use core::fmt;
use std::{
    collections::HashMap,
    sync::{Arc, Mutex},
};

use mlua::{Function, RegistryKey, Result};
use ratatui::crossterm::event::KeyEvent;

use crate::lua;

#[derive(Default, Clone)]
pub struct KeyMapStore {
    store: Option<HashMap<KeyEvent, Arc<Mutex<dyn Runnable>>>>,
}

impl KeyMapStore {
    pub const fn new() -> Self {
        Self { store: None }
    }

    pub fn get(&mut self, event: KeyEvent) -> Option<Arc<Mutex<dyn Runnable>>> {
        match &self.store {
            Some(store) => match store.get(&event) {
                Some(func) => Some(Arc::clone(func)),
                None => None,
            },
            None => {
                self.store = Some(HashMap::new());
                None
            }
        }
    }

    pub fn map(&mut self, event: KeyEvent, func: impl Runnable + 'static) {
        match &self.store {
            Some(_) => {}
            None => self.store = Some(HashMap::new()),
        }

        if let Some(store) = &mut self.store {
            store.insert(event, Arc::new(Mutex::new(func)));
        }
    }
}

pub trait Runnable
where
    Self: Send,
{
    fn run(&self) -> Result<()>;
}

impl<T> Runnable for T
where
    T: Fn(),
    Self: Send,
{
    fn run(&self) -> Result<()> {
        self();
        Ok(())
    }
}

impl Runnable for RegistryKey
where
    Self: Send,
{
    fn run(&self) -> Result<()> {
        let lua = lua::get();
        let func: Function = lua.registry_value(self)?;
        func.call::<(), ()>(())?;
        Ok(())
    }
}

impl fmt::Debug for KeyMapStore {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "KeyMapStore")
    }
}