import type { ComponentDef } from "./component";

// ── Query ─────────────────────────────────────────────
/**
 * Describes a component filter.
 *
 * Use `query()` to construct one, optionally chaining `.without()`.
 *
 * @example
 * ```ts
 * query(Position, Velocity)           // entities with both
 * query(Position).without(Dead)       // Position but not Dead
 * ```
 */
export class Query {
  /** Components an entity must have to match. */
  readonly with: ComponentDef<any>[];
  /** Components an entity must NOT have to match. */
  readonly not: ComponentDef<any>[];

  constructor(
    withComponents: ComponentDef<any>[],
    withoutComponents: ComponentDef<any>[] = [],
  ) {
    this.with = withComponents;
    this.not = withoutComponents;
  }

  /** Return a new Query that also excludes these components. */
  without(...components: ComponentDef<any>[]): Query {
    return new Query(this.with, [...this.not, ...components]);
  }
}

/**
 * Build a query matching entities that have all the given components.
 */
export function query(...components: ComponentDef<any>[]): Query {
  return new Query(components);
}