use std::net::*;

use rand::Rng;

use nardol::Bytes;
use nardol::{Packet, PacketKind};

/// This checks only if size of Packet was calculated correctly.
#[test]
fn new() {
    let packet = Packet::new(PacketKind::Empty, Bytes::from([1_u8, 2_u8, 3_u8, 4_u8])).unwrap();
    assert_eq!(packet.size(), 8_u16);
}

/// Checks if FromBytes::from_buff implementation for Packet correctly returns an error if buffer is to small.
#[test]
fn from_buff_size_test() {
    let too_short_buff = [1_u8, 2_u8, 3_u8];

    let mut returns_error = false;

    if Packet::try_from(too_short_buff.as_slice()).is_err() {
        returns_error = true;
    }

    assert!(returns_error);
}

/// Checks if FromBytes::from_buff implementation for Packet correctly builds a packet from_buff.
#[test]
fn from_buff_correctness_test() {
    // This should create a Packet with size 6, kind Unit and two bytes in its content.
    let buff = vec![0_u8, 6_u8, 4_u8, 0_u8, 1_u8, 2_u8];

    let packet = Packet::new(PacketKind::Unit, Bytes::from([1_u8, 2_u8])).unwrap();

    let packet_from_buff = Packet::try_from(buff.as_slice()).unwrap();

    assert_eq!(packet, packet_from_buff);
}

/// Checks if IntoBytes::into_Bytes creates a correct buff from a Packet.
#[test]
#[allow(non_snake_case)]
fn into_Bytes() {
    let packet = Packet::new(PacketKind::Unit, Bytes::from([1_u8, 2_u8])).unwrap();

    let buff = vec![0_u8, 6_u8, 4_u8, 0_u8, 1_u8, 2_u8];

    let buff_from_packet = Bytes::from(packet).into_vec();

    assert_eq!(buff, buff_from_packet);
}

/// Tests if Packet::receive works and returns the same data for successive calls.
/// Also tests Packet::send if correct data are sent.
#[test]
fn receive() {
    let addrs = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8000);
    let listener = TcpListener::bind(addrs).unwrap();

    let created_packet = Packet::new(PacketKind::Unit, Bytes::from([0, 1, 2, 3, 4, 5])).unwrap();
    let created_packet_in_thread = created_packet.clone();

    std::thread::spawn(move || {
        std::thread::sleep(std::time::Duration::from_secs(1));

        let packet = created_packet_in_thread;

        let mut stream = TcpStream::connect(addrs).unwrap();
        packet.send(&mut stream).unwrap();
    });

    let (mut stream, _) = listener.accept().unwrap();

    let packet = Packet::receive(&mut stream).unwrap();

    assert_eq!(created_packet, packet);
}

/// Tests if Packet::receive_from works and returns the same data for successive calls.
/// Also tests Packet::send_to if correct data are sent.
#[test]
fn receive_from() {
    let addrs1 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8001);
    let addrs2 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8002);

    let socket1 = UdpSocket::bind(addrs1).unwrap();
    let socket2 = UdpSocket::bind(addrs2).unwrap();

    let created_packet = Packet::new(PacketKind::Unit, Bytes::from([0, 1, 2, 3, 4, 5])).unwrap();

    created_packet.clone().send_to(socket1, addrs2).unwrap();

    let (packet, _) = Packet::receive_from(socket2.try_clone().unwrap()).unwrap();

    assert_eq!(created_packet, packet);
}

/// Tests if Packet::peek_from_connected works and returns the same data for successive calls.
/// Also tests Packet::send_to_connected if correct data are sent.
#[test]
fn receive_from_connected() {
    let addrs1 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8003);
    let addrs2 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8004);

    let socket1 = UdpSocket::bind(addrs1).unwrap();
    let socket2 = UdpSocket::bind(addrs2).unwrap();

    socket1.connect(addrs2).unwrap();

    let created_packet = Packet::new(PacketKind::Unit, Bytes::from([0, 1, 2, 3, 4, 5])).unwrap();

    created_packet.clone().send_to_connected(socket1).unwrap();

    let packet = Packet::receive_from_connected(socket2.try_clone().unwrap()).unwrap();

