import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import '../../data/models/maintenance_dto.dart';
import '../../domain/entities/maintenance_schedule.dart';
import 'controllers/maintenance_controller.dart';
import 'maintenance_form_dialog.dart';
import 'components/maintenance_calendar.dart';

class MaintenanceScheduleScreen extends StatefulWidget {
  const MaintenanceScheduleScreen({super.key});

  @override
  State<MaintenanceScheduleScreen> createState() =>
      _MaintenanceScheduleScreenState();
}

class _MaintenanceScheduleScreenState extends State<MaintenanceScheduleScreen>
    with SingleTickerProviderStateMixin {
  late TabController _tabController;
  bool _isCalendarView = false;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 3, vsync: this);

    // 초기 데이터 로드
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final controller = context.read<MaintenanceController>();
      controller.loadMaintenances(refresh: true);
      controller.loadAlerts();
    });
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.grey[100],
      body: Column(
        children: [
          _buildHeader(),
          _buildFilterBar(),
          Expanded(
            child: Consumer<MaintenanceController>(
              builder: (context, controller, child) {
                if (controller.isLoading && controller.maintenances.isEmpty) {
                  return const Center(child: CircularProgressIndicator());
                }

                if (controller.error != null) {
                  return Center(
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        Text(
                          '오류 발생',
                          style: Theme.of(context).textTheme.headlineSmall,
                        ),
                        const SizedBox(height: 8),
                        Text(controller.error!),
                        const SizedBox(height: 16),
                        ShadButton(
                          onPressed:
                              () => controller.loadMaintenances(refresh: true),
                          child: const Text('다시 시도'),
                        ),
                      ],
                    ),
                  );
                }

                return _isCalendarView
                    ? MaintenanceCalendar(
                      maintenances: controller.maintenances,
                      onDateSelected: (date) {
                        // 날짜 선택시 해당 날짜의 유지보수 표시
                        _showMaintenancesForDate(date, controller.maintenances);
                      },
                    )
                    : _buildListView(controller);
              },
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildHeader() {
    return Container(
      padding: const EdgeInsets.all(24),
      decoration: BoxDecoration(
        color: Colors.white,
        boxShadow: [
          BoxShadow(
            color: Colors.grey.withValues(alpha: 0.1),
            spreadRadius: 1,
            blurRadius: 3,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: Column(
        children: [
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    '유지보수 일정 관리',
                    style: Theme.of(context).textTheme.headlineSmall?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                  const SizedBox(height: 4),
                  Consumer<MaintenanceController>(
                    builder: (context, controller, child) {
                      return Text(
                        '총 ${controller.totalCount}건 | '
                        '예정 ${controller.upcomingCount}건 | '
                        '지연 ${controller.overdueCount}건',
                        style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                          color: Colors.grey[600],
                        ),
                      );
                    },
                  ),
                ],
              ),
              Row(
                children: [
                  IconButton(
                    icon: Icon(
                      _isCalendarView ? Icons.list : Icons.calendar_month,
                    ),
                    onPressed: () {
                      setState(() {
                        _isCalendarView = !_isCalendarView;
                      });
                    },
                    tooltip: _isCalendarView ? '리스트 보기' : '캘린더 보기',
                  ),
                  const SizedBox(width: 8),
                  IconButton(
                    icon: const Icon(Icons.refresh),
                    onPressed: () {
                      context.read<MaintenanceController>().loadMaintenances(
                        refresh: true,
                      );
                    },
                    tooltip: '새로고침',
                  ),
                ],
              ),
            ],
          ),
          const SizedBox(height: 16),
          _buildStatisticsCards(),
        ],
      ),
    );
  }

  Widget _buildStatisticsCards() {
    return Consumer<MaintenanceController>(
      builder: (context, controller, child) {
        // 백엔드에 통계 API가 없으므로 빈 위젯 반환
        return const SizedBox.shrink();
      },
    );
  }

