// Copyright 2018 Yuya Nishihara <yuya@tcha.org>

//

// This software may be used and distributed according to the terms of the

// GNU General Public License version 2 or any later version.

extern crate chg;

extern crate futures;

extern crate log;

extern crate tokio;

extern crate tokio_hglib;

use chg::procutil;

use chg::{ChgClientExt, ChgUiHandler};

use futures::sync::oneshot;

use std::env;

use std::io;

use std::process;

use std::time::Instant;

use tokio::prelude::*;

struct DebugLogger {

    start: Instant,

}

impl DebugLogger {

    pub fn new() -> DebugLogger {

        DebugLogger {

            start: Instant::now(),

        }

    }

}

impl log::Log for DebugLogger {

    fn enabled(&self, metadata: &log::Metadata) -> bool {

        metadata.target().starts_with("chg::")

    }

    fn log(&self, record: &log::Record) {

        if self.enabled(record.metadata()) {

            // just make the output looks similar to chg of C

            let l = format!("{}", record.level()).to_lowercase();

            let t = self.start.elapsed();

            writeln!(

                io::stderr(),

                "chg: {}: {}.{:06} {}",

                l,

                t.as_secs(),

                t.subsec_micros(),

                record.args()

            )

            .unwrap_or(());

        }

    }

    fn flush(&self) {}

}

fn main() {

    if env::var_os("CHGDEBUG").is_some() {

        log::set_boxed_logger(Box::new(DebugLogger::new()))

            .expect("any logger should not be installed yet");

        log::set_max_level(log::LevelFilter::Debug);

    }

    // TODO: add loop detection by $CHGINTERNALMARK

    let code = run().unwrap_or_else(|err| {

        writeln!(io::stderr(), "chg: abort: {}", err).unwrap_or(());

        255

    });

    process::exit(code);

}

fn run() -> io::Result<i32> {

    let handler = ChgUiHandler::new();

    let (result_tx, result_rx) = oneshot::channel();

    let fut = loc

        .connect()

        .and_then(|(_, client)| client.attach_io(io::stdin(), io::stdout(), io::stderr()))

        .and_then(|client| {

            let pid = client.server_spec().process_id.unwrap();

            let pgid = client.server_spec().process_group_id;

            procutil::setup_signal_handler_once(pid, pgid)?;

            Ok(client)

        })

        .and_then(|client| client.run_command_chg(handler, env::args_os().skip(1)))

        .map(|(_client, _handler, code)| {

            procutil::restore_signal_handler_once()?;

            Ok(code)

        })

        .or_else(|err| Ok(Err(err))) // pass back error to caller

        .map(|res| result_tx.send(res).unwrap());

    tokio::run(fut);

    result_rx.wait().unwrap_or(Err(io::Error::new(

        io::ErrorKind::Other,

        "no exit code set",

    )))

}