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

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

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

handle!(TuiIn: |self: Example, input|Ok(None));
enum ExampleCommand { Next, Prev }
impl ExampleCommand {
    fn eval (&self, state: &mut Example) -> Perhaps<Self> {
        match self {
            Self::Next => {
                state.0 = (state.0 + 1) % Example::VIEWS.len();
                Ok(Some(Self::Prev))
            },
            Self::Prev => {
                state.0 = if state.0 > 0 { state.0 - 1 } else { Example::VIEWS.len() - 1 };
                Ok(Some(Self::Next))
            }
        }
    }
}

tui_draw!(|self: Example, to|{
    to.place(&self.content());
});
content!(TuiOut: |self: Example|{
    let index   = self.0 + 1;
    let wh      = self.1.wh();
    let src     = Self::VIEWS.get(self.0).unwrap_or(&"");
    let heading = format!("Example {}/{} in {:?}", index, Self::VIEWS.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, CstIter::new(src)));
    self.1.of(Bsp::s(title, Bsp::n(""/*code*/, content)))
});
impl View<TuiOut, ()> for Example {
    fn view_expr <'a> (&'a self, to: &mut TuiOut, expr: &'a impl DslExpr) -> Usually<()> {
        if evaluate_output_expression(self, to, expr)?
        || evaluate_output_expression_tui(self, to, expr)? {
            Ok(())
        } else {
            Err(format!("Example::view_expr: unexpected: {expr:?}").into())
        }
    }
}

impl Example {
    fn new () -> Arc<RwLock<Self>> {
        Arc::new(RwLock::new(Example(10, Measure::new())))
    }
    const BINDS: &'static str = stringify! {
        (@left prev)
        (@right next)
    };
    const VIEWS: &'static [&'static str] = &[
        stringify! { :hello-world },
        stringify! { (fill/xy :hello-world) },
        stringify! { (bsp/s :hello :world) },
        stringify! { (fixed/xy 20 10 :hello-world) },
        stringify! { (bsp/s (fixed/xy 5 6 :hello) (fixed/xy 7 8 :world)) },
        stringify! { (bsp/e (fixed/xy 5 6 :hello) (fixed/xy 7 8 :world)) },
        stringify! { (bsp/n (fixed/xy 5 6 :hello) (fixed/xy 7 8 :world)) },
        stringify! { (bsp/w (fixed/xy 5 6 :hello) (fixed/xy 7 8 :world)) },
        stringify! { (bsp/a (fixed/xy 5 6 :hello) (fixed/xy 7 8 :world)) },
        stringify! { (bsp/b (fixed/xy 5 6 :hello) (fixed/xy 7 8 :world)) },
        stringify! {
            (bsp/s
              (bsp/e       (align/nw (fixed/xy 5 3 :hello))
                (bsp/e     (align/n  (fixed/xy 5 3 :hello))
                           (align/ne (fixed/xy 5 3 :hello))))
                (bsp/s
                  (bsp/e   (align/w  (fixed/xy 5 3 :hello))
                    (bsp/e (align/c  (fixed/xy 5 3 :hello))
                           (align/e  (fixed/xy 5 3 :hello))))
                  (bsp/e   (align/sw (fixed/xy 5 3 :hello))
                    (bsp/e (align/s  (fixed/xy 5 3 :hello))
                           (align/se (fixed/xy 5 3 :hello))))))
        },
        stringify! {
            (bsp/s
              (bsp/e     (fixed/xy 8 5 (align/nw :hello))
                (bsp/e   (fixed/xy 8 5 (align/n  :hello))
                         (fixed/xy 8 5 (align/ne :hello))))
              (bsp/s
                (bsp/e   (fixed/xy 8 5 (align/w  :hello))
                  (bsp/e (fixed/xy 8 5 (align/c  :hello))
                         (fixed/xy 8 5 (align/e  :hello))))
                (bsp/e   (fixed/xy 8 5 (align/sw :hello))
                  (bsp/e (fixed/xy 8 5 (align/s  :hello))
                         (fixed/xy 8 5 (align/se :hello))))))
        },
        stringify! {
            (bsp/s
              (bsp/e     (grow/xy 1 1 (fixed/xy 8 5 (align/nw :hello)))
                (bsp/e   (grow/xy 1 1 (fixed/xy 8 5 (align/n  :hello)))
                         (grow/xy 1 1 (fixed/xy 8 5 (align/ne :hello)))))
              (bsp/s
                (bsp/e   (grow/xy 1 1 (fixed/xy 8 5 (align/w  :hello)))
                  (bsp/e (grow/xy 1 1 (fixed/xy 8 5 (align/c  :hello)))
                         (grow/xy 1 1 (fixed/xy 8 5 (align/e  :hello)))))
                (bsp/e   (grow/xy 1 1 (fixed/xy 8 5 (align/sw :hello)))
                  (bsp/e (grow/xy 1 1 (fixed/xy 8 5 (align/s  :hello)))
                         (grow/xy 1 1 (fixed/xy 8 5 (align/se :hello)))))))
        },
        stringify! { :map-e },
        stringify! { (align/c :map-e) },
        stringify! { :map-s },
        stringify! { (align/c :map-s) },
        stringify! {
            (align/c (bg/behind :bg0 (margin/xy 1 1 (col
              (bg/behind :bg1 (border/around :border1 (margin/xy 2 1 :label1)))
              (bg/behind :bg2 (border/around :border2 (margin/xy 4 2 :label2)))
              (bg/behind :bg3 (border/around :border3 (margin/xy 6 3 :label3)))))))
        },
    ];
}