import {AfterViewInit, Component, ElementRef, OnInit, ViewChild} from '@angular/core';
import {FormBuilder, FormGroup} from '@angular/forms';
import { MatAutocompleteSelectedEvent } from '@angular/material/autocomplete';
import { MatDialog } from '@angular/material/dialog';
import {ActivatedRoute, Router} from '@angular/router';
import {BehaviorSubject, Observable, of as observableOf} from 'rxjs';
import {EmployeeBenefitsDataSource} from './employee-benefits-datasource';
import {VoucherService} from '../core/voucher.service';
import {EmployeeBenefit, Voucher} from '../core/voucher';
import * as moment from 'moment';
import {AuthService} from '../auth/auth.service';
import {ConfirmDialogComponent} from '../shared/confirm-dialog/confirm-dialog.component';
import {ToasterService} from '../core/toaster.service';
import {debounceTime, distinctUntilChanged, map, startWith, switchMap} from 'rxjs/operators';
import {Employee} from '../employee/employee';
import {EmployeeService} from '../employee/employee.service';

@Component({
  selector: 'app-employee-benefits',
  templateUrl: './employee-benefits.component.html',
  styleUrls: ['./employee-benefits.component.css']
})
export class EmployeeBenefitsComponent implements OnInit, AfterViewInit {
  @ViewChild('employeeElement', { static: true }) employeeElement: ElementRef;
  public benefitsObservable = new BehaviorSubject<EmployeeBenefit[]>([]);
  dataSource: EmployeeBenefitsDataSource;
  form: FormGroup;
  voucher: Voucher;
  employee: Employee;
  accBal: any;

  displayedColumns = [
    'name', 'designation', 'department', 'grossSalary', 'daysWorked', 'esiEmployee', 'pfEmployee', 'esiEmployer', 'pfEmployer'
  ];

  employees: Observable<Employee[]>;

  constructor(
    private route: ActivatedRoute,
    private router: Router,
    private fb: FormBuilder,
    private dialog: MatDialog,
    private toaster: ToasterService,
    private auth: AuthService,
    private ser: VoucherService,
    private employeeSer: EmployeeService
  ) {
    this.createForm();
    this.setupEmployeeAutocomplete();
  }

  ngOnInit() {
    this.route.data
      .subscribe((data: { voucher: Voucher }) => {
        this.voucher = data.voucher;
        this.form.setValue({
          date: moment(this.voucher.date, 'DD-MMM-YYYY').toDate(),
          addRow: {
            employee: '1',
            grossSalary: '',
            daysWorked: ''
          }
        });
        this.dataSource = new EmployeeBenefitsDataSource(this.benefitsObservable);
        this.benefitsObservable.next(this.voucher.employeeBenefits);
      });
  }

  ngAfterViewInit() {
    setTimeout(() => {
      this.employeeElement.nativeElement.focus();
    }, 0);
  }

  createForm() {
    this.form = this.fb.group({
      date: '',
      addRow: this.fb.group({
        employee: '',
        grossSalary: '',
        daysWorked: ''
      }),
    });
  }

  setupEmployeeAutocomplete(): void {
    const control = this.form.get('addRow').get('employee');
    this.employees = control.valueChanges
      .pipe(
        startWith(null),
        map(x => (x !== null && x.length >= 1) ? x : null),
        debounceTime(150),
        distinctUntilChanged(),
        switchMap(x => (x === null) ? observableOf([]) : this.employeeSer.autocomplete(x))
      );

