use tek_tui::{*, tek_layout::{*, tek_engine::*}};
use tek_edn::*;
use std::sync::{Arc, RwLock};
use crossterm::event::{*, KeyCode::*};

const EDN: &'static [&'static str] = &[
    include_str!("edn01.edn"),
    include_str!("edn02.edn"),
];

fn main () -> Usually<()> {
    let state = Arc::new(RwLock::new(Example(0)));
    Tui::new().unwrap().run(&state)?;
    Ok(())
}

pub struct Example(usize);

impl EdnViewData<Tui> for &Example {
    fn get_content <'a> (&'a self, sym: &'a str) -> RenderBox<'a, Tui> {
        Box::new(Thunk::new(move||match sym {
            ":hello-world" => "Hello world!",
            ":hello" => "Hello",
            ":world" => "world",
            _ => ""
        }))
    }
}

impl Content<Tui> for Example {
    fn content (&self) -> impl Render<Tui> {
        EdnView::new(self, EDN[self.0]).unwrap()
    }
}

impl Handle<Tui> for Example {
    fn handle (&mut self, input: &TuiIn) -> Perhaps<bool> {
        match input.event() {
            kpat!(Right) => self.0 = (self.0 + 1) % EDN.len(),
            kpat!(Left) => self.0 = if self.0 > 0 { self.0 - 1 } else { EDN.len() - 1 },
            _ => return Ok(None)
        }
        Ok(Some(true))
    }
}