// Copyright lowRISC contributors.
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0

use anyhow::{anyhow, Result};
use erased_serde::Serialize;
use nix::unistd::isatty;
use raw_tty::TtyModeGuard;
use regex::Regex;
use std::any::Any;
use std::fs::File;
use std::os::unix::io::AsRawFd;
use std::time::Duration;
use structopt::StructOpt;

use opentitanlib::app::command::CommandDispatch;
use opentitanlib::app::TransportWrapper;
use opentitanlib::io::uart::UartParams;
use opentitanlib::transport::Capability;
use opentitanlib::uart::console::{ExitStatus, UartConsole};

#[derive(Debug, StructOpt)]
pub struct Console {
    #[structopt(flatten)]
    params: UartParams,

    #[structopt(short, long, help = "Do not print console start end exit messages.")]
    quiet: bool,

    #[structopt(short, long, help = "Log console output to a file")]
    logfile: Option<String>,

    #[structopt(
        short,
        long, parse(try_from_str=humantime::parse_duration),
        help = "Duration of ROM detection timeout",
    )]
    timeout: Option<Duration>,

    #[structopt(long, help = "Print a timestamp on each line of console output.")]
    timestamp: bool,

    #[structopt(long, help = "Exit with success if the specified regex is matched.")]
    exit_success: Option<String>,

    #[structopt(long, help = "Exit with failure if the specified regex is matched.")]
    exit_failure: Option<String>,
}

impl CommandDispatch for Console {
    fn run(
        &self,
        _context: &dyn Any,
        transport: &TransportWrapper,
    ) -> Result<Option<Box<dyn Serialize>>> {
        // We need the UART for the console command to operate.
        transport.capabilities()?.request(Capability::UART).ok()?;
        let mut stdout = std::io::stdout();
        let mut stdin = std::io::stdin();

        // Set up resources specified by the command line parameters.
        let mut console = UartConsole {
            logfile: self.logfile.as_ref().map(File::create).transpose()?,
            timeout: self.timeout,
            exit_success: self
                .exit_success
                .as_ref()
                .map(|s| Regex::new(s.as_str()))
                .transpose()?,
            exit_failure: self
                .exit_failure
                .as_ref()
                .map(|s| Regex::new(s.as_str()))
                .transpose()?,
            timestamp: self.timestamp,
            newline: true,
            ..Default::default()
        };

        if !self.quiet {
            println!("Starting interactive console");
            println!("[CTRL+C] to exit.\n");
        }
        let status = {
            // Put the terminal into raw mode.  The tty guard will restore the
            // console settings when it goes out of scope.
            let _stdin_guard = if isatty(stdin.as_raw_fd())? {
                let mut guard = TtyModeGuard::new(stdin.as_raw_fd())?;
                guard.set_raw_mode()?;
                Some(guard)
            } else {
                None
            };
            let _stdout_guard = if isatty(stdout.as_raw_fd())? {
                let mut guard = TtyModeGuard::new(stdout.as_raw_fd())?;
                guard.set_raw_mode()?;
                Some(guard)
            } else {
                None
            };
            let uart = self.params.create(transport)?;
            console.interact(&*uart, Some(&mut stdin), Some(&mut stdout))?
        };
        if !self.quiet {
            println!("\n\nExiting interactive console.");
        }

        match status {
            ExitStatus::None | ExitStatus::CtrlC => Ok(None),
            ExitStatus::Timeout => {
                if console.exit_success.is_some() {
                    // If there was a console exit success condition, then a timeout
                    // represents an error.
                    Err(anyhow!("Console timeout exceeded"))
                } else {
                    // If there was no console exit success condition, then a timeout
                    // is not an error.
                    Ok(None)
                }
            }
            ExitStatus::ExitSuccess => {
                log::info!(
                    "ExitSuccess({:?})",
                    console.captures(status).unwrap().get(0).unwrap().as_str()
                );
                Ok(None)
            }
            ExitStatus::ExitFailure => {
                log::info!(
                    "ExitFailure({:?})",
                    console.captures(status).unwrap().get(0).unwrap().as_str()
                );
                Err(anyhow!("Matched exit_failure expression"))
            }
        }
    }
}