#ifndef CODE_POINT_H
#define CODE_POINT_H

#include <cstdint>

typedef wchar_t code_point_t;

namespace CodePoints {
    struct CodePointMap {
        code_point_t key;
        code_point_t value;
    };
    
    const code_point_t TAB = 0x0009;
    const code_point_t LF = 0x000A;
    const code_point_t FF = 0x00C;
    const code_point_t SPACE = 0x020;
    const code_point_t SOLIDUS = 0x02F;
    const code_point_t LOWERCASE_A = 0x0061;
    const code_point_t LOWERCASE_Z = 0x007A;
    const code_point_t LOWERCASE_F = 0x0066;
    const code_point_t UPPERCASE_A = 0x041;
    const code_point_t UPPERCASE_Z = 0x05A;
    const code_point_t UPPERCASE_F = 0x0046;
    const code_point_t NULL_CHAR = 0x0000;
    const code_point_t REPLACEMENT_CHAR = 0xFFFD;
    const code_point_t GREATER_THAN_SIGN = 0x003E;
    const code_point_t LESS_THAN_SIGN = 0x003C;
    const code_point_t AMPERSAND = 0x0026;
    const code_point_t EXCLAMATION_MARK = 0x0021;
    const code_point_t NUMBER_SIGN = 0x0023;
    const code_point_t LOWERCASE_X = 0x0078;
    const code_point_t UPPERCASE_X = 0x0058;
    const code_point_t DIGIT_ZERO = 0x0030;
    const code_point_t DIGIT_NINE = 0x0039;
    const code_point_t SEMICOLON = 0x003B;

    inline bool is_decimal(code_point_t c) {
        return c >= CodePoints::DIGIT_ZERO && c <= CodePoints::DIGIT_NINE;
    }

    inline bool is_hex(code_point_t c) {
        return (c >= CodePoints::DIGIT_ZERO && c <= CodePoints::DIGIT_NINE)
            || (c >= CodePoints::LOWERCASE_A && c <= CodePoints::LOWERCASE_F)
            || (c >= CodePoints::UPPERCASE_A && c <= CodePoints::UPPERCASE_F);
    }

    inline bool in_range(code_point_t c, code_point_t lo, code_point_t hi) {
        return c >= lo && c <= hi;
    }

    constexpr CodePointMap CHARACTER_REF_PARSE_ERROR_REPALCEMENT[] = {
        { 0x00, 0xFFFD },
        { 0x0D, 0X000D },
        { 0x80, 0x20AC },
        { 0x81, 0x0081 },
        { 0x82, 0x201A },
        { 0x83, 0x0192 },
        { 0x84, 0x201E },
        { 0x85, 0x2026 },
        { 0x86, 0x2020 },
        { 0x87, 0x2021 },
        { 0x88, 0x02C6 },
        { 0x89, 0x2030 },
        { 0x8A, 0x0160 },
        { 0x8B, 0x2039 },
        { 0x8C, 0x0152 },
        { 0x8D, 0x008D },
        { 0x8E, 0x017D },
        { 0x8F, 0x008F },
        { 0x90, 0x0090 },
        { 0x91, 0x2018 },
        { 0x92, 0x2019 },
        { 0x93, 0x201C },
        { 0x94, 0x201D },
        { 0x95, 0x2022 },
        { 0x96, 0x2013 },
        { 0x97, 0x2014 },
        { 0x98, 0x02DC },
        { 0x99, 0x2122 },
        { 0x9A, 0x0161 },
        { 0x9B, 0x203A },
        { 0x9C, 0x0153 },
        { 0x9D, 0x009D },
        { 0x9E, 0x017E },
        { 0x9F, 0x0178 }
    };
    constexpr int CHARACTER_REF_PARSE_ERROR_REPALCEMENT_LEN = sizeof(CHARACTER_REF_PARSE_ERROR_REPALCEMENT) / sizeof(CodePointMap);

    /**
     * Attempts to get a character reference from the provided parsed code point value.
     * See the following link for validation: https://dev.w3.org/html5/spec-LC/tokenization.html#consume-a-character-reference
     * @param c Input character value
     * @param out Output character reference
     * @returns true if there wasn't a parse error, otherwise false
     */
    inline bool try_get_character_ref(code_point_t c, code_point_t& out) {
        for (int i = 0; i < CHARACTER_REF_PARSE_ERROR_REPALCEMENT_LEN; i++) {
            if (CHARACTER_REF_PARSE_ERROR_REPALCEMENT[i].key == c) {
                out = CHARACTER_REF_PARSE_ERROR_REPALCEMENT[i].value;
                return false;
            }
        }

        if ((c >= 0xD800 && c <= 0xDFFF) || c >= 0x10FFFF) {
            out = REPLACEMENT_CHAR;
            return false;
        }

        if (in_range(c, 0x0001, 0x0008)
            || in_range(c, 0x000E, 0x001F)
            || in_range(c, 0x007F, 0x009F)
            || in_range(c, 0xFDD0, 0xFDEF)
            || c == 0x000B
            || c == 0xFFFE
            || c == 0xFFFF
            || c == 0x1FFFE
            || c == 0x1FFFF
            || c == 0x2FFFE
            || c == 0x2FFFF
            || c == 0x3FFFE
            || c == 0x3FFFF
            || c == 0x4FFFE
            || c == 0x4FFFF
            || c == 0x5FFFE
            || c == 0x5FFFF
            || c == 0x6FFFE
            || c == 0x6FFFF
            || c == 0x7FFFE
            || c == 0x7FFFF
            || c == 0x8FFFE
            || c == 0x8FFFF
            || c == 0x9FFFE
            || c == 0x9FFFF
            || c == 0xAFFFE
            || c == 0xAFFFF
            || c == 0xBFFFE
            || c == 0xBFFFF
            || c == 0xCFFFE
            || c == 0xCFFFF
            || c == 0xDFFFE
            || c == 0xDFFFF
            || c == 0xEFFFE
            || c == 0xEFFFF
            || c == 0xFFFFE
            || c == 0xFFFFF
            || c == 0x10FFFE
            || c == 0x10FFFF) {
            out = c;
            return false;
        }

        out = c;
        return true;
    }
};

#endif