use std::{
    io::ErrorKind,
    net::{SocketAddr, UdpSocket},
    str::FromStr,
};

use pea_2_pea::*;

use super::types;

// return data_lenght and number of retryes
pub fn send_and_recv_with_retry(
    buf: &mut [u8; BUFFER_SIZE],
    send_buf: &[u8],
    dst: &SocketAddr,
    socket: &UdpSocket,
    retry_max: usize,
) -> Result<(usize, usize), ServerErrorResponses> {
    let mut retry_count: usize = 0;
    loop {
        match socket.send_to(send_buf, dst) {
            Ok(s) => {
                #[cfg(debug_assertions)]
                eprintln!("send {} bytes", s);
            }
            Err(e) => {
                panic!("Error sending data: {}", e);
            }
        }

        match socket.recv_from(buf) {
            Ok((data_lenght, src)) => {
                if src != *dst {
                    continue;
                }
                match buf[0] {
                    x if x == send_buf[0] as u8 => {
                        return Ok((data_lenght, retry_count));
                    }
                    x if x == ServerResponse::GENERAL_ERROR as u8 => {
                        return Err(ServerErrorResponses::IO(std::io::Error::new(
                            std::io::ErrorKind::InvalidData,
                            match std::str::from_utf8(&buf[1..data_lenght]) {
                                // the firts byte is compensated for sice this is len not index
                                Ok(s) => s.to_string(),
                                Err(e) => format!("invalid error string: {}", e).to_string(),
                            },
                        )));
                    }
                    x if x == ServerResponse::ID_DOESNT_EXIST as u8 => {
                        return Err(ServerErrorResponses::ID_DOESNT_EXIST);
                    }
                    x if x == ServerResponse::ID_EXISTS as u8 => {
                        return Err(ServerErrorResponses::ID_EXISTS);
                    }
                    _ => {
                        continue;
                    }
                }
            }
            Err(e) if e.kind() == ErrorKind::WouldBlock || e.kind() == ErrorKind::TimedOut => {
                // timedout
                if retry_count >= retry_max {
                    return Err(ServerErrorResponses::IO(std::io::Error::new(
                        ErrorKind::TimedOut,
                        "max retry count reached without responce",
                    )));
                }
                retry_count += 1;
                continue;
            }
            Err(e) => {
                return Err(ServerErrorResponses::IO(e));
            }
        }
    }
}

pub fn query_request(
    buf: &mut [u8; BUFFER_SIZE],
    dst: &SocketAddr,
    socket: &UdpSocket,
) -> Result<String, ServerErrorResponses> {
    match send_and_recv_with_retry(
        buf,
        &[ServerMethods::QUERY as u8],
        dst,
        socket,
        STANDARD_RETRY_MAX,
    ) {
        Ok((data_lenght, _)) => {
            return Ok(match std::str::from_utf8(&buf[1..data_lenght]) {
                Ok(s) => s.to_string(),
                Err(e) => {
                    eprint!("id to utf-8 failed: {}", e);
                    return Err(ServerErrorResponses::GENERAL_ERROR(format!("{}", e)));
                }
            });
        }
        Err(e) => return Err(e),
    }
}

pub fn register_request(
    buf: &mut [u8; BUFFER_SIZE],
    dst: &SocketAddr,
    socket: &UdpSocket,
    network: &types::Network,
    public_sock_addr: &Box<[u8]>,
    iv: &[u8; SALT_AND_IV_SIZE as usize],
) -> Result<usize, ServerErrorResponses> {
    let mut send_buf: Box<[u8]> = vec![
        0u8;
        RegisterRequestDataPositions::DATA as usize
            + network.net_id.len()
            + public_sock_addr.len()
    ]
    .into_boxed_slice();

