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 {BehaviorSubject, Observable, of as observableOf} from 'rxjs';
import {debounceTime, distinctUntilChanged, map, startWith, switchMap} from 'rxjs/operators';
import {IssueDataSource} from './issue-datasource';
import {VoucherService} from '../core/voucher.service';
import {Batch, Inventory, Journal, 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 {IssueDialogComponent} from './issue-dialog.component';
import {BatchService} from '../core/batch.service';
import {IssueGridService} from './issue-grid.service';
import {CostCentre} from '../core/cost-centre';
import {IssueGridDataSource} from './issue-grid-datasource';
import {Hotkey, HotkeysService} from "angular2-hotkeys";

@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;
  sourceJournal: Journal;
  destinationJournal: Journal;
  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 ser: VoucherService,
    private batchSer: BatchService,
    private issueGridSer: IssueGridService
  ) {
    this.createForm();
    this.listenToBatchAutocompleteChange();
    this.listenToDateChange();
  }

  ngOnInit() {
    this.gridDataSource = new IssueGridDataSource(this.gridObservable);
    this.route.data
      .subscribe((data: { voucher: Voucher, costCentres: CostCentre[] }) => {
        this.costCentres = data.costCentres;
        this.loadVoucher(data.voucher);
      });
    this.hotkeys.add(new Hotkey('f2', (event: KeyboardEvent): boolean => {
      setTimeout(() => {
        this.dateElement.nativeElement.focus();
      }, 0);
      return false; // Prevent bubbling
    }, ['INPUT', 'SELECT', 'TEXTAREA']));
    this.hotkeys.add(new Hotkey('ctrl+s', (event: KeyboardEvent): 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.sourceJournal = this.voucher.journals.filter(x => x.debit === -1)[0];
    this.destinationJournal = this.voucher.journals.filter(x => x.debit === 1)[0];
    this.form.setValue({
      date: moment(this.voucher.date, 'DD-MMM-YYYY').toDate(),
      sourceCostCentre: this.sourceJournal.costCentre.id,
      destinationCostCentre: this.destinationJournal.costCentre.id,
      amount: this.sourceJournal.amount,
      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 = +(formValue.quantity);
    const isConsumption = this.voucher.journals
      .filter(
        x => x.debit === -1
      )[0].costCentre.id === '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: 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 = Math.abs(this.voucher.inventories.map((x) => x.amount).reduce((p, c) => p + c, 0));
    this.sourceJournal.amount = amount;
    this.destinationJournal.amount = amount;
    this.form.get('amount').setValue(amount);
  }

  editRow(row: Inventory) {
    const dialogRef = this.dialog.open(IssueDialogComponent, {
      width: '750px',
      data: {inventory: Object.assign({}, 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();
  }

  createForm() {
    this.form = this.fb.group({
      date: '',
      sourceCostCentre: '',
      destinationCostCentre: '',
      amount: {value: '', disabled: true},
      addRow: this.fb.group({
        batch: '',
        quantity: ''
      }),
      narration: ''
    });
  }

  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;
    }
  }

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

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

  getVoucher(): Voucher {
    const formModel = this.form.value;
    this.voucher.date = moment(formModel.date).format('DD-MMM-YYYY');
    this.sourceJournal.costCentre.id = formModel.sourceCostCentre;
    this.destinationJournal.costCentre.id = formModel.destinationCostCentre;
    this.voucher.narration = formModel.narration;
    return this.voucher;
  }

  delete() {
    this.ser.delete(this.voucher.id)
      .subscribe(
        (result) => {
          this.toaster.show('Success', '');
          this.router.navigate(['/issue'], {replaceUrl: true});
        },
        (error) => {
          this.toaster.show('Danger', error.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),
        map(x => (x !== null && x.length >= 1) ? x : null),
        debounceTime(150),
        distinctUntilChanged(),
        switchMap(
          x => (x === null) ? observableOf([]) : 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)
      );
  }

  displayBatchName(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]);
  }

}