import { EventEmitter } from "utils";
import { getRequestManagerEvents } from "managers";

/**
 * **Request Manager** is used to emit `request lifecycle events` like - request start, request end, upload and download progress.
 * It is also the place of `request aborting` system, here we store all the keys and controllers that are isolated for each client instance.
 */
export class RequestManager {
  emitter = new EventEmitter();
  events = getRequestManagerEvents(this.emitter);

  constructor() {
    this.emitter?.setMaxListeners(1000);
  }

  abortControllers = new Map<string, Map<string, AbortController>>();

  addAbortController = (abortKey: string, requestId: string) => {
    let abortGroup = this.abortControllers.get(abortKey);
    if (!abortGroup) {
      const newAbortGroup = new Map();
      abortGroup = newAbortGroup;
      this.abortControllers.set(abortKey, newAbortGroup);
    }

    const abortController = abortGroup.get(requestId);
    if (!abortController || abortController.signal.aborted) {
      abortGroup.set(requestId, new AbortController());
    }
  };

  getAbortController = (abortKey: string, requestId: string) => {
    return this.abortControllers.get(abortKey)?.get(requestId);
  };

  removeAbortController = (abortKey: string, requestId: string) => {
    this.abortControllers.get(abortKey)?.delete(requestId);
  };

  // Aborting

  useAbortController = (abortKey: string, requestId: string) => {
    const controller = this.abortControllers.get(abortKey)?.get(requestId);
    controller?.abort();
  };

  abortByKey = (abortKey: string) => {
    const controllers = this.abortControllers.get(abortKey);

    if (controllers) {
      const entries = Array.from(controllers.entries());
      entries.forEach(([key]) => {
        this.useAbortController(abortKey, key);
      });
    }
  };

  abortByRequestId = (abortKey: string, requestId: string) => {
    this.useAbortController(abortKey, requestId);
  };

  abortAll = () => {
    const entries = Array.from(this.abortControllers.entries());
    entries.forEach(([abortKey, value]) => {
      const controllers = Array.from(value.entries());
      controllers.forEach(([requestId]) => {
        this.useAbortController(abortKey, requestId);
      });
    });
  };
}