/**
 * Copyright since 2025 Mifos Initiative
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/** Angular Imports */
import { Component, OnInit, inject } from '@angular/core';
import {
  AbstractControl,
  UntypedFormBuilder,
  UntypedFormGroup,
  ValidationErrors,
  ValidatorFn,
  Validators
} from '@angular/forms';
import { RouterLink } from '@angular/router';
import { MatIconModule } from '@angular/material/icon';
import { MatButtonModule } from '@angular/material/button';
import { MatTableModule } from '@angular/material/table';
import { MatPaginatorModule, PageEvent } from '@angular/material/paginator';
import { MatSnackBar, MatSnackBarModule } from '@angular/material/snack-bar';
import { MatTooltipModule } from '@angular/material/tooltip';
import { MatDialog } from '@angular/material/dialog';
import { FaIconComponent } from '@fortawesome/angular-fontawesome';
import { STANDALONE_SHARED_IMPORTS } from 'app/standalone-shared.module';

/** Custom Services */
import { LockerService } from '../locker.service';
import { SettingsService } from 'app/settings/settings.service';
import { AuthenticationService } from 'app/core/authentication/authentication.service';
import { Dates } from 'app/core/utils/dates';
import { DeleteDialogComponent } from 'app/shared/delete-dialog/delete-dialog.component';

/** End locker no must not be below the start, and effective-to must not be before effective-from. */
const rangeValidator: ValidatorFn = (group: AbstractControl): ValidationErrors | null => {
  const errors: ValidationErrors = {};
  const start = Number(group.get('startLockerNo')?.value);
  const end = Number(group.get('endLockerNo')?.value);
  if (start && end && end < start) {
    errors['endBeforeStart'] = true;
  }
  const from = group.get('effectiveFromDate')?.value;
  const to = group.get('effectiveToDate')?.value;
  if (from && to && new Date(to) < new Date(from)) {
    errors['toBeforeFrom'] = true;
  }
  return Object.keys(errors).length ? errors : null;
};

/**
 * Locker class master — one row per locker number range of a class (a class such as A1 can have several ranges),
 * with member / non-member rent and deposit and an effective period. Occupied is counted from allotments by the
 * server, never stored. Only a Branch Manager (own branch) or the Super user (any branch) may change it; the
 * server enforces both, the buttons here are only hidden to match.
 */
@Component({
  selector: 'mifosx-locker-class-master',
  templateUrl: './class-master.component.html',
  styleUrls: ['./class-master.component.scss'],
  imports: [
    ...STANDALONE_SHARED_IMPORTS,
    RouterLink,
    MatIconModule,
    MatButtonModule,
    MatTableModule,
    MatPaginatorModule,
    MatSnackBarModule,
    MatTooltipModule,
    FaIconComponent
  ]
})
export class ClassMasterComponent implements OnInit {
  private formBuilder = inject(UntypedFormBuilder);
  private lockerService = inject(LockerService);
  private settingsService = inject(SettingsService);
  private dateUtils = inject(Dates);
  private authenticationService = inject(AuthenticationService);
  private dialog = inject(MatDialog);
  private snackBar = inject(MatSnackBar);

  private notify(message: string, isError = false): void {
    this.snackBar.open(message, 'Dismiss', { duration: isError ? 6000 : 3000 });
  }

  /** The server's own reason (overlapping range, allotted lockers, other branch) rather than a generic failure. */
  private serverMessage(err: any, fallback: string): string {
    const body = err?.error;
    return body?.errors?.[0]?.defaultUserMessage || body?.defaultUserMessage || fallback;
  }

  /** Super user picks any branch; everyone else is fixed to their own. */
  isSuperUser = false;
  ownOfficeId: number | null = null;
  ownOfficeName = '';
  offices: any[] = [];

  classList: any[] = [];
  showForm = false;
  busy = false;
  loadFailed = false;
  /** Id of the row being edited; null while adding. */
  editingId: number | null = null;

  statusFilter = 'ACTIVE';
  pageSize = 10;
  pageIndex = 0;
  totalRecords = 0;
  pageSizeOptions = [
    10,
    25,
    50,
    100
  ];

  classNames = [
    'SMALL',
    'MEDIUM',
    'LARGE'
  ];

