buoyant 0.7.0-alpha.1

use crate::{
    environment::LayoutEnvironment,
    event::EventResult,
    layout::{Alignment, HorizontalAlignment, ResolvedLayout, VerticalAlignment},
    primitives::{Dimension, Dimensions, Point, ProposedDimension, ProposedDimensions},
    view::{ViewLayout, ViewMarker},
};

#[derive(Debug, Clone)]
pub struct FixedFrame<T> {
    width: Option<u32>,
    height: Option<u32>,
    horizontal_alignment: HorizontalAlignment,
    vertical_alignment: VerticalAlignment,
    child: T,
}

impl<T: ViewMarker> FixedFrame<T> {
    pub const fn new(child: T) -> Self {
        Self {
            width: None,
            height: None,
            horizontal_alignment: HorizontalAlignment::Center,
            vertical_alignment: VerticalAlignment::Center,
            child,
        }
    }

    /// Sets the width of the frame.
    pub const fn with_width(mut self, width: u32) -> Self {
        self.width = Some(width);
        self
    }

    /// Sets the height of the frame.
    pub const fn with_height(mut self, height: u32) -> Self {
        self.height = Some(height);
        self
    }

    /// Sets the size of the frame.
    pub const fn with_size(mut self, width: u32, height: u32) -> Self {
        self.width = Some(width);
        self.height = Some(height);
        self
    }

    /// The horizontal alignment to apply when the child view is larger or smaller than the frame.
    pub const fn with_horizontal_alignment(mut self, alignment: HorizontalAlignment) -> Self {
        self.horizontal_alignment = alignment;
        self
    }

    /// The vertical alignment to apply when the child view is larger or smaller than the frame.
    pub const fn with_vertical_alignment(mut self, alignment: VerticalAlignment) -> Self {
        self.vertical_alignment = alignment;
        self
    }

    /// The alignment to apply when the child view is larger or smaller than the frame.
    pub const fn with_alignment(mut self, alignment: Alignment) -> Self {
        self.horizontal_alignment = alignment.horizontal();
        self.vertical_alignment = alignment.vertical();
        self
    }
}

impl<T> PartialEq for FixedFrame<T> {
    fn eq(&self, other: &Self) -> bool {
        self.width == other.width
            && self.height == other.height
            && self.horizontal_alignment == other.horizontal_alignment
            && self.vertical_alignment == other.vertical_alignment
    }
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Layout<T> {
    inner: T,
    frame_size: Dimensions,
    inner_size: Dimensions,
}

impl<V> ViewMarker for FixedFrame<V>
where
    V: ViewMarker,
{
    type Renderables = V::Renderables;
    type Transition = V::Transition;
}

impl<Captures: ?Sized, V> ViewLayout<Captures> for FixedFrame<V>
where
    V: ViewLayout<Captures>,
{
    type Sublayout = Layout<V::Sublayout>;
    type State = V::State;

    fn priority(&self) -> i8 {
        self.child.priority()
    }

    fn is_empty(&self) -> bool {
        self.child.is_empty()
    }

    fn transition(&self) -> Self::Transition {
        self.child.transition()
    }

    fn build_state(&self, captures: &mut Captures) -> Self::State {
        self.child.build_state(captures)
    }

    fn layout(
        &self,
        offer: &ProposedDimensions,
        env: &impl LayoutEnvironment,
        captures: &mut Captures,
        state: &mut Self::State,
    ) -> ResolvedLayout<Self::Sublayout> {
        let modified_offer = ProposedDimensions {
            width: self.width.map_or(offer.width, ProposedDimension::Exact),
            height: self.height.map_or(offer.height, ProposedDimension::Exact),
        };
        let child_layout = self.child.layout(&modified_offer, env, captures, state);
        let resolved_size = Dimensions {
            width: self
                .width
                .map_or(child_layout.resolved_size.width, Dimension::from),
            height: self
                .height
                .map_or(child_layout.resolved_size.height, Dimension::from),
        };

        let layout = Layout {
            inner: child_layout.sublayouts,
            frame_size: resolved_size,
            inner_size: child_layout.resolved_size,
        };

        ResolvedLayout {
            sublayouts: layout,
            resolved_size,
        }
    }

    fn render_tree(
        &self,
        layout: &Self::Sublayout,
        origin: Point,
        env: &impl LayoutEnvironment,
        captures: &mut Captures,
        state: &mut Self::State,
    ) -> Self::Renderables {
        let new_origin = origin
            + Point::new(
                self.horizontal_alignment.align(
                    layout.frame_size.width.into(),
                    layout.inner_size.width.into(),
                ),
                self.vertical_alignment.align(
                    layout.frame_size.height.into(),
                    layout.inner_size.height.into(),
                ),
            );

        self.child
            .render_tree(&layout.inner, new_origin, env, captures, state)
    }

    fn handle_event(
        &self,
        event: &crate::view::Event,
        context: &crate::event::EventContext,
        render_tree: &mut Self::Renderables,
        captures: &mut Captures,
        state: &mut Self::State,
    ) -> EventResult {
        self.child
            .handle_event(event, context, render_tree, captures, state)
    }
}