use bevy::{prelude::*, window::PrimaryWindow};
use kayak_ui_macros::rsx;

use crate::{
    children::KChildren,
    context::WidgetName,
    prelude::KayakWidgetContext,
    styles::{ComputedStyles, KStyle, RenderCommand, StyleProp, Units},
    widget::{EmptyState, Widget, WidgetParam},
    CameraUIKayak,
};

use super::ClipBundle;

#[derive(Component, Default, Clone, PartialEq, Eq)]
pub struct KayakApp;

impl Widget for KayakApp {}

/// Kayak's default root widget
/// This widget provides a width/height that matches the camera's width and height.
/// It will auto update if bevy's camera changes.
#[derive(Bundle)]
pub struct KayakAppBundle {
    pub app: KayakApp,
    pub styles: KStyle,
    pub computed_styles: ComputedStyles,
    pub children: KChildren,
    pub widget_name: WidgetName,
}

impl Default for KayakAppBundle {
    fn default() -> Self {
        Self {
            app: Default::default(),
            styles: Default::default(),
            computed_styles: ComputedStyles::default(),
            children: Default::default(),
            widget_name: KayakApp.get_name(),
        }
    }
}

pub fn app_update(
    In((entity, previous_props_entity)): In<(Entity, Entity)>,
    widget_context: Res<KayakWidgetContext>,
    widget_param: WidgetParam<KayakApp, EmptyState>,
    camera: Query<&Camera, With<CameraUIKayak>>,
    windows: Query<&Window, With<PrimaryWindow>>,
) -> bool {
    let mut window_change = false;

    if let Ok(app_style) = widget_param.computed_style_query.get(entity) {
        if let Some(camera_entity) = widget_context.camera_entity {
            if let Ok(camera) = camera.get(camera_entity) {
                if let Some(size) = camera.logical_viewport_size() {
                    if app_style.0.width != StyleProp::Value(Units::Pixels(size.x)) {
                        window_change = true;
                    }
                    if app_style.0.height != StyleProp::Value(Units::Pixels(size.y)) {
                        window_change = true;
                    }
                } else {
                    let primary_window = windows.single();
                    if app_style.0.width != StyleProp::Value(Units::Pixels(primary_window.width()))
                    {
                        window_change = true;
                    }
                    if app_style.0.height
                        != StyleProp::Value(Units::Pixels(primary_window.height()))
                    {
                        window_change = true;
                    }
                }
            }
        }
    }

    widget_param.has_changed(&widget_context, entity, previous_props_entity) || window_change
}

/// TODO: USE CAMERA INSTEAD OF WINDOW!!
pub fn app_render(
    In(entity): In<Entity>,
    widget_context: Res<KayakWidgetContext>,
    mut commands: Commands,
    mut query: Query<(&KStyle, &mut ComputedStyles, &KChildren)>,
    camera: Query<&Camera, With<CameraUIKayak>>,
) -> bool {
    let (mut width, mut height) = (0.0, 0.0);

    if let Some(camera_entity) = widget_context.camera_entity {
        if let Ok(camera) = camera.get(camera_entity) {
            if let Some(size) = camera.logical_viewport_size() {
                width = size.x;
                height = size.y;
            } else if let Some(viewport) = &camera.viewport {
                width = viewport.physical_size.x as f32;
                height = viewport.physical_size.y as f32;
            }
        }
    }

    if let Ok((app_style, mut computed_styles, children)) = query.get_mut(entity) {
        *computed_styles = KStyle::default()
            .with_style(KStyle {
                render_command: RenderCommand::Layout.into(),
                width: Units::Pixels(width).into(),
                height: Units::Pixels(height).into(),
                ..Default::default()
            })
            .with_style(app_style)
            .into();
        let parent_id = Some(entity);
        rsx! {
            <ClipBundle
                children={children.clone()}
            />
        };
    }

    true
}