use orbtk::api::widget::StatesContext;
use orbtk::prelude::*;

#[derive(Debug)]
pub enum Event {
    Increment(Entity),
}

#[derive(AsAny, Default)]
pub struct AppState {
    events: VecDeque<Event>,
    pub notes: Entity,
    count: u32,
}

//rbtk_api::widget::states_context::StatesContext<'_>
#[derive(Debug, Copy, Clone)]
enum Action {
    Increment(usize),
}

#[derive(Default, AsAny)]
pub struct MainViewState {
    num: usize,
    action: Option<Action>,
}

impl MainViewState {
    fn action(&mut self, action: impl Into<Option<Action>>) {
	self.action = action.into();
    }
}

impl Template for MainView {
    fn template(self, id: Entity, ctx: &mut BuildContext) -> Self {
	self.name("MainView")
	    .counter(0)
	    .result("Button count: 0")
	    .child(
		Button::create()
		    .selector(Selector::from("button").id("btn"))
		    .min_size(100.0, 50.0)
		    .text(("result", id))
		    .on_click(move |states, _| -> bool {
			state(id, states).action(Action::Increment(10));
			true
		    })
		    .build(ctx),
	    )
    }
}

impl State for MainViewState {
    fn update(&mut self, _: &mut Registry, ctx: &mut Context<'_>) {
	if let Some(action) = self.action {
	    match action {
		Action::Increment(digit) => {
		    *ctx.widget().get_mut::<usize>("counter") += digit as usize;
		    let counter = *ctx.widget().get::<usize>("counter");
		    ctx.widget().set(
			"result",
			String16::from(format!("Button count: {}", counter)),
		    );
		}
		_ => {}
	    }

	    // Is it possible to get rid of this line ?
	    self.action = None;
	}

	if let Some(event) = self.events.pop_front() {
	    match event {
		// Create and append the note to the UI.
		Event::Increment(entity) => {
		    if let Some(copy) = Self::fetch_text(ctx, entity) {
			self.append_note(ctx, copy);
			let count = self.count + 1;
			self.count = count;
			if count == 1 {
			    ctx.widget().set::<f64>("spacing", 12.0);
			}
		    }
		}
	    }
	}
    }
}

widget!(MainView<MainViewState> {
    age:i32,
    counter:usize,
    result: String16
});

fn main() {
    Application::new()
	.window(|ctx| {
	    Window::create()
		.title("OrbTk - counter example")
		.position((100.0, 100.0))
		.size(400.0, 400.0)
		.child(MainView::create().build(ctx))
		.build(ctx)
	})
	.run();
}

fn state<'a>(id: Entity, states: &'a mut StatesContext) -> &'a mut MainViewState {
    states.get_mut(id)
}