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

impl Content<TuiOut> for Example {
    fn content (&self) -> impl Render<TuiOut> {
        Bsp::a(
            Push::xy(1, 1, Align::n(format!("Example {}/{}:", self.0 + 1, EDN.len()))),
            EdnView::from_source(self, EDN[self.0])
        )
    }
}

impl Handle<TuiIn> 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))
    }
}