  Widget _buildStatCard(
    String title,
    String value,
    IconData icon,
    Color color,
  ) {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: color.withValues(alpha: 0.1),
        borderRadius: BorderRadius.circular(8),
      ),
      child: Row(
        children: [
          Icon(icon, color: color, size: 32),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  title,
                  style: TextStyle(fontSize: 12, color: Colors.grey[600]),
                ),
                const SizedBox(height: 4),
                Text(
                  value,
                  style: TextStyle(
                    fontSize: 18,
                    fontWeight: FontWeight.bold,
                    color: color,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildFilterBar() {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 12),
      decoration: BoxDecoration(
        color: Colors.white,
        border: Border(bottom: BorderSide(color: Colors.grey[300]!)),
      ),
      child: Row(
        children: [
          Expanded(
            child: ShadInput(
              placeholder: const Text('장비명, 일련번호로 검색'),
              onChanged: (value) {
                context.read<MaintenanceController>().setSearchQuery(value);
              },
            ),
          ),
          const SizedBox(width: 12),
          PopupMenuButton<String>(
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
              decoration: BoxDecoration(
                border: Border.all(color: Colors.grey[300]!),
                borderRadius: BorderRadius.circular(8),
              ),
              child: Row(
                children: const [
                  Icon(Icons.filter_list),
                  SizedBox(width: 8),
                  Text('상태 필터'),
                ],
              ),
            ),
            onSelected: (status) {
              context.read<MaintenanceController>().setMaintenanceFilter(status);
            },
            itemBuilder:
                (context) => [
                  const PopupMenuItem(value: null, child: Text('전체')),
                  const PopupMenuItem(
                    value: 'active',
                    child: Text('진행중 (시작됨, 완료되지 않음)'),
                  ),
                  const PopupMenuItem(
                    value: 'completed',
                    child: Text('완료됨'),
                  ),
                  const PopupMenuItem(
                    value: 'upcoming',
                    child: Text('예정됨'),
                  ),
                ],
          ),
          const SizedBox(width: 12),
          PopupMenuButton<String>(
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
              decoration: BoxDecoration(
                border: Border.all(color: Colors.grey[300]!),
                borderRadius: BorderRadius.circular(8),
              ),
              child: Row(
                children: const [
                  Icon(Icons.sort),
                  SizedBox(width: 8),
                  Text('정렬'),
                ],
              ),
            ),
            onSelected: (value) {
              final parts = value.split('_');
              context.read<MaintenanceController>().setSorting(
                parts[0],
                parts[1] == 'asc',
              );
            },
            itemBuilder:
                (context) => [
                  const PopupMenuItem(
                    value: 'started_at_asc',
                    child: Text('시작일 오름차순'),
                  ),
                  const PopupMenuItem(
                    value: 'started_at_desc',
                    child: Text('시작일 내림차순'),
                  ),
                  const PopupMenuItem(
                    value: 'registered_at_desc',
                    child: Text('최신 등록순'),
                  ),
                  const PopupMenuItem(
                    value: 'period_month_desc',
                    child: Text('주기 긴 순'),
                  ),
                ],
          ),
        ],
      ),
    );
  }

  Widget _buildListView(MaintenanceController controller) {
    if (controller.maintenances.isEmpty) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(
              Icons.build_circle_outlined,
              size: 64,
              color: Colors.grey[400],
            ),
            const SizedBox(height: 16),
            Text(
              '등록된 유지보수가 없습니다',
              style: Theme.of(
                context,
              ).textTheme.titleLarge?.copyWith(color: Colors.grey[600]),
            ),
            const SizedBox(height: 8),
            Text('새로운 유지보수를 등록해주세요', style: TextStyle(color: Colors.grey[500])),
          ],
        ),
      );
    }

    return ListView.builder(
      padding: const EdgeInsets.all(24),
      itemCount: controller.maintenances.length,
      itemBuilder: (context, index) {
        final maintenance = controller.maintenances[index];
        return _buildMaintenanceCard(maintenance);
      },
    );
  }

  Widget _buildMaintenanceCard(MaintenanceDto maintenance) {
    final schedule = context
        .read<MaintenanceController>()
        .getScheduleForMaintenance(maintenance.startedAt);
    // generateAlert is not available, using null for now
    final alert = null; // schedule?.generateAlert();

    return Container(
      margin: const EdgeInsets.only(bottom: 12),
      child: ShadCard(
        child: InkWell(
        onTap: () => _showMaintenanceDetails(maintenance),
        borderRadius: BorderRadius.circular(8),
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Row(
                children: [
                  _buildStatusChip(maintenance),
                  const SizedBox(width: 8),
                  _buildTypeChip(maintenance.maintenanceType),
                  const SizedBox(width: 8),
                  if (alert != null) _buildAlertChip(alert),
                  const Spacer(),
                  PopupMenuButton<String>(
                    onSelected:
                        (value) => _handleMaintenanceAction(value, maintenance),
                    itemBuilder:
                        (context) => [
                          const PopupMenuItem(value: 'edit', child: Text('수정')),
                          const PopupMenuItem(
                            value: 'toggle',
                            child: Text('상태 변경'),
                          ),
                          const PopupMenuItem(
                            value: 'delete',
                            child: Text('삭제'),
                          ),
                        ],
                  ),
                ],
              ),
              const SizedBox(height: 12),
              Text(
                'Equipment History #${maintenance.equipmentHistoryId}',
                style: Theme.of(
                  context,
                ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.bold),
              ),
              const SizedBox(height: 8),
              Row(
                children: [
                  Icon(Icons.calendar_today, size: 16, color: Colors.grey[600]),
                  const SizedBox(width: 4),
                  Text(
                    '시작일: ${maintenance.startedAt ?? "미정"}',
                    style: TextStyle(color: Colors.grey[600]),
                  ),
                  const SizedBox(width: 16),
                  Icon(Icons.check_circle, size: 16, color: Colors.grey[600]),
                  const SizedBox(width: 4),
                  Text(
                    '완료일: ${maintenance.endedAt ?? "미완료"}',
                    style: TextStyle(color: Colors.grey[600]),
                  ),
                ],
              ),
              const SizedBox(height: 8),
              Row(
                children: [
                  Icon(Icons.repeat, size: 16, color: Colors.grey[600]),
                  const SizedBox(width: 4),
                  Text(
                    '주기: ${maintenance.periodMonth ?? 0}개월',
                    style: TextStyle(color: Colors.grey[600]),
                  ),
                  const SizedBox(width: 16),
                  Icon(Icons.settings, size: 16, color: Colors.grey[600]),
                  const SizedBox(width: 4),
                  Text(
                    '유형: ${maintenance.maintenanceType == 'O' ? '현장' : '원격'}',
                    style: TextStyle(color: Colors.grey[600]),
                  ),
                ],
              ),
              const SizedBox(height: 8),
              Row(
                children: [
                  Icon(Icons.schedule, size: 16, color: Colors.grey[600]),
                  const SizedBox(width: 4),
                  Text(
                    '등록일: ${DateFormat('yyyy-MM-dd').format(maintenance.registeredAt)}',
                    style: TextStyle(color: Colors.grey[600]),
                  ),
                ],
              ),
            ],
          ),
        ),
        ),
      ),
    );
  }

