// Copyright (C) 2026 Whiterun LLC,
// This software is licensed under the GNU Lesser General Public License (LGPL), version 3.0 or later.
// A copy of the license can be found in the LICENSE file or at https://www.gnu.org/licenses/lgpl-3.0.html

import { ProtocolMessage } from "./protocols/hdwalletv1.js";
import { debug, Scope } from "./log.js";

interface QueuedMessage {
  message: ProtocolMessage;
  resolve: () => void;
  reject: (_error: Error) => void;
}

export class MessageQueue {
  private queue: QueuedMessage[] = [];
  private isReady: boolean = false;
  private logActivity: boolean = false;

  constructor(options?: { logActivity?: boolean }) {
    this.logActivity = options?.logActivity ?? false;
  }

  getReady(): boolean {
    return this.isReady;
  }

  getQueueLength(): number {
    return this.queue.length;
  }

  enqueue(message: ProtocolMessage): Promise<void> {
    if (this.isReady) {
      return Promise.resolve();
    }

    if (this.logActivity) {
      debug(
        Scope.Relay,
        `net: Relays not ready, queuing message ${message.action}`,
      );
    }

    return new Promise<void>((resolve, reject) => {
      this.queue.push({ message, resolve, reject });
    });
  }

  async setReady(
    publishFn: (_message: ProtocolMessage) => Promise<void>,
  ): Promise<void> {
    this.isReady = true;

    const queuedMessages = [...this.queue];
    this.queue = [];

    if (queuedMessages.length > 0 && this.logActivity) {
      debug(Scope.Relay, `Processing ${queuedMessages.length} queued messages`);
    }

    for (const queued of queuedMessages) {
      try {
        await publishFn(queued.message);
        queued.resolve();
      } catch (error) {
        queued.reject(error as Error);
      }
    }
  }

  setNotReady(
    errorMessage: string = "Connection closed before message could be sent",
  ): void {
    this.isReady = false;

    const queuedMessages = [...this.queue];
    this.queue = [];

    for (const queued of queuedMessages) {
      queued.reject(new Error(errorMessage));
    }
  }

  clear(): void {
    const queuedMessages = [...this.queue];
    this.queue = [];

    for (const queued of queuedMessages) {
      queued.reject(new Error("Queue cleared"));
    }
  }
}