package coffee.liz.ecs.model;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.Getter;
import lombok.RequiredArgsConstructor;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

@Getter
@Builder
@RequiredArgsConstructor
@AllArgsConstructor
@Data
public class Entity {
	/** Unique id. */
	private final int id;

	/** Instances of {@link Component}s. */
	@Builder.Default
	private Map<Class<? extends Component>, Component> componentMap = Collections.synchronizedMap(new HashMap<>());

	/**
	 * Check if entity has component type.
	 *
	 * @param componentType
	 *            the {@link Component} class
	 * @return true if component exists
	 */
	public boolean has(final Class<? extends Component> componentType) {
		return componentMap.containsKey(componentType);
	}

	/**
	 * Check if entity has all component types.
	 *
	 * @param components
	 *            collection of {@link Component} classes
	 * @return true if all components exist
	 */
	public boolean hasAll(final Collection<Class<? extends Component>> components) {
		return components.stream().allMatch(this::has);
	}

	/**
	 * Get component by type.
	 *
	 * @param componentType
	 *            the {@link Component} class
	 * @param <C>
	 *            component type
	 * @return the component or throw {@link IllegalArgumentException}
	 */
	@SuppressWarnings("unchecked")
	public <C extends Component> C get(final Class<C> componentType) {
		final C component = (C) componentMap.get(componentType);
		if (component == null) {
			throw new IllegalArgumentException(
					"Entity with id " + getId() + " does not have required component " + componentType.getSimpleName());
		}
		return component;
	}

	/**
	 * Add component to entity.
	 *
	 * @param component
	 *            the {@link Component} to add
	 * @param <C>
	 *            component type
	 * @return this {@link Entity} for chaining
	 */
	public <C extends Component> Entity add(final C component) {
		componentMap.put(component.getKey(), component);
		return this;
	}

	/**
	 * Remove component from entity.
	 *
	 * @param componentType
	 *            the {@link Component} class to remove
	 * @param <C>
	 *            component type
	 * @return this {@link Entity} for chaining
	 */
	public <C extends Component> Entity remove(final Class<C> componentType) {
		componentMap.remove(componentType);
		return this;
	}

	/**
	 * Get all component types.
	 *
	 * @return set of {@link Component} classes
	 */
	public Set<Class<? extends Component>> componentTypes() {
		return componentMap.keySet();
	}
}