use std::process::Command;

use crate::Session;

pub use error::Error;

mod error;

#[derive(Debug)]
pub struct Tmux {
    socket_name: String,
}

impl Tmux {
    const SESSION_FORMAT: &str = r##"Session(name: "#S", state: #{?session_last_attached,Attached(#{session_last_attached}),Created(#{session_created})})"##;

    pub fn new(socket_name: String) -> Self {
        Self { socket_name }
    }

    pub fn list(&self, name: Option<String>) -> Result<Vec<Session>, Error> {
        let filter = name
            .map(|s| vec!["-f".into(), format!("#{{==:#S,{s}}}")])
            .unwrap_or_default();

        let stdout = Command::new("tmux")
            .arg("-L")
            .arg(&self.socket_name)
            .arg("list-sessions")
            .args(filter)
            .arg("-F")
            .arg(Self::SESSION_FORMAT)
            .output()?
            .stdout;

        let sessions: Vec<Session> = std::str::from_utf8(&stdout)?
            .lines()
            .filter_map(|s| match ron::from_str(s) {
                Ok(session) => Some(session),
                Err(err) => {
                    tracing::warn!(%err, "Invalid session format");
                    None
                }
            })
            .collect();

        Ok(sessions)
    }

    pub fn host(&self) -> Result<Session, Error> {
        let stdout = Command::new("tmux")
            .arg("-L")
            .arg(&self.socket_name)
            .arg("display")
            .arg("-p")
            .arg("#h")
            .output()?
            .stdout;

        let name = std::str::from_utf8(&stdout)?.trim().into();

        Ok(Session {
            state: crate::State::LocalHost,
            name,
        })
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    const SOCKET_NAME: &str = "test";

    #[test]
    fn test_tmux_list() -> Result<(), Error> {
        let names = Vec::from(["test_1", "test_2", "test_3", "test_4"]);

        for name in names.iter().cloned() {
            Command::new("tmux")
                .arg("-L")
                .arg(SOCKET_NAME)
                .arg("new-session")
                .arg("-ds")
                .arg(name)
                .status()?;
        }

        let tmux = Tmux::new(SOCKET_NAME.to_owned());
        let sessions: Vec<_> = tmux.list(None)?.into_iter().map(|s| s.name).collect();

        Command::new("tmux")
            .arg("-L")
            .arg(SOCKET_NAME)
            .arg("kill-server")
            .status()?;

        assert_eq!(names, sessions);

        Ok(())
    }

    #[test]
    fn test_tmux_host() -> Result<(), Error> {
        Command::new("tmux")
            .arg("-L")
            .arg(SOCKET_NAME)
            .arg("new-session")
            .arg("-d")
            .status()?;

        let name = hostname::get()?.to_string_lossy().into();
        let expected_session = Session {
            state: crate::State::LocalHost,
            name,
        };

        let tmux = Tmux::new(SOCKET_NAME.to_owned());
        let session = tmux.host()?;

        Command::new("tmux")
            .arg("-L")
            .arg(SOCKET_NAME)
            .arg("kill-server")
            .status()?;

        assert_eq!(expected_session, session);

        Ok(())
    }
}