import 'package:flutter/material.dart';
import 'package:uto_manager/domain/entities/unit_node.dart';
import 'package:uto_manager/domain/services/unit_tree_service.dart';

/// Displays a single unit node as a card in the org chart canvas.
///
/// Shows the unit's echelon, branch, name, and fill rate indicator.
class UnitNodeCard extends StatelessWidget {
  const UnitNodeCard({
    super.key,
    required this.treeNode,
    required this.isSelected,
    required this.onTap,
  });

  final UnitTreeNode treeNode;
  final bool isSelected;
  final VoidCallback onTap;

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

    return GestureDetector(
      onTap: onTap,
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 150),
        width: 160,
        decoration: BoxDecoration(
          color: isSelected
              ? theme.colorScheme.primaryContainer
              : theme.colorScheme.surfaceContainerHighest,
          border: Border.all(
            color: isSelected ? theme.colorScheme.primary : _echelonColor(unit),
            width: isSelected ? 2.5 : 1.5,
          ),
          borderRadius: BorderRadius.circular(6),
          boxShadow: isSelected
              ? [
                  BoxShadow(
                    color: theme.colorScheme.primary.withValues(alpha: 0.3),
                    blurRadius: 8,
                    offset: const Offset(0, 2),
                  ),
                ]
              : null,
        ),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            // Header: echelon badge
            Container(
              width: double.infinity,
              padding: const EdgeInsets.symmetric(vertical: 4, horizontal: 8),
              decoration: BoxDecoration(
                color: _echelonColor(unit).withValues(alpha: 0.85),
                borderRadius: const BorderRadius.vertical(top: Radius.circular(4)),
              ),
              child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  Text(
                    unit.echelon.displayName.toUpperCase(),
                    style: theme.textTheme.labelSmall?.copyWith(
                      color: Colors.white,
                      fontWeight: FontWeight.bold,
                      letterSpacing: 0.8,
                    ),
                  ),
                  Text(
                    unit.branch.displayName,
                    style: theme.textTheme.labelSmall?.copyWith(
                      color: Colors.white70,
                      fontSize: 9,
                    ),
                  ),
                ],
              ),
            ),
            // Body: unit name
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 6),
              child: Text(
                unit.name,
                style: theme.textTheme.bodySmall?.copyWith(
                  fontWeight: FontWeight.w600,
                  color: isSelected
                      ? theme.colorScheme.onPrimaryContainer
                      : theme.colorScheme.onSurface,
                ),
                maxLines: 2,
                overflow: TextOverflow.ellipsis,
                textAlign: TextAlign.center,
              ),
            ),
            // Footer: fill rate bar
            Padding(
              padding: const EdgeInsets.fromLTRB(8, 0, 8, 6),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      Text(
                        'Fill',
                        style: theme.textTheme.labelSmall?.copyWith(fontSize: 9),
                      ),
                      Text(
                        '${fillRate.toStringAsFixed(0)}%',
                        style: theme.textTheme.labelSmall?.copyWith(
                          fontSize: 9,
                          color: _fillRateColor(fillRate),
                          fontWeight: FontWeight.bold,
                        ),
                      ),
                    ],
                  ),
                  const SizedBox(height: 2),
                  ClipRRect(
                    borderRadius: BorderRadius.circular(2),
                    child: LinearProgressIndicator(
                      value: fillRate / 100.0,
                      minHeight: 4,
                      backgroundColor: theme.colorScheme.surfaceContainerLow,
                      valueColor: AlwaysStoppedAnimation<Color>(_fillRateColor(fillRate)),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  Color _echelonColor(UnitNode unit) {
    switch (unit.echelon.level) {
      case 1:
        return const Color(0xFF1B3A6B); // Brigade — Army blue
      case 2:
        return const Color(0xFF2E5FA3); // Battalion
      case 3:
        return const Color(0xFF3A7BD5); // Company
      case 4:
        return const Color(0xFF4A90D9); // Platoon
      case 5:
        return const Color(0xFF5BA3E0); // Section
      case 6:
        return const Color(0xFF6CB4E8); // Squad
      default:
        return const Color(0xFF7EC8F0); // Team
    }
  }

  Color _fillRateColor(double rate) {
    if (rate >= 90) return const Color(0xFF4CAF50); // Green
    if (rate >= 70) return const Color(0xFFFF9800); // Amber
    return const Color(0xFFF44336); // Red
  }
}