import 'package:flutter/services.dart' show rootBundle;
import 'package:pdf/pdf.dart' as pdf;
import 'package:pdf/widgets.dart' as pw;

/// Shared brand assets and letterhead widget for CRMC PDF documents.
class PdfBrand {
  final pw.Font regular;
  final pw.Font bold;
  final pw.ImageProvider logo;

  const PdfBrand({
    required this.regular,
    required this.bold,
    required this.logo,
  });

  /// Load fonts and logo from the Flutter asset bundle.
  static Future<PdfBrand> load() async {
    final logoData = await rootBundle.load('assets/crmc_logo.png');
    final logo = pw.MemoryImage(logoData.buffer.asUint8List());

    final regular = pw.Font.ttf(
      await rootBundle.load('assets/fonts/Roboto-Regular.ttf'),
    );
    final bold = pw.Font.ttf(
      await rootBundle.load('assets/fonts/Roboto-Bold.ttf'),
    );

    return PdfBrand(regular: regular, bold: bold, logo: logo);
  }

  /// Standard CRMC letterhead: 60×60 logo + four-line organisation text.
  pw.Widget letterhead() {
    return pw.Row(
      mainAxisAlignment: pw.MainAxisAlignment.center,
      crossAxisAlignment: pw.CrossAxisAlignment.center,
      children: [
        pw.Image(logo, width: 60, height: 60),
        pw.SizedBox(width: 16),
        pw.Column(
          crossAxisAlignment: pw.CrossAxisAlignment.center,
          children: [
            pw.Text(
              'Republic of the Philippines',
              style: pw.TextStyle(font: regular, fontSize: 9),
            ),
            pw.Text(
              'Department of Health',
              style: pw.TextStyle(font: regular, fontSize: 9),
            ),
            pw.Text(
              'Cotabato Regional and Medical Center',
              style: pw.TextStyle(font: regular, fontSize: 9),
            ),
            pw.SizedBox(height: 3),
            pw.Text(
              'Integrated Hospital Operations and Management Program (IHOMP)',
              style: pw.TextStyle(font: bold, fontSize: 9),
            ),
          ],
        ),
      ],
    );
  }

  /// Convenience: create a ThemeData from these fonts.
  pw.ThemeData theme() => pw.ThemeData.withFont(base: regular, bold: bold);

  /// Footer widget: right-aligned "Page x of y".
  pw.Widget pageFooter(pw.Context ctx) => pw.Align(
        alignment: pw.Alignment.centerRight,
        child: pw.Text(
          'Page ${ctx.pageNumber} of ${ctx.pagesCount}',
          style: pw.TextStyle(
            font: regular,
            fontSize: 8,
            color: pdf.PdfColors.grey600,
          ),
        ),
      );
}