import {Component, EventEmitter, ViewChild} from '@angular/core';
import {MatExpansionModule, MatExpansionPanel} from "@angular/material/expansion";
import {MatChipListbox, MatChipsModule} from '@angular/material/chips';
import {FormControl, FormsModule, ReactiveFormsModule} from "@angular/forms";
import {catchError} from "rxjs";
import {LoadingIndicatorComponent} from "@component/common/loading-indicator/loading-indicator.component";
import {GroupResponse} from "@api/v1/groupResponse";
import {FacultyResponse} from "@api/v1/facultyResponse";
import {FacultyService} from "@api/v1/faculty.service";
import {GroupService} from "@api/v1/group.service";
import {IScheduleTab} from "@component/schedule/tabs/ischedule-tab";
import {TabSelect, TabStorageService} from "@service/tab-storage.service";

enum Enclosure {
  faculty, course, group
}

@Component({
  selector: 'app-group',
  standalone: true,
  imports: [
    MatExpansionModule,
    MatChipsModule,
    ReactiveFormsModule,
    LoadingIndicatorComponent,
    FormsModule
  ],
  templateUrl: './group.component.html',
  styleUrl: './group.component.css',
  providers: [FacultyService, GroupService]
})
export class GroupComponent implements IScheduleTab {
  protected faculties: FacultyResponse[] | null = null;
  protected courseNumbers: number[] | null = null;
  private groups: GroupResponse[] | null = null;
  protected filteredGroupsBehaviour: GroupResponse[] | null = null;
  protected filteredGroupsMagistracy: GroupResponse[] | null = null;
  protected filteredGroupsSpecialist: GroupResponse[] | null = null;

  protected facultyId: number | null = null;
  protected courseNumber: number | null = null;

  protected formChipCourse: FormControl = new FormControl();
  protected formChipGroup: FormControl = new FormControl();

  @ViewChild('courseNumberPanel') courseNumberPanel!: MatExpansionPanel;
  @ViewChild('groupPanel') groupPanel!: MatExpansionPanel;

  @ViewChild('facultyChip') facultyChip!: MatChipListbox;
  @ViewChild('courseChip') courseChip!: MatChipListbox;
  @ViewChild('groupChip') groupChip!: MatChipListbox;

  @ViewChild('facultyIndicator') facultyIndicator!: LoadingIndicatorComponent;
  @ViewChild('courseIndicator') courseIndicator!: LoadingIndicatorComponent;
  @ViewChild('groupIndicator') groupIndicator!: LoadingIndicatorComponent;

  private resetCourse() {
    this.courseNumber = null;
    this.groups = [];
    this.formChipCourse.reset();
    this.courseChip.value = undefined;
  }

  private resetGroup() {
    this.filteredGroupsBehaviour = [];
    this.filteredGroupsMagistracy = [];
    this.filteredGroupsSpecialist = [];
    this.formChipGroup.reset();
    this.groupChip.value = undefined;
  }

  public eventResult = new EventEmitter<number>();
  public selectChangeEvent = new EventEmitter<TabSelect[]>();

  constructor(private facultyApi: FacultyService, private groupApi: GroupService) {
  }

  private getSelectedTabs(): TabSelect[] {
    const faculty = this.facultyChip.value;
    const course = this.courseChip.value;
    const group = this.groupChip.value;

    const result: TabSelect[] = [];

    if (faculty)
      result.push(new TabSelect(faculty, this.faculties!.find(x => x.id === faculty)?.name ?? ''));

    if (course)
      result.push(new TabSelect(course, course.toString()));

    if (group)
      result.push(new TabSelect(group, this.groups!.find(x => x.id == group)?.name ?? ''));

    return result;
  }

  public getEnclosureList(): string[] {
    return Object.keys(Enclosure).filter((item) => {
      return isNaN(Number(item));
    });
  }

  protected loadFaculties() {
    this.facultyApi.getFaculties()
      .pipe(catchError(error => {
        this.facultyIndicator.loading = false;
        throw error;
      }))
      .subscribe(data => {
        this.faculties = data;

        let selected = TabStorageService.selected?.selected[this.getEnclosureList()[Enclosure.faculty]];

        if (selected) {
          let selectedFaculty = data.find(x => x.id === selected.index);

