/* 
 * QR Code generator library (C)
 * 
 * Copyright (c) Project Nayuki. (MIT License)
 * https://www.nayuki.io/page/qr-code-generator-library
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 * - The above copyright notice and this permission notice shall be included in
 *   all copies or substantial portions of the Software.
 * - The Software is provided "as is", without warranty of any kind, express or
 *   implied, including but not limited to the warranties of merchantability,
 *   fitness for a particular purpose and noninfringement. In no event shall the
 *   authors or copyright holders be liable for any claim, damages or other
 *   liability, whether in an action of contract, tort or otherwise, arising from,
 *   out of or in connection with the Software or the use or other dealings in the
 *   Software.
 */

#pragma once

// -- Fake MSXgl --

#define assert(a)

// Boolean
typedef unsigned char				bool;	// 8 bits boolean type
#define TRUE						1		// Value for "TRUE" boolean
#define FALSE						0		// Value for "FALSE" boolean

#define TOGGLE(a)					(a) = !(a)     // Toggle boolean value
#define IS_TRUE(a)					((a) != FALSE) // Check if boolean is TRUE
#define IS_FALSE(a)					((a) == FALSE) // Check if boolean is FALSE

// Integer
typedef signed char					i8;		// 8 bits signed integer type
typedef unsigned char				u8;		// 8 bits unsigned integer type
typedef signed short				i16;	// 16 bits signed integer type
typedef unsigned short				u16;	// 16 bits unsigned integer type
typedef signed long					i32;	// 32 bits signed integer type
typedef unsigned long				u32;	// 32 bits unsigned integer type
typedef signed long long			i64;	// 64 bits signed integer type
typedef unsigned long long			u64;	// 64 bits unsigned integer type

// Float
typedef float						f32;	// 32 bits float type (IEEE 754)

// Character
typedef unsigned char				c8;		// 8 bits character type
typedef unsigned short				c16;	// 16 bits character type (UTF-16, JIS, etc.)

#define INT16_MAX					0x7FFF

//#define NULL						0x0000

// Config

#define QRCODE_MASK_CUSTOM			0x10000

#define QRCODE_VERSION_MIN			1  // The minimum version number supported in the QR Code Model 2 standard
#define QRCODE_VERSION_MAX			40  // The maximum version number supported in the QR Code Model 2 standard
#define QRCODE_VERSION_CUSTOM		FALSE
#define QRCODE_USE_EXTRA			TRUE
//#define QRCODE_MASK_DEF				QRCODE_MASK_CUSTOM


// External definition

#if (QRCODE_VERSION_CUSTOM)
extern u8 g_QRCode_VersionMin;
extern u8 g_QRCode_VersionMax;
#endif

//#if (QRCODE_MASK_DEF == QRCODE_MASK_CUSTOM)
//extern u8 g_QRCode_Mask;
//#endif


/*
 * This library creates QR Code symbols, which is a type of two-dimension barcode.
 * Invented by Denso Wave and described in the ISO/IEC 18004 standard.
 * A QR Code structure is an immutable square grid of dark and light cells.
 * The library provides functions to create a QR Code from text or binary data.
 * The library covers the QR Code Model 2 specification, supporting all versions (sizes)
 * from 1 to 40, all 4 error correction levels, and 4 character encoding modes.
 * 
 * Ways to create a QR Code object:
 * - High level: Take the payload data and call QRCode_EncodeText() or QRCode_EncodeBinary().
 * - Low level: Custom-make the list of segments and call
 *   QRCode_encodeSegments() or QRCode_encodeSegmentsAdvanced().
 * (Note that all ways require supplying the desired error correction level and various byte buffers.)
 */


/*---- Enum and struct types----*/

/* 
 * The error correction level in a QR Code symbol.
 */
enum QRCODE_ECC
{
	// Must be declared in ascending order of error protection
	// so that an internal qrcodegen function works properly
	QRCODE_ECC_LOW = 0 ,  // The QR Code can tolerate about  7% erroneous codewords
	QRCODE_ECC_MEDIUM  ,  // The QR Code can tolerate about 15% erroneous codewords
	QRCODE_ECC_QUARTILE,  // The QR Code can tolerate about 25% erroneous codewords
	QRCODE_ECC_HIGH    ,  // The QR Code can tolerate about 30% erroneous codewords
	// 
	QRCODE_ECC_MAX,
};


