import {createWorld, createComponent, createEntity, addComponent, createQuery, removeComponent, removeEntity} from 'concept-ecs'

const maxEntityCount = 1_000_000

// The world object stores all state required by the ECS
const world = createWorld(maxEntityCount)

// Components are based on Typed Arrays. The createComponent function takes a schema of TypedArray constructors
const Position = createComponent(world, {x: Float32Array, y: Float32Array})
const Velocity = createComponent(world, {value: Float32Array})

// Entities are indexes which are used to store data in any component
const entityId = createEntity(world)
addComponent(world, Position, entityId)
addComponent(world, Velocity, entityId)
Velocity.value[entityId] = 2

// Queries will find all entities with specified components
const query = createQuery(world, [Position, Velocity])

// Systems can be simple functions which iterate over query results
function system() {
    const [entities] = query.run()
    for (let index = 0; index < entities.length; index += 1) {
        const entityId = entities[index]
        Position.x[entityId] += Velocity.value[entityId]
        console.log(Position.x[entityId])
    }
}

system()

// All components must be removed from an entity before the entity can be removed
removeComponent(world, Position, entityId)
removeComponent(world, Velocity, entityId)

// Entity ID's that are removed are placed on a stack and will be resused first before new entity ID's are issued
removeEntity(world, entityId)