    assert_eq!(created_packet, packet);
}

/// Tests if Packet::peek works and returns the same data for successive calls.
/// Also tests Packet::send if correct data are sent.
#[test]
fn peek() {
    let addrs = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8005);
    let listener = TcpListener::bind(addrs).unwrap();

    let created_packet = Packet::new(PacketKind::Unit, Bytes::from([0, 1, 2, 3, 4, 5])).unwrap();
    let created_packet_in_thread = created_packet.clone();

    std::thread::spawn(move || {
        std::thread::sleep(std::time::Duration::from_secs(1));

        let packet = created_packet_in_thread;

        let mut stream = TcpStream::connect(addrs).unwrap();
        packet.send(&mut stream).unwrap();
    });

    let mut received = Vec::new();

    let (mut stream, _) = listener.accept().unwrap();

    for _ in 0..10 {
        let packet = Packet::peek(&mut stream);
        received.push(packet);
    }

    assert!(received
        .into_iter()
        .map(|recv| recv.unwrap())
        .collect::<Vec<Packet>>()
        .into_iter()
        .all(|packet| packet == created_packet))
}

/// Tests if Packet::peek_from a works and returns the same data for successive calls.
/// Also tests Packet::send_to if correct data are sent.
#[test]
fn peek_from_and_send_to() {
    let addrs1 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8006);
    let addrs2 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8007);

    let socket1 = UdpSocket::bind(addrs1).unwrap();
    let socket2 = UdpSocket::bind(addrs2).unwrap();

    let created_packet = Packet::new(PacketKind::Unit, Bytes::from([0, 1, 2, 3, 4, 5])).unwrap();

    created_packet.clone().send_to(socket1, addrs2).unwrap();

    let mut received = Vec::new();

    for _ in 0..10 {
        let packet = Packet::peek_from(socket2.try_clone().unwrap());
        received.push(packet);
    }

    assert!(received
        .into_iter()
        .map(|recv| {
            let (packet, _) = recv.unwrap();
            packet
        })
        .collect::<Vec<Packet>>()
        .into_iter()
        .all(|packet| packet == created_packet))
}

/// Tests if Packet::peek_from_connected works and returns the same data for successive calls.
/// Also tests Packet::send_to_connected if correct data are sent.
#[test]
fn peek_from_and_send_to_connected() {
    let addrs1 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8008);
    let addrs2 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8009);

    let socket1 = UdpSocket::bind(addrs1).unwrap();
    let socket2 = UdpSocket::bind(addrs2).unwrap();

    socket1.connect(addrs2).unwrap();

    let created_packet = Packet::new(PacketKind::Unit, Bytes::from([0, 1, 2, 3, 4, 5])).unwrap();

    created_packet.clone().send_to_connected(socket1).unwrap();

    let mut received = Vec::new();

    for _ in 0..10 {
        let packet = Packet::peek_from_connected(socket2.try_clone().unwrap());
        received.push(packet);
    }

    assert!(received
        .into_iter()
        .map(|recv| recv.unwrap())
        .collect::<Vec<Packet>>()
        .into_iter()
        .all(|packet| packet == created_packet))
}

/// Tests if Packet::number_of_packets returns a correct number of packets.
#[test]
fn number_of_packets() {
    assert_eq!(5, Packet::number_of_packets(5000));
}

/// Tests if Packet::split_to_max_packet_size splits given buffer to correctly sized packets.
///
/// This test might fail if Packet::max_size is changed between setting it in this test and call of
/// Packet::split_to_max_packet_size by other test which makes it to created differently sized buffers than
/// those against it is checked.
///
/// It is not a design problem of the function, it actually shows that the function
/// works correctly, but the test itself is poorly written.
///
/// The simplest solutions is to run it by itself or run all tests limited to one thread, so there is no call that
/// would change the maximum size of the Packet.
#[test]
fn split_to_max_packet_size() {
    let buff: Bytes = vec![0_u8; 9].into();

