import { Component, Input, Output, EventEmitter, OnChanges } from '@angular/core';
import { ClientSidePagingProxy } from '../../base/serviceCall';
import { ServiceProviderPagingBase, IProviderContent } from './serviceProviderPagingBase';

@Component({
  selector: 'rd-service-provider:[rd-client-side-paging]',
  template: ""
})
export class ServiceProviderClientSide extends ServiceProviderPagingBase implements OnChanges {
  @Input("rd-service-proxy") serviceProxy: ClientSidePagingProxy;
  @Input("rd-page-size") pageSize = 10;

  @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 ClientSidePagingProxy)) this.error("rd-service-proxy is not an instance of ClientSidePagingProxy");
    }
    if (changes.pageSize) {
      this.pageSize = changes.pageSize.currentValue;
      if (this.content.state.serviceCalled) this.gotoPage(1);
    }
  }

  private responseListener;

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

    this.serviceProxy.call(params, (response) => {
      if (this.responseListener) this.responseListener();
      this.successState(response);
      this.gotoPage(this.content.paging.currentPage ? this.content.paging.currentPage : 1);
      this.successEvent.emit(this.content);
    }, () => {
      if (this.responseListener) this.responseListener();
      this.errorState();
      this.errorEvent.emit(this.content);
    });
  }

  gotoPage(pageNumber) {
    var allItems = this.content.response.allItems;
    if (!allItems) return;
    this.content.items = allItems.slice((pageNumber - 1) * this.pageSize, pageNumber * this.pageSize);
    this.content.paging = {
      currentPage: pageNumber,
      totalPageCount: Math.ceil(allItems.length / this.pageSize),
      pageSize: this.pageSize,
      totalItemCount: allItems.length
    };
  };

  refresh() {
    this.call(this.content.params);
  }

  getAllItems(progressCallback = (currentIteration, totalIterationCount) => { }): Promise<any[]> {
    return new Promise((resolve, reject) => {
      if (this.content.state.responseIsRecieved) {
        if (!this.content.state.serviceCallFailed) resolve(this.content.response.allItems);
        else reject();
      }
      else {
        this.responseListener = function () {
          this.responseListener = undefined;
          if (!this.content.state.serviceCallFailed) resolve(this.content.response.allItems);
          else reject();
        }
      }
    });
  }
}