    #[cfg(debug_assertions)]
    eprintln!(
        "registering network:\niv: {}\nSockAddr: {}\nsalt: {}",
        iv.iter().map(|x| format!("{:02X} ", x)).collect::<String>(),
        public_sock_addr
            .iter()
            .map(|x| format!("{:02X} ", x))
            .collect::<String>(),
        network
            .salt
            .iter()
            .map(|x| format!("{:02X} ", x))
            .collect::<String>(),
    );

    send_buf[0] = ServerMethods::REGISTER as u8; // set metod identification byte
    send_buf[RegisterRequestDataPositions::ENCRYPTED as usize] = network.encrypted as u8;

    send_buf[RegisterRequestDataPositions::ID_LEN as usize] = network.net_id.len() as u8;

    send_buf[RegisterRequestDataPositions::DATA as usize
        ..RegisterRequestDataPositions::DATA as usize + network.net_id.len()]
        .copy_from_slice(network.net_id.as_bytes()); // store network id

    send_buf[RegisterRequestDataPositions::IV as usize
        ..RegisterRequestDataPositions::IV as usize + SALT_AND_IV_SIZE as usize]
        .copy_from_slice(iv); // copy iv ad salt do the request
    send_buf[RegisterRequestDataPositions::SALT as usize
        ..RegisterRequestDataPositions::SALT as usize + SALT_AND_IV_SIZE as usize]
        .copy_from_slice(&network.salt);

    send_buf[RegisterRequestDataPositions::SOCKADDR_LEN as usize] = public_sock_addr.len() as u8;

    send_buf[RegisterRequestDataPositions::DATA as usize + network.net_id.len()
        ..RegisterRequestDataPositions::DATA as usize
            + network.net_id.len()
            + public_sock_addr.len()]
        .copy_from_slice(&public_sock_addr);

    match send_and_recv_with_retry(buf, &send_buf, dst, socket, STANDARD_RETRY_MAX) {
        Ok((data_lenght, _)) => return Ok(data_lenght),
        Err(e) => return Err(e),
    }
}

pub fn get_request(
    buf: &mut [u8; BUFFER_SIZE],
    dst: &SocketAddr,
    socket: &UdpSocket,
    network_id: &String,
    password: &Option<String>,
) -> Result<types::Network, ServerErrorResponses> {
    let mut send_buf: Box<[u8]> =
        vec![0u8; GetRequestDataPositions::ID as usize + network_id.len()].into_boxed_slice();
    send_buf[0] = ServerMethods::GET as u8;
    send_buf[GetRequestDataPositions::ID as usize
        ..GetRequestDataPositions::ID as usize + network_id.len()]
        .copy_from_slice(network_id.as_bytes());

    // this is unused now it will be used to bounds check in the future
    let data_lenght: usize =
        match send_and_recv_with_retry(buf, &send_buf, dst, socket, STANDARD_RETRY_MAX) {
            Ok((data_lenght, _)) => data_lenght,
            Err(e) => return Err(e),
        };

    let encrypted: bool = if buf[GetResponseDataPositions::ENCRYPTED as usize] != 0 {
        match password {
            Some(_) => true,
            None => panic!("Network is encrypted but no password was provided"),
        }
    } else {
        match password {
            Some(_) => {
                eprintln!(
                    "Warning! Network is not encrypted but password was provided, ignoring password!"
                )
            }
            None => {}
        }
        false
    };

    let mut num_of_clients: u8 = buf[GetResponseDataPositions::NUM_OF_CLIENTS as usize];

    let salt: [u8; SALT_AND_IV_SIZE as usize] = buf[GetResponseDataPositions::SALT as usize
        ..GetResponseDataPositions::SALT as usize + SALT_AND_IV_SIZE as usize]
        .try_into()
        .unwrap();

    let mut offset: usize = 0;
    let mut peers: Vec<SocketAddr> = Vec::with_capacity(1); // at least one client

    let key: [u8; 32] = match password {
        Some(p) => shared::crypto::derive_key_from_password(p.as_bytes(), &salt),
        None => [0; 32],
    };
    #[cfg(debug_assertions)]
    eprintln!(
        "key: {}",
        key.iter()
            .map(|x| format!("{:02X} ", x))
            .collect::<String>()
    );

