use async_channel::{Receiver, Sender};
use chrono::NaiveDate;

use crate::{
    app::{calendar, form, utils, App},
    model::{event, event::Event},
};

pub fn send(tx: Sender<Msg>, msg: Msg) {
    utils::spawn(async move {
        let _ = tx.send(msg).await;
    })
}

pub enum Msg {
    ShowAddForm { date: NaiveDate },
    ShowUpdateForm { event: Event },
    AddEvent { new: Event },
    UpdateEvent { old: Event, new: Event },
}

pub async fn event_handler(rx: Receiver<Msg>, mut app: App) {
    while let Ok(msg) = rx.recv().await {
        match msg {
            Msg::ShowAddForm { date } => {
                form::show(&app, event::init(date), true).await;
            }
            Msg::ShowUpdateForm { event } => {
                form::show(&app, event, false).await;
            }
            Msg::AddEvent { new } => {
                let date = new.date.clone();
                app.events.push(new);
                calendar::refresh_date(&app, date);
            }
            Msg::UpdateEvent { old, new } => {
                let new_date = new.date.clone();
                match app.events.iter().position(|e| e.id == new.id) {
                    Some(index) => {
                        app.events.remove(index);
                        app.events.push(new);
                        calendar::refresh_date(&app, new_date);
                        if old.date != new_date {
                            calendar::refresh_date(&app, old.date.clone())
                        }
                    }
                    None => println!("Event not found when updating from {:?} to {:?}", old, new),
                }
            }
        }
    }
}