import type { Jetstream } from "@skyware/jetstream";

/**
 * Event operation types supported by Jetstream
 */
export type EventOperation = "create" | "update" | "delete";

/**
 * Handler function signature for any event operation
 */
export type EventHandler<_T extends string = string> = (event: any) => Promise<void>;

/**
 * Configuration for a single collection's event handlers
 */
export interface CollectionHandlers {
  collection: string;
  onCreate?: EventHandler;
  onUpdate?: EventHandler;
  onDelete?: EventHandler;
}

/**
 * Registry for managing Jetstream event handler registrations.
 * Eliminates boilerplate by automating handler setup for collections.
 */
export class EventHandlerRegistry {
  private registrations: CollectionHandlers[] = [];

  /**
   * Register handlers for a collection
   */
  register(handlers: CollectionHandlers): this {
    this.registrations.push(handlers);
    return this; // Fluent interface
  }

  /**
   * Apply all registered handlers to a Jetstream instance
   */
  applyTo(jetstream: Jetstream): void {
    for (const { collection, onCreate, onUpdate, onDelete } of this.registrations) {
      if (onCreate) {
        jetstream.onCreate(collection as any, onCreate);
      }
      if (onUpdate) {
        jetstream.onUpdate(collection as any, onUpdate);
      }
      if (onDelete) {
        jetstream.onDelete(collection as any, onDelete);
      }
    }
  }

  /**
   * Get all registered collection names
   */
  getCollections(): string[] {
    return this.registrations.map((r) => r.collection);
  }

  /**
   * Clear all registrations (useful for testing)
   */
  clear(): void {
    this.registrations = [];
  }
}