use flecs::*;

#[derive(Copy, Clone, Default, Debug, PartialEq)]
struct Position {
	x: f32,
	y: f32,
}

#[derive(Copy, Clone, Default, Debug, PartialEq)]
struct Velocity {
	x: f32,
	y: f32,
}

// Tag
struct Human {}

// Two tags used to create a pair
struct Eats {}
struct Apples {}

fn iterate_components(e: Entity) {
	// 1. The easiest way to print the components is to use type::str
	println!("{}", e.type_info().to_str());

	// 2. To get individual component ids, use entity::each
	let mut i = 0;
	e.each(|id| {
		println!("{}: [{}] {}", i, id.raw(), id.to_str());
		i += 1;
	});
	println!("");

	// // 3. we can also inspect and print the ids in our own way. This is a
	// // bit more complicated as we need to handle the edge cases of what can be
	// // encoded in an id, but provides the most flexibility.
	i = 0;
	e.each(|id| {
		if id.is_pair() {
			// If id is a pair, extract & print both parts of the pair
			let rel = id.relation();
			let obj = id.object();
			println!("rel: {}, obj: {}", rel.name(), obj.name());
		} else {
			// Id contains a regular entity. Strip role before printing.
			let e = id.entity();
			println!("{}: entity: {}  [{}]", i, e.name(), e.symbol());
		}
		i += 1;
	});

	println!("");
}

fn main() {
	println!("Entity Iterate Components starting...");

	let mut world = World::new();

	// We have to manually register all components
	world.component::<Position>();
	world.component::<Velocity>();
	world.component::<Human>();
	world.component::<Eats>();
	world.component::<Apples>();

	let bob = world
		.entity()
		.set::<Position>(Position { x: 10.0, y: 20.0 })
		.set::<Velocity>(Velocity { x: 1.0, y: 1.0 })
		.add::<Human>()
		.add_relation::<Eats, Apples>();

	println!("\nBob's components");
	iterate_components(bob);

	// We can use the same function to iterate the components of a component
	println!("Position's components");
	iterate_components(world.component::<Position>());
}

// Output:

// Bob's components:
// ecs_type_str: Position,Velocity,Human,(Eats,Apples)

// 0: Position
// 1: Velocity
// 2: Human
// 3: (Eats,Apples)

// 0: entity: Position
// 1: entity: Velocity
// 2: entity: Human
// 3: role: PAIR, rel: Eats, obj: Eats

// Position's components:
// ecs_type_str: EcsComponent,(Identifier,Name),(Identifier,Symbol),(OnDelete,Throw)

// 0: Component
// 1: (Identifier,Name)
// 2: (Identifier,Symbol)
// 3: (OnDelete,Throw)

// 0: entity: Component
// 1: role: PAIR, rel: Identifier, obj: Identifier
// 2: role: PAIR, rel: Identifier, obj: Identifier
// 3: role: PAIR, rel: OnDelete, obj: OnDelete

#[cfg(test)]
mod tests {
	#[test]
	fn flecs_entity_iterate_components() {
		super::main();
	}
}