import { AfterViewInit, Component, ElementRef, OnInit, OnDestroy, ViewChild } from '@angular/core';
import { FormBuilder, FormControl, FormGroup } from '@angular/forms';
import { MatAutocompleteSelectedEvent } from '@angular/material/autocomplete';
import { MatDialog } from '@angular/material/dialog';
import { ActivatedRoute, Router } from '@angular/router';
import { Hotkey, HotkeysService } from 'angular2-hotkeys';
import { round } from 'mathjs';
import * as moment from 'moment';
import { BehaviorSubject, Observable, of as observableOf } from 'rxjs';
import { debounceTime, distinctUntilChanged, map, startWith, switchMap } from 'rxjs/operators';

import { AuthService } from '../auth/auth.service';
import { Account } from '../core/account';
import { AccountBalance } from '../core/account-balance';
import { AccountService } from '../core/account.service';
import { DbFile } from '../core/db-file';
import { Journal } from '../core/journal';
import { ToasterService } from '../core/toaster.service';
import { User } from '../core/user';
import { Voucher } from '../core/voucher';
import { VoucherService } from '../core/voucher.service';
import { ConfirmDialogComponent } from '../shared/confirm-dialog/confirm-dialog.component';
import { ImageDialogComponent } from '../shared/image-dialog/image-dialog.component';
import { ImageService } from '../shared/image.service';
import { MathService } from '../shared/math.service';

import { ReceiptDataSource } from './receipt-datasource';
import { ReceiptDialogComponent } from './receipt-dialog.component';

@Component({
  selector: 'app-receipt',
  templateUrl: './receipt.component.html',
  styleUrls: ['./receipt.component.css'],
})
export class ReceiptComponent implements OnInit, AfterViewInit, OnDestroy {
  @ViewChild('accountElement', { static: true }) accountElement?: ElementRef;
  @ViewChild('dateElement', { static: true }) dateElement?: ElementRef;
  public journalObservable = new BehaviorSubject<Journal[]>([]);
  dataSource: ReceiptDataSource = new ReceiptDataSource(this.journalObservable);
  form: FormGroup;
  receiptAccounts: Account[] = [];
  receiptJournal: Journal = new Journal();
  voucher: Voucher = new Voucher();
  account: Account | null = null;
  accBal: AccountBalance | null = null;

  displayedColumns = ['account', 'amount', 'action'];

  accounts: Observable<Account[]>;

  constructor(
    private route: ActivatedRoute,
    private router: Router,
    private fb: FormBuilder,
    private dialog: MatDialog,
    private hotkeys: HotkeysService,
    private toaster: ToasterService,
    public auth: AuthService,
    private math: MathService,
    public image: ImageService,
    private ser: VoucherService,
    private accountSer: AccountService,
  ) {
    this.form = this.fb.group({
      date: '',
      receiptAccount: '',
      receiptAmount: { value: '', disabled: true },
      addRow: this.fb.group({
        account: '',
        amount: '',
      }),
      narration: '',
    });
    this.accBal = null;
    // Listen to Account Autocomplete Change
    this.accounts = ((this.form.get('addRow') as FormControl).get(
      'account',
    ) as FormControl).valueChanges.pipe(
      startWith(null),
      map((x) => (x !== null && x.length >= 1 ? x : null)),
      debounceTime(150),
      distinctUntilChanged(),
      switchMap((x) => (x === null ? observableOf([]) : this.accountSer.autocomplete(x))),
    );
    // Listen to Receipt Account Change
    (this.form.get('receiptAccount') as FormControl).valueChanges.subscribe((x) =>
      this.router.navigate([], {
        relativeTo: this.route,
        queryParams: { a: x },
        replaceUrl: true,
      }),
    );
  }

  ngOnInit() {
    this.route.data.subscribe((value) => {
      const data = value as { voucher: Voucher; receiptAccounts: Account[] };

      this.receiptAccounts = data.receiptAccounts;
      this.loadVoucher(data.voucher);
    });
    this.hotkeys.add(
      new Hotkey(
        'f2',
        (): boolean => {
          setTimeout(() => {
            if (this.dateElement) {
              this.dateElement.nativeElement.focus();
            }
          }, 0);
          return false; // Prevent bubbling
        },
        ['INPUT', 'SELECT', 'TEXTAREA'],
      ),
    );
    this.hotkeys.add(
      new Hotkey(
        'ctrl+s',
        (): boolean => {
          if (this.canSave()) {
            this.save();
          }
          return false; // Prevent bubbling
        },
        ['INPUT', 'SELECT', 'TEXTAREA'],
      ),
    );
    this.hotkeys.add(
      new Hotkey(
        'ctrl+p',
        (): boolean => {
          if (this.voucher.id && !this.voucher.posted && this.auth.allowed('post-vouchers')) {
            this.post();
          }
          return false; // Prevent bubbling
        },
        ['INPUT', 'SELECT', 'TEXTAREA'],
      ),
    );
  }

