import { Component, Input, Output, EventEmitter, OnChanges } from '@angular/core';
import { RdLib } from '../../base/rdLib';
import { ServiceProxy } from '../../base/serviceCall';
import { RdComponent } from '../../base/rdComponent';

export interface IProviderContent { 
  params: any;
  response: any;
  state: {
    serviceCalled: boolean;
    waitingForResponse: boolean;
    responseIsRecieved: boolean;
    serviceCallFailed: boolean;
  };
}

@Component({
  selector: 'rd-service-provider:not([rd-client-side-paging]):not([rd-server-side-paging])',
  template: ""
})
export class ServiceProvider extends RdComponent implements OnChanges {
  @Input("rd-service-proxy") serviceProxy: ServiceProxy;

  @Output("rd-success") successEvent: EventEmitter<IProviderContent> = new EventEmitter<IProviderContent>();
  @Output("rd-error") errorEvent: EventEmitter<IProviderContent> = new EventEmitter<IProviderContent>();

  ngOnChanges(changes) {
    if (changes.serviceProxy) {
      if (!(this.serviceProxy instanceof ServiceProxy)) this.error("rd-service-proxy is not an instance of ServiceProxy");
    }
  }

  content = {
    params: null,
    response: null,
    state: {
      waitingForResponse: false,
      serviceCalled: false,
      responseIsRecieved: false,
      serviceCallFailed: false
    }
  };

  private callState(params) {
    this.content = {
      params: RdLib.objectOperations.deepCopy(params),
      response: null,
      state: {
        waitingForResponse: true,
        serviceCalled: true,
        responseIsRecieved: false,
        serviceCallFailed: false
      }
    };
  }

  private successState(response) {
    this.content.response = response;
    this.content.state = {
      waitingForResponse: false,
      serviceCalled: true,
      responseIsRecieved: true,
      serviceCallFailed: false
    };
  }

  private errorState() {
    this.content.state = {
      waitingForResponse: false,
      serviceCalled: true,
      responseIsRecieved: true,
      serviceCallFailed: true
    };
  }

  call(params?) {
    if (this.content.state.waitingForResponse) return;
    this.callState(params);

    this.serviceProxy.call(params, (response) => {
      this.successState(response);
      this.successEvent.emit(this.content);
    }, () => {
      this.errorState();
      this.errorEvent.emit(this.content);
    });
  }
}