use tengri::{self, Usually, Perhaps, input::*, output::*, tui::*, dsl::*};
use std::sync::{Arc, RwLock};
use crossterm::event::{*, KeyCode::*};
use crate::ratatui::style::Color;

fn main () -> Usually<()> {
    let state = Arc::new(RwLock::new(Example(10, Measure::new())));
    Tui::new().unwrap().run(&state)?;
    Ok(())
}

#[derive(Debug)] pub struct Example(usize, Measure<TuiOut>);

const KEYMAP: &str = "(@left prev) (@right next)";
const EXAMPLES: &'static [&'static str] = &[
    include_str!("edn01.edn"),
    include_str!("edn02.edn"),
    include_str!("edn03.edn"),
    include_str!("edn04.edn"),
    include_str!("edn05.edn"),
    include_str!("edn06.edn"),
    include_str!("edn07.edn"),
    include_str!("edn08.edn"),
    include_str!("edn09.edn"),
    include_str!("edn10.edn"),
    include_str!("edn11.edn"),
    include_str!("edn12.edn"),
    //include_str!("edn13.edn"),
    include_str!("edn14.edn"),
    include_str!("edn15.edn"),
    include_str!("edn16.edn"),
    include_str!("edn17.edn"),
];

handle!(TuiIn: |self: Example, input|{
    Ok(if let Some(command) = SourceIter::new(KEYMAP).command::<_, ExampleCommand, _>(self, input) {
        command.execute(self)?;
        Some(true)
    } else {
        None
    })
});

#[tengri_proc::expose]
impl Example {
    fn _todo_u16_stub (&self) -> u16 { todo!() }
    fn _todo_bool_stub (&self) -> bool { todo!() }
    fn _todo_usize_stub (&self) -> usize { todo!() }
    //[bool]  => {}
    //[u16]   => {}
    //[usize] => {}
}

#[tengri_proc::command(Example)]
impl ExampleCommand {
    fn next (state: &mut Example) -> Perhaps<Self> {
        state.0 = (state.0 + 1) % EXAMPLES.len();
        Ok(None)
    }
    fn prev (state: &mut Example) -> Perhaps<Self> {
        state.0 = if state.0 > 0 { state.0 - 1 } else { EXAMPLES.len() - 1 };
        Ok(None)
    }
}

view!(TuiOut: |self: Example|{
    let index   = self.0 + 1;
    let wh      = self.1.wh();
    let src     = EXAMPLES.get(self.0).unwrap_or(&"");
    let heading = format!("Example {}/{} in {:?}", index, EXAMPLES.len(), &wh);
    let title   = Tui::bg(Color::Rgb(60, 10, 10), Push::y(1, Align::n(heading)));
    let code    = Tui::bg(Color::Rgb(10, 60, 10), Push::y(2, Align::n(format!("{}", src))));
    let content = Tui::bg(Color::Rgb(10, 10, 60), View(self, TokenIter::new(src)));
    self.1.of(Bsp::s(title, Bsp::n(""/*code*/, content)))
}; {
    ":title" => Tui::bg(Color::Rgb(60,  10, 10), Push::y(1, Align::n(format!("Example {}/{}:", self.0 + 1, EXAMPLES.len())))).boxed(),
    ":code"  => Tui::bg(Color::Rgb(10,  60, 10), Push::y(2, Align::n(format!("{}", EXAMPLES[self.0])))).boxed(),
    ":hello" => Tui::bg(Color::Rgb(10, 100, 10), "Hello").boxed(),
    ":world" => Tui::bg(Color::Rgb(100, 10, 10), "world").boxed(),
    ":hello-world" => "Hello world!".boxed(),
    ":map-e" => Map::east(5u16, ||0..5u16, |n, i|format!("{n}")).boxed(),
    ":map-s" => Map::south(5u16, ||0..5u16, |n, i|format!("{n}")).boxed(),
});