/* 
 * The mask pattern used in a QR Code symbol.
 */
enum QRCODE_MASK
{
	// A special value to tell the QR Code encoder to
	// automatically select an appropriate mask pattern
	QRCODE_MASK_AUTO = -1,
	// The eight actual mask patterns
	QRCODE_MASK_0 = 0, // (i + j) % 2 = 0
	QRCODE_MASK_1,     // i % 2 = 0
	QRCODE_MASK_2,     // j % 3 = 0
	QRCODE_MASK_3,     // (i + j) % 3 = 0
	QRCODE_MASK_4,     // (i / 2 + j / 3) % 2 = 0
	QRCODE_MASK_5,     // (i * j) % 2 + (i * j) % 3 = 0
	QRCODE_MASK_6,     // ((i * j) % 3 + i * j) % 2 = 0
	QRCODE_MASK_7,     // ((i * j) % 3 + i + j) % 2 = 0
	// 
	QRCODE_MASK_MAX,
};


/* 
 * Describes how a segment's data bits are interpreted.
 */
enum QRCODE_MODE
{
	QRCODE_MODE_NUMERIC      = 0x1,
	QRCODE_MODE_ALPHANUMERIC = 0x2,
	QRCODE_MODE_BYTE         = 0x4,
	QRCODE_MODE_KANJI        = 0x8,
	QRCODE_MODE_ECI          = 0x7,
};


/* 
 * A segment of character/binary/control data in a QR Code symbol.
 * The mid-level way to create a segment is to take the payload data
 * and call a factory function such as QRCode_MakeNumeric().
 * The low-level way to create a segment is to custom-make the bit buffer
 * and initialize a QRCode_Segment struct with appropriate values.
 * Even in the most favorable conditions, a QR Code can only hold 7089 characters of data.
 * Any segment longer than this is meaningless for the purpose of generating QR Codes.
 * Moreover, the maximum allowed bit length is 32767 because
 * the largest QR Code (version 40) has 31329 modules.
 */
struct QRCode_Segment
{
	// The mode indicator of this segment.
	enum QRCODE_MODE mode;
	
	// The length of this segment's unencoded data. Measured in characters for
	// numeric/alphanumeric/kanji mode, bytes for byte mode, and 0 for ECI mode.
	// Always zero or positive. Not the same as the data's bit length.
	i16 numChars;
	
	// The data bits of this segment, packed in bitwise big endian.
	// Can be null if the bit length is zero.
	u8 *data;
	
	// The number of valid data bits used in the buffer. Requires
	// 0 <= bitLength <= 32767, and bitLength <= (capacity of data array) * 8.
	// The character count (numChars) must agree with the mode and the bit buffer length.
	i16 bitLength;
};



/*---- Macro constants and functions ----*/


// Calculates the number of bytes needed to store any QR Code up to and including the given version number,
// as a compile-time constant. For example, 'u8 buffer[QRCODE_BUFFER_LEN_FOR_VERSION(25)];'
// can store any single QR Code from version 1 to 25 (inclusive). The result fits in an i16 (or int16).
// Requires QRCODE_VERSION_MIN <= n <= QRCODE_VERSION_MAX.
#define QRCODE_BUFFER_LEN_FOR_VERSION(n)  ((((n) * 4 + 17) * ((n) * 4 + 17) + 7) / 8 + 1)

// The worst-case number of bytes needed to store one QR Code, up to and including
// version 40. This value equals 3918, which is just under 4 kilobytes.
// Use this more convenient value to avoid calculating tighter memory bounds for buffers.
#define QRCODE_BUFFER_LEN_MAX  QRCODE_BUFFER_LEN_FOR_VERSION(QRCODE_VERSION_MAX)