    Packet::set_max_size(6);
    let packets = Packet::split_to_max_packet_size(buff);

    let manual_packets: Vec<Bytes> = vec![
        vec![0_u8; 2].into(),
        vec![0_u8; 2].into(),
        vec![0_u8; 2].into(),
        vec![0_u8; 2].into(),
        vec![0_u8; 1].into(),
    ];

    assert_eq!(
        manual_packets, packets,
        "Check the test description, this might be a false failure."
    );
}

/// Tests if Packet::max_size works correctly in single threaded context.
#[test]
fn max_size_single_threaded_access() {
    Packet::set_max_size(1024);

    assert_eq!(1024, Packet::max_size())
}

/// Tests if Packet::max_size works correctly in multi threaded context.
#[test]
fn max_size_multiple_threads_access() {
    Packet::set_max_size(1024);

    let mut receivers = Vec::new();

    for _ in 0..10 {
        let (p, c) = std::sync::mpsc::channel();

        receivers.push(c);

        std::thread::spawn(move || {
            let mut is_correct = true;

            for _ in 0..100 {
                if Packet::max_size() != 1024 {
                    is_correct = false;
                }

                std::thread::sleep(std::time::Duration::new(0, 0));
            }

            p.send(is_correct).unwrap();
        });
    }

    assert!(
        receivers
            .iter()
            .map(|recv| recv.recv().unwrap())
            .collect::<Vec<bool>>()
            .into_iter()
            .all(|v| v),
        "This might be a false failure if tests are run in parallel."
    );
}

/// Tests if Packet::set_max_size works correctly in multi threaded context by creating multiple threads
/// and successively setting MAX_SIZE to randomly generated number.
#[test]
fn set_max_size_multiple_threads_access() {
    let (p, c) = std::sync::mpsc::sync_channel(1000);

    for _ in 0..10 {
        let p_into_thread = p.clone();

        std::thread::spawn(move || {
            let mut rng = rand::thread_rng();

            for _ in 0..100 {
                let x: u16 = rng.gen();

                Packet::set_max_size(x);

                p_into_thread.send(x).unwrap();
            }
        });
    }

    // Drop producer in main thread, so last value can be recognized.
    drop(p);

    let mut last = None;

    loop {
        match c.recv() {
            Ok(v) => last = Some(v),
            Err(_) => {
                // Just a safe check if there is any slowdown from some reason.
                std::thread::sleep(std::time::Duration::from_secs(1));
                match c.recv() {
                    Ok(v) => last = Some(v),
                    Err(_) => {
                        if last.is_none() {
                            panic!();
                        }
                        break;
                    }
                }
            }
        }
    }

    assert_eq!(Packet::max_size(), last.unwrap());
}

/// Tests if Packet::max_description_size works correctly in single threaded context.
#[test]
fn description_size_single_threaded_access() {
    assert_eq!(4, Packet::description_size())
}

/// Tests if Packet::max_size works correctly in multi threaded context.
#[test]
fn description_size_multiple_threads_access() {
    let mut receivers = Vec::new();

    for _ in 0..10 {
        let (p, c) = std::sync::mpsc::channel();

        receivers.push(c);

        std::thread::spawn(move || {
            let mut is_correct = true;

            for _ in 0..100 {
                if Packet::description_size() != 4 {
                    is_correct = false;
                }

                std::thread::sleep(std::time::Duration::new(0, 0));
            }

            p.send(is_correct).unwrap();
        });
    }

    assert!(receivers
        .iter()
        .map(|recv| recv.recv().unwrap())
        .collect::<Vec<bool>>()
        .into_iter()
        .all(|v| v));
}

/// Tests if Packet::max_content_size returns correct value.
///
/// This test might fail if Packet::max_size is changed between setting it in this test and call of
/// Packet::max_content_size by other test which makes it to created differently sized buffers than
/// those against it is checked.
///
/// The simplest solutions is to run it by itself or run all tests limited to one thread, so there is no call that
/// would change the maximum size of the Packet.
#[test]
fn max_content_size() {
    Packet::set_max_size(1024);

    if (Packet::max_size() == 1024) && (Packet::description_size() == 4) {
        assert_eq!(
            1020,
            Packet::max_content_size(),
            "Check test description, might be false failure."
        );
    }
}