//! The `entity` module contains structures of all entities including players and enimies.

use crate::{Direction, FPos, Pos, const_pos};

/// The `Item` type represents any item an entity may be using
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum Item {
	Potion { heal: u32 },
	Weapon { atack: u32 },
	Armor { defense: u32 },
}

/// The `EntityKind` represents what kind of entity this is.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum EntityKind {
	/// The main player
	Player,
	/// An item (not in an inventory) on the floor of the dungeon
	Item(Item),
}

/// The `Entity` kind represents the main player, or any other
/// ai autonomous character that can move freely across the
/// dungeon.
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct Entity {
	/// The fixed grid position of the entity
	pub pos: Pos,
	/// The floating (real) current position of the entity
	pub fpos: FPos,
	/// Which direction this entity is facing
	pub dir: Direction,
	/// Which kind this entity is (along with entity kind specific data)
	pub kind: EntityKind,
	/// The amount of health this entity has (None if this Entity does not use health)
	pub health: Option<u32>,
}
impl Entity {
	/// Creates a new `Entity` at a given `Pos`, `Direction`, and `EntityKind`.
	///
	/// # Examples
	///
	/// ```
	/// use dungeon::{Pos, Direction, Entity, EntityKind};
	///
	/// let pos = Pos::new(0, 0).unwrap();
	/// let dir = Direction::North;
	/// let kind = EntityKind::Player;
	/// let health = Some(100);
	/// let entity = Entity::new(pos, dir, kind, health);
	/// ```
	#[must_use]
	pub const fn new(
		pos: Pos,
		dir: Direction,
		kind: EntityKind,
		health: Option<u32>,
	) -> Self {
		let fpos = FPos::from_pos(pos);
		Self {
			pos,
			fpos,
			dir,
			kind,
			health,
		}
	}

	/// Creates the Player version of the `Entity`
	///
	/// # Examples
	///
	/// ```
	/// use dungeon::{Pos, Entity};
	///
	/// let pos = Pos::new(0, 0).unwrap();
	/// let player = Entity::player(pos);
	/// ```
	#[must_use]
	pub const fn player(pos: Pos) -> Self {
		let dir = Direction::East;
		let kind = EntityKind::Player;
		let health = Some(100);
		Self::new(pos, dir, kind, health)
	}
}

/// The `Player` type represents the main player entity
#[derive(Clone, Debug, PartialEq)]
pub struct Player {
	pub entity: Entity,
	pub inventory: Vec<Item>,
}
impl Player {
	/// Instantiates the game player at a given `Pos`
	///
	/// # Examples
	///
	/// ```
	/// use dungeon::{Pos, Player};
	///
	/// let pos = Pos::new(1, 2).unwrap();
	/// let player = Player::new(pos);
	/// ```
	pub fn new(pos: Pos) -> Self {
		let entity = Entity::player(pos);
		let inventory = vec![];
		Self { entity, inventory }
	}
}
impl Default for Player {
	fn default() -> Self {
		let pos = const_pos!(1, 1);
		Self::new(pos)
	}
}