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

          if (selectedFaculty !== undefined) {
            TabStorageService.trySelectChip(selectedFaculty.id, this.facultyChip);
            this.onFacultySelected(selectedFaculty.id, true);
          }
        }
      });
  }

  protected loadCourseGroup() {
    if (this.facultyId === null)
      return;

    if (this.groups === null || this.groups.length === 0 || this.groups[0].facultyId !== this.facultyId) {
      this.groupApi.getByFaculty(this.facultyId)
        .pipe(catchError(error => {
          this.groupIndicator.loading = false;
          this.courseIndicator.loading = false;
          throw error;
        }))
        .subscribe(data => {
          this.groups = data;
          this.courseNumbers = Array.from(
            new Set(
              this.groups!
                .map(x => x.courseNumber)
                .sort((a, b) => a - b))
          );

          let selected = TabStorageService.selected?.selected[this.getEnclosureList()[Enclosure.course]];
          if (selected) {
            let selectedCourse = this.courseNumbers.find(x => x === selected.index);

            if (selectedCourse === undefined)
              selectedCourse = this.courseNumbers.find(x => x.toString() === selected.name);

            if (selectedCourse !== undefined) {
              TabStorageService.trySelectChip(selectedCourse, this.courseChip);
              this.onCourseSelected(selectedCourse, true);
            }
          }

          let selectedGroupStorage = TabStorageService.selected?.selected[this.getEnclosureList()[Enclosure.group]];
          if (selectedGroupStorage) {
            let selectedGroup = data.find(x => x.id === selectedGroupStorage.index);

            if (selectedGroup === undefined || selectedGroup.name !== selectedGroupStorage.name)
              selectedGroup = data.find(x => x.name === selectedGroupStorage.name);

            if (selectedGroup !== undefined) {
              TabStorageService.trySelectChip(selectedGroup.id, this.groupChip);
              this.onGroupSelected(selectedGroup.id, true);
            }
          }
        });

      return;
    }

    if (this.courseNumber !== null) {
      const groupByCourse = this.groups!.filter(x => x.courseNumber === this.courseNumber);
      groupByCourse.forEach(x => {
        if (x.name[2].toUpperCase() === 'Б')
          this.filteredGroupsBehaviour?.push(x);
        else if (x.name[2].toUpperCase() === 'С')
          this.filteredGroupsSpecialist?.push(x);
        else
          this.filteredGroupsMagistracy?.push(x);
      });
    }
  }

  protected onFacultySelected(index: number, loadMode: boolean = false) {
    this.resetCourse();
    this.resetGroup();

    if (index === undefined) {
      this.facultyId = null;
      return;
    }

    if (loadMode)
      this.facultyChip.value = index;
    else
      this.selectChangeEvent.emit(this.getSelectedTabs());

    this.facultyId = index;
    this.courseNumberPanel.open();

    this.loadCourseGroup();
  }

  protected onCourseSelected(course: number, loadMode: boolean = false) {
    this.resetGroup();

    if (course === undefined) {
      this.courseNumber = null;
      return;
    }

    if (loadMode)
      this.courseChip.value = course;
    else
      this.selectChangeEvent.emit(this.getSelectedTabs());

    this.courseNumber = course;
    this.groupPanel.open();
    this.loadCourseGroup();
  }

  protected onGroupSelected(index: number, loadMode: boolean = false) {
    if (index === undefined)
      return;

    if (loadMode)
      this.groupChip.value = index;

    this.selectChangeEvent.emit(this.getSelectedTabs());

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

  public load() {
    if (this.faculties === null)
      this.loadFaculties();
  }
}