import 'package:flutter/material.dart';
import 'package:uto_manager/domain/entities/personnel_record.dart';
import 'package:uto_manager/domain/entities/position_slot.dart';

/// Displays a single position slot as a card in the inspector panel.
///
/// Shows the slot's position title, MOS, rank, and assigned soldier (or VACANT).
/// Supports drag-and-drop target for soldier assignment.
class PositionSlotCard extends StatelessWidget {
  const PositionSlotCard({
    required this.slot,
    super.key,
    this.assignedSoldier,
    this.onUnassign,
    this.onAcceptDrop,
    this.onEdit,
    this.onDelete,
  });

  final PositionSlot slot;
  final PersonnelRecord? assignedSoldier;
  final VoidCallback? onUnassign;
  final void Function(PersonnelRecord soldier)? onAcceptDrop;

  /// Called when the user taps the edit button on this slot.
  final VoidCallback? onEdit;

  /// Called when the user taps the delete button on this slot.
  final VoidCallback? onDelete;

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

    return DragTarget<PersonnelRecord>(
      onWillAcceptWithDetails: (details) => slot.isVacant,
      onAcceptWithDetails: (details) => onAcceptDrop?.call(details.data),
      builder: (context, candidateData, rejectedData) {
        final isDragOver = candidateData.isNotEmpty;
        return AnimatedContainer(
          duration: const Duration(milliseconds: 120),
          margin: const EdgeInsets.symmetric(vertical: 3, horizontal: 8),
          decoration: BoxDecoration(
            color: isDragOver
                ? theme.colorScheme.primaryContainer.withValues(alpha: 0.6)
                : slot.isFilled
                    ? theme.colorScheme.surfaceContainerHighest
                    : theme.colorScheme.surfaceContainerLow,
            border: Border.all(
              color: isDragOver
                  ? theme.colorScheme.primary
                  : slot.isKeyLeader
                      ? const Color(0xFFFFD700) // Gold for key leaders
                      : theme.colorScheme.outlineVariant,
              width: isDragOver ? 2 : 1,
            ),
            borderRadius: BorderRadius.circular(6),
          ),
          child: ListTile(
            dense: true,
            contentPadding: const EdgeInsets.symmetric(horizontal: 10, vertical: 2),
            leading: _buildMosBadge(theme),
            title: Text(
              slot.positionTitle,
              style: theme.textTheme.bodySmall?.copyWith(
                fontWeight: slot.isKeyLeader ? FontWeight.bold : FontWeight.normal,
              ),
            ),
            subtitle: Text(
              slot.isFilled ? (assignedSoldier?.name ?? 'Assigned') : 'VACANT',
              style: theme.textTheme.labelSmall?.copyWith(
                color: slot.isFilled
                    ? _readinessColor(assignedSoldier?.readinessState)
                    : theme.colorScheme.error,
                fontWeight: slot.isVacant ? FontWeight.bold : FontWeight.normal,
              ),
            ),
            trailing: _buildTrailing(theme),
          ),
        );
      },
    );
  }

  Widget? _buildTrailing(ThemeData theme) {
    final hasActions = onUnassign != null || onEdit != null || onDelete != null;
    if (!hasActions) return null;

    return Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        if (slot.isFilled && onUnassign != null)
          IconButton(
            icon: const Icon(Icons.person_remove, size: 15),
            onPressed: onUnassign,
            tooltip: 'Unassign soldier',
            padding: EdgeInsets.zero,
            constraints: const BoxConstraints(minWidth: 26, minHeight: 26),
          ),
        if (onEdit != null)
          IconButton(
            icon: const Icon(Icons.edit_outlined, size: 15),
            onPressed: onEdit,
            tooltip: 'Edit slot',
            padding: EdgeInsets.zero,
            constraints: const BoxConstraints(minWidth: 26, minHeight: 26),
          ),
        if (onDelete != null)
          IconButton(
            icon: Icon(Icons.delete_outline, size: 15, color: theme.colorScheme.error),
            onPressed: onDelete,
            tooltip: 'Delete slot',
            padding: EdgeInsets.zero,
            constraints: const BoxConstraints(minWidth: 26, minHeight: 26),
          ),
      ],
    );
  }

  Widget _buildMosBadge(ThemeData theme) {
    return Container(
      width: 40,
      height: 40,
      decoration: BoxDecoration(
        color: theme.colorScheme.primary.withValues(alpha: 0.15),
        borderRadius: BorderRadius.circular(4),
      ),
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Text(
            slot.dutyMos.code,
            style: theme.textTheme.labelSmall?.copyWith(
              fontWeight: FontWeight.bold,
              fontSize: 10,
              color: theme.colorScheme.primary,
            ),
          ),
          Text(
            slot.authorizedRank.payGrade,
            style: theme.textTheme.labelSmall?.copyWith(
              fontSize: 9,
              color: theme.colorScheme.onSurfaceVariant,
            ),
          ),
        ],
      ),
    );
  }

  Color _readinessColor(ReadinessState? state) {
    switch (state) {
      case ReadinessState.fullyMissionCapable:
        return const Color(0xFF4CAF50);
      case ReadinessState.partiallyMissionCapable:
        return const Color(0xFFFF9800);
      case ReadinessState.notMissionCapable:
        return const Color(0xFFF44336);
      case ReadinessState.unknown:
        return Colors.grey;
      case null:
        return Colors.grey;
    }
  }
}