import { SelectionModel } from '@angular/cdk/collections';
import { AsyncPipe, CurrencyPipe } from '@angular/common';
import { AfterViewInit, Component, ElementRef, HostListener, inject, OnInit, ViewChild } from '@angular/core';
import { FormControl, FormGroup, ReactiveFormsModule } from '@angular/forms';
import { MatAutocompleteModule, MatAutocompleteSelectedEvent } from '@angular/material/autocomplete';
import { MatButtonModule } from '@angular/material/button';
import { MatCardModule } from '@angular/material/card';
import { MatCheckboxModule } from '@angular/material/checkbox';
import { MatChipsModule } from '@angular/material/chips';
import { MatOptionModule } from '@angular/material/core';
import { MatDatepickerModule } from '@angular/material/datepicker';
import { MatDialog } from '@angular/material/dialog';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatIconModule } from '@angular/material/icon';
import { MatInputModule } from '@angular/material/input';
import { MatPaginator, MatPaginatorModule } from '@angular/material/paginator';
import { MatSelectModule } from '@angular/material/select';
import { MatSort, MatSortModule } from '@angular/material/sort';
import { MatTableModule } from '@angular/material/table';
import { ActivatedRoute, Router, RouterModule } from '@angular/router';
import moment from 'moment';
import { BehaviorSubject, Observable, of as observableOf } from 'rxjs';
import { debounceTime, distinctUntilChanged, switchMap } from 'rxjs/operators';

import { Account } from '../core/account';
import { AccountService } from '../core/account.service';
import { AccountingPipe } from '../shared/accounting.pipe';
import { ClearPipe } from '../shared/clear.pipe';
import { ToCsvService } from '../shared/to-csv.service';
import { TagDialogComponent } from '../tag-dialog/tag-dialog.component';
import { Tag } from '../tag/tag';
import { TagService } from '../tag/tag.service';
import { Ledger } from './ledger';
import { LedgerDataSource } from './ledger-datasource';
import { LedgerItem } from './ledger-item';

@Component({
  selector: 'app-ledger',
  templateUrl: './ledger.component.html',
  styleUrls: ['./ledger.component.css'],
  imports: [
    MatCardModule,
    MatCheckboxModule,
    MatChipsModule,
    MatIconModule,
    ReactiveFormsModule,
    MatFormFieldModule,
    MatInputModule,
    MatDatepickerModule,
    MatAutocompleteModule,
    MatOptionModule,
    MatButtonModule,
    MatTableModule,
    MatSelectModule,
    MatSortModule,
    RouterModule,
    MatPaginatorModule,
    AsyncPipe,
    CurrencyPipe,
    AccountingPipe,
    ClearPipe,
  ],
})
export class LedgerComponent implements OnInit, AfterViewInit {
  private route = inject(ActivatedRoute);
  private router = inject(Router);
  private dialog = inject(MatDialog);
  private toCsv = inject(ToCsvService);
  private accountSer = inject(AccountService);
  private tagSer = inject(TagService);

  @ViewChild('accountElement', { static: true }) accountElement!: ElementRef<HTMLInputElement>;
  @ViewChild('startDateElement', { static: true }) startDate!: ElementRef<HTMLInputElement>;
  @ViewChild(MatPaginator, { static: true }) paginator!: MatPaginator;
  @ViewChild(MatSort, { static: true }) sort!: MatSort;
  info: Ledger = new Ledger();
  body = new BehaviorSubject<LedgerItem[]>([]);
  filter = new BehaviorSubject<string[]>([]);
  dataSource: LedgerDataSource = new LedgerDataSource(this.body, this.filter);
  selection = new SelectionModel<LedgerItem>(true, []);

  allTags: Tag[] = [];
  tags: string[] = [];
  form: FormGroup<{
    startDate: FormControl<Date>;
    finishDate: FormControl<Date>;
    account: FormControl<string | null>;
    tags: FormControl<string[]>;
  }>;

  selectedRowId = '';
  /** Columns displayed in the table. Columns IDs can be added, removed, or reordered. */
  displayedColumns = ['date', 'particulars', 'type', 'narration', 'debit', 'credit', 'running'];

  accounts: Observable<Account[]>;

  @HostListener('window:keydown.f2', ['$event'])
  focusDate(event: KeyboardEvent) {
    event.preventDefault();
    this.startDate.nativeElement.focus();
    this.startDate.nativeElement.select();
  }

  constructor() {
    this.form = new FormGroup({
      startDate: new FormControl(new Date(), { nonNullable: true }),
      finishDate: new FormControl(new Date(), { nonNullable: true }),
      account: new FormControl<string | null>(null),
      tags: new FormControl<string[]>([], { nonNullable: true }),
    });

    this.accounts = this.form.controls.account.valueChanges.pipe(
      debounceTime(150),
      distinctUntilChanged(),
      switchMap((x) => (x === null ? observableOf([]) : this.accountSer.autocomplete(x))),
    );
  }

  ngOnInit() {
    this.route.data.subscribe((value) => {
      const data = value as { tags: Tag[]; info: Ledger };

      this.allTags = data.tags;
      this.info = data.info;
      this.tags = [
        '(None)',
        ...Array.from(new Set(this.info.body.map((x) => x.tags).reduce((list, tags) => list.concat(tags), []))),
      ];
      this.form.setValue({
        account: this.info.account?.name ?? '',
        startDate: moment(this.info.startDate, 'DD-MMM-YYYY').toDate(),
        finishDate: moment(this.info.finishDate, 'DD-MMM-YYYY').toDate(),
        tags: this.tags,
      });
      this.body.next(this.info.body);
      this.filter.next(this.tags);
      if (!this.dataSource.paginator) {
        this.dataSource.paginator = this.paginator;
      }
      if (!this.dataSource.sort) {
        this.dataSource.sort = this.sort;
      }
      this.selection.clear();
    });
  }

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

  displayFn(account?: Account | string): string {
    return !account ? '' : typeof account === 'string' ? account : account.name;
  }

  tagChanges(value: string[]) {
    this.filter.next(value);
  }

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

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

  /** Whether the number of selected elements matches the total number of rows. */
  isAllSelected() {
    const numSelected = this.selection.selected.length;
    const numRows = this.dataSource.data.length;
    return numSelected === numRows;
  }

  /** Selects all rows if they are not all selected; otherwise clear selection. */
  toggleAllRows() {
    if (this.isAllSelected()) {
      this.selection.clear();
      return;
    }

    this.selection.select(...this.dataSource.data);
  }

  labels() {
    if (!this.selection.selected.length) {
      return;
    }

    this.dialog
      .open(TagDialogComponent, {
        width: '750px',
        data: {
          tags: this.allTags,
          vouchers: this.selection.selected,
        },
      })
      .afterClosed()
      .subscribe({
        next: (result) => {
          if (result) {
            this.router.navigateByUrl(this.router.url);
          }
        },
      });
  }

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

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

    return new Ledger({
      account: this.info.account,
      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);
  }
}