#include "protocol_indala_40134.h"
#include <furi.h>

typedef uint64_t Indala40134CardData;

static void set_bit(bool bit, uint8_t position, Indala40134CardData* card_data) {
    position = (sizeof(Indala40134CardData) * 8) - 1 - position;
    if(bit) {
        *card_data |= 1ull << position;
    } else {
        *card_data &= ~(1ull << position);
    }
}

static bool get_bit(uint8_t position, const Indala40134CardData* card_data) {
    position = (sizeof(Indala40134CardData) * 8) - 1 - position;
    return (*card_data >> position) & 1;
}

uint8_t ProtocolIndala40134::get_encoded_data_size() {
    return sizeof(Indala40134CardData);
}

uint8_t ProtocolIndala40134::get_decoded_data_size() {
    return 3;
}

void ProtocolIndala40134::encode(
    const uint8_t* decoded_data,
    const uint8_t decoded_data_size,
    uint8_t* encoded_data,
    const uint8_t encoded_data_size) {
    furi_check(decoded_data_size >= get_decoded_data_size());
    furi_check(encoded_data_size >= get_encoded_data_size());

    uint32_t fc_and_card = (decoded_data[0] << 16) | (decoded_data[1] << 8) | decoded_data[2];
    Indala40134CardData card_data = 0;

    // preamble
    set_bit(1, 0, &card_data);
    set_bit(1, 2, &card_data);
    set_bit(1, 32, &card_data);

    // factory code
    set_bit(((fc_and_card >> 23) & 1), 57, &card_data);
    set_bit(((fc_and_card >> 22) & 1), 49, &card_data);
    set_bit(((fc_and_card >> 21) & 1), 44, &card_data);
    set_bit(((fc_and_card >> 20) & 1), 47, &card_data);
    set_bit(((fc_and_card >> 19) & 1), 48, &card_data);
    set_bit(((fc_and_card >> 18) & 1), 53, &card_data);
    set_bit(((fc_and_card >> 17) & 1), 39, &card_data);
    set_bit(((fc_and_card >> 16) & 1), 58, &card_data);

    // card number
    set_bit(((fc_and_card >> 15) & 1), 42, &card_data);
    set_bit(((fc_and_card >> 14) & 1), 45, &card_data);
    set_bit(((fc_and_card >> 13) & 1), 43, &card_data);
    set_bit(((fc_and_card >> 12) & 1), 40, &card_data);
    set_bit(((fc_and_card >> 11) & 1), 52, &card_data);
    set_bit(((fc_and_card >> 10) & 1), 36, &card_data);
    set_bit(((fc_and_card >> 9) & 1), 35, &card_data);
    set_bit(((fc_and_card >> 8) & 1), 51, &card_data);
    set_bit(((fc_and_card >> 7) & 1), 46, &card_data);
    set_bit(((fc_and_card >> 6) & 1), 33, &card_data);
    set_bit(((fc_and_card >> 5) & 1), 37, &card_data);
    set_bit(((fc_and_card >> 4) & 1), 54, &card_data);
    set_bit(((fc_and_card >> 3) & 1), 56, &card_data);
    set_bit(((fc_and_card >> 2) & 1), 59, &card_data);
    set_bit(((fc_and_card >> 1) & 1), 50, &card_data);
    set_bit(((fc_and_card >> 0) & 1), 41, &card_data);

    // checksum
    uint8_t checksum = 0;
    checksum += ((fc_and_card >> 14) & 1);
    checksum += ((fc_and_card >> 12) & 1);
    checksum += ((fc_and_card >> 9) & 1);
    checksum += ((fc_and_card >> 8) & 1);
    checksum += ((fc_and_card >> 6) & 1);
    checksum += ((fc_and_card >> 5) & 1);
    checksum += ((fc_and_card >> 2) & 1);
    checksum += ((fc_and_card >> 0) & 1);

    // wiegand parity bits
    // even parity sum calculation (high 12 bits of data)
    uint8_t even_parity_sum = 0;
    for(int8_t i = 12; i < 24; i++) {
        if(((fc_and_card >> i) & 1) == 1) {
            even_parity_sum++;
        }
    }

    // odd parity sum calculation (low 12 bits of data)
    uint8_t odd_parity_sum = 1;
    for(int8_t i = 0; i < 12; i++) {
        if(((fc_and_card >> i) & 1) == 1) {
            odd_parity_sum++;
        }
    }

    // even parity bit
    set_bit((even_parity_sum % 2), 34, &card_data);

    // odd parity bit
    set_bit((odd_parity_sum % 2), 38, &card_data);

