use crate::utils::ReadUtils;
use aes::cipher::generic_array::GenericArray;
use aes::cipher::BlockEncrypt;
use std::io::{Read, Result as IoResult};

#[allow(dead_code)]
pub struct AesDecoder<Io: Read, Aes: BlockEncrypt> {
    io: Io,
    aes: Aes,

    counter: u128,
    block: [u8; 16],
    cursor: usize,
}

impl<Io: Read, Aes: BlockEncrypt> AesDecoder<Io, Aes> {
    pub fn new(mut io: Io, aes: Aes) -> IoResult<Self> {
        let block = io.read_arr::<16>()?;
        let mut decoder = Self {
            io,
            aes,
            counter: 1,
            block,
            cursor: 0,
        };
        decoder.decrypt_block();
        Ok(decoder)
    }

    #[inline]
    fn decrypt_block(&mut self) {
        let mut mask = self.counter.to_le_bytes();
        self.aes
            .encrypt_block(GenericArray::from_mut_slice(&mut mask));
        for (b, m) in self.block.iter_mut().zip(mask) {
            *b ^= m
        }
        self.counter += 1;
    }
}

impl<Io: Read, Aes: BlockEncrypt> Read for AesDecoder<Io, Aes> {
    fn read(&mut self, buf: &mut [u8]) -> IoResult<usize> {
        todo!()
    }
}