#![allow(dead_code)]

include!(concat!(env!("OUT_DIR"), "/keys.rs"));

// ── XOR Obfuscation ──────────────────────────────────────────────────────────

pub const fn xor_transform<const N: usize>(data: &[u8], key: u8) -> [u8; N] {
    let mut r = [0u8; N];
    let mut i = 0;
    while i < N {
        r[i] = data[i] ^ key;
        i += 1;
    }
    r
}

#[macro_export]
macro_rules! xstr {
    ($s: literal) => {{
        const INPUT: &[u8] = $s.as_bytes();
        const N: usize = INPUT.len();
        const KEY: u8 = $crate::XOR_KEY;
        const ENC: [u8; N] = $crate::xor_transform::<N>(INPUT, KEY);
        let mut buf = ENC;
        let mut i = 0;
        while i < N {
            buf[i] ^= KEY;
            i += 1;
        }
        unsafe { String::from_utf8_unchecked(buf.to_vec()) }
    }};
}

// ── AES Obfuscation ──────────────────────────────────────────────────────────

const SBOX: [u8; 256] = [
    0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
    0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
    0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
    0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
    0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
    0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
    0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
    0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
    0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
    0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
    0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
    0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
    0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
    0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
    0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
    0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16,
];

const INV_SBOX: [u8; 256] = [
    0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
    0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
    0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
    0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
    0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
    0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
    0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
    0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
    0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
    0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
    0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
    0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
    0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
    0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
    0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
    0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d,
];

const RCON: [u8; 11] = [0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36];

const fn gf_mul(a: u8, b: u8) -> u8 {
    let mut r = 0u8;
    let mut aa = a;
    let mut bb = b;
    let mut i = 0;
    while i < 8 {
        if bb & 1 == 1 {
            r ^= aa;
        }
        let hi = aa & 0x80;
        aa <<= 1;
        if hi == 0x80 {
            aa ^= 0x1b;
        }
        bb >>= 1;
        i += 1;
    }
    r
}

const fn aes_key_expansion(key: &[u8; 16]) -> [[u8; 16]; 11] {
    let mut w = [0u8; 176];
    let mut i = 0;
    while i < 16 {
        w[i] = key[i];
        i += 1;
    }

    let mut i = 4;
    while i < 44 {
        let wi_1_0 = w[(i - 1) * 4];
        let wi_1_1 = w[(i - 1) * 4 + 1];
        let wi_1_2 = w[(i - 1) * 4 + 2];
        let wi_1_3 = w[(i - 1) * 4 + 3];

        let (t0, t1, t2, t3) = if i % 4 == 0 {
            let rot0 = wi_1_1;
            let rot1 = wi_1_2;
            let rot2 = wi_1_3;
            let rot3 = wi_1_0;

            let sub0 = SBOX[rot0 as usize];
            let sub1 = SBOX[rot1 as usize];
            let sub2 = SBOX[rot2 as usize];
            let sub3 = SBOX[rot3 as usize] ^ RCON[i / 4];

            (sub0, sub1, sub2, sub3)
        } else {
            (wi_1_0, wi_1_1, wi_1_2, wi_1_3)
        };

        w[i * 4]     = w[(i - 4) * 4]     ^ t0;
        w[i * 4 + 1] = w[(i - 4) * 4 + 1] ^ t1;
        w[i * 4 + 2] = w[(i - 4) * 4 + 2] ^ t2;
        w[i * 4 + 3] = w[(i - 4) * 4 + 3] ^ t3;

        i += 1;
    }

    let mut rk = [[0u8; 16]; 11];
    let mut r = 0;
    while r < 11 {
        let mut j = 0;
        while j < 16 {
            rk[r][j] = w[r * 16 + j];
            j += 1;
        }
        r += 1;
    }
    rk
}

const fn sub_bytes(state: &mut [u8; 16]) {
    let mut i = 0;
    while i < 16 {
        state[i] = SBOX[state[i] as usize];
        i += 1;
    }
}

const fn inv_sub_bytes(state: &mut [u8; 16]) {
    let mut i = 0;
    while i < 16 {
        state[i] = INV_SBOX[state[i] as usize];
        i += 1;
    }
}

const fn shift_rows(state: &mut [u8; 16]) {
    let t = state[1];
    state[1] = state[5];
    state[5] = state[9];
    state[9] = state[13];
    state[13] = t;

    let t0 = state[2];
    let t1 = state[6];
    state[2] = state[10];
    state[6] = state[14];
    state[10] = t0;
    state[14] = t1;

    let t = state[15];
    state[15] = state[11];
    state[11] = state[7];
    state[7] = state[3];
    state[3] = t;
}

const fn inv_shift_rows(state: &mut [u8; 16]) {
    let t = state[1];
    state[1] = state[13];
    state[13] = state[9];
    state[9] = state[5];
    state[5] = t;

    let t0 = state[2];
    let t1 = state[6];
    state[2] = state[10];
    state[6] = state[14];
    state[10] = t0;
    state[14] = t1;

    let t = state[3];
    state[3] = state[7];
    state[7] = state[11];
    state[11] = state[15];
    state[15] = t;
}

const fn mix_columns(state: &mut [u8; 16]) {
    let mut i = 0;
    while i < 16 {
        let a = state[i];
        let b = state[i + 1];
        let c = state[i + 2];
        let d = state[i + 3];

        state[i]     = gf_mul(2, a) ^ gf_mul(3, b) ^ c       ^ d;
        state[i + 1] = a       ^ gf_mul(2, b) ^ gf_mul(3, c) ^ d;
        state[i + 2] = a       ^ b       ^ gf_mul(2, c) ^ gf_mul(3, d);
        state[i + 3] = gf_mul(3, a) ^ b       ^ c       ^ gf_mul(2, d);

