use std::{
    fmt,
    io::{BufRead, BufReader},
    process::{Child, Command, Stdio},
};
use sysinfo::{Pid, ProcessRefreshKind, RefreshKind, System, SystemExt};

#[derive(Debug, Clone)]
struct AddrInUse;

impl fmt::Display for AddrInUse {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "address is in use")
    }
}

pub struct Driver {
    child: Child,
}

impl Driver {
    pub fn new() -> Result<Self, anyhow::Error> {
        let mut child = Command::new("chromedriver")
            .stdout(Stdio::piped())
            .arg("--port=6444")
            .spawn()?;
        let child_id = child.id();
        let mut child_out = BufReader::new(child.stdout.as_mut().unwrap());
        let mut line = String::new();

        let mut sys_info = System::new_with_specifics(
            RefreshKind::new().with_processes(ProcessRefreshKind::new()),
        );

        // Wait for it to say Chromedriver started successfully
        loop {
            child_out.read_line(&mut line).unwrap();
            if line.contains("ChromeDriver was started successfully.") {
                break;
            }
            if line.contains("bind() failed: Address already in use") || line.contains("Exiting...")
            {
                return Err(anyhow::anyhow!(line));
            }

            // Check if chromedriver has exited
            sys_info.refresh_all();
            if let None = sys_info.process(Pid::from(child_id.clone() as i32)) {
                let status_code = child.wait()?;
                println!("{}", status_code.code().unwrap());
                return Err(anyhow::anyhow!(
                    "chromedriver exited with status code {}",
                    status_code.code().unwrap_or(1337),
                ));
            }
        }

        println!("chromedriver started");
        Ok(Self { child })
    }

    pub fn exit(&mut self) -> Result<(), anyhow::Error> {
        self.child.kill()?;
        Ok(())
    }
}