#ifndef BASE64_CONVERTER_HPP
#define BASE64_CONVERTER_HPP

#include <iostream>
#include <vector>

static const char characterMap[] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L',
'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '/', '+'};

static const std::vector<int> base64InverseMap = [] {
    std::vector<int> map(256, -1);
    for (int i = 0; i < 64; ++i) {
        map[characterMap[i]] = i;
    }
    return map;
 }();


inline bool is_base64(unsigned char c) {
    return (isalnum(c) || (c == '+') || (c == '/'));
}

inline std::string Base64Encode(const unsigned char* buffer, size_t size) {
    std::string ret;
    int i = 0;
    int j = 0;
    unsigned char char_array_3[3];
    unsigned char char_array_4[4];

    while (size--) {
        char_array_3[i++] = *(buffer++);
        if (i == 3) {
            char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
            char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
            char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
            char_array_4[3] = char_array_3[2] & 0x3f;

            for (i = 0; (i < 4); i++)
                ret += characterMap[char_array_4[i]];
            i = 0;
        }
    }

    if (i) {
        for (j = i; j < 3; j++)
            char_array_3[j] = '\0';

        char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
        char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
        char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
        char_array_4[3] = char_array_3[2] & 0x3f;

        for (j = 0; (j < i + 1); j++)
            ret += characterMap[char_array_4[j]];

        while ((i++ < 3))
            ret += '=';
    }

    return ret;
}

inline char* Base64Encode(char* buffer, size_t& size)
{
    std::string encodedString = Base64Encode(reinterpret_cast<const unsigned char*>(buffer), size);
    size = encodedString.size(); // Update size to the new encoded string size

    char* encodedBuffer = new char[size + 1];
    std::copy(encodedString.begin(), encodedString.end(), encodedBuffer);
    encodedBuffer[size] = '\0'; // Null-terminate the string

    return encodedBuffer;
}

inline std::vector<unsigned char> Base64Decode(const std::string& encoded_string) {
    int in_len = encoded_string.size();
    int i = 0;
    int j = 0;
    int in_ = 0;
    unsigned char char_array_4[4], char_array_3[3];
    std::vector<unsigned char> ret;

    while (in_len-- && (encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
        char_array_4[i++] = encoded_string[in_]; in_++;
        if (i == 4) {
            for (i = 0; i < 4; i++)
                char_array_4[i] = base64InverseMap[char_array_4[i]];

            char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
            char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
            char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

            for (i = 0; (i < 3); i++)
                ret.push_back(char_array_3[i]);
            i = 0;
        }
    }

    if (i) {
        for (j = i; j < 4; j++)
            char_array_4[j] = 0;

        for (j = 0; j < 4; j++)
            char_array_4[j] = base64InverseMap[char_array_4[j]];

        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

        for (j = 0; (j < i - 1); j++) ret.push_back(char_array_3[j]);
    }

    return ret;
}

inline char* Base64Decode(char* buffer, size_t& size) {
    std::string encodedString(buffer);
    std::vector<unsigned char> decodedData = Base64Decode(encodedString);
    size = decodedData.size();

    char* decodedBuffer = new char[size];
    std::copy(decodedData.begin(), decodedData.end(), decodedBuffer);

    return decodedBuffer;
}


#endif