social-app/apps/lib/shared/widgets/ui_schema/ui_schema_renderer.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:go_router/go_router.dart';
import 'package:url_launcher/url_launcher.dart';

import 'package:social_app/core/l10n/l10n.dart';
import 'package:social_app/core/logging/logger.dart';
import 'package:social_app/core/theme/design_tokens.dart';
import 'package:social_app/core/ui_schema/navigation/ui_schema_navigation.dart';
import 'package:social_app/shared/widgets/toast/toast.dart';
import 'package:social_app/shared/widgets/toast/toast_type.dart';

const _titleFontSize = AppSpacing.xl + AppSpacing.xs;
const _subtitleFontSize = AppSpacing.lg + AppSpacing.xs / 2;
const _bodyFontSize = AppSpacing.md + AppSpacing.xs / 2;
const _captionFontSize = AppSpacing.md - AppSpacing.xs / 2;
const _codeFontSize = AppSpacing.md;
const _buttonFontSize = AppSpacing.md;
const _statusLabelTokenPrefix = 'ui.status.';

class UiSchemaRenderer {
  final BuildContext context;
  final ColorScheme colorScheme;
  final Logger _logger = getLogger('shared.widgets.ui_schema.renderer');

  UiSchemaRenderer(this.context, this.colorScheme);

  Widget renderSchema(Map<String, dynamic>? schema) {
    if (schema == null || schema.isEmpty) {
      return const SizedBox.shrink();
    }

    final root = _asMap(schema['root']);
    if (root == null) {
      return _fallback(L10n.current.uiSchemaInvalid);
    }

    final schemaStatus = _nodeStatus(root, _asString(schema['status']));
    final hero = _extractHeroHeader(root);
    final content = _buildRootContent(
      root: root,
      schemaStatus: schemaStatus,
      hero: hero,
    );

    return _buildRootShell(status: schemaStatus, child: content);
  }

  Widget _buildRootContent({
    required Map<String, dynamic> root,
    required String schemaStatus,
    required _HeroHeader hero,
  }) {
    final children = hero.remainingChildren;
    final gap = _asDouble(root['gap'], fallback: AppSpacing.lg);

    final blocks = <Widget>[];
    if (hero.hasContent) {
      blocks.add(_buildHeroHeader(hero: hero, status: schemaStatus));
    }
    if (children.isNotEmpty) {
      blocks.add(
        _renderLayoutContent(
          root,
          schemaStatus: schemaStatus,
          depth: 0,
          overrideChildren: children,
        ),
      );
    }

    if (blocks.isEmpty) {
      return const SizedBox.shrink();
    }

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: _withGap(blocks, gap),
    );
  }

  Widget _buildRootShell({required String status, required Widget child}) {
    final borderColor = _statusColor(status).withValues(alpha: 0.2);
    final ambientColor = colorScheme.shadow.withValues(alpha: 0.08);
    final highlightColor = _statusTint(status).withValues(alpha: 0.22);

    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(AppSpacing.xl),
      decoration: BoxDecoration(
        gradient: LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [
            colorScheme.surface.withValues(alpha: 0.98),
            colorScheme.surfaceContainerLow.withValues(alpha: 0.96),
            highlightColor,
          ],
        ),
        borderRadius: BorderRadius.circular(AppRadius.xxl),
        border: Border.all(color: borderColor),
        boxShadow: [
          BoxShadow(
            color: ambientColor,
            blurRadius: AppSpacing.xxl,
            offset: const Offset(0, AppSpacing.sm),
          ),
          BoxShadow(
            color: colorScheme.surface.withValues(alpha: 0.75),
            blurRadius: AppSpacing.sm,
            offset: const Offset(0, -1),
          ),
        ],
      ),
      child: child,
    );
  }

  _HeroHeader _extractHeroHeader(Map<String, dynamic> root) {
    if (_asString(root['type']) != 'stack' ||
        _asString(root['direction'], fallback: 'vertical') != 'vertical') {
      return _HeroHeader.empty(root);
    }

    final children = _visibleChildren(root);
    if (children.isEmpty) {
      return _HeroHeader.empty(root);
    }

    Map<String, dynamic>? titleNode;
    Map<String, dynamic>? badgeNode;
    Map<String, dynamic>? subtitleNode;
    Map<String, dynamic>? iconNode;
    var consumed = 0;

    final first = children.first;
    final firstType = _asString(first['type']);
    if (firstType == 'stack' &&
        _asString(first['direction'], fallback: 'horizontal') == 'horizontal') {
      final rowChildren = _visibleChildren(first);
      titleNode = _firstTextByRole(rowChildren, const {'title', 'subtitle'});
      badgeNode = _firstNodeByType(rowChildren, 'badge');
      iconNode = _firstNodeByType(rowChildren, 'icon');
      if (titleNode != null) {
        consumed = 1;
      }
    } else if (firstType == 'text' &&
        _isTextRole(first, const {'title', 'subtitle'})) {
      titleNode = first;
      consumed = 1;

      if (children.length > consumed && _asString(children[consumed]['type']) == 'badge') {
        badgeNode = children[consumed];
        consumed += 1;
      }
    }

    if (titleNode == null) {
      return _HeroHeader.empty(root);
    }

    if (children.length > consumed &&
        _asString(children[consumed]['type']) == 'text' &&
        _isTextRole(children[consumed], const {'body', 'caption'})) {
      subtitleNode = children[consumed];
      consumed += 1;
    }

    return _HeroHeader(
      titleNode: titleNode,
      badgeNode: badgeNode,
      subtitleNode: subtitleNode,
      iconNode: iconNode,
      remainingChildren: children.skip(consumed).toList(),
    );
  }