  classForm: UntypedFormGroup;

  columns = [
    'srNo',
    'office',
    'classCode',
    'className',
    'area',
    'rent',
    'lockerRange',
    'totalLockers',
    'occupied',
    'deposit',
    'effectiveFrom',
    'effectiveTo',
    'active',
    'actions'
  ];

  constructor() {
    this.classForm = this.formBuilder.group(
      {
        officeId: [''],
        classCode: [
          '',
          [
            Validators.required,
            Validators.maxLength(10),
            Validators.pattern(/^[A-Za-z0-9]+$/)
          ]
        ],
        className: [
          '',
          Validators.required
        ],
        area: [
          '',
          [
            Validators.required,
            Validators.min(1)
          ]
        ],
        rent: [
          '',
          [
            Validators.required,
            Validators.min(0)
          ]
        ],
        memberRent: [
          '',
          Validators.min(0)
        ],
        deposit: [
          '',
          [
            Validators.required,
            Validators.min(0)
          ]
        ],
        memberDeposit: [
          '',
          Validators.min(0)
        ],
        startLockerNo: [
          '',
          [
            Validators.required,
            Validators.min(1),
            Validators.pattern(/^\d+$/)
          ]
        ],
        endLockerNo: [
          '',
          [
            Validators.required,
            Validators.min(1),
            Validators.pattern(/^\d+$/)
          ]
        ],
        effectiveFromDate: [
          new Date(),
          Validators.required
        ],
        effectiveToDate: ['']
      },
      { validators: rangeValidator }
    );
  }

  ngOnInit(): void {
    const credentials = this.authenticationService.getCredentials();
    this.isSuperUser = !!credentials?.permissions?.includes('ALL_FUNCTIONS');
    this.ownOfficeId = credentials?.officeId ?? null;
    this.ownOfficeName = credentials?.officeName ?? '';
    if (this.isSuperUser) {
      this.lockerService.getOffices().subscribe({
        next: (offices: any[]) => (this.offices = offices ?? []),
        error: () => (this.offices = [])
      });
    }
    this.loadClasses();
  }

  /** Lockers the entered range will create — shown live so the user can check it before saving. */
  get totalLockers(): number {
    const start = Number(this.classForm.get('startLockerNo')?.value);
    const end = Number(this.classForm.get('endLockerNo')?.value);
    return start && end && end >= start ? end - start + 1 : 0;
  }

  /** Another active range of the same class already covering any of the entered locker numbers (on the loaded page). */
  get overlappingRange(): any | null {
    const code = String(this.classForm.get('classCode')?.value || '').toUpperCase();
    const start = Number(this.classForm.get('startLockerNo')?.value);
    const end = Number(this.classForm.get('endLockerNo')?.value);
    const officeId = Number(this.classForm.get('officeId')?.value || this.ownOfficeId);
    if (!code || !start || !end || end < start) {
      return null;
    }
    return (
      this.classList.find(
        (c) =>
          c.active &&
          c.id !== this.editingId &&
          c.officeId === officeId &&
          String(c.classCode).toUpperCase() === code &&
          start <= c.endLockerNo &&
          end >= c.startLockerNo
      ) ?? null
    );
  }

  loadClasses(): void {
    this.loadFailed = false;
    this.lockerService
      .getClasses(this.statusFilter || undefined, this.pageIndex * this.pageSize, this.pageSize)
      .subscribe({
        next: (res: any) => {
          this.classList = res?.pageItems ?? [];
          this.totalRecords = Number(res?.totalFilteredRecords ?? 0);
        },
        error: () => {
          this.classList = [];
          this.totalRecords = 0;
          this.loadFailed = true;
        }
      });
  }

  filterByStatus(status: string): void {
    this.statusFilter = this.statusFilter === status ? '' : status;
    this.pageIndex = 0;
    this.loadClasses();
  }

  onPageChange(event: PageEvent): void {
    this.pageSize = event.pageSize;
    this.pageIndex = event.pageIndex;
    this.loadClasses();
  }

  openAddForm(): void {
    this.editingId = null;
    this.resetForm();
    this.showForm = true;
  }

