use std::{
	io::{ stdout, IsTerminal },
	path::PathBuf
};

use tmux_interface::{
	Session, StdIO, Tmux,

	commands,
	variables::session::SessionsCtl
};

use crate::error;

pub const NULL: Option<StdIO> = Some(StdIO::Null);

pub fn session_name() -> Option<String> {
	let message = commands::DisplayMessage::new().print().message("#{session_name}");

	let result = Tmux::new().add_command(message).output();
	if let Ok(output) = result {
		let text = String::from_utf8(output.0.stdout);
		if let Ok(title) = text {
			Some(title[0..title.len() - 1].to_owned())
		} else { None }
	} else { None }
}

///	return a Vec of all sessions or None
pub fn get_sessions() -> Option<Vec<Session>> {
	let sessions = SessionsCtl::new().get_all();
	if let Ok(sessions) = sessions {
		return Some(sessions.0);
	} else { return None; }
}

///	check whether a target session exists
pub fn session_exists<S: Into<String>>(target: S) -> bool {
	let has_session = commands::HasSession::new()
		.target_session(target.into());
	Tmux::new().add_command(has_session)
		.stderr(NULL)
		.status()
		.unwrap()
		.success()
}

///	enforce a command is being run in a terminal
pub fn terminal_enforce() {
	if !stdout().is_terminal() { error::not_terminal(); }
}

///	recursively propagate up directories to find a child
pub fn find(target: &'static str, path: PathBuf) -> Option<PathBuf> {
	if path.join(target).exists() { return Some(path); }

	let parent = path.parent();
	if let Some(parent) = parent { return find(target, parent.to_path_buf()) }
	else { None }
}