//! The tabs example's widget tree -- the five demo panes plus the message
//! composer that exercises `TextEdit`. Factored out of
//! `iris/examples/tabs/main.rs` (I2, RUST.md) so the same UI runs under
//! both backends: the winit example binary calls `build` from
//! `DefaultAppState::new`, and `iris-android-app`'s cdylib calls it from
//! `AndroidAppState::new`. Nothing here mentions either backend by name --
//! it only needs `Rsc: HasEvents` (for `.on(...)`) and `Rsc::State:
//! FocusHost` (for `.attr::<Selectable>(())`), both of which every backend
//! implements.

use iris::prelude::*;
use std::{cell::RefCell, rc::Rc};

pub struct ClientWidgets {
    pub info: WeakWidget<Text>,
}

pub fn build<Rsc: HasEvents>(rsc: &mut Rsc, ui_state: &mut impl HasRoot) -> ClientWidgets
where
    Rsc::State: FocusHost,
{
    let rrect = rect(Color::WHITE).radius(20);
    let pad_test = (
        rrect.color(Color::BLUE),
        (
            rrect
                .color(Color::RED)
                .sized((100, 100))
                .center()
                .width(rest(2)),
            (
                rrect.color(Color::ORANGE),
                rrect.color(Color::LIME).pad(10.0),
            )
                .span(Dir::RIGHT)
                .width(rest(2)),
            rrect.color(Color::YELLOW),
        )
            .span(Dir::RIGHT)
            .pad(10)
            .width(rest(3)),
    )
        .span(Dir::RIGHT)
        .add(rsc);

    let span_test = (
        rrect.color(Color::GREEN).width(100),
        rrect.color(Color::ORANGE),
        rrect.color(Color::CYAN),
        rrect.color(Color::BLUE).width(rel(0.5)),
        rrect.color(Color::MAGENTA).width(100),
        rrect.color(Color::RED).width(100),
    )
        .span(Dir::LEFT)
        .add(rsc);

    let span_add = Span::empty(Dir::RIGHT).add(rsc);

    let add_button = rect(Color::LIME)
        .radius(30)
        .on(CursorSense::click(), move |_, rsc| {
            let child = image(include_bytes!("../assets/sungals.png"))
                .center()
                .add_strong(rsc);
            span_add(rsc).push(child);
        })
        .sized((150, 150))
        .align(Align::BOT_RIGHT);

    let del_button = rect(Color::RED)
        .radius(30)
        .on(CursorSense::click(), move |_, rsc| {
            span_add(rsc).pop();
        })
        .sized((150, 150))
        .align(Align::BOT_LEFT);

    let span_add_test = (span_add, add_button, del_button).stack().add(rsc);

    let btext = |content| wtext(content).size(30);

    let text_test = (
        btext("this is a").align(Align::LEFT),
        btext("teeeeeeeest").align(Align::RIGHT),
        btext("okkk\nokkkkkk!").align(Align::LEFT),
        btext("hmm"),
        btext("a"),
        (
            btext("'").family(Family::Monospace).align(Align::TOP),
            btext("'").family(Family::Monospace),
            btext(":gamer mode").family(Family::Monospace),
            rect(Color::CYAN).sized((10, 10)).center(),
            rect(Color::RED).sized((100, 100)).center(),
            rect(Color::PURPLE).sized((50, 50)).align(Align::TOP),
        )
            .span(Dir::RIGHT)
            .center(),
        wtext("pretty cool right?").size(50),
    )
        .span(Dir::DOWN)
        .add(rsc);

    let texts = Span::empty(Dir::DOWN).gap(10).add(rsc);
    let msg_area = texts
        .scrollable(Axis::Y, Pin::Start)
        .masked()
        .background(rect(Color::SKY));
    let add_text = wtext("add")
        .editable(EditMode::MultiLine)
        .text_align(Align::LEFT)
        .size(30)
        .attr::<Selectable>(())
        .on(Submit, move |ctx, rsc| {
            let w = ctx.widget;
            let content = w.edit(rsc).take();
            let text = wtext(content)
                .editable(EditMode::MultiLine)
                .size(30)
                .text_align(Align::LEFT)
                .wrap(true)
                .attr::<Selectable>(());
            let msg_box = text
                .background(rect(Color::WHITE.darker(0.5)))
                .add_strong(rsc);
            texts(rsc).push(msg_box);
        })
        .add(rsc);

    let text_edit_scroll = (
        msg_area.height(rest(1)),
        (
            Rect::new(Color::WHITE.darker(0.9)),
            (
                add_text.width(rest(1)),
                Rect::new(Color::GREEN)
                    .on(CursorSense::click(), move |ctx, rsc: &mut Rsc| {
                        rsc.run_event::<Submit>(add_text, (), ctx.state);
                    })
                    .sized((40, 40)),
            )
                .span(Dir::RIGHT)
                .pad(10),
        )
            .stack()
            .size(StackSize::Child(1))
            .layer_offset(1)
            .align(Align::BOT),
    )
        .span(Dir::DOWN)
        .add(rsc);

    let main = WidgetPtr::new().add(rsc);

    let vals = Rc::new(RefCell::new((0, Vec::new())));
    let mut switch_button = |color, to: WeakWidget, label| {
        let to = to.upgrade(rsc);
        let vec = &mut vals.borrow_mut().1;
        let i = vec.len();
        if vec.is_empty() {
            vec.push(None);
            main(rsc).set(to);
        } else {
            vec.push(Some(to));
        }
        let vals = vals.clone();
        let rect = rect(color)
            .on(CursorSense::click(), move |ctx, rsc| {
                let (prev, vec) = &mut *vals.borrow_mut();
                if let Some(h) = vec[i].take() {
                    vec[*prev] = main(rsc).replace(h);
                    *prev = i;
                }
                ctx.widget(rsc).color = color.darker(0.3);
            })
            .on(
                CursorSense::HoverStart | CursorSense::unclick(),
                move |ctx, rsc| {
                    ctx.widget(rsc).color = color.brighter(0.2);
                },
            )
            .on(CursorSense::HoverEnd, move |ctx, rsc| {
                ctx.widget(rsc).color = color;
            })
            // I4 (RUST.md): the tabs screen's only named controls, and the
            // ones the emulator step at the bottom of that box taps by
            // name -- `ui-trace record --do "tap 'pad'"` and so on. `.label`
            // slots into this chain like any other widget combinator
            // (`RefFnTag` in `core/src/widget/tag.rs`); it does not have to
            // be the last thing before `.add`.
            .label(label);
        (rect, wtext(label).size(30).text_align(Align::CENTER)).stack()
    };

    let tabs = (
        switch_button(Color::RED, pad_test, "pad"),
        switch_button(Color::GREEN, span_test, "span"),
        switch_button(Color::BLUE, span_add_test, "image span"),
        switch_button(Color::MAGENTA, text_test, "text layout"),
        switch_button(
            Color::YELLOW.mul_rgb(0.5),
            text_edit_scroll,
            "text edit scroll",
        ),
    )
        .span(Dir::RIGHT);

    let info = wtext("").add(rsc);
    let info_sect = info.pad(10).align(Align::RIGHT);

    ((tabs.height(40), main.pad(10)).span(Dir::DOWN), info_sect)
        .stack()
        .set_root(rsc, ui_state);

    ClientWidgets { info }
}