  Widget _buildHeroHeader({required _HeroHeader hero, required String status}) {
    final titleWidget = hero.titleNode == null
        ? const SizedBox.shrink()
        : _renderText(hero.titleNode!, inheritedStatus: status, emphasize: true);
    final badgeWidget = hero.badgeNode == null
        ? null
        : _renderBadge(hero.badgeNode!, inheritedStatus: status);
    final subtitleWidget = hero.subtitleNode == null
        ? null
        : _renderText(hero.subtitleNode!, inheritedStatus: status);
    final glyph = hero.iconNode == null
        ? _buildHeroGlyph(status: status)
        : _renderIcon(hero.iconNode!, inheritedStatus: status, heroStyle: true);
    final titleRowChildren = <Widget>[titleWidget];
    if (badgeWidget != null) {
      titleRowChildren.add(badgeWidget);
    }

    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        glyph,
        const SizedBox(width: AppSpacing.lg),
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Wrap(
                spacing: AppSpacing.sm,
                runSpacing: AppSpacing.sm,
                crossAxisAlignment: WrapCrossAlignment.center,
                children: titleRowChildren,
              ),
              if (subtitleWidget != null) ...[
                const SizedBox(height: AppSpacing.sm),
                subtitleWidget,
              ],
            ],
          ),
        ),
      ],
    );
  }

  Widget _buildHeroGlyph({required String status}) {
    final tint = _statusColor(status);
    return Container(
      width: AppSpacing.xxl + AppSpacing.xl,
      height: AppSpacing.xxl + AppSpacing.xl,
      decoration: BoxDecoration(
        gradient: LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [
            tint.withValues(alpha: 0.92),
            tint.withValues(alpha: 0.72),
          ],
        ),
        borderRadius: BorderRadius.circular(AppRadius.lg),
        boxShadow: [
          BoxShadow(
            color: tint.withValues(alpha: 0.22),
            blurRadius: AppSpacing.lg,
            offset: const Offset(0, AppSpacing.xs),
          ),
        ],
      ),
      child: Icon(
        _statusLeadingIcon(status),
        size: AppSpacing.xl,
        color: colorScheme.onPrimary,
      ),
    );
  }

  Widget _renderNode(
    Map<String, dynamic> node, {
    required String schemaStatus,
    required int depth,
  }) {
    if (node['visible'] == false) {
      return const SizedBox.shrink();
    }

    final type = _asString(node['type']);
    return switch (type) {
      'text' => _renderText(node, inheritedStatus: schemaStatus),
      'icon' => _renderIcon(node, inheritedStatus: schemaStatus),
      'badge' => _renderBadge(node, inheritedStatus: schemaStatus),
      'button' => _renderButton(node),
      'kv' => _renderKv(node, inheritedStatus: schemaStatus),
      'divider' => _renderDivider(node),
      'stack' => _renderStack(node, schemaStatus: schemaStatus, depth: depth),
      'grid' => _renderGrid(node, schemaStatus: schemaStatus, depth: depth),
      _ => _fallback(L10n.current.uiSchemaUnknownNode(type)),
    };
  }

  Widget _renderLayoutContent(
    Map<String, dynamic> node, {
    required String schemaStatus,
    required int depth,
    List<Map<String, dynamic>>? overrideChildren,
  }) {
    final type = _asString(node['type']);
    return switch (type) {
      'stack' => _buildStackContent(
          node,
          schemaStatus: schemaStatus,
          depth: depth,
          overrideChildren: overrideChildren,
        ),
      'grid' => _buildGridContent(
          node,
          schemaStatus: schemaStatus,
          depth: depth,
          overrideChildren: overrideChildren,
        ),
      _ => _fallback(L10n.current.uiSchemaUnsupportedLayout(type)),
    };
  }

  Widget _renderStack(
    Map<String, dynamic> node, {
    required String schemaStatus,
    required int depth,
  }) {
    final content = _buildStackContent(
      node,
      schemaStatus: schemaStatus,
      depth: depth,
    );
    return _wrapSurface(
      node,
      child: content,
      inheritedStatus: schemaStatus,
      depth: depth,
    );
  }

