use std::cell::RefCell;
use std::rc::Rc;
use raidillon_core::scene::Scene;
use indexmap::IndexMap;
use winit::event::Event;
use raidillon_core::context::PlatformContext;
use raidillon_core::DebugUIBuffer;

pub struct SystemContext<'a> {
    // TODO: time delta etc.
    pub scene: &'a mut Scene,
    pub platform_context: PlatformContext,
    pub debug_ui_buffer: Rc<RefCell<DebugUIBuffer>>,
}

pub trait System {
    /// Initialize the system.
    fn initialize(&mut self) {}
    /// Spawn the first entities of the world.
    fn load_world(&mut self, ctx: &mut SystemContext) {}
    fn update(&mut self, ctx: &mut SystemContext) {}
}

pub type SystemID = &'static str;
pub struct SystemManager {
    pub systems: IndexMap<SystemID, Box<dyn System>>,
}

impl SystemManager {
    pub fn new() -> Self {
        let systems = IndexMap::default();
        Self { systems }
    }

    pub fn add_system(&mut self, id: SystemID, system: Box<dyn System>) {
        self.systems.insert(id, system);
    }

    pub fn remove_system(&mut self, id: SystemID) {
        self.systems.shift_remove(&id);
    }
}