import { JsonPipe } from '@angular/common';
import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { ResourceFields } from '@syncfusion/ej2-angular-gantt';


@Injectable({
  providedIn: 'root'
})


/**
 *The DataService manages the communication between Frontend and Backend, fetches Data from the Backend and maps it to the Frontend Data Structure. Additionally it updates data on the Backend.
 *
 */
export class DataService {
  private states: any []; //Array of statuses and possible statuses, which is queried once at the beginning by backend and stored in dataservice
  private supportGroups: any [];
  private contracts: any [];
  private paketTypes: any [];
  private totalSize: number = null;
  /**
   * This constructor builds the dataService and fetches the states from the backend
   * @param http
   */
  constructor(private http: HttpClient) {
    this.fetchStates().then((res: any [])=>{
      this.states = res;
    });
    this.fetchSupportGroups().then((res: any [])=>{
      this.supportGroups = res;
    });
    this.fetchContracts().then((res: any [])=>{
      this.contracts = res;
    });
    this.fetchPaketTypes().then((res: any [])=>{
      this.paketTypes = res;
      // console.log(res);
    });
  }

/**
 *
 * @returns an array of states and possible states per state
 */
  public getStates():any[]{
    return this.states;
  }

  public getSupportGroups():any[]{
    return this.supportGroups;
  }

  public getContracts():any[]{
    return this.contracts;
  }

  public getPaketTypes():any[]{
    return this.paketTypes;
  }

  public getTotalSize():number{
    return this.totalSize;
  }

  /**
  * The function fetchStates fetches an array from the possible statuses per state
  * @returns promise for the fetched Status Array
  */
  public async fetchStates(){
    const promise = new Promise(resolve=>{
      let res : any[] = [];
      this.http.get('http://localhost:8080/api/getStates')
      .subscribe((response: any)=>{
        response.forEach(state => {
          res.push(state)
        });
        resolve(res);
      })
    })
    return promise;
  }

  public async fetchSupportGroups(){
    const promise = new Promise(resolve=>{
      let res : any[] = [];
      this.http.get('http://localhost:8080/api/getSupportGroups')
      .subscribe((response: any)=>{
        response.forEach(supportGroup => {
          res.push(supportGroup)
        });
        resolve(res);
      })
    })
    return promise;
  }

  public async fetchContracts(){
    const promise = new Promise(resolve=>{
      let res : any[] = [];
      this.http.get('http://localhost:8080/api/getContracts')
      .subscribe((response: any)=>{
        response.forEach(contract => {
          res.push(contract)
        });
        resolve(res);
      })
    })
    return promise;
  }

  public async fetchPaketTypes(){
    const promise = new Promise(resolve=>{
      let res : any[] = [];
      this.http.get('http://localhost:8080/api/getPackageTypes')
      .subscribe((response: any)=>{
        response.forEach(paketType => {
          res.push(paketType)
        });
        resolve(res);
      })
    })
    return promise;
  }

/**
 * The function updateDatePerChange sends the new date to the backend if the date was moved
 * @param change the Change (the Resource) from which the date should be changed
 */
  public updateDatePerChange(change: any){
    //console.log(change);
    let serializableResource = { resourceId: change.resourceId, d2: change.tasks[1].StartDate, changeNr: change.changeNr, state: change.state};
    let strigifiedResource = JSON.stringify(serializableResource);
    let resJson = JSON.parse(strigifiedResource) as typeof strigifiedResource;
    // console.log(resJson);
    this.http.post('http://localhost:8080/api/updateChange', resJson).toPromise().then((value)=>{
      console.log(value);
    });

  }

/**
 * The function updateStatePerChange performs a status transition on the backend
 * @param change The Change for which the status transition is to be performed
 * @returns a Promise
 */
  public async updateStatePerChange(change: any){
    const promise = new Promise(resolve=>{
      let obj = {changeNr : change.changeNr, currentState : change.currentState, nextState : change.nextState};
      let stringyfiedData = JSON.stringify(obj);
      let dataJson = JSON.parse(stringyfiedData) as typeof stringyfiedData;
      // console.log(dataJson);
      this.http.post('http://localhost:8080/api/updateState', dataJson).subscribe((response:any)=>{
        resolve(response);
      },(error:any)=>{
        console.log(error);
        resolve(error);
      });
    })

    return promise;
  }

  public async updateImplementerPerChange(change: any){
    const promise = new Promise(resolve=>{
      // console.log(change);
      let obj = {pkgId : change.resourceId, loginId : change.loginId};
      let stringyfiedData = JSON.stringify(obj);
      let dataJson = JSON.parse(stringyfiedData) as typeof stringyfiedData;
      // console.log(dataJson);
      this.http.post('http://localhost:8080/api/updateImplementer', dataJson).subscribe((response:any)=>{
        resolve(response);
      },(error:any)=>{
        console.log(error);
        resolve(error);
      });
    })