    // checksum
    if((checksum & 1) == 1) {
        set_bit(0, 62, &card_data);
        set_bit(1, 63, &card_data);
    } else {
        set_bit(1, 62, &card_data);
        set_bit(0, 63, &card_data);
    }

    memcpy(encoded_data, &card_data, get_encoded_data_size());
}

// factory code
static uint8_t get_fc(const Indala40134CardData* card_data) {
    uint8_t fc = 0;

    fc = fc << 1 | get_bit(57, card_data);
    fc = fc << 1 | get_bit(49, card_data);
    fc = fc << 1 | get_bit(44, card_data);
    fc = fc << 1 | get_bit(47, card_data);
    fc = fc << 1 | get_bit(48, card_data);
    fc = fc << 1 | get_bit(53, card_data);
    fc = fc << 1 | get_bit(39, card_data);
    fc = fc << 1 | get_bit(58, card_data);

    return fc;
}

// card number
static uint16_t get_cn(const Indala40134CardData* card_data) {
    uint16_t cn = 0;

    cn = cn << 1 | get_bit(42, card_data);
    cn = cn << 1 | get_bit(45, card_data);
    cn = cn << 1 | get_bit(43, card_data);
    cn = cn << 1 | get_bit(40, card_data);
    cn = cn << 1 | get_bit(52, card_data);
    cn = cn << 1 | get_bit(36, card_data);
    cn = cn << 1 | get_bit(35, card_data);
    cn = cn << 1 | get_bit(51, card_data);
    cn = cn << 1 | get_bit(46, card_data);
    cn = cn << 1 | get_bit(33, card_data);
    cn = cn << 1 | get_bit(37, card_data);
    cn = cn << 1 | get_bit(54, card_data);
    cn = cn << 1 | get_bit(56, card_data);
    cn = cn << 1 | get_bit(59, card_data);
    cn = cn << 1 | get_bit(50, card_data);
    cn = cn << 1 | get_bit(41, card_data);

    return cn;
}

void ProtocolIndala40134::decode(
    const uint8_t* encoded_data,
    const uint8_t encoded_data_size,
    uint8_t* decoded_data,
    const uint8_t decoded_data_size) {
    furi_check(decoded_data_size >= get_decoded_data_size());
    furi_check(encoded_data_size >= get_encoded_data_size());

    const Indala40134CardData* card_data =
        reinterpret_cast<const Indala40134CardData*>(encoded_data);

    uint8_t fc = get_fc(card_data);
    uint16_t card = get_cn(card_data);

    decoded_data[0] = fc;
    decoded_data[1] = card >> 8;
    decoded_data[2] = card;
}

bool ProtocolIndala40134::can_be_decoded(
    const uint8_t* encoded_data,
    const uint8_t encoded_data_size) {
    furi_check(encoded_data_size >= get_encoded_data_size());
    bool can_be_decoded = false;

    const Indala40134CardData* card_data =
        reinterpret_cast<const Indala40134CardData*>(encoded_data);

    do {
        // preambula
        if((*card_data >> 32) != 0xa0000000UL) break;

        // data
        const uint32_t fc_and_card = get_fc(card_data) << 16 | get_cn(card_data);

        // checksum
        const uint8_t checksum = get_bit(62, card_data) << 1 | get_bit(63, card_data);
        uint8_t checksum_sum = 0;
        checksum_sum += ((fc_and_card >> 14) & 1);
        checksum_sum += ((fc_and_card >> 12) & 1);
        checksum_sum += ((fc_and_card >> 9) & 1);
        checksum_sum += ((fc_and_card >> 8) & 1);
        checksum_sum += ((fc_and_card >> 6) & 1);
        checksum_sum += ((fc_and_card >> 5) & 1);
        checksum_sum += ((fc_and_card >> 2) & 1);
        checksum_sum += ((fc_and_card >> 0) & 1);
        checksum_sum = checksum_sum & 0b1;

        if(checksum_sum == 1 && checksum == 0b01) {
        } else if(checksum_sum == 0 && checksum == 0b10) {
        } else {
            break;
        }

        // wiegand parity bits
        // even parity sum calculation (high 12 bits of data)
        const bool even_parity = get_bit(34, card_data);
        uint8_t even_parity_sum = 0;
        for(int8_t i = 12; i < 24; i++) {
            if(((fc_and_card >> i) & 1) == 1) {
                even_parity_sum++;
            }
        }
        if(even_parity_sum % 2 != even_parity) break;

        // odd parity sum calculation (low 12 bits of data)
        const bool odd_parity = get_bit(38, card_data);
        uint8_t odd_parity_sum = 1;
        for(int8_t i = 0; i < 12; i++) {
            if(((fc_and_card >> i) & 1) == 1) {
                odd_parity_sum++;
            }
        }
        if(odd_parity_sum % 2 != odd_parity) break;

        can_be_decoded = true;
    } while(false);

    return can_be_decoded;
}