//! Keep overlay Escape ahead of modal cancellation in the ordinary widget tree.
//!
//! Iced skips root.update when an overlay captures an event. Keeping this
//! wrapper present even when inactive preserves the child's widget state. A
//! current-overlay preflight also handles pickers opened mid-batch. Passive
//! overlays may see an ignored Escape again: the raw-input observer only makes
//! pending focus requests stale; it does not publish modal cancellation.
use super::{App, Message, Page, architecture_authoring};
use iced::advanced::{Clipboard, Layout, Shell, Widget, layout, overlay, renderer, widget};
use iced::{Element, Event, Length, Rectangle, Size, Theme, Vector, keyboard, mouse};

pub(crate) fn root<'a, R: renderer::Renderer + 'a>(
    app: &App,
    content: Element<'a, Message, Theme, R>,
) -> Element<'a, Message, Theme, R> {
    let modal = app.text_workspace.menu().is_none()
        && (app.behavior.creation.has_pending()
            || app.diagram_usages.is_some()
            || app.behavior.source_active()
            || (app.page == Page::Text
                && (app.text_workspace.drawer().is_some()
                    || app.source_navigation.open
                    || app.source_rename.open())
                && app.architecture.is_none()));
    Element::new(Bridge {
        content,
        messages: [
            architecture_authoring::captured_escape_message(app),
            modal.then_some(Message::Escape),
        ],
    })
}

struct Bridge<'a, R> {
    content: Element<'a, Message, Theme, R>,
    messages: [Option<Message>; 2],
}

impl<R: renderer::Renderer> Widget<Message, Theme, R> for Bridge<'_, R> {
    fn children(&self) -> Vec<widget::Tree> {
        vec![widget::Tree::new(self.content.as_widget())]
    }

    fn diff(&self, tree: &mut widget::Tree) {
        tree.diff_children(std::slice::from_ref(&self.content));
    }

    fn size(&self) -> Size<Length> {
        self.content.as_widget().size()
    }

    fn size_hint(&self) -> Size<Length> {
        self.content.as_widget().size_hint()
    }

    fn layout(
        &mut self,
        tree: &mut widget::Tree,
        renderer: &R,
        limits: &layout::Limits,
    ) -> layout::Node {
        self.content
            .as_widget_mut()
            .layout(&mut tree.children[0], renderer, limits)
    }

    fn operate(
        &mut self,
        tree: &mut widget::Tree,
        layout: Layout<'_>,
        renderer: &R,
        operation: &mut dyn widget::Operation,
    ) {
        self.content
            .as_widget_mut()
            .operate(&mut tree.children[0], layout, renderer, operation);
    }

    fn update(
        &mut self,
        tree: &mut widget::Tree,
        event: &Event,
        layout: Layout<'_>,
        cursor: mouse::Cursor,
        renderer: &R,
        clipboard: &mut dyn Clipboard,
        shell: &mut Shell<'_, Message>,
        viewport: &Rectangle,
    ) {
        let escape = matches!(
            event,
            Event::Keyboard(keyboard::Event::KeyPressed {
                key: keyboard::Key::Named(keyboard::key::Named::Escape),
                ..
            })
        );
        // Iced collects overlays before processing a batch of base events. A
        // preceding click in that batch can therefore open a picker whose
        // Escape would otherwise reach focused fields underneath it. Offer only
        // Escape to the current overlay before updating the ordinary tree.
        if escape {
            if let Some(element) = self.content.as_widget_mut().overlay(
                &mut tree.children[0],
                layout,
                renderer,
                viewport,
                Vector::ZERO,
            ) {
                let mut overlay = overlay::Nested::new(element);
                let node = overlay.layout(renderer, viewport.size());
                overlay.update(
                    event,
                    Layout::new(&node),
                    cursor,
                    renderer,
                    clipboard,
                    shell,
                );
            }
            if shell.is_event_captured() {
                return;
            }
        }
        self.content.as_widget_mut().update(
            &mut tree.children[0],
            event,
            layout,
            cursor,
            renderer,
            clipboard,
            shell,
            viewport,
        );
        if shell.is_event_captured() && escape {
            for message in self.messages.iter().flatten() {
                shell.publish(message.clone());
            }
        }
    }

    fn draw(
        &self,
        tree: &widget::Tree,
        renderer: &mut R,
        theme: &Theme,
        style: &renderer::Style,
        layout: Layout<'_>,
        cursor: mouse::Cursor,
        viewport: &Rectangle,
    ) {
        self.content.as_widget().draw(
            &tree.children[0],
            renderer,
            theme,
            style,
            layout,
            cursor,
            viewport,
        );
    }

    fn mouse_interaction(
        &self,
        tree: &widget::Tree,
        layout: Layout<'_>,
        cursor: mouse::Cursor,
        viewport: &Rectangle,
        renderer: &R,
    ) -> mouse::Interaction {
        self.content.as_widget().mouse_interaction(
            &tree.children[0],
            layout,
            cursor,
            viewport,
            renderer,
        )
    }

    fn overlay<'b>(
        &'b mut self,
        tree: &'b mut widget::Tree,
        layout: Layout<'b>,
        renderer: &R,
        viewport: &Rectangle,
        translation: Vector,
    ) -> Option<overlay::Element<'b, Message, Theme, R>> {
        self.content.as_widget_mut().overlay(
            &mut tree.children[0],
            layout,
            renderer,
            viewport,
            translation,
        )
    }
}

#[cfg(test)]
pub(crate) mod tests;