#include "yarp/util/yp_char.h"

#define YP_CHAR_BIT_WHITESPACE (1 << 0)
#define YP_CHAR_BIT_INLINE_WHITESPACE (1 << 1)
#define YP_CHAR_BIT_REGEXP_OPTION (1 << 2)

#define YP_NUMBER_BIT_BINARY_DIGIT (1 << 0)
#define YP_NUMBER_BIT_BINARY_NUMBER (1 << 1)
#define YP_NUMBER_BIT_OCTAL_DIGIT (1 << 2)
#define YP_NUMBER_BIT_OCTAL_NUMBER (1 << 3)
#define YP_NUMBER_BIT_DECIMAL_DIGIT (1 << 4)
#define YP_NUMBER_BIT_DECIMAL_NUMBER (1 << 5)
#define YP_NUMBER_BIT_HEXADECIMAL_DIGIT (1 << 6)
#define YP_NUMBER_BIT_HEXADECIMAL_NUMBER (1 << 7)

static const uint8_t yp_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, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 4x
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 5x
    0, 0, 0, 0, 0, 4, 0, 0, 0, 4, 0, 0, 0, 4, 4, 4, // 6x
    0, 0, 0, 4, 0, 4, 0, 0, 4, 0, 0, 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 yp_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
};

static inline size_t
yp_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 && (yp_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
yp_strspn_whitespace(const uint8_t *string, ptrdiff_t length) {
    return yp_strspn_char_kind(string, length, YP_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
yp_strspn_whitespace_newlines(const uint8_t *string, ptrdiff_t length, yp_newline_list_t *newline_list) {
    if (length <= 0) return 0;

    size_t size = 0;
    size_t maximum = (size_t) length;

    while (size < maximum && (yp_byte_table[string[size]] & YP_CHAR_BIT_WHITESPACE)) {
        if (string[size] == '\n') {
            yp_newline_list_append(newline_list, string + size);
        }

        size++;
    }

    return size;
}

// Returns the number of characters at the start of the string that are inline
// whitespace. Disallows searching past the given maximum number of characters.
size_t
yp_strspn_inline_whitespace(const uint8_t *string, ptrdiff_t length) {
    return yp_strspn_char_kind(string, length, YP_CHAR_BIT_INLINE_WHITESPACE);
}

// 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
yp_strspn_regexp_option(const uint8_t *string, ptrdiff_t length) {
    return yp_strspn_char_kind(string, length, YP_CHAR_BIT_REGEXP_OPTION);
}

static inline bool
yp_char_is_char_kind(const uint8_t b, uint8_t kind) {
    return (yp_byte_table[b] & kind) != 0;
}

// Returns true if the given character is a whitespace character.
bool
yp_char_is_whitespace(const uint8_t b) {
    return yp_char_is_char_kind(b, YP_CHAR_BIT_WHITESPACE);
}

// Returns true if the given character is an inline whitespace character.
bool
yp_char_is_inline_whitespace(const uint8_t b) {
    return yp_char_is_char_kind(b, YP_CHAR_BIT_INLINE_WHITESPACE);
}

// 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 inline size_t
yp_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 && (yp_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 inline size_t
yp_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 && (yp_number_table[string[size]] & kind)) {
        if (string[size] == '_') {
            if (underscore) *invalid = string + size;
            underscore = true;
        } else {
            underscore = false;
        }

        size++;
    }

    if (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
yp_strspn_binary_number(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid) {
    return yp_strspn_number_kind_underscores(string, length, invalid, YP_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
yp_strspn_octal_number(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid) {
    return yp_strspn_number_kind_underscores(string, length, invalid, YP_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
yp_strspn_decimal_digit(const uint8_t *string, ptrdiff_t length) {
    return yp_strspn_number_kind(string, length, YP_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
yp_strspn_decimal_number(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid) {
    return yp_strspn_number_kind_underscores(string, length, invalid, YP_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
yp_strspn_hexadecimal_digit(const uint8_t *string, ptrdiff_t length) {
    return yp_strspn_number_kind(string, length, YP_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
yp_strspn_hexadecimal_number(const uint8_t *string, ptrdiff_t length, const uint8_t **invalid) {
    return yp_strspn_number_kind_underscores(string, length, invalid, YP_NUMBER_BIT_HEXADECIMAL_NUMBER);
}

static inline bool
yp_char_is_number_kind(const uint8_t b, uint8_t kind) {
    return (yp_number_table[b] & kind) != 0;
}

// Returns true if the given character is a binary digit.
bool
yp_char_is_binary_digit(const uint8_t b) {
    return yp_char_is_number_kind(b, YP_NUMBER_BIT_BINARY_DIGIT);
}

// Returns true if the given character is an octal digit.
bool
yp_char_is_octal_digit(const uint8_t b) {
    return yp_char_is_number_kind(b, YP_NUMBER_BIT_OCTAL_DIGIT);
}

// Returns true if the given character is a decimal digit.
bool
yp_char_is_decimal_digit(const uint8_t b) {
    return yp_char_is_number_kind(b, YP_NUMBER_BIT_DECIMAL_DIGIT);
}

// Returns true if the given character is a hexadecimal digit.
bool
yp_char_is_hexadecimal_digit(const uint8_t b) {
    return yp_char_is_number_kind(b, YP_NUMBER_BIT_HEXADECIMAL_DIGIT);
}

#undef YP_CHAR_BIT_WHITESPACE
#undef YP_CHAR_BIT_INLINE_WHITESPACE
#undef YP_CHAR_BIT_REGEXP_OPTION

#undef YP_NUMBER_BIT_BINARY_DIGIT
#undef YP_NUMBER_BIT_BINARY_NUMBER
#undef YP_NUMBER_BIT_OCTAL_DIGIT
#undef YP_NUMBER_BIT_OCTAL_NUMBER
#undef YP_NUMBER_BIT_DECIMAL_DIGIT
#undef YP_NUMBER_BIT_DECIMAL_NUMBER
#undef YP_NUMBER_BIT_HEXADECIMAL_NUMBER
#undef YP_NUMBER_BIT_HEXADECIMAL_DIGIT