import BullQueue, { Queue } from "bull";
import { injectable, BindingScope, ContextTags, Application, inject, CoreBindings, Binding, config } from '@loopback/core';

import { BullQueueComponentBindings, BullQueueComponentTags } from "../keys";
import { BullQueueComponentOptions, SeawaspQueue } from "../types";

@injectable({
  scope: BindingScope.SINGLETON
})
export class QueueService {
  
  constructor(
    @inject(CoreBindings.APPLICATION_INSTANCE) public application: Application,
    @config({ fromBinding: BullQueueComponentBindings.COMPONENT}) private config: BullQueueComponentOptions
  ) {}
  

  // TODO: Check if the queue already exists
  initializeQueue(queueNames: string[], options?: any): void {
    queueNames.map((queueName: string) => {
      try {
        const queue: SeawaspQueue = new BullQueue(queueName, this.config);

        let tags: any = {
          [ContextTags.KEY]: BullQueueComponentTags.QUEUE_KEY,
          [BullQueueComponentBindings.BULL_QUEUE_TYPE.key]: BullQueueComponentTags.QUEUE_TYPE_QUEUE,
          [BullQueueComponentBindings.BULL_QUEUE_NAME.key]: queueName,
        }

        if (options?.tags) {
          tags = {
            ...tags,
            ...options?.tags
          }
        }

        queue.on('error', e => console.error('Error event', e));

        this.application
          .bind(`queue.${queueName}`)
          .to(queue)
          .tag(tags);
      } catch (err) {
        console.log(err)
      }
    })

  }

  async getQueue(keyName: string): Promise<SeawaspQueue | undefined> {
    if (keyName.split('.')[0] !== 'queue') {
      keyName = `queue.${keyName}`;
    }

    return this.application.getValueOrPromise<SeawaspQueue>(keyName);
  }

  async getQueues(): Promise<(Queue | undefined)[]> {
    const queueBindings = this.application.findByTag({
      [ContextTags.KEY]: BullQueueComponentTags.QUEUE_KEY
    });
    
    return Promise.all(queueBindings.map((queueBinding) => this.application.get<Queue | undefined>(queueBinding.key)));
  }

  async sendMessage(queueName: string, data: any, options: any) {
    const queue = await this.getQueue(queueName);
    if (options?.delay) {
      return queue?.add(data, {delay: options?.delay});
    }
    return queue?.add(data);
  }

  async cleanQueue(queueName: string) {
    const queue = await this.getQueue(queueName);
    await queue?.clean(1000, 'delayed');
    await queue?.clean(1000, 'active');
    await queue?.clean(1000, 'completed');
    await queue?.clean(1000, 'wait');
    await queue?.clean(1000, 'failed');
  }
}