import type { Constructor } from '@rsdk/common';

import type { PipelineException } from '../base';

export interface ExceptionMetadata {
  description: string;
}

export interface ThrowsMetadata {
  // eslint-disable-next-line @typescript-eslint/ban-types
  class: Function;
  method: string;
  exceptions: Constructor<PipelineException>[];
}

const isExceptionMeta = (
  arg: ExceptionMetadata | ThrowsMetadata,
): arg is ExceptionMetadata => !!(arg as any).description;

export class ExceptionsRegistry {
  private static _instance: ExceptionsRegistry;

  private exceptions: ExceptionMetadata[] = [];
  private throws: ThrowsMetadata[] = [];

  // eslint-disable-next-line @typescript-eslint/no-empty-function
  private constructor() {}

  static getInstance(): ExceptionsRegistry {
    if (!this._instance) {
      this._instance = new ExceptionsRegistry();
    }

    return this._instance;
  }

  register(meta: ThrowsMetadata): void;
  register(meta: ExceptionMetadata): void;
  register(meta: ThrowsMetadata | ExceptionMetadata): void {
    if (isExceptionMeta(meta)) {
      this.exceptions.push(meta);
    } else {
      this.throws.push(meta);
    }
  }

  getAll(): { exceptions: ExceptionMetadata[]; throws: ThrowsMetadata[] } {
    return { exceptions: this.exceptions, throws: this.throws };
  }
}