  }

  displayEmployeeName(employee?: Employee): string | undefined {
    return employee ? employee.name : undefined;
  }

  employeeSelected(event: MatAutocompleteSelectedEvent): void {
    this.employee = event.option.value;
  }

  addRow() {
    const oldFiltered = this.voucher.employeeBenefits.filter((x) => x.employee.id === this.employee.id);
    if (oldFiltered.length) {
      this.toaster.show('Danger', 'Employee has already been added');
      return;
    }

    const formValue = this.form.get('addRow').value;
    const grossSalary = +formValue.grossSalary;
    const daysWorked = +formValue.daysWorked;
    const date = this.form.get('date').value;
    const daysInMonth = moment(date).daysInMonth();
    const esi = this.getEsi(grossSalary, daysWorked, daysInMonth);
    const pf = this.getPf(grossSalary, daysWorked, daysInMonth);

    this.voucher.employeeBenefits.push({
      employee: this.employee,
      grossSalary: grossSalary,
      daysWorked: daysWorked,
      esiEmployee: esi.ee,
      pfEmployee: pf.ee,
      esiEmployer: esi.er,
      pfEmployer: pf.er
    });
    this.benefitsObservable.next(this.voucher.employeeBenefits);
    this.resetAddRow();
  }

  resetAddRow() {
    this.form.get('addRow').reset({
      employee: '',
      grossSalary: null,
      daysWorked: null
    });
    this.employee = null;
    setTimeout(() => {
      this.employeeElement.nativeElement.focus();
    }, 0);
  }

  deleteRow(row: EmployeeBenefit) {
    this.voucher.employeeBenefits.splice(this.voucher.employeeBenefits.indexOf(row), 1);
    this.benefitsObservable.next(this.voucher.employeeBenefits);
  }

  getEsi(grossSalary, daysWorked, daysInMonth) {
    const limit = 21000,
      employeeRate = 0.0175,
      employerRate = 0.0475,
      employee = (grossSalary > limit) ? 0 : Math.ceil(employeeRate * grossSalary * daysWorked / daysInMonth),
      employer = (grossSalary > limit) ? 0 : Math.ceil(employerRate * grossSalary * daysWorked / daysInMonth);
    return {ee: employee, er: employer, both: employee + employer};
  }

  getPf(grossSalary, daysWorked, daysInMonth) {
    const limit = 15000,
      employeeRate = 0.12,
      employerRate = 0.12 + 0.011 + 0.005 + 0.0001,
      employee = (grossSalary > limit) ? 0 : Math.ceil(employeeRate * grossSalary * daysWorked / daysInMonth),
      employer = (grossSalary > limit) ? 0 : Math.ceil(employerRate * grossSalary * daysWorked / daysInMonth);
    return {ee: employee, er: employer, both: employee + employer};
  }

  canSave() {
    if (!this.voucher.id) {
      return true;
    } else if (this.voucher.posted && this.auth.user.perms.indexOf('edit-posted-vouchers') !== -1) {
      return true;
    } else {
      return this.voucher.user.id === this.auth.user.id || this.auth.user.perms.indexOf("edit-other-user's-vouchers") !== -1;
    }
  }

  post() {
    this.ser.post(this.voucher.id)
      .subscribe(
        (result) => {
          this.toaster.show('Success', 'Voucher Posted');
        },
        (error) => {
          this.toaster.show('Danger', error);
        }
      );
  }

  save() {
    this.ser.saveOrUpdate(this.getVoucher())
      .subscribe(
        (result) => {
          this.toaster.show('Success', '');
          this.router.navigate(['/employee-benefits', result.id]);
        },
        (error) => {
          this.toaster.show('Danger', error);
        }
      );
  }

  getVoucher(): Voucher {
    const formModel = this.form.value;
    this.voucher.date = moment(formModel.date).format('DD-MMM-YYYY');
    return this.voucher;
  }

  delete() {
    this.ser.delete(this.voucher.id)
      .subscribe(
        (result) => {
          this.toaster.show('Success', '');
          this.router.navigate(['/employee-benefits'], {replaceUrl: true});
        },
        (error) => {
          this.toaster.show('Danger', error);
        }
      );
  }

  confirmDelete(): void {
    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '250px',
      data: {title: 'Delete Voucher?', content: 'Are you sure? This cannot be undone.'}
    });

    dialogRef.afterClosed().subscribe((result: boolean) => {
      if (result) {
        this.delete();
      }
    });
  }
}