import type { Plugin } from "@segment/analytics-next";
import { Signal } from "@segment/analytics-signals-runtime";
import { Signals } from "../core/signals";
import { version } from "../generated/version";
import { assertBrowserEnv } from "../lib/assert-browser-env";
import { logger } from "../lib/logger";
import { AnyAnalytics, SignalsPluginSettingsConfig } from "../types";
import { createUserDefinedSignal } from "../types/factories";

export type OnSignalCb = (signal: Signal) => void;

interface SignalsAugmentedFunctionality {
  stop(): void;
  /**
   * Listen to signals
   */
  onSignal: (fn: OnSignalCb) => this;

  /**
   * Emit/add a custom signal of type 'userDefined'
   */
  addSignal(userDefinedData: Record<string, unknown>): this;
}

export class SignalsPlugin implements Plugin, SignalsAugmentedFunctionality {
  readonly type = "utility";
  readonly name = "SignalsPlugin";
  readonly version = version;
  public signals: Signals;
  constructor(settings: SignalsPluginSettingsConfig = {}) {
    assertBrowserEnv();

    // assign to window.SegmentSignalsPlugin for debugging purposes (e.g window.SegmentSignalsPlugin.debug())
    Object.assign(window, { SegmentSignalsPlugin: this });

    this.signals = new Signals(settings);

    logger.debug(`SignalsPlugin v${version} initializing`, {
      settings,
    });
  }

  isLoaded() {
    return true;
  }

  public async load(_ctx: unknown, analytics: AnyAnalytics) {
    try {
      await this.signals.start(analytics);
      logger.debug("SignalsPlugin loaded");
    } catch (err) {
      console.error(err);
    }
  }

  stop() {
    return this.signals.stop();
  }

  onSignal(cb: (signal: Signal) => void): this {
    this.signals.signalEmitter.subscribe(cb);
    return this;
  }

  addSignal(data: Record<string, unknown>): this {
    this.signals.signalEmitter.emit(createUserDefinedSignal(data));
    return this;
  }

  /**
   * Enable redaction and disable ingestion of signals. Also, logs signals to the console.
   */
  debug(...args: Parameters<(typeof this.signals)["debug"]>): this {
    this.signals.debug(...args);
    return this;
  }
}