  /** Class code and locker range stay fixed once saved — a different range is added as a new row. */
  edit(row: any): void {
    this.editingId = row.id;
    this.classForm.reset({
      officeId: row.officeId,
      classCode: row.classCode,
      className: row.className,
      area: row.area,
      rent: row.rent,
      memberRent: row.memberRent,
      deposit: row.deposit,
      memberDeposit: row.memberDeposit,
      startLockerNo: row.startLockerNo,
      endLockerNo: row.endLockerNo,
      effectiveFromDate: row.effectiveFromDate ? this.dateUtils.parseDate(row.effectiveFromDate) : '',
      effectiveToDate: row.effectiveToDate ? this.dateUtils.parseDate(row.effectiveToDate) : ''
    });
    this.classForm.get('officeId')?.disable();
    this.classForm.get('classCode')?.disable();
    this.classForm.get('startLockerNo')?.disable();
    this.classForm.get('endLockerNo')?.disable();
    this.showForm = true;
  }

  cancel(): void {
    this.showForm = false;
    this.editingId = null;
    this.resetForm();
  }

  submit(): void {
    if (this.classForm.invalid || this.overlappingRange || this.busy) {
      return;
    }
    this.busy = true;
    const raw = this.classForm.getRawValue();
    const dateFormat = this.settingsService.dateFormat;
    // Member rate falls back to the normal rate when left blank, as in the legacy class master.
    const payload: any = {
      className: raw.className,
      area: Number(raw.area),
      rent: Number(raw.rent),
      memberRent: raw.memberRent !== '' && raw.memberRent != null ? Number(raw.memberRent) : Number(raw.rent),
      deposit: Number(raw.deposit),
      memberDeposit:
        raw.memberDeposit !== '' && raw.memberDeposit != null ? Number(raw.memberDeposit) : Number(raw.deposit),
      effectiveFromDate: this.dateUtils.formatDate(raw.effectiveFromDate, dateFormat),
      dateFormat,
      locale: this.settingsService.language.code
    };
    if (raw.effectiveToDate) {
      payload.effectiveToDate = this.dateUtils.formatDate(raw.effectiveToDate, dateFormat);
    } else if (this.editingId != null) {
      // Sent blank on edit so a previously set end date can be cleared.
      payload.effectiveToDate = null;
    }
    if (this.editingId == null) {
      if (this.isSuperUser && raw.officeId) {
        payload.officeId = Number(raw.officeId);
      }
      payload.classCode = String(raw.classCode).toUpperCase();
      payload.startLockerNo = Number(raw.startLockerNo);
      payload.endLockerNo = Number(raw.endLockerNo);
    }

    const request =
      this.editingId == null
        ? this.lockerService.createClass(payload)
        : this.lockerService.updateClass(this.editingId, payload);
    request.subscribe({
      next: () => {
        this.busy = false;
        this.notify(this.editingId == null ? 'Locker class saved' : 'Locker class updated');
        this.cancel();
        this.loadClasses();
      },
      error: (err: any) => {
        this.busy = false;
        this.notify(this.serverMessage(err, 'Failed to save locker class'), true);
      }
    });
  }

  deactivate(row: any): void {
    const dialogRef = this.dialog.open(DeleteDialogComponent, {
      data: { deleteContext: `locker class ${row.classCode} (lockers ${row.startLockerNo}-${row.endLockerNo})` }
    });
    dialogRef.afterClosed().subscribe((response: any) => {
      if (!response?.delete) {
        return;
      }
      this.lockerService.deactivateClass(row.id).subscribe({
        next: () => {
          this.notify('Locker class deactivated');
          this.loadClasses();
        },
        error: (err: any) => this.notify(this.serverMessage(err, 'Failed to deactivate locker class'), true)
      });
    });
  }

  private resetForm(): void {
    this.classForm.reset({
      officeId: this.ownOfficeId ?? '',
      className: '',
      effectiveFromDate: new Date(),
      effectiveToDate: ''
    });
    if (this.isSuperUser) {
      this.classForm.get('officeId')?.enable();
    } else {
      this.classForm.get('officeId')?.disable();
    }
    this.classForm.get('classCode')?.enable();
    this.classForm.get('startLockerNo')?.enable();
    this.classForm.get('endLockerNo')?.enable();
  }
}