orbtk-core 0.3.1-alpha4

use std::{cell::RefCell, collections::BTreeMap};

use dces::prelude::*;

use crate::{
    prelude::*, proc_macros::IntoLayout, render::RenderContext2D, theming::*, tree::Tree,
    utils::prelude::*,
};

use super::{component, component_or_default, component_try_mut, try_component, Layout};

/// The `PopupLayout` handles measuring and arrangement of a `Popup` widget.
#[derive(Default, IntoLayout)]
pub struct PopupLayout {
    // TODO: Add padding to the widget.
    desired_size: RefCell<DirtySize>,
}

/// Associated functions, that react on any given state change inside the `Popup` widget.
impl PopupLayout {
    /// Instatiate a new PopupLayout object.
    pub fn new() -> Self {
        PopupLayout::default()
    }
}

impl Layout for PopupLayout {
    fn measure(
        &self,
        render_context_2_d: &mut RenderContext2D,
        entity: Entity,
        ecm: &mut EntityComponentManager<Tree>,
        layouts: &BTreeMap<Entity, Box<dyn Layout>>,
        theme: &Theme,
    ) -> DirtySize {
        // if visibility is collapsed, the entity is rendered but
        // shouldn't consume any size in the render buffer.
        if component::<Visibility>(ecm, entity, "visibility") == Visibility::Collapsed {
            self.desired_size.borrow_mut().set_size(0.0, 0.0);
            return *self.desired_size.borrow();
        }

        if let Some(target) = try_component::<PopupTarget>(ecm, entity, "target") {
            let current_bounds: Rectangle = component(ecm, entity, "bounds");
            let current_constraint: Constraint = component(ecm, entity, "constraint");

            let real_target_bounds = match target {
                PopupTarget::Entity(entity) => {
                    let target_position: Point = component(ecm, entity, "position");

                    // WARNING: widget bounds (width an height values)
                    // will be measured as available space for the
                    // widget. Only in state `post_layout_update` it
                    // will reflect the effective size of the given
                    // entity.
                    let mut target_bounds: Rectangle = component(ecm, entity, "bounds");
                    target_bounds.set_position(target_position);
                    target_bounds
                }
                PopupTarget::Point(mut point) => {
                    point.set_x(point.x() + current_bounds.width() / 2.0);
                    point.set_y(point.y() + current_bounds.height() / 2.0);
                    Rectangle::new(point, (0.0, 0.0))
                }
            };

            let placement: Placement = component_or_default(ecm, entity, "placement");

            let new_popup_size = match placement {
                Placement::Bottom => {
                    let current_h_align: Alignment = component(ecm, entity, "h_align");

                    let width = current_h_align.align_measure(
                        real_target_bounds.width(),
                        current_bounds.width(),
                        0.0,
                        0.0,
                    );
                    let height = current_bounds.height();

                    //let y = real_target_bounds.y() - current_bounds.height();

                    current_constraint.perform((width, height))
                }
                Placement::Left => {
                    let current_v_align: Alignment = component(ecm, entity, "v_align");

                    let width = current_bounds.width();
                    let height = current_v_align.align_measure(
                        real_target_bounds.height(),
                        current_bounds.height(),
                        0.0,
                        0.0,
                    );

                    // respect given bound constraints
                    current_constraint.perform((width, height))
                }
                Placement::Right => {
                    let current_v_align: Alignment = component(ecm, entity, "v_align");

                    let width = current_bounds.width();
                    let height = current_v_align.align_measure(
                        real_target_bounds.height(),
                        current_bounds.height(),
                        0.0,
                        0.0,
                    );

                    current_constraint.perform((width, height))
                }
                Placement::Top => {
                    let current_h_align: Alignment = component(ecm, entity, "h_align");

                    let width = current_h_align.align_measure(
                        real_target_bounds.width(),
                        current_bounds.width(),
                        0.0,
                        0.0,
                    );
                    let height = current_bounds.height();

                    current_constraint.perform((width, height))
                }
            };