  Widget _buildStackContent(
    Map<String, dynamic> node, {
    required String schemaStatus,
    required int depth,
    List<Map<String, dynamic>>? overrideChildren,
  }) {
    final children = (overrideChildren ?? _visibleChildren(node))
        .map((child) => _renderNode(child, schemaStatus: schemaStatus, depth: depth + 1))
        .toList();
    final gap = _asDouble(node['gap'], fallback: AppSpacing.md);
    final direction = _asString(node['direction'], fallback: 'vertical');

    if (direction == 'horizontal') {
      final shouldWrap = node['wrap'] == true || _looksLikeActionRow(node);
      if (shouldWrap) {
        return Wrap(
          spacing: gap,
          runSpacing: gap,
          alignment: _wrapAlignment(_asString(node['justify'], fallback: 'start')),
          crossAxisAlignment: WrapCrossAlignment.center,
          children: children,
        );
      }

      return Row(
        mainAxisAlignment: _mainAxisAlignment(
          _asString(node['justify'], fallback: 'start'),
        ),
        crossAxisAlignment: _crossAxisAlignment(
          _asString(node['align'], fallback: 'center'),
        ),
        children: _withHorizontalGap(children, gap),
      );
    }

    final appearance = _asString(node['appearance'], fallback: 'plain');
    final isSection = appearance == 'section';
    final sectionTitle = isSection &&
            (overrideChildren ?? _visibleChildren(node)).isNotEmpty &&
            _asString((overrideChildren ?? _visibleChildren(node)).first['type']) == 'text' &&
            _isTextRole((overrideChildren ?? _visibleChildren(node)).first, const {'title'})
        ? (overrideChildren ?? _visibleChildren(node)).first
        : null;

    if (sectionTitle != null && children.isNotEmpty) {
      final promotedTitle = _buildSectionHeader(sectionTitle, schemaStatus);
      final remaining = children.skip(1).toList();
      return Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: _withGap([promotedTitle, ...remaining], gap),
      );
    }

    return Column(
      crossAxisAlignment: _columnCrossAxisAlignment(
        _asString(node['align'], fallback: 'start'),
      ),
      children: _withGap(children, gap),
    );
  }

  Widget _renderGrid(
    Map<String, dynamic> node, {
    required String schemaStatus,
    required int depth,
  }) {
    final content = _buildGridContent(
      node,
      schemaStatus: schemaStatus,
      depth: depth,
    );
    return _wrapSurface(
      node,
      child: content,
      inheritedStatus: schemaStatus,
      depth: depth,
    );
  }

  Widget _buildGridContent(
    Map<String, dynamic> node, {
    required String schemaStatus,
    required int depth,
    List<Map<String, dynamic>>? overrideChildren,
  }) {
    final children = (overrideChildren ?? _visibleChildren(node))
        .map((child) => _renderNode(child, schemaStatus: schemaStatus, depth: depth + 1))
        .toList();
    if (children.isEmpty) {
      return const SizedBox.shrink();
    }

    final gap = _asDouble(node['gap'], fallback: AppSpacing.md);
    final columns = _asInt(node['columns'], fallback: 2).clamp(1, 3);

    return LayoutBuilder(
      builder: (context, constraints) {
        final totalGap = gap * (columns - 1);
        final itemWidth = columns == 1
            ? constraints.maxWidth
            : (constraints.maxWidth - totalGap) / columns;

        return Wrap(
          spacing: gap,
          runSpacing: gap,
          children: children
              .map(
                (child) => SizedBox(
                  width: itemWidth,
                  child: _buildGridCell(child, schemaStatus),
                ),
              )
              .toList(),
        );
      },
    );
  }

  Widget _buildGridCell(Widget child, String status) {
    return Container(
      padding: const EdgeInsets.symmetric(
        horizontal: AppSpacing.md,
        vertical: AppSpacing.lg,
      ),
      decoration: BoxDecoration(
        color: colorScheme.surface.withValues(alpha: 0.84),
        borderRadius: BorderRadius.circular(AppRadius.lg),
        border: Border.all(
          color: _statusColor(status).withValues(alpha: 0.12),
        ),
      ),
      child: child,
    );
  }

  Widget _buildSectionHeader(Map<String, dynamic> node, String schemaStatus) {
    return Row(
      children: [
        Container(
          width: AppSpacing.sm,
          height: AppSpacing.xl,
          decoration: BoxDecoration(
            color: _statusColor(_nodeStatus(node, schemaStatus)),
            borderRadius: BorderRadius.circular(AppRadius.full),
          ),
        ),
        const SizedBox(width: AppSpacing.md),
        Expanded(
          child: _renderText(node, inheritedStatus: schemaStatus, emphasize: true),
        ),
      ],
    );
  }