  ngAfterViewInit() {
    this.focusAccount();
  }

  ngOnDestroy() {
    this.hotkeys.reset();
  }

  loadVoucher(voucher: Voucher) {
    this.voucher = voucher;
    [this.receiptJournal] = this.voucher.journals.filter((x) => x.debit === 1);
    this.form.setValue({
      date: moment(this.voucher.date, 'DD-MMM-YYYY').toDate(),
      receiptAccount: this.receiptJournal.account.id,
      receiptAmount: this.receiptJournal.amount,
      addRow: {
        account: '',
        amount: 0,
      },
      narration: this.voucher.narration,
    });
    this.dataSource = new ReceiptDataSource(this.journalObservable);
    this.updateView();
  }

  focusAccount() {
    setTimeout(() => {
      if (this.accountElement) {
        this.accountElement.nativeElement.focus();
      }
    }, 0);
  }

  addRow() {
    const amount = this.math.parseAmount((this.form.get('addRow') as FormControl).value.amount, 2);
    const debit = -1;
    if (this.account === null || amount <= 0) {
      return;
    }
    const oldFiltered = this.voucher.journals.filter(
      (x) => x.account.id === (this.account as Account).id,
    );
    const old = oldFiltered.length ? oldFiltered[0] : null;
    if (old && (old.debit === 1 || old.id === this.receiptJournal.id)) {
      return;
    }
    if (old) {
      old.amount += amount;
    } else {
      this.voucher.journals.push(
        new Journal({
          debit,
          amount,
          account: this.account,
          costCentre: null,
        }),
      );
    }
    this.resetAddRow();
    this.updateView();
  }

  resetAddRow() {
    (this.form.get('addRow') as FormControl).reset({
      account: null,
      amount: null,
    });
    this.account = null;
    this.accBal = null;
    setTimeout(() => {
      if (this.accountElement) {
        this.accountElement.nativeElement.focus();
      }
    }, 0);
  }

  updateView() {
    const journals = this.voucher.journals.filter((x) => x.debit === -1);
    this.journalObservable.next(journals);
    this.receiptJournal.amount = round(
      Math.abs(journals.map((x) => x.amount).reduce((p, c) => p + c, 0)),
      2,
    );
    (this.form.get('receiptAmount') as FormControl).setValue(this.receiptJournal.amount);
  }

  editRow(row: Journal) {
    const dialogRef = this.dialog.open(ReceiptDialogComponent, {
      width: '750px',
      data: {
        journal: { ...row },
        date: moment((this.form.get('date') as FormControl).value).format('DD-MMM-YYYY'),
      },
    });

    dialogRef.afterClosed().subscribe((result: boolean | Journal) => {
      if (!result) {
        return;
      }
      const j = result as Journal;
      if (
        j.account.id !== row.account.id &&
        this.voucher.journals.filter((x) => x.account.id === j.account.id).length
      ) {
        return;
      }
      Object.assign(row, j);
      this.updateView();
    });
  }

  deleteRow(row: Journal) {
    this.voucher.journals.splice(this.voucher.journals.indexOf(row), 1);
    this.updateView();
  }

  canSave() {
    if (!this.voucher.id) {
      return true;
    }
    if (this.voucher.posted && this.auth.allowed('edit-posted-vouchers')) {
      return true;
    }
    return (
      this.voucher.user.id === (this.auth.user as User).id ||
      this.auth.allowed('edit-other-user\'s-vouchers')
    );
  }

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

  save() {
    const voucher: Voucher = this.getVoucher();
    this.ser.saveOrUpdate(voucher).subscribe(
      (result) => {
        this.toaster.show('Success', '');
        if (voucher.id === result.id) {
          this.loadVoucher(result);
        } else {
          this.router.navigate(['/receipt', 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');
    this.receiptJournal.account.id = formModel.receiptAccount;
    this.voucher.narration = formModel.narration;
    return this.voucher;
  }

  delete() {
    this.ser.delete(this.voucher.id as string).subscribe(
      () => {
        this.toaster.show('Success', '');
        this.router.navigate(['/receipt'], { 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();
      }
    });
  }

  displayFn(account?: Account): string {
    return account ? account.name : '';
  }

  accountSelected(event: MatAutocompleteSelectedEvent): void {
    const account = event.option.value;
    this.account = account;
    const date = moment((this.form.get('date') as FormControl).value).format('DD-MMM-YYYY');
    this.accountSer.balance(account.id as string, date).subscribe((v) => {
      this.accBal = v;
    });
  }

  zoomImage(file: DbFile) {
    this.dialog.open(ImageDialogComponent, {
      width: '750px',
      data: file.resized,
    });
  }

  deleteImage(file: DbFile) {
    const index = this.voucher.files.indexOf(file);
    this.voucher.files.splice(index, 1);
  }
}