            {
                let mut desired_size = self.desired_size.borrow_mut();
                desired_size.set_width(new_popup_size.0);
                desired_size.set_height(new_popup_size.1);
            }

            let padding: Thickness = component(ecm, entity, "padding");
            for index in 0..ecm.entity_store().children[&entity].len() {
                let child = ecm.entity_store().children[&entity][index];

                if let Some(child_layout) = layouts.get(&child) {
                    let child_desired_size =
                        child_layout.measure(render_context_2_d, child, ecm, layouts, theme);
                    let mut desired_size = self.desired_size.borrow().size();

                    let dirty = child_desired_size.dirty() || self.desired_size.borrow().dirty();
                    self.desired_size.borrow_mut().set_dirty(dirty);

                    let child_margin = *ecm
                        .component_store()
                        .get::<Thickness>("margin", child)
                        .unwrap();

                    desired_size.0 = desired_size.0.max(
                        child_desired_size.width()
                            + padding.left()
                            + padding.right()
                            + child_margin.left()
                            + child_margin.right(),
                    );
                    desired_size.1 = desired_size.1.max(
                        child_desired_size.height()
                            + padding.top()
                            + padding.bottom()
                            + child_margin.top()
                            + child_margin.left(),
                    );

                    self.desired_size
                        .borrow_mut()
                        .set_size(desired_size.0, desired_size.1);
                }
            }
        } else {
            println!("Target not found");
        }

        *self.desired_size.borrow()
    }

    fn arrange(
        &self,
        render_context_2_d: &mut RenderContext2D,
        parent_size: (f64, f64),
        entity: Entity,
        ecm: &mut EntityComponentManager<Tree>,
        layouts: &BTreeMap<Entity, Box<dyn Layout>>,
        theme: &Theme,
    ) -> (f64, f64) {
        if component::<Visibility>(ecm, entity, "visibility") == Visibility::Collapsed {
            self.desired_size.borrow_mut().set_size(0.0, 0.0);
            return (0.0, 0.0);
        }

        if !self.desired_size.borrow().dirty() {
            return self.desired_size.borrow().size();
        }

        let horizontal_alignment: Alignment = component(ecm, entity, "h_align");
        let vertical_alignment: Alignment = component(ecm, entity, "v_align");
        let margin = *ecm
            .component_store()
            .get::<Thickness>("margin", entity)
            .unwrap();
        let padding: Thickness = component(ecm, entity, "padding");
        let constraint: Constraint = component(ecm, entity, "constraint");

        let size = constraint.perform((
            horizontal_alignment.align_measure(
                parent_size.0,
                self.desired_size.borrow().width(),
                margin.left(),
                margin.right(),
            ),
            vertical_alignment.align_measure(
                parent_size.1,
                self.desired_size.borrow().height(),
                margin.top(),
                margin.bottom(),
            ),
        ));

        if let Some(bounds) = component_try_mut::<Rectangle>(ecm, entity, "bounds") {
            bounds.set_width(size.0);
            bounds.set_height(size.1);
        }

        mark_as_dirty("bounds", entity, ecm);

        let available_size = (
            size.0 - padding.left() - padding.right(),
            size.1 - padding.top() - padding.bottom(),
        );

        for index in 0..ecm.entity_store().children[&entity].len() {
            let child = ecm.entity_store().children[&entity][index];

            let child_margin: Thickness = component(ecm, entity, "margin");

            if let Some(child_layout) = layouts.get(&child) {
                child_layout.arrange(
                    render_context_2_d,
                    available_size,
                    child,
                    ecm,
                    layouts,
                    theme,
                );
            }

            let child_horizontal_alignment: Alignment =
                *ecm.component_store().get("h_align", child).unwrap();
            let child_vertical_alignment: Alignment =
                *ecm.component_store().get("v_align", child).unwrap();
            if let Ok(child_bounds) = ecm
                .component_store_mut()
                .get_mut::<Rectangle>("bounds", child)
            {
                child_bounds.set_x(
                    padding.left()
                        + child_horizontal_alignment.align_position(
                            available_size.0,
                            child_bounds.width(),
                            child_margin.left(),
                            child_margin.right(),
                        ),
                );
                child_bounds.set_y(
                    padding.top()
                        + child_vertical_alignment.align_position(
                            available_size.1,
                            child_bounds.height(),
                            child_margin.top(),
                            child_margin.bottom(),
                        ),
                );
            }

            mark_as_dirty("bounds", child, ecm);
        }

        self.desired_size.borrow_mut().set_dirty(false);
        size
    }
}