  Widget _renderText(
    Map<String, dynamic> node, {
    required String inheritedStatus,
    bool emphasize = false,
  }) {
    final content = _asString(node['content']);
    if (content.isEmpty) {
      return const SizedBox.shrink();
    }

    final role = _asString(node['role'], fallback: 'body');
    final status = _nodeStatus(node, inheritedStatus);
    final style = switch (role) {
      'title' => TextStyle(
          fontSize: _titleFontSize,
          fontWeight: FontWeight.w700,
          height: 1.2,
          color: colorScheme.onSurface,
        ),
      'subtitle' => TextStyle(
          fontSize: _subtitleFontSize,
          fontWeight: FontWeight.w600,
          height: 1.25,
          color: colorScheme.onSurface,
        ),
      'caption' => TextStyle(
          fontSize: _captionFontSize,
          fontWeight: emphasize ? FontWeight.w600 : FontWeight.w500,
          height: 1.35,
          color: colorScheme.onSurfaceVariant,
        ),
      'code' => TextStyle(
          fontSize: _codeFontSize,
          fontFamily: 'monospace',
          fontWeight: FontWeight.w500,
          height: 1.3,
          color: colorScheme.onSurfaceVariant,
        ),
      _ => TextStyle(
          fontSize: _bodyFontSize,
          fontWeight: emphasize ? FontWeight.w600 : FontWeight.w500,
          height: 1.4,
          color: colorScheme.onSurfaceVariant,
        ),
    };

    return Text(
      content,
      maxLines: _asIntOrNull(node['maxLines']),
      overflow: TextOverflow.ellipsis,
      style: style.copyWith(color: _statusTextColor(status, style.color)),
    );
  }

  Widget _renderIcon(
    Map<String, dynamic> node, {
    required String inheritedStatus,
    bool heroStyle = false,
  }) {
    final status = _nodeStatus(node, inheritedStatus);
    final source = _asString(node['source'], fallback: 'icon');
    final value = _asString(node['value']);
    final size = _asDouble(
      node['size'],
      fallback: heroStyle ? AppSpacing.xl : AppSpacing.lg + AppSpacing.xs,
    );

    if (source == 'emoji' && value.isNotEmpty) {
      return Text(value, style: TextStyle(fontSize: size));
    }

    final icon = _iconForValue(value, fallbackStatus: status);
    final tint = _statusColor(status);
    final containerSize = heroStyle
        ? AppSpacing.xxl + AppSpacing.xl
        : AppSpacing.xxl + AppSpacing.sm;

    return Container(
      width: containerSize,
      height: containerSize,
      decoration: BoxDecoration(
        color: colorScheme.surface.withValues(alpha: 0.92),
        shape: BoxShape.circle,
        border: Border.all(color: tint.withValues(alpha: 0.2)),
      ),
      child: Icon(icon, size: size, color: tint),
    );
  }

  Widget _renderBadge(
    Map<String, dynamic> node, {
    required String inheritedStatus,
  }) {
    final status = _nodeStatus(node, inheritedStatus);
    final resolvedLabel = _resolveStatusLabel(
      rawLabel: _asString(node['label']),
      status: status,
    );

    final tint = _statusColor(status);
    return Container(
      padding: const EdgeInsets.symmetric(
        horizontal: AppSpacing.md,
        vertical: AppSpacing.sm,
      ),
      decoration: BoxDecoration(
        color: tint.withValues(alpha: 0.08),
        borderRadius: BorderRadius.circular(AppRadius.md),
        border: Border.all(color: tint.withValues(alpha: 0.2)),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(
            _statusBadgeIcon(status),
            size: AppSpacing.md + AppSpacing.xs,
            color: tint,
          ),
          const SizedBox(width: AppSpacing.xs + AppSpacing.xs / 2),
          Text(
            resolvedLabel,
            style: TextStyle(
              fontSize: _captionFontSize,
              fontWeight: FontWeight.w700,
              color: tint,
            ),
          ),
        ],
      ),
    );
  }

  Widget _renderButton(Map<String, dynamic> node) {
    final style = _asString(node['style'], fallback: 'secondary');
    final action = _asMap(node['action']);
    final disabled = node['disabled'] == true;
    final isPrimary = style == 'primary';
    final isGhost = style == 'ghost';
    final isDanger = style == 'danger';

    final backgroundColor = isPrimary
        ? colorScheme.primary
        : isDanger
            ? colorScheme.errorContainer
            : isGhost
                ? colorScheme.surface.withValues(alpha: 0.88)
                : colorScheme.primaryContainer.withValues(alpha: 0.55);
    final foregroundColor = isPrimary
        ? colorScheme.onPrimary
        : isDanger
            ? colorScheme.onErrorContainer
            : isGhost
                ? colorScheme.onSurfaceVariant
                : colorScheme.onPrimaryContainer;
    final borderColor = isPrimary
        ? colorScheme.primary.withValues(alpha: 0.18)
        : isDanger
            ? colorScheme.error.withValues(alpha: 0.2)
            : colorScheme.primary.withValues(alpha: 0.14);

    return ElevatedButton(
      onPressed: disabled
          ? null
          : () async {
              await _handleAction(action);
            },
      style: ElevatedButton.styleFrom(
        elevation: 0,
        backgroundColor: backgroundColor,
        foregroundColor: foregroundColor,
        disabledBackgroundColor: colorScheme.surfaceContainer,
        disabledForegroundColor: colorScheme.onSurfaceVariant,
        padding: const EdgeInsets.symmetric(
          horizontal: AppSpacing.lg,
          vertical: AppSpacing.md,
        ),
        minimumSize: const Size(0, AppSpacing.xxl + AppSpacing.sm),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(AppRadius.full),
          side: BorderSide(color: borderColor),
        ),
      ),
      child: Text(
        _asString(node['label'], fallback: L10n.current.uiSchemaActionFallback),
        style: TextStyle(
          fontSize: _buttonFontSize,
          fontWeight: FontWeight.w700,
        ),
      ),
    );
  }

