import { Component } from '@angular/core';
import {
  BackendService,
  ScrumUserstory,
  ScrumStatus,
  ScrumCategory,
  ScrumSprint,
} from '../../services/backend.service';
import { NgbModal } from '@ng-bootstrap/ng-bootstrap';
import { SprintFormComponent } from '../sprint-form/sprint-form.component';

@Component({
  selector: 'app-backlog',
  templateUrl: './backlog.component.html',
  styleUrls: ['./backlog.component.css'],
})
export class BacklogComponent {
  public status: ScrumStatus[] = [];
  public categories: ScrumCategory[] = [];
  public sprints: ScrumSprint[] = [];
  public storys: ScrumUserstory[] = [];
  public selectedSprint: ScrumSprint;

  /**
   * Constructor of the class that initialized the communication with the backend
   * @param backendService
   * @param modalService
   */
  constructor(
    private backendService: BackendService,
    private modalService: NgbModal
  ) {
    backendService.getSprints().subscribe((response) => {
      if (response.status > 399) {
        alert('Fehler');
      } else {
        this.sprints.push(...response.body);
        this.selectedSprint = this.currentSprint;
      }
    });
    backendService.getUserstories().subscribe((response) => {
      if (response.status > 399) {
        alert('Fehler');
      } else {
        this.storys.push(...response.body);
      }
    });
    backendService.getAllStatus().subscribe((response) => {
      if (response.status > 399) {
        alert('Fehler');
      } else {
        this.status.push(...response.body);
      }
    });
    backendService.getCategories().subscribe((response) => {
      if (response.status > 399) {
        alert('Fehler');
      } else {
        this.categories.push(...response.body);
      }
    });
  }

  /**
   * Formats an ISO DateString to a simple date string in the format "DD.MM.YYYY"
   * @param isoFormatString date formatted as an ISO DateString (Date objects get converted implicitly)
   */
  public toDateString(isoFormatString) {
    const date = new Date(isoFormatString);
    return `${date.getDate()}.${date.getMonth() + 1}.${date.getFullYear()}`;
  }

  //#region getters

  /**
   * Getter that returns an array with all userstories that are in the currently selected sprint.
   * The relation to the sprint is determined by the userstory's sprintId.
   * If no sprint is selected it just returns an empty array.
   */
  public get choosen(): ScrumUserstory[] {
    if (this.selectedSprint === undefined) {
      return null;
    }
    return this.storys.filter((u) => u.sprintId == this.selectedSprint.id);
  }

  /**
   * Getter that returns an array with all userstories that aren't in any sprint.
   * The relation to no sprint is determined by the userstory's sprintId being undefined.
   */
  public get backlog(): ScrumUserstory[] {
    return this.storys.filter((u) => u.sprintId === undefined);
  }

  /**
   * Getter that returns the current sprint.
   * The current sprint is selected by determining if todays date is between the startDate and the endDate of the sprint.
   */
  public get currentSprint(): ScrumSprint {
    const now = Date.now();
    return this.sprints.find(
      (s) => Date.parse(s.startDate) < now && Date.parse(s.endDate) > now
    );
  }

  //#endregion getters

  //#region backlogFunctions

  /**
   * Adds a userstory to the currently selected sprint by changing it's sprintId to the current sprint's id
   * @param userstory userstory object that shall be added to the selected sprint's backlog
   */
  public addToSprintBacklog(userstory: ScrumUserstory) {
    userstory.sprintId = this.selectedSprint.id;
    this.backendService.putUserstory(userstory).subscribe((response) => {
      if (response.status > 399) {
        alert('Fehler');
      }
    });
  }

  /**
   * Deletes a userstory from the currently selected sprint by changing it's sprintId to undefined
   * @param userstory userstory object that shall be removed from the selected sprint's backlog
   */
  public deleteFromSprintBacklog(userstory: ScrumUserstory) {
    userstory.sprintId = undefined;
    this.backendService.putUserstory(userstory).subscribe((response) => {
      if (response.status > 399) {
        alert('Fehler');
      }
    });
  }

  //#endregion backlogFunctions

  //#region modals
  /**
   * Opens the SprintForm Modal to let the user create a new sprint.
   * The created sprint get pushed to the database and the local sprints array.
   */
  public openSprintForm() {
    const modalRef = this.modalService.open(SprintFormComponent, {
      backdrop: 'static',
      keyboard: true,
      size: 'md',
    });

    modalRef.result.then((result) => {
      this.sprints.push(result);
    });
  }
  //#endregion modals
}