    while num_of_clients != 0 {
        let sock_addr_len: u8 = buf[GetResponseDataPositions::CLIENTS as usize + offset];
        let mut iv: [u8; SALT_AND_IV_SIZE as usize] = [0; SALT_AND_IV_SIZE as usize];
        let sock_addr_raw: Box<[u8]> =
            buf[GetResponseDataPositions::CLIENTS as usize + 1 + offset + SALT_AND_IV_SIZE as usize
                ..GetResponseDataPositions::CLIENTS as usize
                    + 1
                    + offset
                    + SALT_AND_IV_SIZE as usize
                    + sock_addr_len as usize]
                .to_vec()
                .into_boxed_slice();
        #[cfg(debug_assertions)]
        eprintln!(
            "sock_addr_raw: {}",
            sock_addr_raw
                .iter()
                .map(|x| format!("{:02X} ", x))
                .collect::<String>()
        );
        loop {
            // loop used to easily skip peer
            let peer: SocketAddr = if encrypted {
                iv.copy_from_slice(
                    &buf[GetResponseDataPositions::CLIENTS as usize + 1 + offset
                        ..GetResponseDataPositions::CLIENTS as usize
                            + 1
                            + offset
                            + SALT_AND_IV_SIZE as usize],
                );
                match SocketAddr::from_str(&{
                    // sacrificed a goat to borrow checker to make this work
                    let decrypted = match shared::crypto::decrypt(&key, &iv, &sock_addr_raw) {
                        Ok(v) => v,
                        Err(_) => {
                            eprintln!("Warning peer ignored due to invalid data");
                            break;
                        }
                    };

                    match std::str::from_utf8(decrypted.as_slice()) {
                        Ok(s) => s.to_string(),
                        Err(e) => {
                            eprint!("id to utf-8 failed: {}", e);
                            eprintln!("Warning peer ignored due to invalid data");
                            break;
                        }
                    }
                }) {
                    Ok(s) => s,
                    Err(_) => {
                        eprintln!("Warning peer ignored due to invalid data");
                        break;
                    }
                }
            } else {
                match SocketAddr::from_str(&match std::str::from_utf8(&sock_addr_raw) {
                    Ok(s) => s.to_string(),
                    Err(e) => {
                        eprint!("id to utf-8 failed: {}", e);
                        eprintln!("Warning peer ignored due to invalid data");
                        break;
                    }
                }) {
                    Ok(s) => s,
                    Err(_) => {
                        eprintln!("Warning peer ignored due to invalid data");
                        break;
                    }
                }
            };

            peers.push(peer);
            break;
        }
        offset += SALT_AND_IV_SIZE as usize + sock_addr_len as usize;
        num_of_clients -= 1;
    }

    return Ok(types::Network::new(
        encrypted,
        key,
        network_id.to_string(),
        salt,
        peers,
    ));
}

pub fn send_heartbeat(
    buf: &mut [u8; BUFFER_SIZE],
    dst: &SocketAddr,
    socket: &UdpSocket,
    network: &types::Network,
    my_public_sock_addr: &Box<[u8]>,
    iv: &[u8; SALT_AND_IV_SIZE as usize],
) -> Result<usize, ServerErrorResponses> {
    let mut send_buf: Box<[u8]> = vec![
        0u8;
        HeartBeatRequestDataPositions::IV as usize
            + SALT_AND_IV_SIZE as usize
            + my_public_sock_addr.len()
            + network.net_id.len()
    ]
    .into_boxed_slice();

    send_buf[0] = ServerMethods::HEARTBEAT as u8;
    send_buf[HeartBeatRequestDataPositions::ID_LEN as usize] = network.net_id.len() as u8;
    send_buf[HeartBeatRequestDataPositions::SOCKADDR_LEN as usize] =
        my_public_sock_addr.len() as u8;

    send_buf[HeartBeatRequestDataPositions::IV as usize
        ..HeartBeatRequestDataPositions::IV as usize + SALT_AND_IV_SIZE as usize]
        .copy_from_slice(iv);

    send_buf[HeartBeatRequestDataPositions::DATA as usize
        ..HeartBeatRequestDataPositions::DATA as usize + network.net_id.len()]
        .copy_from_slice(network.net_id.as_bytes());

    send_buf[HeartBeatRequestDataPositions::DATA as usize + network.net_id.len()
        ..HeartBeatRequestDataPositions::DATA as usize
            + network.net_id.len()
            + my_public_sock_addr.len()]
        .copy_from_slice(&my_public_sock_addr);

    match send_and_recv_with_retry(buf, &send_buf, dst, socket, STANDARD_RETRY_MAX) {
        Ok((data_lenght, _)) => return Ok(data_lenght),
        Err(e) => return Err(e),
    }
}