import { CurrencyPipe } from '@angular/common';
import { Component, inject, computed, linkedSignal, input } from '@angular/core';
import { form, FormField } from '@angular/forms/signals';
import { MatButtonModule } from '@angular/material/button';
import { MatDatepickerModule } from '@angular/material/datepicker';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatIconModule } from '@angular/material/icon';
import { MatInputModule } from '@angular/material/input';
import { MatSnackBar } from '@angular/material/snack-bar';
import { MatTableModule } from '@angular/material/table';
import { Router } from '@angular/router';
import { DateTime } from 'luxon';

import { ErrorStateComponent } from '../shared/error-state/error-state.component';
import { SkeletonLoaderComponent } from '../shared/skeleton-loader/skeleton-loader.component';
import { ToCsvService } from '../shared/to-csv.service';
import { DiscountReport } from './discount-report';
import { DiscountReportService } from './discount-report.service';

export interface DiscountReportFormData {
  startDate: DateTime;
  finishDate: DateTime;
}

@Component({
  selector: 'app-discount-report',
  templateUrl: './discount-report.component.html',
  styleUrls: ['./discount-report.component.css'],
  imports: [
    CurrencyPipe,
    MatButtonModule,
    MatDatepickerModule,
    MatFormFieldModule,
    MatIconModule,
    MatInputModule,
    MatTableModule,
    FormField,
    ErrorStateComponent,
    SkeletonLoaderComponent,
  ],
})
export class DiscountReportComponent {
  private router = inject(Router);
  private toCsv = inject(ToCsvService);
  private snackBar = inject(MatSnackBar);
  private ser = inject(DiscountReportService);
  startDate = input(null, { transform: (v: string | null | undefined) => v ?? null });
  finishDate = input(null, { transform: (v: string | null | undefined) => v ?? null });

  infoResource = this.ser.get(this.startDate, this.finishDate);

  info = computed(() => this.infoResource.value() ?? new DiscountReport());
  dataSource = computed(() => this.info().amounts);
  formModel = linkedSignal({
    source: this.info,
    computation: (infoVal): DiscountReportFormData => {
      if (infoVal) {
        return {
          startDate: DateTime.fromFormat(this.info().startDate, 'dd-MMM-yyyy'),
          finishDate: DateTime.fromFormat(this.info().finishDate, 'dd-MMM-yyyy'),
        };
      }
      return {
        startDate: DateTime.now(),
        finishDate: DateTime.now(),
      };
    },
  });

  form = form(this.formModel);

  /** Columns displayed in the table. Columns IDs can be added, removed, or reordered. */
  displayedColumns = ['name', 'amount'];

  show() {
    const info = this.getInfo();
    this.router.navigate(['discount-report'], {
      queryParams: {
        startDate: info.startDate,
        finishDate: info.finishDate,
      },
    });
  }

  getInfo(): DiscountReport {
    const formModel = this.formModel();

    return new DiscountReport({
      startDate: formModel.startDate.toFormat('dd-MMM-yyyy'),
      finishDate: formModel.finishDate.toFormat('dd-MMM-yyyy'),
    });
  }

  print() {
    this.ser.print(this.info().startDate, this.info().finishDate).subscribe({
      next: () => {
        this.snackBar.open('Successfully Printed', '');
      },
      error: (error: unknown) => {
        this.snackBar.open(error as string, 'Error');
      },
    });
  }

  exportCsv() {
    const headers = {
      Name: 'name',
      Amount: 'amount',
    };
    const csvData = new Blob([this.toCsv.toCsv(headers, this.dataSource())], {
      type: 'text/csv;charset=utf-8;',
    });
    const link = document.createElement('a');
    link.href = window.URL.createObjectURL(csvData);
    link.setAttribute('download', 'discount-report.csv');
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
  }
}