    return promise;
  }



  public async fetchImplementers(change: any){
    const promise = new Promise(resolve=>{
      let obj = {entryId : change.resourceId, supportGroup : change.supportGroupId};
      let stringyfiedData = JSON.stringify(obj);
      let dataJson = JSON.parse(stringyfiedData) as typeof stringyfiedData;
      // console.log(dataJson);
      let res : any[] = [];
      this.http.post('http://localhost:8080/api/getImplementer', dataJson)
      .subscribe((response: any)=>{
          response.members.forEach(implementer => {
            res.push(implementer)
          });
        resolve(res);
      })
    })
    return promise;
  }

  public async updateApproval(change: any, approvalAction){
    const promise = new Promise(resolve=>{
      let obj = {changeNr : change.changeNr, approvalAction: approvalAction};
      let stringyfiedData = JSON.stringify(obj);
      let dataJson = JSON.parse(stringyfiedData) as typeof stringyfiedData;
      console.log(dataJson);
      this.http.post('http://localhost:8080/api/updateApproval', dataJson).subscribe((response:any)=>{
        resolve(response);
      },(error:any)=>{
        console.log(error);
        resolve(error);
      });
    })

    return promise;
  }


  /**
   * The function fetchChanges fetches the changes from backend and maps them to a structure that the Gannt component can interpret
   * @returns promise for the fetched Changes Array
   */
  public async fetchChanges(reqestParams: any = null){
    let stringyfiedData = JSON.stringify(reqestParams);
    let dataJson = JSON.parse(stringyfiedData) as typeof stringyfiedData;
    const promise = new Promise(resolve=>{
      let first : boolean = true;
      let res : any[] = [];
      console.log(dataJson);
      this.http.post('http://localhost:8080/api/getChanges', dataJson)
      .subscribe((response:any)=>{
        // console.log(response);
        this.totalSize = response.totalSize;
        response.changes.forEach(resp=>{
          let tasks : any[] = [];
          if(resp.d1!=null){
            tasks.push(
              {
                TaskID: resp.resourceId+"D1", TaskName: "Requested Start Date", StartDate: new Date(resp.d1), Duration: 0, isFixed: true,
                resources: [{resourceId: resp.resourceId},],  Progress: 0, work: 0, isRes: false
              }
            );
          }

          if(resp.d2!=null){
            let isFixed = true;
            if(resp.state == 0 || resp.state == 3){
              isFixed = false;
            }
            tasks.push(
              {
                TaskID: resp.resourceId+"D2", TaskName: "Sheduled Start Date", StartDate: new Date(resp.d2), Duration: 0, isFixed: isFixed,
                resources: [{resourceId: resp.resourceId},],  Progress: 0, work: 0, isRes: false
              }
            );
          }

          if(resp.d3!=null && resp.state>1){
            tasks.push(
              {
                TaskID: resp.resourceId+"D3", TaskName: "Approved Start Date", StartDate: new Date(resp.d3), Duration: 0, isFixed: true,
                resources: [{resourceId: resp.resourceId},],  Progress: 0, work: 0, isRes: false
              }
            );
          }

          if(resp.d4!=null && resp.state == 10){
            tasks.push(
              {
                TaskID: resp.resourceId+"D4", TaskName: "Actual End Date", StartDate: new Date(resp.d4), Duration: 0, isFixed: true,
                resources: [{resourceId: resp.resourceId},],  Progress: 0, work: 0, isRes: false
              }
            );
          }

            res.push({resourceId: resp.resourceId, approvalStatus: this.validateApproval(resp.approvalStatus), statusReason: resp.statusReason , changeNr: resp.changeNr, resourceName: resp.resourceName, vertrag: resp.contract, vertragName: this.getContractName(resp.contract), isExpand: false ,isRes: true, state: resp.state, stateName: this.getStateNameById(resp.state), supportGroup: resp.supportGroup, tasks: tasks, supportGroupId: resp.supportGroupId,  implementerEdit: resp.implementerEdit});


        })
        console.log(res);
        resolve(res);
      })
    })
    return promise;
  }

  validateApproval(approval):number{
    if(approval!=""){
      return 1;
    }else{
      return 0;
    }


  }

  getStateNameById(stateNr): String {
    for (let state of this.states) {
       if(stateNr == state.actualState){
        return state.stateNameDE;
       }
    }
    return "";
  }

  getStateIdByName(stateName: string): number {
    for (let state of this.states) {
       if(stateName == state.stateNameEN){
        return state.id;
       }
    }
    return -1;
  }

  getContractName(contractId: string): string{
    return this.contracts.find((contract)=> {return contract.id == contractId;}).name;
  }

}