/*---- Functions (high level) to generate QR Codes ----*/

/* 
 * Encodes the given text string to a QR Code, returning TRUE if successful.
 * If the data is too long to fit in any version in the given range
 * at the given ECC level, then FALSE is returned.
 * 
 * The input text must be encoded in UTF-8 and contain no NULs.
 * Requires 1 <= minVersion <= maxVersion <= 40.
 * 
 * The smallest possible QR Code version within the given range is automatically
 * chosen for the output. Iff boostEcl is TRUE, then the ECC level of the result
 * may be higher than the ecl argument if it can be done without increasing the
 * version. The mask is either between QRCODE_MASK_0 to 7 to force that mask, or
 * QRCODE_MASK_AUTO to automatically choose an appropriate mask (which may be slow).
 * 
 * About the arrays, letting len = QRCODE_BUFFER_LEN_FOR_VERSION(maxVersion):
 * - Before calling the function:
 *   - The array ranges tempBuffer[0 : len] and qrcode[0 : len] must allow
 *     reading and writing; hence each array must have a length of at least len.
 *   - The two ranges must not overlap (aliasing).
 *   - The initial state of both ranges can be uninitialized
 *     because the function always writes before reading.
 * - After the function returns:
 *   - Both ranges have no guarantee on which elements are initialized and what values are stored.
 *   - tempBuffer contains no useful data and should be treated as entirely uninitialized.
 *   - If successful, qrcode can be passed into QRCode_GetSize() and QRCode_GetModule().
 * 
 * If successful, the resulting QR Code may use numeric,
 * alphanumeric, or byte mode to encode the text.
 * 
 * In the most optimistic case, a QR Code at version 40 with low ECC
 * can hold any UTF-8 string up to 2953 bytes, or any alphanumeric string
 * up to 4296 characters, or any digit string up to 7089 characters.
 * These numbers represent the hard upper limit of the QR Code standard.
 * 
 * Please consult the QR Code specification for information on
 * data capacities per version, ECC level, and text encoding mode.
 */
bool QRCode_EncodeText(const char *text, u8 tempBuffer[], u8 qrcode[], enum QRCODE_ECC ecl, enum QRCODE_MASK mask, bool boostEcl);

/* 
 * Encodes the given binary data to a QR Code, returning TRUE if successful.
 * If the data is too long to fit in any version in the given range
 * at the given ECC level, then FALSE is returned.
 * 
 * Requires 1 <= minVersion <= maxVersion <= 40.
 * 
 * The smallest possible QR Code version within the given range is automatically
 * chosen for the output. Iff boostEcl is TRUE, then the ECC level of the result
 * may be higher than the ecl argument if it can be done without increasing the
 * version. The mask is either between QRCODE_MASK_0 to 7 to force that mask, or
 * QRCODE_MASK_AUTO to automatically choose an appropriate mask (which may be slow).
 * 
 * About the arrays, letting len = QRCODE_BUFFER_LEN_FOR_VERSION(maxVersion):
 * - Before calling the function:
 *   - The array ranges dataAndTemp[0 : len] and qrcode[0 : len] must allow
 *     reading and writing; hence each array must have a length of at least len.
 *   - The two ranges must not overlap (aliasing).
 *   - The input array range dataAndTemp[0 : dataLen] should normally be
 *     valid UTF-8 text, but is not required by the QR Code standard.
 *   - The initial state of dataAndTemp[dataLen : len] and qrcode[0 : len]
 *     can be uninitialized because the function always writes before reading.
 * - After the function returns:
 *   - Both ranges have no guarantee on which elements are initialized and what values are stored.
 *   - dataAndTemp contains no useful data and should be treated as entirely uninitialized.
 *   - If successful, qrcode can be passed into QRCode_GetSize() and QRCode_GetModule().
 * 
 * If successful, the resulting QR Code will use byte mode to encode the data.
 * 
 * In the most optimistic case, a QR Code at version 40 with low ECC can hold any byte
 * sequence up to length 2953. This is the hard upper limit of the QR Code standard.
 * 
 * Please consult the QR Code specification for information on
 * data capacities per version, ECC level, and text encoding mode.
 */
#if (QRCODE_USE_EXTRA)
bool QRCode_EncodeBinary(u8 dataAndTemp[], u16 dataLen, u8 qrcode[], enum QRCODE_ECC ecl, enum QRCODE_MASK mask, bool boostEcl);
#endif

