use anyhow::{anyhow, bail, Result};

use argparse::{ArgumentParser, Store};

use base64::{engine::general_purpose, Engine};

use hedgewars_network_protocol::{

    messages::HwProtocolMessage as ClientMessage, messages::HwServerMessage::*, parser,

};

use ini::Ini;

use log::{debug, info, warn};

use netbuf::Buf;

use std::{io::Write, str::FromStr};

use tokio::time::MissedTickBehavior;

use tokio::{io, io::AsyncWriteExt, net::TcpStream, process::Command, sync::mpsc};

async fn check(executable: &str, data_prefix: &str, buffer: &[String]) -> Result<Vec<String>> {

    let mut replay = tempfile::NamedTempFile::new()?;

    for line in buffer.iter() {

        replay.write_all(&general_purpose::STANDARD.decode(line)?)?;

    }

    let temp_file_path = replay.path();

    let mut home_dir = dirs::home_dir().ok_or(anyhow!("Home path not detected"))?;

    home_dir.push(".hedgewars");

    debug!("Checking replay in {}", temp_file_path.to_string_lossy());

    let output = Command::new(executable)

        .arg("--user-prefix")

        .arg(&home_dir)

        .arg("--prefix")

        .arg(data_prefix)

        .arg("--nomusic")

        .arg("--nosound")

        .arg("--stats-only")

        .arg(temp_file_path)

        //.spawn()?

        //.wait_with_output()

        .output()

        .await?;

    debug!("Engine finished!");

    let mut result = Vec::new();

    let mut engine_lines = output

        .stderr

        .split(|b| *b == b'\n')

        .skip_while(|l| *l != b"WINNERS" && *l != b"DRAW");

    // debug!("Engine lines: {:?}", &engine_lines);

    loop {

        match engine_lines.next() {

            Some(b"DRAW") => result.push("DRAW".to_owned()),

            Some(b"WINNERS") => {

                result.push("WINNERS".to_owned());

                let winners = engine_lines.next().unwrap();

                let winners_num = u32::from_str(&String::from_utf8(winners.to_vec())?)?;

                result.push(String::from_utf8(winners.to_vec())?);

                for _i in 0..winners_num {

                    result.push(String::from_utf8(engine_lines.next().unwrap().to_vec())?);

                }

            }

            Some(b"GHOST_POINTS") => {

                result.push("GHOST_POINTS".to_owned());

                let points = engine_lines.next().unwrap();

                let points_num = u32::from_str(&String::from_utf8(points.to_vec())?)? * 2;

                result.push(String::from_utf8(points.to_vec())?);

                for _i in 0..points_num {

                    result.push(String::from_utf8(engine_lines.next().unwrap().to_vec())?);

                }

            }

            Some(b"ACHIEVEMENT") => {

                result.push("ACHIEVEMENT".to_owned());

                for _i in 0..4 {

                    result.push(String::from_utf8(engine_lines.next().unwrap().to_vec())?);

                }

            }

            _ => break,

        }

    }

    // println!("Engine lines: {:?}", &result);

    if !result.is_empty() {

        Ok(result)

    } else {

        bail!("no data from engine")

    }

}

async fn check_loop(

    executable: &str,

    data_prefix: &str,

    results_sender: mpsc::Sender<Result<Vec<String>>>,

    mut replay_receiver: mpsc::Receiver<Vec<String>>,

) -> Result<()> {

    while let Some(replay) = replay_receiver.recv().await {

        results_sender

            .send(check(executable, data_prefix, &replay).await)

            .await?;

    }

    Ok(())

}

async fn connect_and_run(

    username: &str,

    password: &str,

    protocol_number: u16,

    replay_sender: mpsc::Sender<Vec<String>>,

    mut results_receiver: mpsc::Receiver<Result<Vec<String>>>,

) -> Result<()> {

    info!("Connecting...");

    let mut stream = TcpStream::connect("hedgewars.org:46631").await?;

    let mut buf = Buf::new();

    let mut interval = tokio::time::interval(tokio::time::Duration::from_secs(30));

    interval.set_missed_tick_behavior(MissedTickBehavior::Delay);

    loop {

        let r = tokio::select! {

            _ = interval.tick() => {

                // Send Ping

                stream.write_all(ClientMessage::Ping.to_raw_protocol().as_bytes()).await?;

                None

            },

            _ = stream.readable() => None,

            r = results_receiver.recv() => r

        };

        //println!("Loop: {:?}", &r);

        if let Some(execution_result) = r {

            match execution_result {

                Ok(result) => {

                    info!("Checked");

                    debug!("Check result: [{:?}]", result);

                    stream

                        .write_all(

                            ClientMessage::CheckedOk(result)

                                .to_raw_protocol()

                                .as_bytes(),

                        )