  Future<void> _handleAction(Map<String, dynamic>? action) async {
    if (action == null || action.isEmpty) {
      Toast.show(
        context,
        L10n.current.uiSchemaActionNotImplemented,
        type: ToastType.warning,
      );
      return;
    }

    final type = _asString(action['type']);
    switch (type) {
      case 'navigation':
        _handleNavigationAction(action);
        return;
      case 'url':
        await _handleUrlAction(action);
        return;
      case 'copy':
        _handleCopyAction(action);
        return;
      case 'event':
      case 'tool':
      case 'payload':
      default:
        Toast.show(
          context,
          L10n.current.uiSchemaActionNotImplemented,
          type: ToastType.info,
        );
    }
  }

  Future<void> _handleUrlAction(Map<String, dynamic> action) async {
    final rawUrl = _asString(action['url']).trim();
    if (!_isValidExternalUrl(rawUrl)) {
      Toast.show(
        context,
        L10n.current.uiSchemaUrlInvalid,
        type: ToastType.error,
      );
      return;
    }

    final uri = Uri.tryParse(rawUrl);
    if (uri == null) {
      Toast.show(
        context,
        L10n.current.uiSchemaUrlInvalid,
        type: ToastType.error,
      );
      return;
    }

    final target = _asString(action['target'], fallback: '_blank');
    final mode = target == '_self'
        ? LaunchMode.platformDefault
        : LaunchMode.externalApplication;

    try {
      final launched = await launchUrl(uri, mode: mode);
      if (!context.mounted) {
        return;
      }
      if (!launched) {
        _logger.error(
          message: 'UI schema URL launch returned false',
          error: StateError('launchUrl returned false'),
          stackTrace: StackTrace.current,
        );
        Toast.show(
          context,
          L10n.current.uiSchemaUrlOpenFailed,
          type: ToastType.error,
        );
      }
    } catch (error, stackTrace) {
      _logger.error(
        message: 'UI schema URL launch failed',
        error: error,
        stackTrace: stackTrace,
      );
      if (!context.mounted) {
        return;
      }
      Toast.show(
        context,
        L10n.current.uiSchemaUrlOpenFailed,
        type: ToastType.error,
      );
    }
  }

  void _handleNavigationAction(Map<String, dynamic> action) {
    final path = _asString(action['path']).trim();
    if (!isValidInternalNavigationPath(path)) {
      Toast.show(
        context,
        L10n.current.uiSchemaNavigationInvalidPath,
        type: ToastType.error,
      );
      return;
    }

    final params = _asMap(action['params']);
    if (params != null && !_areScalarNavigationParams(params)) {
      Toast.show(
        context,
        L10n.current.uiSchemaNavigationInvalidParams,
        type: ToastType.error,
      );
      return;
    }

    final target = buildUiSchemaNavigationTarget(path: path, params: params);

    try {
      context.push(target);
    } catch (error, stackTrace) {
      _logger.error(
        message: 'UI schema navigation failed',
        error: error,
        stackTrace: stackTrace,
      );
      Toast.show(
        context,
        L10n.current.uiSchemaNavigationInvalidPath,
        type: ToastType.error,
      );
    }
  }

  void _handleCopyAction(Map<String, dynamic> action) {
    final content = _asString(action['content']);
    if (content.isEmpty) {
      Toast.show(
        context,
        L10n.current.uiSchemaActionNotImplemented,
        type: ToastType.warning,
      );
      return;
    }

    Clipboard.setData(ClipboardData(text: content));
    final successMessage = _asString(
      action['successMessage'],
      fallback: L10n.current.commonCopySuccess,
    );
    Toast.show(context, successMessage, type: ToastType.success);
  }

  static bool _isValidExternalUrl(String url) {
    if (url.isEmpty) return false;
    final uri = Uri.tryParse(url);
    if (uri == null || !uri.hasScheme) return false;
    final scheme = uri.scheme.toLowerCase();
    if (scheme == 'http' || scheme == 'https') {
      if (uri.host.isEmpty || uri.userInfo.isNotEmpty) {
        return false;
      }
      if (_isLocalOrPrivateHost(uri.host)) {
        return false;
      }
      return true;
    }

