use super::*;

pub type Modes = Arc<RwLock<BTreeMap<Arc<str>, Arc<Mode<Arc<str>>>>>>;

/// A set of currently active view and keys definitions,
/// with optional name and description.
#[derive(Default, Debug)]
pub struct Mode<D: Dsl + Ord> {
    pub path:  PathBuf,
    pub name:  Vec<D>,
    pub info:  Vec<D>,
    pub view:  Vec<D>,
    pub keys:  Vec<D>,
    pub modes: Modes,
}

impl<D: Dsl + Ord> Draw<TuiOut> for Mode<D> {
    fn draw (&self, to: &mut TuiOut) {
        self.content().draw(to)
    }
}

impl Mode<Arc<str>> {

    pub fn load_into (modes: &Modes, name: &impl AsRef<str>, body: &impl Dsl) -> Usually<()> {
        let mut mode = Self::default();
        println!("Mode::load_into: {}: {body:?}", name.as_ref());
        body.each(|item|mode.load_one(item))?;
        modes.write().unwrap().insert(name.as_ref().into(), Arc::new(mode));
        Ok(())
    }

    fn load_one (&mut self, dsl: impl Dsl) -> Usually<()> {
        Ok(if let Ok(Some(expr)) = dsl.expr() && let Ok(Some(head)) = expr.head() {
            println!("Mode::load_one: {head} {:?}", expr.tail());
            let tail = expr.tail()?.map(|x|x.trim()).unwrap_or("");
            match head {
                "name" => self.name.push(tail.into()),
                "info" => self.info.push(tail.into()),
                "view" => self.view.push(tail.into()),
                "keys" => tail.each(|expr|{self.keys.push(expr.trim().into()); Ok(())})?,
                "mode" => if let Some(id) = tail.head()? {
                    Self::load_into(&self.modes, &id, &tail.tail())?;
                } else {
                    return Err(format!("Mode::load_one: self: incomplete: {expr:?}").into());
                },
                _ => {
                    return Err(format!("Mode::load_one: unexpected expr: {head:?} {tail:?}").into())
                },
            };
        } else if let Ok(Some(word)) = dsl.word() {
            self.view.push(word.into());
        } else {
            return Err(format!("Mode::load_one: unexpected: {dsl:?}").into());
        })
    }

}