use crate::content;
use cgmath::{Deg, Point2, Point3};

/// The location of a UI element, in one of a few
/// possible coordinate systems.
///
/// Positive Y always points up,
/// positive X always points right.
#[derive(Debug, Clone)]
pub enum AnchoredUiPosition {
	/// Position of this sprite's center,
	/// relative to the nw corner of the window.
	NwC(Point2<f32>),

	/// Position of this sprite's nw corner,
	/// relative to the nw corner of the window.
	NwNw(Point2<f32>),

	/// Position of this sprite's ne corner,
	/// relative to the nw corner of the window.
	NwNe(Point2<f32>),

	/// Position of this sprite's sw corner,
	/// relative to the nw corner of the window.
	NwSw(Point2<f32>),

	/// Position of this sprite's se corner,
	/// relative to the nw corner of the window.
	NwSe(Point2<f32>),
}

/// A sprite that represents a ui element
#[derive(Debug, Clone)]
pub struct UiSprite {
	/// The texture to use for this sprite
	pub texture: content::TextureHandle,

	/// This object's position, in logical (dpi-adjusted) pixels
	pub pos: AnchoredUiPosition,

	/// This sprite's color will be multiplied by this value.
	/// If this is None, color will not be changed.
	pub color: Option<[f32; 4]>,

	/// The size of this sprite, in logical (dpi-adjusted) pixels
	pub dimensions: Point2<f32>,

	/// This sprite's rotation, measured ccw
	pub angle: Deg<f32>,
}

/// A sprite that represents a world object:
/// Ships, planets, debris, etc
#[derive(Debug, Clone)]
pub struct ObjectSprite {
	/// The texture to use for this sprite
	pub texture: content::TextureHandle,

	/// This object's center, in world coordinates.
	pub pos: Point3<f32>,

	/// The size of this sprite,
	/// given as height in world units.
	pub size: f32,

	/// This sprite's rotation
	/// (relative to north, measured ccw)
	/// Note that this is different from the angle used by our physics system.
	pub angle: Deg<f32>,

	/// Sprites that should be drawn relative to this sprite.
	pub children: Option<Vec<ObjectSubSprite>>,
}

/// A sprite that is drawn relative to an ObjectSprite.
#[derive(Debug, Clone)]
pub struct ObjectSubSprite {
	/// The sprite texture to draw
	pub texture: content::TextureHandle,

	/// This object's position, in world coordinates.
	/// This is relative to this sprite's parent.
	pub pos: Point3<f32>,

	/// The size of this sprite,
	/// given as height in world units.
	pub size: f32,

	/// This sprite's rotation
	/// (relative to north, measured ccw)
	/// Just as position, this is relative to this
	/// subsprite's parent sprite.
	pub angle: Deg<f32>,
}