mod lfsr;
mod period;
mod tea3;

use lfsr::Lfsr;
use period::{period_bruteforce, period_floyd, period_paper};
use tea3::Tea3;

fn main() {
    let mut lfsr = Lfsr::new(4, vec![0, 3], vec![0x12, 0x34, 0x56, 0x78]);

    for _ in 0..16 {
        let byte = lfsr.next();
        println!("{:02x} | state: {:?}", byte, lfsr.state());
    }

    let key = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
    let state = vec![0; 8];

    let mut cipher = Tea3::new(key.clone(), state.clone());
    cipher.init();

    println!("\nKeystream:");
    for _ in 0..10 {
        let byte = cipher.next_byte();
        println!("{:#04x}", byte);
    }

    let plaintext = b"hello world";

    let mut cipher_enc = Tea3::new(key.clone(), state.clone());
    cipher_enc.init();

    let ciphertext: Vec<u8> = plaintext
        .iter()
        .map(|&b| b ^ cipher_enc.next_byte())
        .collect();

    println!("\nPlaintext : {:?}", plaintext);
    println!("Ciphertext: {:?}", ciphertext);

    let mut cipher_dec = Tea3::new(key, state);
    cipher_dec.init();

    let decrypted: Vec<u8> = ciphertext
        .iter()
        .map(|&b| b ^ cipher_dec.next_byte())
        .collect();

    println!("Decrypted : {:?}", decrypted);

    println!(
        "\nPaper period: {}",
        // period_paper(vec![0xc2, 0xc2, 0xc2, 0xc2, 0xc2])
        period_paper(vec![0x05, 0x58, 0x6f, 0xe1, 0xa3])
    );
}