    return scheme == 'mailto' || scheme == 'tel' || scheme == 'sms';
  }

  static bool _areScalarNavigationParams(Map<String, dynamic> params) {
    for (final value in params.values) {
      if (value is String || value is num || value is bool) {
        continue;
      }
      return false;
    }
    return true;
  }

  static bool _isLocalOrPrivateHost(String host) {
    final normalizedHost = host.toLowerCase();
    if (normalizedHost.contains(':')) {
      return true;
    }
    if (int.tryParse(normalizedHost) != null) {
      return true;
    }
    if (normalizedHost == 'localhost' ||
        normalizedHost == '127.0.0.1' ||
        normalizedHost == '::1') {
      return true;
    }

    final ipv4 = normalizedHost.split('.');
    if (ipv4.length != 4) {
      return false;
    }

    final octets = <int>[];
    for (final part in ipv4) {
      final parsed = int.tryParse(part);
      if (parsed == null || parsed < 0 || parsed > 255) {
        return false;
      }
      octets.add(parsed);
    }

    final first = octets[0];
    final second = octets[1];
    if (first == 10 || first == 127 || first == 0) {
      return true;
    }
    if (first == 169 && second == 254) {
      return true;
    }
    if (first == 192 && second == 168) {
      return true;
    }
    if (first == 172 && second >= 16 && second <= 31) {
      return true;
    }
    return false;
  }

  Widget _renderKv(
    Map<String, dynamic> node, {
    required String inheritedStatus,
  }) {
    final items = _asList(node['items']).whereType<Map<String, dynamic>>().toList();
    if (items.isEmpty) {
      return const SizedBox.shrink();
    }

    final columns = _asInt(node['columns'], fallback: 1).clamp(1, 2);
    final gap = AppSpacing.md;

    return LayoutBuilder(
      builder: (context, constraints) {
        final totalGap = gap * (columns - 1);
        final itemWidth = columns == 1
            ? constraints.maxWidth
            : (constraints.maxWidth - totalGap) / columns;

        return Wrap(
          spacing: gap,
          runSpacing: gap,
          children: items
              .map(
                (item) => SizedBox(
                  width: itemWidth,
                  child: _buildKvItem(item, inheritedStatus),
                ),
              )
              .toList(),
        );
      },
    );
  }

  Widget _buildKvItem(Map<String, dynamic> item, String inheritedStatus) {
    final label = _asString(item['label'], fallback: _asString(item['key']));
    final value = item['value']?.toString() ?? '-';
    final copyable = item['copyable'] == true;

    return Container(
      padding: const EdgeInsets.all(AppSpacing.md),
      decoration: BoxDecoration(
        color: colorScheme.surface.withValues(alpha: 0.88),
        borderRadius: BorderRadius.circular(AppRadius.lg),
        border: Border.all(
          color: _statusColor(inheritedStatus).withValues(alpha: 0.1),
        ),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(
            label,
            style: TextStyle(
              fontSize: _captionFontSize,
              fontWeight: FontWeight.w600,
              color: colorScheme.onSurfaceVariant,
            ),
          ),
          const SizedBox(height: AppSpacing.sm),
          Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Expanded(
                child: Text(
                  value,
                  style: TextStyle(
                    fontSize: _bodyFontSize,
                    fontWeight: FontWeight.w600,
                    color: colorScheme.onSurface,
                    height: 1.35,
                  ),
                ),
              ),
              if (copyable) ...[
                const SizedBox(width: AppSpacing.sm),
                InkWell(
                  borderRadius: BorderRadius.circular(AppRadius.full),
                  onTap: () {
                    _handleCopyAction({'content': value});
                  },
                  child: Padding(
                    padding: const EdgeInsets.all(AppSpacing.xs),
                    child: Icon(
                      Icons.content_copy_rounded,
                      size: AppSpacing.md + AppSpacing.xs,
                      color: colorScheme.onSurfaceVariant,
                    ),
                  ),
                ),
              ],
            ],
          ),
        ],
      ),
    );
  }

  Widget _renderDivider(Map<String, dynamic> node) {
    final inset = _asDouble(node['inset'], fallback: 0);
    return Padding(
      padding: EdgeInsets.symmetric(horizontal: inset),
      child: Container(
        height: 1,
        decoration: BoxDecoration(
          gradient: LinearGradient(
            colors: [
              colorScheme.primary.withValues(alpha: 0.0),
              colorScheme.primary.withValues(alpha: 0.14),
              colorScheme.primary.withValues(alpha: 0.0),
            ],
          ),
        ),
      ),
    );
  }

