	struct TINYEXIF_LIB MicroVideo_t {  // Google camera video file in metadata
		uint32_t HasMicroVideo;         // not zero if exists
		uint32_t MicroVideoVersion;     // just regularinfo
		uint32_t MicroVideoOffset;      // offset from end of file
	} MicroVideo;
};

} // namespace TinyEXIF

#endif // __TINYEXIF_H__