#include "prism/internal/char.h"

#include "prism/compiler/inline.h"

#include "prism/internal/line_offset_list.h"

#define PRISM_CHAR_BIT_REGEXP_OPTION (1 << 2)

#define PRISM_NUMBER_BIT_BINARY_DIGIT (1 << 0)

#define PRISM_NUMBER_BIT_BINARY_NUMBER (1 << 1)

#define PRISM_NUMBER_BIT_OCTAL_DIGIT (1 << 2)

#define PRISM_NUMBER_BIT_OCTAL_NUMBER (1 << 3)

#define PRISM_NUMBER_BIT_DECIMAL_DIGIT (1 << 4)

#define PRISM_NUMBER_BIT_DECIMAL_NUMBER (1 << 5)

#define PRISM_NUMBER_BIT_HEXADECIMAL_DIGIT (1 << 6)

#define PRISM_NUMBER_BIT_HEXADECIMAL_NUMBER (1 << 7)

const uint8_t pm_byte_table[256] = {

//  0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F

    0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 1, 3, 3, 3, 0, 0, // 0x

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 1x

    3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 2x

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 3x

    0, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, // 4x

    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, // 5x

    0, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, // 6x

    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, // 7x

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 8x

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 9x

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Ax

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Bx

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Cx

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Dx

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Ex

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // Fx

};

static const uint8_t pm_number_table[256] = {

    // 0     1     2     3     4     5     6     7     8     9     A     B     C     D     E     F

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 0x

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 1x

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 2x

    0xff, 0xff, 0xfc, 0xfc, 0xfc, 0xfc, 0xfc, 0xfc, 0xf0, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 3x

    0x00, 0xc0, 0xc0, 0xc0, 0xc0, 0xc0, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 4x

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xaa, // 5x

    0x00, 0xc0, 0xc0, 0xc0, 0xc0, 0xc0, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 6x

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 7x

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 8x

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 9x

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Ax

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Bx

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Cx

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Dx

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Ex

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Fx

};

/**

 * Returns the number of characters at the start of the string that match the

 * given kind. Disallows searching past the given maximum number of characters.

 */

static PRISM_INLINE size_t

pm_strspn_char_kind(const uint8_t *string, ptrdiff_t length, uint8_t kind) {

    if (length <= 0) return 0;

    size_t size = 0;

    size_t maximum = (size_t) length;

    while (size < maximum && (pm_byte_table[string[size]] & kind)) size++;

    return size;

}

/**

 * Returns the number of characters at the start of the string that are

 * whitespace. Disallows searching past the given maximum number of characters.

 */

size_t

pm_strspn_whitespace(const uint8_t *string, ptrdiff_t length) {

    return pm_strspn_char_kind(string, length, PRISM_CHAR_BIT_WHITESPACE);

}

/**

 * Returns the number of characters at the start of the string that are

 * whitespace while also tracking the location of each newline. Disallows

 * searching past the given maximum number of characters.

 */

size_t

pm_strspn_whitespace_newlines(const uint8_t *string, ptrdiff_t length, pm_arena_t *arena, pm_line_offset_list_t *line_offsets, uint32_t start_offset) {

    if (length <= 0) return 0;

    uint32_t size = 0;

    uint32_t maximum = (uint32_t) length;

    while (size < maximum && (pm_byte_table[string[size]] & PRISM_CHAR_BIT_WHITESPACE)) {

        if (string[size] == '\n') {

            pm_line_offset_list_append(arena, line_offsets, start_offset + size + 1);

        }

        size++;

    }

    return size;

}

/**

 * Returns the number of characters at the start of the string that are regexp

 * options. Disallows searching past the given maximum number of characters.

 */

size_t

pm_strspn_regexp_option(const uint8_t *string, ptrdiff_t length) {

    return pm_strspn_char_kind(string, length, PRISM_CHAR_BIT_REGEXP_OPTION);

}

/**

 * Scan through the string and return the number of characters at the start of

 * the string that match the given kind. Disallows searching past the given

 * maximum number of characters.

 */

static PRISM_INLINE size_t

pm_strspn_number_kind(const uint8_t *string, ptrdiff_t length, uint8_t kind) {

    if (length <= 0) return 0;

    size_t size = 0;

    size_t maximum = (size_t) length;

    while (size < maximum && (pm_number_table[string[size]] & kind)) size++;

    return size;

}

/**

 * Scan through the string and return the number of characters at the start of

 * the string that match the given kind. Disallows searching past the given

 * maximum number of characters.

 *

 * Additionally, report the location of the last invalid underscore character

 * found in the string through the out invalid parameter.

