mod trace;
mod ui;
use std::{
    io::{self, Write},
    str,
};

use crate::trace::{exec, trace};
use crate::ui::run_tui;
use clap::Parser;
use fork::{fork, Fork};
use nix::unistd::Pid;

#[derive(Parser)]
#[command(author, version, about, long_about = None)]
struct Args {
    /// Command to execute from ptrace
    command: String,

    /// Write the output to a file instead of the standard output
    #[arg(short = 'f', long = "file")]
    file_to_print: Option<String>,

    /// If defined, it hides the TUI
    #[arg(long = "no-tui", default_value_t = false)]
    no_tui: bool,
}

/// Create a fork of the program and execute the process in the child. Parent gets the pid
/// value and trace it.
fn main() -> anyhow::Result<()> {
    let args = Args::parse();

    let pid = match fork() {
        Ok(Fork::Child) => return exec(&args.command),
        Ok(Fork::Parent(child)) => Pid::from_raw(child),
        Err(err) => panic!("fork() failed: {err}"),
    };
    let output = trace(pid, args.file_to_print)?;
    let lines = str::from_utf8(&output)?.trim();

    if !args.no_tui {
        run_tui(pid, lines)?;
    } else {
        writeln!(io::stdout(), "{lines}")?;
    }

    Ok(())
}