  Widget _wrapSurface(
    Map<String, dynamic> node, {
    required Widget child,
    required String inheritedStatus,
    required int depth,
  }) {
    final appearance = _asString(node['appearance'], fallback: 'plain');
    if (appearance == 'plain') {
      return child;
    }

    final status = _nodeStatus(node, inheritedStatus);
    final tint = _statusColor(status);
    final isSection = appearance == 'section';
    final background = isSection
        ? colorScheme.surface.withValues(alpha: 0.55)
        : colorScheme.surfaceContainerLow.withValues(alpha: 0.78);
    final shadowColor = colorScheme.shadow.withValues(
      alpha: isSection ? 0.03 : 0.06,
    );

    return Container(
      width: double.infinity,
      padding: EdgeInsets.all(isSection ? AppSpacing.lg : AppSpacing.xl),
      decoration: BoxDecoration(
        color: background,
        borderRadius: BorderRadius.circular(
          isSection ? AppRadius.xl : AppRadius.xxl,
        ),
        border: Border.all(color: tint.withValues(alpha: 0.12)),
        boxShadow: [
          BoxShadow(
            color: shadowColor,
            blurRadius: depth <= 1 ? AppSpacing.xl : AppSpacing.md,
            offset: const Offset(0, AppSpacing.xs),
          ),
        ],
      ),
      child: child,
    );
  }

  Widget _fallback(String text) {
    return Container(
      padding: const EdgeInsets.all(AppSpacing.md),
      decoration: BoxDecoration(
        color: colorScheme.secondaryContainer,
        border: Border.all(color: colorScheme.secondary),
        borderRadius: BorderRadius.circular(AppRadius.md),
      ),
      child: Text(
        text,
        style: TextStyle(
          fontSize: _buttonFontSize,
          color: colorScheme.onSecondaryContainer,
        ),
      ),
    );
  }

  List<Widget> _withGap(List<Widget> widgets, double gap) {
    if (widgets.isEmpty) {
      return const [];
    }

    return [
      widgets.first,
      for (var i = 1; i < widgets.length; i++) ...[
        SizedBox(height: gap),
        widgets[i],
      ],
    ];
  }

  List<Widget> _withHorizontalGap(List<Widget> widgets, double gap) {
    if (widgets.isEmpty) {
      return const [];
    }

    return [
      widgets.first,
      for (var i = 1; i < widgets.length; i++) ...[
        SizedBox(width: gap),
        widgets[i],
      ],
    ];
  }

  List<Map<String, dynamic>> _visibleChildren(Map<String, dynamic> node) {
    return _asList(node['children'])
        .whereType<Map<String, dynamic>>()
        .where((child) => child['visible'] != false)
        .toList();
  }

  Map<String, dynamic>? _firstNodeByType(
    List<Map<String, dynamic>> nodes,
    String type,
  ) {
    for (final node in nodes) {
      if (_asString(node['type']) == type) {
        return node;
      }
    }
    return null;
  }

  Map<String, dynamic>? _firstTextByRole(
    List<Map<String, dynamic>> nodes,
    Set<String> roles,
  ) {
    for (final node in nodes) {
      if (_asString(node['type']) == 'text' && _isTextRole(node, roles)) {
        return node;
      }
    }
    return null;
  }

  bool _isTextRole(Map<String, dynamic> node, Set<String> roles) {
    return roles.contains(_asString(node['role'], fallback: 'body'));
  }

  bool _looksLikeActionRow(Map<String, dynamic> node) {
    final children = _visibleChildren(node);
    return children.isNotEmpty &&
        children.every((child) => _asString(child['type']) == 'button');
  }

  MainAxisAlignment _mainAxisAlignment(String justify) {
    return switch (justify) {
      'center' => MainAxisAlignment.center,
      'end' => MainAxisAlignment.end,
      'space-between' => MainAxisAlignment.spaceBetween,
      _ => MainAxisAlignment.start,
    };
  }

  CrossAxisAlignment _crossAxisAlignment(String align) {
    return switch (align) {
      'start' => CrossAxisAlignment.start,
      'end' => CrossAxisAlignment.end,
      'stretch' => CrossAxisAlignment.stretch,
      _ => CrossAxisAlignment.center,
    };
  }

  CrossAxisAlignment _columnCrossAxisAlignment(String align) {
    return switch (align) {
      'center' => CrossAxisAlignment.center,
      'end' => CrossAxisAlignment.end,
      'stretch' => CrossAxisAlignment.stretch,
      _ => CrossAxisAlignment.start,
    };
  }

  WrapAlignment _wrapAlignment(String justify) {
    return switch (justify) {
      'center' => WrapAlignment.center,
      'end' => WrapAlignment.end,
      'space-between' => WrapAlignment.spaceBetween,
      _ => WrapAlignment.start,
    };
  }

  Color _statusTint(String status) {
    return switch (status) {
      'success' => colorScheme.primaryContainer,
      'warning' => colorScheme.secondaryContainer,
      'error' => colorScheme.errorContainer,
      'pending' => colorScheme.primaryContainer,
      _ => colorScheme.primaryContainer,
    };
  }

  Color _statusColor(String status) {
    return switch (status) {
      'success' => colorScheme.primary,
      'warning' => colorScheme.secondary,
      'error' => colorScheme.error,
      'pending' => colorScheme.tertiary,
      _ => colorScheme.primary,
    };
  }

