import { CommonModule, isPlatformBrowser } from '@angular/common';
import { Component, ElementRef, Inject, PLATFORM_ID, ViewChild, AfterViewInit, OnInit } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';
import { firstValueFrom } from 'rxjs';

import Chart from 'chart.js/auto';
import {
  ParcelamentoService,
  ParcelamentoKpis,
  ParcelamentoMonthlyPoint,
  ParcelamentoTopLine
} from '../../services/parcelamento.service';

@Component({
  selector: 'app-parcelamento',
  standalone: true,
  imports: [CommonModule, FormsModule, HttpClientModule],
  templateUrl: './parcelamento.html',
  styleUrl: './parcelamento.scss'
})
export class Parcelamento implements OnInit, AfterViewInit {
  @ViewChild('monthlyCanvas') monthlyCanvas!: ElementRef<HTMLCanvasElement>;
  @ViewChild('topLinesCanvas') topLinesCanvas!: ElementRef<HTMLCanvasElement>;

  private monthlyChart?: Chart;
  private topLinesChart?: Chart;

  loading = false;

  clients: string[] = [];
  selectedClient: string = '';
  lineSearch: string = '';

  kpis: ParcelamentoKpis = {
    linhas: 0,
    clientes: 0,
    totalValorCheio: 0,
    totalDesconto: 0,
    totalComDesconto: 0,
    meses: 0
  };

  monthlySeries: ParcelamentoMonthlyPoint[] = [];
  topLines: ParcelamentoTopLine[] = [];

  constructor(
    private parcelamentoService: ParcelamentoService,
    @Inject(PLATFORM_ID) private platformId: Object
  ) {}

  async ngOnInit() {
    await this.loadClients();
    await this.refreshAll();
  }

  ngAfterViewInit() {
    if (isPlatformBrowser(this.platformId)) {
      this.renderCharts();
    }
  }

  private buildOpts() {
    const cliente = this.selectedClient?.trim() || undefined;
    const linha = this.onlyDigits(this.lineSearch) || undefined;
    return { cliente, linha };
  }

  async loadClients() {
    try {
      this.clients = await firstValueFrom(this.parcelamentoService.getClients());
    } catch {
      this.clients = [];
    }
  }

  async refreshAll() {
    this.loading = true;

    try {
      const opts = this.buildOpts();

      this.kpis = await firstValueFrom(this.parcelamentoService.getKpis(opts));
      this.monthlySeries = await firstValueFrom(this.parcelamentoService.getMonthlySeries(opts));
      this.topLines = await firstValueFrom(
        this.parcelamentoService.getTopLines({ cliente: opts.cliente, take: 10 })
      );

      this.renderCharts();
    } finally {
      this.loading = false;
    }
  }

  onClearFilters() {
    this.selectedClient = '';
    this.lineSearch = '';
    this.refreshAll();
  }

  onApplyFilters() {
    this.refreshAll();
  }

  private renderCharts() {
    if (!isPlatformBrowser(this.platformId)) return;
    if (!this.monthlyCanvas || !this.topLinesCanvas) return;

    this.renderMonthlyChart();
    this.renderTopLinesChart();
  }

  private renderMonthlyChart() {
    const labels = this.monthlySeries.map(x => x.label);
    const values = this.monthlySeries.map(x => x.total ?? 0);

    if (this.monthlyChart) this.monthlyChart.destroy();

    this.monthlyChart = new Chart(this.monthlyCanvas.nativeElement.getContext('2d')!, {
      type: 'bar',
      data: {
        labels,
        datasets: [{ label: 'Valor por mês (R$)', data: values }]
      },
      options: {
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
          legend: { display: true },
          tooltip: {
            callbacks: {
              label: (ctx) => {
                const y = (ctx.parsed as any)?.y;
                return ` ${this.money(typeof y === 'number' ? y : 0)}`;
              }
            }
          }
        },
        scales: {
          y: {
            ticks: {
              callback: (v: any) => this.money(Number(v) || 0)
            }
          }
        }
      }
    });
  }

  private renderTopLinesChart() {
    const labels = this.topLines.map(x => (x.linha ?? '').toString());
    const values = this.topLines.map(x => x.total ?? 0);

    if (this.topLinesChart) this.topLinesChart.destroy();

    this.topLinesChart = new Chart(this.topLinesCanvas.nativeElement.getContext('2d')!, {
      type: 'bar',
      data: {
        labels,
        datasets: [{ label: 'Top 10 linhas (Total R$)', data: values }]
      },
      options: {
        indexAxis: 'y',
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
          legend: { display: true },
          tooltip: {
            callbacks: {
              label: (ctx) => {
                const x = (ctx.parsed as any)?.x;
                return ` ${this.money(typeof x === 'number' ? x : 0)}`;
              }
            }
          }
        },
        scales: {
          x: {
            ticks: {
              callback: (v: any) => this.money(Number(v) || 0)
            }
          }
        }
      }
    });
  }

  money(v: number) {
    return new Intl.NumberFormat('pt-BR', { style: 'currency', currency: 'BRL' }).format(v ?? 0);
  }

  private onlyDigits(s: string) {
    return (s ?? '').replace(/\D/g, '');
  }
}