/*---- Functions (low level) to generate QR Codes ----*/

/* 
 * Encodes the given segments to a QR Code, returning TRUE if successful.
 * If the data is too long to fit in any version at the given ECC level,
 * then FALSE is returned.
 * 
 * The smallest possible QR Code version is automatically chosen for
 * the output. The ECC level of the result may be higher than the
 * ecl argument if it can be done without increasing the version.
 * 
 * About the byte arrays, letting len = QRCODE_BUFFER_LEN_FOR_VERSION(QRCODE_VERSION_MAX):
 * - Before calling the function:
 *   - The array ranges tempBuffer[0 : len] and qrcode[0 : len] must allow
 *     reading and writing; hence each array must have a length of at least len.
 *   - The two ranges must not overlap (aliasing).
 *   - The initial state of both ranges can be uninitialized
 *     because the function always writes before reading.
 *   - The input array segs can contain segments whose data buffers overlap with tempBuffer.
 * - After the function returns:
 *   - Both ranges have no guarantee on which elements are initialized and what values are stored.
 *   - tempBuffer contains no useful data and should be treated as entirely uninitialized.
 *   - Any segment whose data buffer overlaps with tempBuffer[0 : len]
 *     must be treated as having invalid values in that array.
 *   - If successful, qrcode can be passed into QRCode_GetSize() and QRCode_GetModule().
 * 
 * Please consult the QR Code specification for information on
 * data capacities per version, ECC level, and text encoding mode.
 * 
 * This function allows the user to create a custom sequence of segments that switches
 * between modes (such as alphanumeric and byte) to encode text in less space.
 * This is a low-level API; the high-level API is QRCode_EncodeText() and QRCode_EncodeBinary().
 */
#if (QRCODE_USE_EXTRA)
bool QRCode_encodeSegments(const struct QRCode_Segment segs[], u16 len, enum QRCODE_ECC ecl, u8 tempBuffer[], u8 qrcode[]);
#endif

/* 
 * Encodes the given segments to a QR Code, returning TRUE if successful.
 * If the data is too long to fit in any version in the given range
 * at the given ECC level, then FALSE is returned.
 * 
 * Requires 1 <= minVersion <= maxVersion <= 40.
 * 
 * The smallest possible QR Code version within the given range is automatically
 * chosen for the output. Iff boostEcl is TRUE, then the ECC level of the result
 * may be higher than the ecl argument if it can be done without increasing the
 * version. The mask is either between QRCODE_MASK_0 to 7 to force that mask, or
 * QRCODE_MASK_AUTO to automatically choose an appropriate mask (which may be slow).
 * 
 * About the byte arrays, letting len = QRCODE_BUFFER_LEN_FOR_VERSION(QRCODE_VERSION_MAX):
 * - Before calling the function:
 *   - The array ranges tempBuffer[0 : len] and qrcode[0 : len] must allow
 *     reading and writing; hence each array must have a length of at least len.
 *   - The two ranges must not overlap (aliasing).
 *   - The initial state of both ranges can be uninitialized
 *     because the function always writes before reading.
 *   - The input array segs can contain segments whose data buffers overlap with tempBuffer.
 * - After the function returns:
 *   - Both ranges have no guarantee on which elements are initialized and what values are stored.
 *   - tempBuffer contains no useful data and should be treated as entirely uninitialized.
 *   - Any segment whose data buffer overlaps with tempBuffer[0 : len]
 *     must be treated as having invalid values in that array.
 *   - If successful, qrcode can be passed into QRCode_GetSize() and QRCode_GetModule().
 * 
 * Please consult the QR Code specification for information on
 * data capacities per version, ECC level, and text encoding mode.
 * 
 * This function allows the user to create a custom sequence of segments that switches
 * between modes (such as alphanumeric and byte) to encode text in less space.
 * This is a low-level API; the high-level API is QRCode_EncodeText() and QRCode_EncodeBinary().
 */
bool QRCode_encodeSegmentsAdvanced(const struct QRCode_Segment segs[], u16 len, enum QRCODE_ECC ecl, enum QRCODE_MASK mask, bool boostEcl, u8 tempBuffer[], u8 qrcode[]);


