import { MessageOptions } from "../interfaces/message-options";
import { EmailReminder } from "./handlers/reminder/email-reminder";
import { Recipient } from "../interfaces/reciptient";
import { Department } from "../interfaces/department";
import { injectable } from "inversify";
import "reflect-metadata";
import { EmailGeneric } from "./handlers/generic/email-generic";
import { DepartmentHandler } from "../interfaces/department-handler";
import { EmailReceipt } from "./handlers/receipt/email-receipt";
import { EmailBooking } from "./handlers/booking/email-booking";

@injectable()
export class EmailDepartment implements Department {
  constructor(
    private _emailReminder: EmailReminder,
    private _emailGeneric: EmailGeneric,
    private _emailReceipt: EmailReceipt,
    private _emailBooking: EmailBooking
  ) {}

  public send(recipients: Recipient[], options: MessageOptions): Promise<any> {
    switch (options.type) {
      case "reminder":
        return this.sendToMany(recipients, options, this._emailReminder);
      case "generic":
        return this.sendToMany(recipients, options, this._emailGeneric);
      case "receipt":
        return this.sendToMany(recipients, options, this._emailReceipt);
      case "booking":
        return this.sendToMany(recipients, options, this._emailBooking);
      default:
        throw `options.type "${options.type}" not supported`;
    }
  }

  private async sendToMany(
    recipients: Recipient[],
    options: MessageOptions,
    handler: DepartmentHandler
  ): Promise<any> {
    let promiseArr: Promise<any>[] = [];

    recipients.forEach(recipient => {
      if (
        !recipient.mediumOverrides ||
        recipient.mediumOverrides.email !== false
      ) {
        promiseArr.push(handler.send(recipient, options));
      }
    });

    try {
      const results = await Promise.all(promiseArr.map(this.reflect));

      const successes = results.filter(x => x.status === "resolved");

      if (successes.length <= 0) {
        throw `none of the email requests was a success`;
      }

      return true;
    } catch (e) {
      throw `something went wrong when trying to send email requests: ${e}`;
    }
  }

  private reflect(promise: Promise<any>) {
    return promise.then(
      res => {
        return { result: res, status: "resolved" };
      },
      err => {
        return { error: err, status: "rejected" };
      }
    );
  }
}