import { Injectable } from '@angular/core';

import { Observable, Subject } from 'rxjs';
import {
  map,
  takeWhile,
  timeout,
  take,
  share,
  filter,
  tap
} from 'rxjs/operators';

import { ProtocolService } from '@ucap-webmessenger/protocol';

import {
  InfoRequest,
  InfoResponse,
  encodeInfo,
  decodeInfo,
  decodeInfoData,
  InfoData
} from '../protocols/info';
import {
  SVC_TYPE_EVENT,
  SSVC_TYPE_EVENT_INFO_REQ,
  SSVC_TYPE_EVENT_INFO_RES,
  SSVC_TYPE_EVENT_INFO_DATA,
  SSVC_TYPE_EVENT_SEND_REQ,
  SSVC_TYPE_EVENT_PUSH_CL_REQ,
  SSVC_TYPE_EVENT_READ_REQ,
  SSVC_TYPE_EVENT_DEL_REQ,
  SSVC_TYPE_EVENT_CANCEL_REQ,
  SSVC_TYPE_EVENT_CANCEL_NOTI,
  SSVC_TYPE_EVENT_SEND_NOTI,
  SSVC_TYPE_EVENT_READ_NOTI,
  SSVC_TYPE_EVENT_DEL_RES,
  SSVC_TYPE_EVENT_SEND_RES,
  SSVC_TYPE_EVENT_READ_RES
} from '../types/service';
import {
  SendRequest,
  SendResponse,
  decodeSend,
  encodeSend,
  decodeSendNotification,
  SendNotification
} from '../protocols/send';
import { PushRequest, encodePush } from '../protocols/push';
import {
  ReadResponse,
  ReadRequest,
  encodeRead,
  decodeRead,
  decodeReadNotification,
  ReadNotification
} from '../protocols/read';
import {
  CancelRequest,
  CancelResponse,
  encodeCancel,
  decodeCancel,
  CancelNotification,
  decodeCancelNotification
} from '../protocols/cancel';
import {
  decodeDelNotification,
  DelNotification,
  DelRequest,
  DelResponse,
  encodeDel,
  decodeDel
} from '../protocols/del';

type Notifications =
  | SendNotification
  | ReadNotification
  | CancelNotification
  | DelNotification;

@Injectable({
  providedIn: 'root'
})
export class EventProtocolService {
  private notificationSubject: Subject<Notifications>;
  public notification$: Observable<Notifications>;

  constructor(private protocolService: ProtocolService) {
    this.notificationSubject = new Subject();
    this.notification$ = this.notificationSubject.asObservable().pipe(share());

    this.protocolService.serverMessage
      .pipe(
        filter(message => message.serviceType === SVC_TYPE_EVENT),
        tap(message => {
          switch (message.subServiceType) {
            case SSVC_TYPE_EVENT_SEND_RES:
            case SSVC_TYPE_EVENT_SEND_NOTI:
              {
                this.notificationSubject.next(decodeSendNotification(message));
              }
              break;
            case SSVC_TYPE_EVENT_READ_RES:
            case SSVC_TYPE_EVENT_READ_NOTI:
              {
                this.notificationSubject.next(decodeReadNotification(message));
              }
              break;
            case SSVC_TYPE_EVENT_CANCEL_NOTI:
              {
                this.notificationSubject.next(
                  decodeCancelNotification(message)
                );
              }
              break;
            case SSVC_TYPE_EVENT_DEL_RES:
              {
                this.notificationSubject.next(decodeDelNotification(message));
              }
              break;
            default:
              break;
          }
        })
      )
      .subscribe();
  }

  public info(req: InfoRequest): Observable<InfoResponse | InfoData> {
    return this.protocolService
      .call(SVC_TYPE_EVENT, SSVC_TYPE_EVENT_INFO_REQ, ...encodeInfo(req))
      .pipe(
        takeWhile(res => SSVC_TYPE_EVENT_INFO_RES !== res.subServiceType, true),
        map(res => {
          if (SSVC_TYPE_EVENT_INFO_DATA === res.subServiceType) {
            return decodeInfoData(res);
          }
          return decodeInfo(res);
        })
      );
  }

  public send(req: SendRequest): Observable<SendResponse> {
    return this.protocolService
      .call(SVC_TYPE_EVENT, SSVC_TYPE_EVENT_SEND_REQ, ...encodeSend(req))
      .pipe(
        take(1),
        map(res => {
          return decodeSend(res);
        })
      );
  }

  public push(req: PushRequest): void {
    return this.protocolService.send(
      SVC_TYPE_EVENT,
      SSVC_TYPE_EVENT_PUSH_CL_REQ,
      ...encodePush(req)
    );
  }

  public read(req: ReadRequest): Observable<ReadResponse> {
    return this.protocolService
      .call(SVC_TYPE_EVENT, SSVC_TYPE_EVENT_READ_REQ, ...encodeRead(req))
      .pipe(
        take(1),
        map(res => {
          return decodeRead(res);
        })
      );
  }

  public del(req: DelRequest): Observable<DelResponse> {
    return this.protocolService
      .call(SVC_TYPE_EVENT, SSVC_TYPE_EVENT_DEL_REQ, ...encodeDel(req))
      .pipe(
        take(1),
        map(res => {
          return decodeDel(res);
        })
      );
  }

  public cancel(req: CancelRequest): Observable<CancelResponse> {
    return this.protocolService
      .call(SVC_TYPE_EVENT, SSVC_TYPE_EVENT_CANCEL_REQ, ...encodeCancel(req))
      .pipe(
        take(1),
        map(res => {
          return decodeCancel(res);
        })
      );
  }
}