pdf_signature/lib/ui/features/pdf/widgets/signature_drawer.dart

import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:pdf_signature/l10n/app_localizations.dart';

import '../../../../data/services/providers.dart';
import '../view_model/view_model.dart';
import 'adjustments_panel.dart';

/// Data passed when dragging a signature card.
class SignatureDragData {
  const SignatureDragData();
}

class SignatureDrawer extends ConsumerStatefulWidget {
  const SignatureDrawer({
    super.key,
    required this.disabled,
    required this.onLoadSignatureFromFile,
    required this.onOpenDrawCanvas,
  });

  final bool disabled;
  final VoidCallback onLoadSignatureFromFile;
  final VoidCallback onOpenDrawCanvas;

  @override
  ConsumerState<SignatureDrawer> createState() => _SignatureDrawerState();
}

class _SignatureDrawerState extends ConsumerState<SignatureDrawer> {
  @override
  Widget build(BuildContext context) {
    final l = AppLocalizations.of(context);
    final sig = ref.watch(signatureProvider);
    final processed = ref.watch(processedSignatureImageProvider);
    final bytes = processed ?? sig.imageBytes;
    final isExporting = ref.watch(exportingProvider);
    final disabled = widget.disabled || isExporting;

    return Card(
      margin: EdgeInsets.zero,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          // Header
          Padding(
            padding: const EdgeInsets.fromLTRB(12, 12, 12, 8),
            child: Text(
              l.signature,
              style: Theme.of(context).textTheme.titleSmall,
            ),
          ),
          // Existing signature card (draggable when bytes available)
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 12),
            child: DecoratedBox(
              decoration: BoxDecoration(
                border: Border.all(color: Theme.of(context).dividerColor),
                borderRadius: BorderRadius.circular(8),
              ),
              child: SizedBox(
                height: 120,
                child:
                    bytes == null
                        ? Center(
                          child: Text(
                            l.noPdfLoaded,
                            textAlign: TextAlign.center,
                          ),
                        )
                        : _DraggableSignaturePreview(
                          bytes: bytes,
                          disabled: disabled,
                        ),
              ),
            ),
          ),
          // Actions under the card
          if (bytes != null)
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 8),
              child: Row(
                children: [
                  PopupMenuButton<String>(
                    key: const Key('popup_signature_card'),
                    tooltip: l.settings,
                    onSelected: (v) {
                      switch (v) {
                        case 'delete':
                          ref
                              .read(signatureProvider.notifier)
                              .clearActiveOverlay();
                          ref.read(signatureProvider.notifier).clearImage();
                          break;
                        default:
                          break;
                      }
                    },
                    itemBuilder:
                        (ctx) => [
                          PopupMenuItem(
                            key: const Key('mi_signature_delete'),
                            value: 'delete',
                            child: Text(l.delete),
                          ),
                        ],
                    child: IconButton(
                      icon: const Icon(Icons.more_horiz),
                      onPressed: disabled ? null : () {},
                    ),
                  ),
                  const SizedBox(width: 4),
                  Text(AppLocalizations.of(context).createNewSignature),
                ],
              ),
            ),
          const SizedBox(height: 12),
          const Divider(height: 1),
          // New signature card
          Padding(
            padding: const EdgeInsets.all(12),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                Text(
                  l.createNewSignature,
                  style: Theme.of(context).textTheme.titleSmall,
                ),
                const SizedBox(height: 8),
                Wrap(
                  spacing: 8,
                  runSpacing: 8,
                  children: [
                    OutlinedButton.icon(
                      key: const Key('btn_drawer_load_signature'),
                      onPressed:
                          disabled ? null : widget.onLoadSignatureFromFile,
                      icon: const Icon(Icons.image_outlined),
                      label: Text(l.loadSignatureFromFile),
                    ),
                    OutlinedButton.icon(
                      key: const Key('btn_drawer_draw_signature'),
                      onPressed: disabled ? null : widget.onOpenDrawCanvas,
                      icon: const Icon(Icons.gesture),
                      label: Text(l.drawSignature),
                    ),
                  ],
                ),
              ],
            ),
          ),
          const Divider(height: 1),
          Expanded(
            child: SingleChildScrollView(
              padding: const EdgeInsets.all(12),
              child: AdjustmentsPanel(sig: sig),
            ),
          ),
        ],
      ),
    );
  }
}

class _DraggableSignaturePreview extends StatelessWidget {
  const _DraggableSignaturePreview({
    required this.bytes,
    required this.disabled,
  });
  final Uint8List bytes;
  final bool disabled;

  @override
  Widget build(BuildContext context) {
    final child = Padding(
      padding: const EdgeInsets.all(8.0),
      child: Image.memory(bytes, fit: BoxFit.contain),
    );
    if (disabled) return child;
    return Draggable<SignatureDragData>(
      data: const SignatureDragData(),
      feedback: Opacity(
        opacity: 0.8,
        child: ConstrainedBox(
          constraints: const BoxConstraints.tightFor(width: 160, height: 80),
          child: DecoratedBox(
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(6),
              boxShadow: const [
                BoxShadow(blurRadius: 8, color: Colors.black26),
              ],
            ),
            child: Padding(
              padding: const EdgeInsets.all(6.0),
              child: Image.memory(bytes, fit: BoxFit.contain),
            ),
          ),
        ),
      ),
      childWhenDragging: Opacity(opacity: 0.5, child: child),
      child: child,
    );
  }
}