                        .await?;

                    stream

                        .write_all(ClientMessage::CheckerReady.to_raw_protocol().as_bytes())

                        .await?;

                }

                Err(e) => {

                    info!("Check failed: {:?}", e);

                    stream

                        .write_all(

                            ClientMessage::CheckedFail("error".to_owned())

                                .to_raw_protocol()

                                .as_bytes(),

                        )

                        .await?;

                    stream

                        .write_all(ClientMessage::CheckerReady.to_raw_protocol().as_bytes())

                        .await?;

                }

            }

        } else {

            let mut msg = [0; 4096];

            // Try to read data, this may still fail with `WouldBlock`

            // if the readiness event is a false positive.

            match stream.try_read(&mut msg) {

                Ok(n) => {

                    //println!("{:?}", &msg);

                    buf.write_all(&msg[0..n])?;

                }

                Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {}

                Err(e) => {

                    return Err(e.into());

                }

            }

        }

        while let Ok((tail, msg)) = parser::server_message(buf.as_ref()) {

            let tail_len = tail.len();

            buf.consume(buf.len() - tail_len);

            // println!("Message from server: {:?}", &msg);

            match msg {

                Connected(_, _) => {

                    info!("Connected");

                    stream

                        .write_all(

                            ClientMessage::Checker(

                                protocol_number,

                                username.to_owned(),

                                password.to_owned(),

                            )

                            .to_raw_protocol()

                            .as_bytes(),

                        )

                        .await?;

                }

                Ping => {

                    stream

                        .write_all(ClientMessage::Pong.to_raw_protocol().as_bytes())

                        .await?;

                }

                Pong => {

                    // do nothing

                }

                LogonPassed => {

                    stream

                        .write_all(ClientMessage::CheckerReady.to_raw_protocol().as_bytes())

                        .await?;

                }

                Replay(lines) => {

                    info!("Got a replay");

                    replay_sender.send(lines).await?;

                }

                Bye(message) => {

                    warn!("Received BYE: {}", message);

                    return Ok(());

                }

                ChatMsg { nick, msg } => {

                    info!("Chat [{}]: {}", nick, msg);

                }

                RoomAdd(fields) => {

                    let mut l = fields.into_iter();

                    info!("Room added: {}", l.nth(1).unwrap());

                }

                RoomUpdated(name, fields) => {

                    let mut l = fields.into_iter();

                    let new_name = l.nth(1).unwrap();

                    if name != new_name {

                        info!("Room renamed: {}", new_name);

                    }

                }

                RoomRemove(_) => {

                    // ignore

                }

                Error(message) => {

                    warn!("Received ERROR: {}", message);

                    return Ok(());

                }

                something => {

                    warn!("Unexpected protocol command: {:?}", something)

                }

            }

        }

    }

}

async fn get_protocol_number(executable: &str) -> Result<u16> {

    let output = Command::new(executable).arg("--protocol").output().await?;

    Ok(u16::from_str(String::from_utf8(output.stdout)?.trim()).unwrap_or(55))

}

#[tokio::main]

async fn main() -> Result<()> {

    stderrlog::new()

        .verbosity(3)

        .timestamp(stderrlog::Timestamp::Second)

        .module(module_path!())

        .init()?;

    let mut frontend_settings = dirs::home_dir().ok_or(anyhow!("Home path not detected"))?;

    frontend_settings.push(".hedgewars/settings.ini");

    let i = Ini::load_from_file(frontend_settings.to_str().unwrap()).unwrap();

    let username = i

        .get_from(Some("net"), "nick")

        .ok_or(anyhow!("Nickname not found in frontend config"))?;

    let password = i

        .get_from(Some("net"), "passwordhash")

        .ok_or(anyhow!("Password not found in frontend config"))?;

    let mut exe = "/usr/local/bin/hwengine".to_string();

    let mut prefix = "/usr/local/share/hedgewars/Data".to_string();

    {

        let mut ap = ArgumentParser::new();

        ap.set_description("Game replay checker for hedgewars.");

        ap.refer(&mut exe)

            .add_option(&["--exe"], Store, "Path to hwengine executable");

        ap.refer(&mut prefix)

            .add_option(&["--prefix"], Store, "Path main Data dir");

        ap.parse_args_or_exit();

    }

    info!("Executable: {}", exe);

    info!("Data dir: {}", prefix);

    let protocol_number = get_protocol_number(exe.as_str()).await?;

    info!("Using protocol number {}", protocol_number);

    let (replay_sender, replay_receiver) = mpsc::channel(1);

    let (results_sender, results_receiver) = mpsc::channel(1);

    let (network_result, checker_result) = tokio::join!(

        connect_and_run(

            username,

            password,

            protocol_number,

            replay_sender,

            results_receiver

        ),

        check_loop(&exe, &prefix, results_sender, replay_receiver)

    );

    network_result?;

    checker_result

}