import "dart:math" as math;

import "package:shadcn_flutter/shadcn_flutter.dart";


class PanelField {
  const PanelField({
    required this.section,
    required this.label,
    required this.child,
    this.enabled = true,
  });

  final String section;
  final Widget label;
  final Widget child;
  final bool enabled;
}

// auto groups fields by section string
class PanelList extends StatelessWidget {
  const PanelList({super.key, required this.fields});

  final List<PanelField> fields;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    final Map<String, List<PanelField>> grouped = {};
    for (final f in fields) {
      grouped.putIfAbsent(f.section, () => []).add(f);
    }

    final entries = grouped.entries.toList();

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        for (int i = 0; i < entries.length; i++) ...[
          PanelSection(
            title: entries[i].key,
            children: entries[i].value
                .map((f) => PanelRow(label: f.label, child: f.child, enabled: f.enabled))
                .toList(),
          ),

          if (i < entries.length - 1)
            Divider(color: theme.colorScheme.border, height: 1),
        ],
        Divider(color: theme.colorScheme.border, height: 1),
        const SizedBox(height: 10),
      ],
    );
  }
}


class PanelSection extends StatefulWidget {
  const PanelSection({
    super.key,
    required this.title,
    required this.children,
  });

  final String title;
  final List<Widget> children;

  @override
  State<PanelSection> createState() => _PanelSectionState();
}

class _PanelSectionState extends State<PanelSection> {
  bool _expanded = true;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [

        GestureDetector(
          onTap: () => setState(() => _expanded = !_expanded),
          behavior: HitTestBehavior.opaque,
          child: ColoredBox(
            color: theme.colorScheme.secondary,
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
              child: Row(
                children: [
                  AnimatedRotation(
                    turns: _expanded ? 0.0 : -0.25,
                    duration: const Duration(milliseconds: 120),
                    child: Icon(LucideIcons.chevronDown, size: 12, color: theme.colorScheme.mutedForeground),
                  ),
                  const SizedBox(width: 4),
                  Text(
                    widget.title,
                    style: TextStyle(
                      fontSize: 11,
                      fontWeight: FontWeight.w600,
                      color: theme.colorScheme.foreground,
                      letterSpacing: 0.4,
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),

        Divider(color: theme.colorScheme.border, height: 1),

        if (_expanded)
          Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              for (int i = 0; i < widget.children.length; i++) ...[
                widget.children[i],
                if (i < widget.children.length - 1)
                  Divider(color: theme.colorScheme.border, height: 1),
              ],
            ],
          ),
      ],
    );
  }
}


class PanelRow extends StatelessWidget {
  const PanelRow({super.key, required this.label, required this.child, this.enabled = true});

  final Widget label;
  final Widget child;
  final bool enabled;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return ConstrainedBox(
      constraints: const BoxConstraints(minHeight: 38),
      child: IntrinsicHeight(
        child: Padding(
          padding: const EdgeInsets.only(left: 12),
          child: Row(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [

              SizedBox(
                width: 120,
                child: Align(
                  alignment: Alignment.centerLeft,
                  child: Padding(
                    padding: const EdgeInsets.symmetric(vertical: 4),
                    child: DefaultTextStyle.merge(
                      style: TextStyle(
                        fontSize: 11,
                        color: theme.colorScheme.mutedForeground,
                        decoration: !enabled ? TextDecoration.lineThrough : null,
                        decorationThickness: !enabled ? 3 : null,
                      ),
                      child: label,
                    ),
                  ),
                ),
              ),

              VerticalDivider(color: theme.colorScheme.border, width: 1),

              Expanded(
                child: Stack(
                  children: [
                    Positioned.fill(
                      child: Padding(
                        padding: const EdgeInsets.symmetric(vertical: 4, horizontal: 8),
                        child: child,
                      ),
                    ),
                    if (!enabled)
                      Positioned.fill(
                        child: GestureDetector(
                          onTap: () {},
                          behavior: HitTestBehavior.opaque,
                          child: CustomPaint(
                            painter: _DisabledStripePainter(theme.colorScheme.border),
                          ),
                        ),
                      ),
                  ],
                ),
              ),

            ],
          ),
        ),
      ),
    );
  }
}


class _DisabledStripePainter extends CustomPainter {
  const _DisabledStripePainter(this.color);

  final Color color;

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = color.withValues(alpha: 1)
      ..strokeWidth = 1.0
      ..style = PaintingStyle.stroke;

    const spacing = 4.0;
    final diag = math.sqrt(size.width * size.width + size.height * size.height);
    final count = (diag / spacing).ceil() + 2;

    canvas.save();
    canvas.clipRect(Offset.zero & size);
    canvas.drawRect(Rect.fromLTWH(1, 1, size.width - 3, size.height - 2), paint);

    canvas.translate(0, size.height);
    canvas.rotate(-math.pi / 4);

    for (int i = -count; i <= count; i++) {
      final x = i * spacing;
      canvas.drawLine(Offset(x, -diag), Offset(x, diag), paint);
    }

    canvas.restore();
  }

  @override
  bool shouldRepaint(_DisabledStripePainter old) => old.color != color;
}