use crate::*;

/// Collection of UI modes.
///
/// ```
/// # use tek::*;
///
/// // Empty mode registry:
/// let state: Config = Default::default();
/// assert_eq!(state.modes_count(), 0);
/// assert!(state.modes_get("Foo").is_none());
///
/// // Add a mode:
/// let _ = state.modes_add(&"Foo (name Foo) (info Bar)").unwrap();
/// assert_eq!(state.modes_count(), 1);
/// assert!(state.modes_get("Foo").is_some());
/// ```
pub trait HasModes {
    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>>;

    /// Register a mode.
    ///
    /// ```
    /// # use ::{std::sync::Arc, tek::*};
    /// let config = Config::default();
    /// config.modes_add(stringify!(Menu
    ///   (name Menu) (info Mode selector.) (axis Y Index) (bind Confirm)
    ///   (view (bg (g 30) (bar/s 7 Logo (full/xy Dialog))))
    /// )).unwrap();
    /// let _: Arc<Mode> = config.modes_get("Menu").unwrap();
    /// ```
    fn modes_add <'a> (&self, expr: impl Language) -> UsuallyRef<'a, ()> {
        let name = expr.head()?.ok_or("mode: missing name")?;
        let body = expr.tail()?.ok_or("mode: missing body")?;
        let mut mode = Mode::default();
        body.each(&mut mode, |c, s|c.add(s))?;
        self.modes().write().insert(name.into(), Arc::new(mode));
        Ok(())
    }
    /// Get a mode by name.
    fn modes_get (&self, name: impl AsRef<str>) -> Option<Arc<Mode>> {
        self.modes().read().get(name.as_ref()).cloned()
    }
    /// Run something for each mode.
    fn modes_for_each <T> (&self, mut ator: impl FnMut(&str, &Mode)->T) {
        for (k, v) in self.modes().read().iter() {
            let _ = ator(k.as_ref(), v.as_ref());
        }
    }
    /// Count modes.
    fn modes_count (&self) -> usize {
        self.modes().read().len()
    }
    /// Clear modes.
    fn modes_clear (&self) {
        *self.modes().write() = Default::default();
    }
}
impl HasModes for App {
    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
        &self.watch.config.modes
    }
}
impl HasModes for Config {
    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
        &self.modes
    }
}
impl HasModes for Mode {
    fn modes (&self) -> &RwLock<BTreeMap<Arc<str>, Arc<Mode>>> {
        &self.modes
    }
}

impl_as_mut!(Mode: |self: Mode| self);

/// Group of view and keys definitions.
///
/// ```
/// let mode = tek::Mode::default();
/// ```
#[derive(Default, Debug)]
pub struct Mode {
    pub path:  PathBuf,
    pub name:  Vec<Arc<str>>,
    pub info:  Vec<Arc<str>>,
    pub view:  Vec<Arc<View<Tui, App>>>,
    pub keys:  Vec<Arc<str>>,
    pub axis:  BTreeMap<Arc<str>, Arc<str>>,
    pub data:  BTreeMap<Arc<str>, usize>,
    pub modes: Arc<RwLock<BTreeMap<Arc<str>, Arc<Mode>>>>,
}

impl Mode {
    /// Add a definition to the mode.
    ///
    /// Supported definitions:
    ///
    ///   - (name ...) -> name
    ///   - (info ...) -> description
    ///   - (keys ...) -> key bindings
    ///   - (mode ...) -> submode
    ///   - ...        -> view
    ///
    /// ```
    /// let mut mode = tek::Mode::default().add("(name hello)").unwrap();
    /// ```
    pub fn add (&mut self, dsl: impl Language) -> Usually<&mut Self> {
        Ok(if let Ok(Some(expr)) = dsl.expr() && let Ok(Some(head)) = expr.head() {
            let tail = expr.tail()?.map(|x|x.trim()).unwrap_or("");
            match head {
                "self" => self.add_mode(tail)?,
                "bind" => self.add_bind(tail)?,
                "axis" => self.add_axis(tail)?,
                "data" => self.add_data(tail)?,
                "name" => { self.name.push(tail.into()); self },
                "info" => { self.info.push(tail.into()); self },
                "view" => { self.view.push(View::new(tail)?.into()); self },
                _      => { self.view.push(View::new(tail)?.into()); self },
            }
        } else if let Ok(Some(word)) = dsl.word() {
            self.view.push(View::new(word)?.into());
            self
        } else {
            return Err(format!("Mode::add: unexpected: {dsl:?}").into());
        })
    }

    fn add_mode (&mut self, tail: &str) -> Usually<&mut Self> {
        let name = tail.head()?.ok_or("submode: missing name")?;
        let body = tail.tail()?.ok_or("submode: missing body")?;
        let mut submode = Mode::default();
        body.each(&mut submode, |c, s|c.add(s))?;
        self.modes.write().insert(name.into(), Arc::new(submode));
        Ok(self)
    }

    fn add_bind (&mut self, tail: &str) -> Usually<&mut Self> {
        tail.each(self, |mode: &mut Self, expr: &str|{
            mode.keys.push(expr.trim().into());
            Ok(mode)
        })
    }

    fn add_axis (&mut self, tail: &str) -> Usually<&mut Self> {
        let mut axis:  Option<Arc<str>> = None;
        let mut param: Option<Arc<str>> = None;
        tail.each(0, |index: usize, src: &str|if index == 0 {
            axis = Some(src.into());
            Ok(1)
        } else if index == 1 {
            param = Some(src.into());
            Ok(2)
        } else {
            err!("mode: expected (axis Name Param), got: {tail}")
        })?;
        if let Some(axis) = axis && let Some(param) = param {
            self.axis.insert(axis.into(), param.into());
            Ok(self)
        } else {
            err!("mode: expected (axis Name Param), got: {tail}")
        }
    }

    fn add_data (&mut self, tail: &str) -> Usually<&mut Self> {
        let mut param: Option<Arc<str>> = None;
        let mut value: Option<usize> = None;
        tail.each(0, |index: usize, src: &str|if index == 0 {
            param = Some(src.into());
            Ok(1)
        } else if index == 1 {
            value = Some(src.parse::<usize>()?);
            Ok(2)
        } else {
            err!("mode: expected (data Param Value), got: {tail}")
        })?;
        if let Some(param) = param && let Some(value) = value {
            self.data.insert(param.into(), value.into());
            Ok(self)
        } else {
            err!("mode: expected (data Param Value), got: {tail}")
        }
    }

}

pub fn print_config_modes (config: &Config) {
    use ::ansi_term::Color::*;
    config.modes_for_each(|k, v|{
        println!();
        for v in v.name.iter() { print!("{}", Green.bold().paint(format!("{v} "))); }
        for v in v.info.iter() { print!("\n{}", Green.paint(format!("{v}"))); }
        print!("\n{} {}", Blue.paint("TOOL"), Green.bold().paint(format!("{k:<16}")));
        print!("\n{}", Blue.paint("KEYS"));
        for v in v.keys.iter() { print!("{}", Green.paint(format!(" {v}"))); }
        println!();
        v.modes_for_each(|k, v|{
            print!("{} {} {:?}", Blue.paint("MODE"), Green.bold().paint(format!("{k:<16}")), v.name);
            print!(  " INFO={:?}", v.info);
            print!(  " VIEW={:?}", v.view);
            println!(" KEYS={:?}", v.keys);
        });
        print!("{}", Blue.paint("VIEW"));
        for v in v.view.iter() { print!("{}", Green.paint(format!(" {v}"))); }
        println!();
    });
}