  Color? _statusTextColor(String status, Color? fallback) {
    return switch (status) {
      'success' => colorScheme.onSurface,
      'warning' => colorScheme.onSurface,
      'error' => colorScheme.onErrorContainer,
      'pending' => colorScheme.onTertiaryContainer,
      _ => fallback,
    };
  }

  IconData _statusLeadingIcon(String status) {
    return switch (status) {
      'success' => Icons.task_alt_rounded,
      'warning' => Icons.priority_high_rounded,
      'error' => Icons.error_outline_rounded,
      'pending' => Icons.hourglass_bottom_rounded,
      _ => Icons.bolt_rounded,
    };
  }

  IconData _statusBadgeIcon(String status) {
    return switch (status) {
      'success' => Icons.check_circle_outline_rounded,
      'warning' => Icons.info_outline_rounded,
      'error' => Icons.error_outline_rounded,
      'pending' => Icons.schedule_rounded,
      _ => Icons.fiber_manual_record_rounded,
    };
  }

  IconData _iconForValue(String value, {required String fallbackStatus}) {
    final normalized = value.trim().toLowerCase();
    return switch (normalized) {
      'calendar' || 'event' || 'schedule' => Icons.calendar_month_rounded,
      'delete' || 'remove' => Icons.event_busy_rounded,
      'summary' || 'document' => Icons.article_outlined,
      'list' || 'items' => Icons.view_list_rounded,
      'success' => Icons.task_alt_rounded,
      'warning' => Icons.priority_high_rounded,
      'error' => Icons.error_outline_rounded,
      _ => _statusLeadingIcon(fallbackStatus),
    };
  }

  String _nodeStatus(Map<String, dynamic> node, String fallback) {
    final status = _asString(node['status']).trim().toLowerCase();
    if (status == 'partial') {
      return 'warning';
    }
    return status.isEmpty ? fallback : status;
  }

  String _resolveStatusLabel({required String rawLabel, required String status}) {
    final normalizedStatus = status.trim().toLowerCase();
    final normalizedLabel = rawLabel.trim().toLowerCase();
    final bareLabel = normalizedLabel.startsWith(_statusLabelTokenPrefix)
        ? normalizedLabel.substring(_statusLabelTokenPrefix.length)
        : normalizedLabel;

    final isTokenLabel = normalizedLabel.startsWith(_statusLabelTokenPrefix);
    final isLegacyStatusLabel = bareLabel == normalizedStatus;

    if (isTokenLabel || isLegacyStatusLabel) {
      return _tryLocalizedStatusLabel(bareLabel) ?? rawLabel;
    }
    return rawLabel;
  }

  String? _tryLocalizedStatusLabel(String status) {
    final l10n = L10n.current;
    return switch (status) {
      'success' => l10n.uiSchemaStatusSuccess,
      'warning' => l10n.uiSchemaStatusWarning,
      'error' => l10n.uiSchemaStatusError,
      'pending' => l10n.uiSchemaStatusPending,
      'info' => l10n.uiSchemaStatusInfo,
      _ => null,
    };
  }

  static Map<String, dynamic>? _asMap(Object? value) {
    if (value is Map<String, dynamic>) {
      return value;
    }
    if (value is Map) {
      return Map<String, dynamic>.from(value);
    }
    return null;
  }

  static List<dynamic> _asList(Object? value) {
    return value is List ? value : const [];
  }

  static String _asString(Object? value, {String fallback = ''}) {
    return value is String ? value : fallback;
  }

  static int _asInt(Object? value, {int fallback = 0}) {
    if (value is int) {
      return value;
    }
    if (value is double) {
      return value.toInt();
    }
    if (value is String) {
      return int.tryParse(value) ?? fallback;
    }
    return fallback;
  }

  static int? _asIntOrNull(Object? value) {
    if (value == null) {
      return null;
    }
    return _asInt(value);
  }

  static double _asDouble(Object? value, {double fallback = 0}) {
    if (value is double) {
      return value;
    }
    if (value is int) {
      return value.toDouble();
    }
    if (value is String) {
      return double.tryParse(value) ?? fallback;
    }
    return fallback;
  }
}

class _HeroHeader {
  final Map<String, dynamic>? titleNode;
  final Map<String, dynamic>? badgeNode;
  final Map<String, dynamic>? subtitleNode;
  final Map<String, dynamic>? iconNode;
  final List<Map<String, dynamic>> remainingChildren;

  const _HeroHeader({
    required this.titleNode,
    required this.badgeNode,
    required this.subtitleNode,
    required this.iconNode,
    required this.remainingChildren,
  });

  factory _HeroHeader.empty(Map<String, dynamic> root) {
    final children = (root['children'] as List?)
            ?.whereType<Map<String, dynamic>>()
            .where((child) => child['visible'] != false)
            .toList() ??
        const [];
    return _HeroHeader(
      titleNode: null,
      badgeNode: null,
      subtitleNode: null,
      iconNode: null,
      remainingChildren: children,
    );
  }

  bool get hasContent => titleNode != null;
}