        i += 4;
    }
}

const fn inv_mix_columns(state: &mut [u8; 16]) {
    let mut i = 0;
    while i < 16 {
        let a = state[i];
        let b = state[i + 1];
        let c = state[i + 2];
        let d = state[i + 3];

        state[i]     = gf_mul(14, a) ^ gf_mul(11, b) ^ gf_mul(13, c) ^ gf_mul(9,  d);
        state[i + 1] = gf_mul(9,  a) ^ gf_mul(14, b) ^ gf_mul(11, c) ^ gf_mul(13, d);
        state[i + 2] = gf_mul(13, a) ^ gf_mul(9,  b) ^ gf_mul(14, c) ^ gf_mul(11, d);
        state[i + 3] = gf_mul(11, a) ^ gf_mul(13, b) ^ gf_mul(9,  c) ^ gf_mul(14, d);

        i += 4;
    }
}

const fn add_round_key(state: &mut [u8; 16], rk: &[u8; 16]) {
    let mut i = 0;
    while i < 16 {
        state[i] ^= rk[i];
        i += 1;
    }
}

pub const fn aes_encrypt_block(block: &[u8; 16], key: &[u8; 16]) -> [u8; 16] {
    let rk = aes_key_expansion(key);
    let mut state = *block;

    add_round_key(&mut state, &rk[0]);

    let mut round = 1;
    while round < 10 {
        sub_bytes(&mut state);
        shift_rows(&mut state);
        mix_columns(&mut state);
        add_round_key(&mut state, &rk[round]);
        round += 1;
    }

    sub_bytes(&mut state);
    shift_rows(&mut state);
    add_round_key(&mut state, &rk[10]);

    state
}

pub fn aes_decrypt_block(block: &[u8; 16], key: &[u8; 16]) -> [u8; 16] {
    let rk = aes_key_expansion(key);
    let mut state = *block;

    add_round_key(&mut state, &rk[10]);

    let mut round = 9;
    loop {
        inv_shift_rows(&mut state);
        inv_sub_bytes(&mut state);
        add_round_key(&mut state, &rk[round]);
        inv_mix_columns(&mut state);

        if round == 1 {
            break;
        }
        round -= 1;
    }

    inv_shift_rows(&mut state);
    inv_sub_bytes(&mut state);
    add_round_key(&mut state, &rk[0]);

    state
}

#[macro_export]
macro_rules! astr {
    ($s: literal) => {{
        const INPUT: &[u8] = $s.as_bytes();
        const N: usize = INPUT.len();
        const NUM_BLOCKS: usize = if N == 0 { 1 } else { (N + 15) / 16 };
        const PAD_LEN: usize = NUM_BLOCKS * 16;
        const PAD_VAL: u8 = (PAD_LEN - N) as u8;

        const PADDED: [u8; PAD_LEN] = {
            let mut p = [0u8; PAD_LEN];
            let mut i = 0;
            while i < N {
                p[i] = INPUT[i];
                i += 1;
            }
            while i < PAD_LEN {
                p[i] = PAD_VAL;
                i += 1;
            }
            p
        };

        const ENCRYPTED: [u8; PAD_LEN] = {
            let mut e = [0u8; PAD_LEN];
            let mut b = 0;
            while b < NUM_BLOCKS {
                let mut blk = [0u8; 16];
                let mut j = 0;
                while j < 16 {
                    blk[j] = PADDED[b * 16 + j];
                    j += 1;
                }
                let enc = $crate::aes_encrypt_block(&blk, &$crate::AES_KEY);
                j = 0;
                while j < 16 {
                    e[b * 16 + j] = enc[j];
                    j += 1;
                }
                b += 1;
            }
            e
        };

        let mut buf = [0u8; PAD_LEN];
        let mut b = 0;
        while b < NUM_BLOCKS {
            let mut blk = [0u8; 16];
            let mut j = 0;
            while j < 16 {
                blk[j] = ENCRYPTED[b * 16 + j];
                j += 1;
            }
            let dec = $crate::aes_decrypt_block(&blk, &$crate::AES_KEY);
            j = 0;
            while j < 16 {
                buf[b * 16 + j] = dec[j];
                j += 1;
            }
            b += 1;
        }

        let pad = buf[PAD_LEN - 1] as usize;
        let actual_len = PAD_LEN - pad;

        unsafe { String::from_utf8_unchecked(buf[..actual_len].to_vec()) }
    }};
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_xor_roundtrip() {
        let s = xstr!("Hello, XOR!");
        assert_eq!(s, "Hello, XOR!");
    }

    #[test]
    fn test_xor_empty() {
        let s = xstr!("");
        assert_eq!(s, "");
    }

    #[test]
    fn test_aes_roundtrip() {
        let s = astr!("Hello, AES!");
        assert_eq!(s, "Hello, AES!");
    }

    #[test]
    fn test_aes_empty() {
        let s = astr!("");
        assert_eq!(s, "");
    }

    #[test]
    fn test_aes_long_string() {
        let s = astr!("The quick brown fox jumps over the lazy dog. This is a longer string to test multiple AES blocks!");
        assert_eq!(s, "The quick brown fox jumps over the lazy dog. This is a longer string to test multiple AES blocks!");
    }

    #[test]
    fn test_aes_exact_block() {
        let s = astr!("1234567890123456");
        assert_eq!(s, "1234567890123456");
    }

    #[test]
    fn test_xor_key_constant() {
        let s1 = xstr!("test");
        assert_eq!(s1, "test");
    }
}