/* 
 * Tests whether the given string can be encoded as a segment in numeric mode.
 * A string is encodable iff each character is in the range 0 to 9.
 */
bool QRCode_isNumeric(const char *text);


/* 
 * Tests whether the given string can be encoded as a segment in alphanumeric mode.
 * A string is encodable iff each character is in the following set: 0 to 9, A to Z
 * (uppercase only), space, dollar, percent, asterisk, plus, hyphen, period, slash, colon.
 */
bool QRCode_isAlphanumeric(const char *text);


/* 
 * Returns the number of bytes (u8) needed for the data buffer of a segment
 * containing the given number of characters using the given mode. Notes:
 * - Returns SIZE_MAX on failure, i.e. numChars > INT16_MAX or the internal
 *   calculation of the number of needed bits exceeds INT16_MAX (i.e. 32767).
 * - Otherwise, all valid results are in the range [0, ceil(INT16_MAX / 8)], i.e. at most 4096.
 * - It is okay for the user to allocate more bytes for the buffer than needed.
 * - For byte mode, numChars measures the number of bytes, not Unicode code points.
 * - For ECI mode, numChars must be 0, and the worst-case number of bytes is returned.
 *   An actual ECI segment can have shorter data. For non-ECI modes, the result is exact.
 */
u16 QRCode_CalcSegmentBufferSize(enum QRCODE_MODE mode, u16 numChars);


/* 
 * Returns a segment representing the given binary data encoded in
 * byte mode. All input byte arrays are acceptable. Any text string
 * can be converted to UTF-8 bytes and encoded as a byte mode segment.
 */
#if (QRCODE_USE_EXTRA)
void QRCode_MakeBytes(const u8 data[], u16 len, u8 buf[], struct QRCode_Segment* seg);
#endif


/* 
 * Returns a segment representing the given string of decimal digits encoded in numeric mode.
 */
void QRCode_MakeNumeric(const char *digits, u8 buf[], struct QRCode_Segment* seg);


/* 
 * Returns a segment representing the given text string encoded in alphanumeric mode.
 * The characters allowed are: 0 to 9, A to Z (uppercase only), space,
 * dollar, percent, asterisk, plus, hyphen, period, slash, colon.
 */
void QRCode_MakeAlphanumeric(const char *text, u8 buf[], struct QRCode_Segment* seg);


/* 
 * Returns a segment representing an Extended Channel Interpretation
 * (ECI) designator with the given assignment value.
 */
#if (QRCODE_USE_EXTRA)
void QRCode_MakeECI(long assignVal, u8 buf[], struct QRCode_Segment* seg);
#endif


/*---- Functions to extract raw data from QR Codes ----*/

/* 
 * Returns the side length of the given QR Code, assuming that encoding succeeded.
 * The result is in the range [21, 177]. Note that the length of the array buffer
 * is related to the side length - every 'u8 qrcode[]' must have length at least
 * QRCODE_BUFFER_LEN_FOR_VERSION(version), which equals ceil(size^2 / 8 + 1).
 */
u8 QRCode_GetSize(const u8 qrcode[]);


/* 
 * Returns the color of the module (pixel) at the given coordinates, which is FALSE
 * for light or TRUE for dark. The top left corner has the coordinates (x=0, y=0).
 * If the given coordinates are out of bounds, then FALSE (light) is returned.
 */
bool QRCode_GetModule(const u8 qrcode[], i16 x, i16 y);

// Function: QRCode_GetSize
inline u8 QRCode_GetVersion(const u8 qrcode[]) { return (QRCode_GetSize(qrcode) - 17) / 4; }

#if (QRCODE_VERSION_CUSTOM)
// Function: QRCode_SetVersion
// Set minimum and maximum version to use for the next encoding.
// Must be called before QRCode_Encode* functions.
inline void QRCode_SetVersion(u8 min, u8 max) { g_QRCode_VersionMin = min; g_QRCode_VersionMax = max; }
#endif

//#if (QRCODE_MASK_DEF == QRCODE_MASK_CUSTOM)
//inline void QRCode_SetMask(u8 mask) { g_QRCode_Mask = mask; }
//#endif