import { AfterViewInit, Component, ElementRef, OnInit, OnDestroy, 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 { Hotkey, HotkeysService } from 'angular2-hotkeys';
import { round } from 'mathjs';
import * as moment from 'moment';
import { BehaviorSubject, Observable } from 'rxjs';
import { debounceTime, distinctUntilChanged, map, startWith, switchMap } from 'rxjs/operators';

import { AuthService } from '../auth/auth.service';
import { Batch } from '../core/batch';
import { BatchService } from '../core/batch.service';
import { CostCentre } from '../core/cost-centre';
import { Inventory } from '../core/inventory';
import { ToasterService } from '../core/toaster.service';
import { Voucher } from '../core/voucher';
import { VoucherService } from '../core/voucher.service';
import { ConfirmDialogComponent } from '../shared/confirm-dialog/confirm-dialog.component';
import { MathService } from '../shared/math.service';

import { IssueDataSource } from './issue-datasource';
import { IssueDialogComponent } from './issue-dialog.component';
import { IssueGridDataSource } from './issue-grid-datasource';
import { IssueGridService } from './issue-grid.service';

@Component({
  selector: 'app-issue',
  templateUrl: './issue.component.html',
  styleUrls: ['./issue.component.css'],
})
export class IssueComponent implements OnInit, AfterViewInit, OnDestroy {
  @ViewChild('batchElement', { static: true }) batchElement: ElementRef;
  @ViewChild('dateElement', { static: true }) dateElement: ElementRef;
  public inventoryObservable = new BehaviorSubject<Inventory[]>([]);
  public gridObservable = new BehaviorSubject<any[]>([]);
  dataSource: IssueDataSource;
  gridDataSource: IssueGridDataSource;
  form: FormGroup;
  voucher: Voucher;
  costCentres: CostCentre[];
  batch: Batch;

  displayedColumns = ['product', 'batch', 'quantity', 'rate', 'amount', 'action'];
  gridColumns = ['source', 'destination', 'gridAmount', 'load'];

  batches: Observable<Batch[]>;

  constructor(
    private route: ActivatedRoute,
    private router: Router,
    private fb: FormBuilder,
    private dialog: MatDialog,
    private hotkeys: HotkeysService,
    private toaster: ToasterService,
    private auth: AuthService,
    private math: MathService,
    private ser: VoucherService,
    private batchSer: BatchService,
    private issueGridSer: IssueGridService,
  ) {
    this.form = this.fb.group({
      date: '',
      source: '',
      destination: '',
      amount: { value: '', disabled: true },
      addRow: this.fb.group({
        batch: '',
        quantity: '',
      }),
      narration: '',
    });
    this.listenToBatchAutocompleteChange();
    this.listenToDateChange();
  }

  ngOnInit() {
    this.gridDataSource = new IssueGridDataSource(this.gridObservable);
    this.route.data.subscribe((value) => {
      const data = value as { voucher: Voucher; costCentres: CostCentre[] };

      this.costCentres = data.costCentres;
      this.loadVoucher(data.voucher);
    });
    this.hotkeys.add(
      new Hotkey(
        'f2',
        (): boolean => {
          setTimeout(() => {
            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'],
      ),
    );
  }

  ngAfterViewInit() {
    this.focusBatch();
  }

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

  loadVoucher(voucher: Voucher) {
    this.voucher = voucher;
    this.form.setValue({
      date: moment(this.voucher.date, 'DD-MMM-YYYY').toDate(),
      source: this.voucher.source.id,
      destination: this.voucher.destination.id,
      amount: Math.abs(this.voucher.inventories.map((x) => x.amount).reduce((p, c) => p + c, 0)),
      addRow: {
        batch: '',
        quantity: '',
      },
      narration: this.voucher.narration,
    });
    this.dataSource = new IssueDataSource(this.inventoryObservable);
    this.updateView();
  }

  focusBatch() {
    setTimeout(() => {
      this.batchElement.nativeElement.focus();
    }, 0);
  }

  addRow() {
    const formValue = this.form.get('addRow').value;
    const quantity = this.math.parseAmount(formValue.quantity, 2);
    const isConsumption = this.form.value.source === '7b845f95-dfef-fa4a-897c-f0baf15284a3';
    if (this.batch === null || quantity <= 0) {
      return;
    }
    const oldFiltered = this.voucher.inventories.filter(
      (x) => x.product.id === this.batch.product.id,
    );
    const old = oldFiltered.length ? oldFiltered[0] : null;
    if (oldFiltered.length) {
      if (old.batch.id !== this.batch.id) {
        this.toaster.show('Danger', 'Product with a different batch already added');
        return;
      }
      if (isConsumption && old.quantity + quantity > this.batch.quantityRemaining) {
        this.toaster.show('Danger', 'Quantity issued cannot be more than quantity available');
        return;
      }
      old.quantity += quantity;
    } else {
      if (isConsumption && quantity > this.batch.quantityRemaining) {
        this.toaster.show('Danger', 'Quantity issued cannot be more than quantity available');
        return;
      }
      this.voucher.inventories.push({
        id: null,
        quantity,
        rate: this.batch.rate,
        tax: this.batch.tax,
        discount: this.batch.discount,
        amount: quantity * this.batch.rate * (1 + this.batch.tax) * (1 - this.batch.discount),
        product: this.batch.product,
        batch: this.batch,
      });
    }
    this.resetAddRow();
    this.updateView();
  }

  resetAddRow() {
    this.form.get('addRow').reset({
      batch: null,
      quantity: '',
    });
    this.batch = null;
    setTimeout(() => {
      this.batchElement.nativeElement.focus();
    }, 0);
  }

  updateView() {
    this.inventoryObservable.next(this.voucher.inventories);
    const amount = round(
      Math.abs(this.voucher.inventories.map((x) => x.amount).reduce((p, c) => p + c, 0)),
      2,
    );
    this.form.get('amount').setValue(amount);
  }

  editRow(row: Inventory) {
    const dialogRef = this.dialog.open(IssueDialogComponent, {
      width: '750px',
      data: {
        inventory: { ...row },
        date: moment(this.form.value.date).format('DD-MMM-YYYY'),
      },
    });

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

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

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

  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(['/issue', result.id]);
        }
      },
      (error) => {
        this.toaster.show('Danger', error);
      },
    );
  }

  newVoucher() {
    this.router.navigate(['/issue']);
  }

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

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

  listenToBatchAutocompleteChange(): void {
    const control = this.form.get('addRow').get('batch');
    this.batches = control.valueChanges.pipe(
      startWith('null'),
      debounceTime(150),
      distinctUntilChanged(),
      switchMap((x) =>
        this.batchSer.autocomplete(moment(this.form.value.date).format('DD-MMM-YYYY'), x),
      ),
    );
  }

  listenToDateChange(): void {
    this.form
      .get('date')
      .valueChanges.pipe(map((x) => moment(x).format('DD-MMM-YYYY')))
      .subscribe((x) => this.showGrid(x));
  }

  showGrid(date: string) {
    this.issueGridSer.issueGrid(date).subscribe((x) => this.gridObservable.next(x));
  }

  displayFn(batch?: Batch): string | undefined {
    return batch ? batch.name : undefined;
  }

  batchSelected(event: MatAutocompleteSelectedEvent): void {
    this.batch = event.option.value;
  }

  goToVoucher(id: string) {
    this.router.navigate(['/issue', id]);
  }
}