 */

static PRISM_INLINE size_t

pm_strspn_number_kind_underscores(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid, uint8_t kind) {

    if (length <= 0) return 0;

    size_t size = 0;

    size_t maximum = (size_t) length;

    bool underscore = false;

    while (size < maximum && (pm_number_table[string[size]] & kind)) {

        if (string[size] == '_') {

            if (underscore) *invalid = string + size;

            underscore = true;

        } else {

            underscore = false;

        }

        size++;

    }

    if (size > 0 && string[size - 1] == '_') *invalid = string + size - 1;

    return size;

}

/**

 * Returns the number of characters at the start of the string that are binary

 * digits or underscores. Disallows searching past the given maximum number of

 * characters.

 *

 * If multiple underscores are found in a row or if an underscore is

 * found at the end of the number, then the invalid pointer is set to the index

 * of the first invalid underscore.

 */

size_t

pm_strspn_binary_number(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid) {

    return pm_strspn_number_kind_underscores(string, length, invalid, PRISM_NUMBER_BIT_BINARY_NUMBER);

}

/**

 * Returns the number of characters at the start of the string that are octal

 * digits or underscores. Disallows searching past the given maximum number of

 * characters.

 *

 * If multiple underscores are found in a row or if an underscore is

 * found at the end of the number, then the invalid pointer is set to the index

 * of the first invalid underscore.

 */

size_t

pm_strspn_octal_number(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid) {

    return pm_strspn_number_kind_underscores(string, length, invalid, PRISM_NUMBER_BIT_OCTAL_NUMBER);

}

/**

 * Returns the number of characters at the start of the string that are decimal

 * digits. Disallows searching past the given maximum number of characters.

 */

size_t

pm_strspn_decimal_digit(const uint8_t *string, ptrdiff_t length) {

    return pm_strspn_number_kind(string, length, PRISM_NUMBER_BIT_DECIMAL_DIGIT);

}

/**

 * Returns the number of characters at the start of the string that are decimal

 * digits or underscores. Disallows searching past the given maximum number of

 * characters.

 *

 * If multiple underscores are found in a row or if an underscore is

 * found at the end of the number, then the invalid pointer is set to the index

 * of the first invalid underscore

 */

size_t

pm_strspn_decimal_number(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid) {

    return pm_strspn_number_kind_underscores(string, length, invalid, PRISM_NUMBER_BIT_DECIMAL_NUMBER);

}

/**

 * Returns the number of characters at the start of the string that are

 * hexadecimal digits. Disallows searching past the given maximum number of

 * characters.

 */

size_t

pm_strspn_hexadecimal_digit(const uint8_t *string, ptrdiff_t length) {

    return pm_strspn_number_kind(string, length, PRISM_NUMBER_BIT_HEXADECIMAL_DIGIT);

}

/**

 * Returns the number of characters at the start of the string that are

 * hexadecimal digits or underscores. Disallows searching past the given maximum

 * number of characters.

 *

 * If multiple underscores are found in a row or if an underscore is

 * found at the end of the number, then the invalid pointer is set to the index

 * of the first invalid underscore.

 */

size_t

pm_strspn_hexadecimal_number(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid) {

    return pm_strspn_number_kind_underscores(string, length, invalid, PRISM_NUMBER_BIT_HEXADECIMAL_NUMBER);

}

/**

 * Returns true if the given character matches the given kind.

 */

static PRISM_INLINE bool

pm_char_is_number_kind(const uint8_t b, uint8_t kind) {

    return (pm_number_table[b] & kind) != 0;

}

/**

 * Returns true if the given character is a binary digit.

 */

bool

pm_char_is_binary_digit(const uint8_t b) {

    return pm_char_is_number_kind(b, PRISM_NUMBER_BIT_BINARY_DIGIT);

}

/**

 * Returns true if the given character is an octal digit.

 */

bool

pm_char_is_octal_digit(const uint8_t b) {

    return pm_char_is_number_kind(b, PRISM_NUMBER_BIT_OCTAL_DIGIT);

}

/**

 * Returns true if the given character is a decimal digit.

 */

bool

pm_char_is_decimal_digit(const uint8_t b) {

    return pm_char_is_number_kind(b, PRISM_NUMBER_BIT_DECIMAL_DIGIT);

}

/**

 * Returns true if the given character is a hexadecimal digit.

 */

bool

pm_char_is_hexadecimal_digit(const uint8_t b) {

    return pm_char_is_number_kind(b, PRISM_NUMBER_BIT_HEXADECIMAL_DIGIT);

}