import { AfterViewInit, Component, ElementRef, OnInit, ViewChild } from '@angular/core';
import { FormBuilder, FormControl, FormGroup } from '@angular/forms';
import { MatAutocompleteSelectedEvent } from '@angular/material/autocomplete';
import { MatPaginator } from '@angular/material/paginator';
import { MatSort } from '@angular/material/sort';
import { ActivatedRoute, Router } from '@angular/router';
import * as moment from 'moment';
import { Observable, of as observableOf } from 'rxjs';
import { debounceTime, distinctUntilChanged, map, startWith, switchMap } from 'rxjs/operators';

import { Product } from '../core/product';
import { ProductService } from '../product/product.service';
import { ToCsvService } from '../shared/to-csv.service';

import { ProductLedger } from './product-ledger';
import { ProductLedgerDataSource } from './product-ledger-datasource';
import { ProductLedgerService } from './product-ledger.service';

@Component({
  selector: 'app-product-ledger',
  templateUrl: './product-ledger.component.html',
  styleUrls: ['./product-ledger.component.css'],
})
export class ProductLedgerComponent implements OnInit, AfterViewInit {
  @ViewChild('productElement', { static: true }) productElement?: ElementRef;
  @ViewChild(MatPaginator, { static: true }) paginator?: MatPaginator;
  @ViewChild(MatSort, { static: true }) sort?: MatSort;
  info: ProductLedger = new ProductLedger();
  dataSource: ProductLedgerDataSource = new ProductLedgerDataSource(this.info.body);
  form: FormGroup;
  selectedRowId = '';
  debitQuantity = 0;
  debitAmount = 0;
  creditQuantity = 0;
  creditAmount = 0;
  runningQuantity = 0;
  runningAmount = 0;
  /** Columns displayed in the table. Columns IDs can be added, removed, or reordered. */
  displayedColumns = [
    'date',
    'particulars',
    'type',
    'narration',
    'debitQuantity',
    'debitAmount',
    'creditQuantity',
    'creditAmount',
    'runningQuantity',
    'runningAmount',
  ];

  products: Observable<Product[]>;

  constructor(
    private route: ActivatedRoute,
    private router: Router,
    private fb: FormBuilder,
    private toCsv: ToCsvService,
    private ser: ProductLedgerService,
    private productSer: ProductService,
  ) {
    this.form = this.fb.group({
      startDate: '',
      finishDate: '',
      product: '',
    });

    this.products = (this.form.get('product') as FormControl).valueChanges.pipe(
      startWith(null),
      map((x) => (x !== null && x.length >= 1 ? x : null)),
      debounceTime(150),
      distinctUntilChanged(),
      switchMap((x) => (x === null ? observableOf([]) : this.productSer.autocomplete(x))),
    );
  }

  ngOnInit() {
    this.route.data.subscribe((value) => {
      const data = value as { info: ProductLedger };

      this.info = data.info;
      this.calculateTotals();
      this.form.setValue({
        product: this.info.product,
        startDate: moment(this.info.startDate, 'DD-MMM-YYYY').toDate(),
        finishDate: moment(this.info.finishDate, 'DD-MMM-YYYY').toDate(),
      });
      this.dataSource = new ProductLedgerDataSource(this.info.body, this.paginator, this.sort);
    });
  }

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

  displayFn(product?: Product): string {
    return product ? product.name : '';
  }

  calculateTotals() {
    this.debitQuantity = 0;
    this.debitAmount = 0;
    this.creditQuantity = 0;
    this.creditAmount = 0;
    this.runningQuantity = 0;
    this.runningAmount = 0;
    this.info.body.forEach((item) => {
      if (item.type !== 'Opening Balance') {
        this.debitAmount += item.debitAmount;
        this.creditQuantity += item.creditQuantity;
        this.creditAmount += item.creditAmount;
      }
      this.runningQuantity += item.debitQuantity - item.creditQuantity;
      this.runningAmount += item.debitAmount - item.creditAmount;
      item.runningQuantity = this.runningQuantity;
      item.runningAmount = this.runningAmount;
    });
  }

  selected(event: MatAutocompleteSelectedEvent): void {
    this.info.product = event.option.value;
  }

  selectRow(id: string): void {
    this.selectedRowId = id;
  }

  show() {
    const info = this.getInfo();
    this.router.navigate(['product-ledger', (info.product as Product).id], {
      queryParams: {
        startDate: info.startDate,
        finishDate: info.finishDate,
      },
    });
  }

  getInfo(): ProductLedger {
    const formModel = this.form.value;

    return new ProductLedger({
      product: formModel.product,
      startDate: moment(formModel.startDate).format('DD-MMM-YYYY'),
      finishDate: moment(formModel.finishDate).format('DD-MMM-YYYY'),
    });
  }

  exportCsv() {
    const headers = {
      Date: 'date',
      Name: 'name',
      Type: 'type',
      Narration: 'narration',
      Debit: 'debit',
      Credit: 'credit',
      Running: 'running',
      Posted: 'posted',
    };
    const csvData = new Blob([this.toCsv.toCsv(headers, this.dataSource.data)], {
      type: 'text/csv;charset=utf-8;',
    });
    const link = document.createElement('a');
    link.href = window.URL.createObjectURL(csvData);
    link.setAttribute('download', 'ledger.csv');
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
  }
}