import {Component, EventEmitter, Output, ViewChild} from '@angular/core';
import {AsyncPipe} from "@angular/common";
import {MatAccordion, MatExpansionModule, MatExpansionPanel} from "@angular/material/expansion";
import {MatChipListbox, MatChipsModule} from "@angular/material/chips";
import {catchError} from "rxjs";
import {FormControl, ReactiveFormsModule} from "@angular/forms";
import {LoadingIndicatorComponent} from "@component/common/loading-indicator/loading-indicator.component";
import {CampusBasicInfoResponse} from "@api/v1/campusBasicInfoResponse";
import {LectureHallResponse} from "@api/v1/lectureHallResponse";
import {CampusService} from "@api/v1/campus.service";
import {LectureHallService} from "@api/v1/lectureHall.service";
import {IScheduleTab} from "@component/schedule/tabs/ischedule-tab";
import {TabSelect, TabSelectData, TabSelectType, TabStorageService} from "@service/tab-storage.service";

@Component({
  selector: 'app-lecture-hall',
  standalone: true,
  imports: [
    MatChipsModule,
    MatExpansionModule,
    AsyncPipe,
    ReactiveFormsModule,
    MatAccordion,
    LoadingIndicatorComponent
  ],
  templateUrl: './lecture-hall.component.html',
  styleUrl: './lecture-hall.component.css',
  providers: [CampusService, LectureHallService]
})

export class LectureHallComponent implements IScheduleTab {
  protected campusId: number | null = null;
  protected formLectureHalls: FormControl = new FormControl();

  protected campuses: CampusBasicInfoResponse[] | null = null;
  protected lectureHallsFiltered: LectureHallResponse[] | null = null;

  @Output() eventResult = new EventEmitter<number>();

  @ViewChild('lecturePanel') lecturePanel!: MatExpansionPanel;
  @ViewChild('lectureIndicator') lectureIndicator!: LoadingIndicatorComponent;
  @ViewChild('campusIndicator') campusIndicator!: LoadingIndicatorComponent;

  @ViewChild('campusChip') campusChip!: MatChipListbox;
  @ViewChild('lectureChip') lectureChip!: MatChipListbox;

  private lectureHalls: LectureHallResponse[] | null = null;

  constructor(private campusApi: CampusService, private lectureHallApi: LectureHallService, private tabStorage: TabStorageService) {
  }

  existParams(data: TabSelectData): boolean {
    return data.selected['campus'] !== undefined || data.selected['lecture'] !== undefined;
  }

  protected loadCampuses() {
    this.campusApi.getCampus()
      .pipe(catchError(error => {
        this.campusIndicator.loading = false;
        throw error;
      }))
      .subscribe(data => {
        this.campuses = data;

        let selected = TabStorageService.selected?.selected['campus'];
        if (selected) {
          let selectedCampus = data.find(x => x.id === selected.index);

          if (selectedCampus === undefined || selectedCampus.codeName !== selected.name)
            selectedCampus = data.find(x => x.codeName === selected.name);

          if (selectedCampus !== undefined) {
            TabStorageService.trySelectChip(selectedCampus.id, this.campusChip);
            this.onCampusSelected(selectedCampus.id);
          }
        }
      });
  }

  private filteringLectureHalls() {
    this.lectureHallsFiltered = this.lectureHalls?.filter(x => x.campusId === this.campusId) ?? null;
  }

  protected onCampusSelected(index: number) {
    this.formLectureHalls.reset();

    this.tabStorage.select(new TabSelect(index, this.campuses!.find(x => x.id === index)?.codeName ?? ''), TabSelectType.lecture, 'campus');

    if (index === undefined) {
      this.campusId = null;
      this.lectureHalls = [];
      return;
    }

    this.campusId = index;
    this.lecturePanel.open();

    if (this.lectureHalls === null)
      this.loadLectureHalls();
    else
      this.filteringLectureHalls();
  }

  protected loadLectureHalls() {
    this.lectureHallApi.getLectureHalls()
      .pipe(catchError(error => {
        this.lectureIndicator.loading = false;
        throw error;
      }))
      .subscribe(data => {
        this.lectureHalls = data;
        this.filteringLectureHalls();

        let selected = TabStorageService.selected?.selected['lecture'];
        if (selected) {
          let selectedLecture = data.find(x => x.id === selected.index);

          if (selectedLecture === undefined || selectedLecture.name !== selected.name)
            selectedLecture = data.find(x => x.name === selected.name);

          if (selectedLecture !== undefined) {
            TabStorageService.trySelectChip(selectedLecture.id, this.lectureChip);
            this.onLectureHallSelected(selectedLecture.id);
          }
        }
      });
  }

  protected onLectureHallSelected(index: number) {
    if (index === undefined)
      return;

    this.tabStorage.select(new TabSelect(index, this.lectureHallsFiltered!.find(x => x.id === index)?.name ?? ''), TabSelectType.lecture, 'lecture');

    this.lecturePanel.close();
    this.eventResult.emit(index);
  }

  public load() {
    if (this.campuses === null)
      this.loadCampuses();
  }
}