  Widget _buildStatusChip(MaintenanceDto maintenance) {
    // 백엔드 스키마 기준으로 상태 판단
    if (maintenance.endedAt != null) {
      return ShadBadge.secondary(
        child: const Text('완료'),
      );
    } else if (maintenance.startedAt != null) {
      return ShadBadge(
        child: const Text('진행중'),
      );
    } else {
      return ShadBadge.outline(
        child: const Text('예정'),
      );
    }
  }

  Widget _buildTypeChip(String type) {
    return ShadBadge.destructive(
      child: Text(type == 'O' ? '현장' : '원격'),
    );
  }

  Widget _buildAlertChip(MaintenanceAlert alert) {
    Color color;
    switch (alert.priority) {
      case AlertPriority.critical:
        color = Colors.red;
        break;
      case AlertPriority.high:
        color = Colors.orange;
        break;
      case AlertPriority.medium:
        color = Colors.yellow[700]!;
        break;
      case AlertPriority.low:
        color = Colors.blue;
        break;
    }

    return Chip(
      label: Text(
        '${alert.daysUntilDue < 0 ? "지연 " : ""}${alert.daysUntilDue.abs()}일',
        style: TextStyle(fontSize: 12, color: Colors.white),
      ),
      backgroundColor: color,
      padding: const EdgeInsets.symmetric(horizontal: 8),
      materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
    );
  }

  void _showCreateMaintenanceDialog() {
    showDialog(
      context: context,
      builder: (context) => const MaintenanceFormDialog(),
    ).then((result) {
      if (result == true) {
        context.read<MaintenanceController>().loadMaintenances(refresh: true);
      }
    });
  }

  void _showMaintenanceDetails(MaintenanceDto maintenance) {
    showDialog(
      context: context,
      builder: (context) => MaintenanceFormDialog(maintenance: maintenance),
    ).then((result) {
      if (result == true) {
        context.read<MaintenanceController>().loadMaintenances(refresh: true);
      }
    });
  }

  void _handleMaintenanceAction(
    String action,
    MaintenanceDto maintenance,
  ) async {
    final controller = context.read<MaintenanceController>();

    switch (action) {
      case 'edit':
        _showMaintenanceDetails(maintenance);
        break;
      case 'toggle':
        // TODO: 백엔드 스키마에 맞는 상태 변경 로직 구현 필요
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('상태 변경 기능은 준비 중입니다')),
        );
        break;
      case 'delete':
        final confirm = await showDialog<bool>(
          context: context,
          builder:
              (context) => AlertDialog(
                title: const Text('유지보수 삭제'),
                content: const Text('정말로 이 유지보수를 삭제하시겠습니까?'),
                actions: [
                  TextButton(
                    onPressed: () => Navigator.of(context).pop(false),
                    child: const Text('취소'),
                  ),
                  TextButton(
                    onPressed: () => Navigator.of(context).pop(true),
                    child: const Text(
                      '삭제',
                      style: TextStyle(color: Colors.red),
                    ),
                  ),
                ],
              ),
        );

        if (confirm == true && maintenance.id != null) {
          await controller.deleteMaintenance(maintenance.id!);
        }
        break;
    }
  }

  void _showMaintenancesForDate(
    DateTime date,
    List<MaintenanceDto> maintenances,
  ) {
    final dateMaintenances =
        maintenances.where((m) {
          // nextMaintenanceDate 필드가 백엔드에 없으므로 startedAt~endedAt 기간으로 확인
          final targetDate = DateTime(date.year, date.month, date.day);
          final startDate = DateTime(m.startedAt.year, m.startedAt.month, m.startedAt.day);
          final endDate = DateTime(m.endedAt.year, m.endedAt.month, m.endedAt.day);
          
          return (targetDate.isAfter(startDate) || targetDate.isAtSameMomentAs(startDate)) &&
                 (targetDate.isBefore(endDate) || targetDate.isAtSameMomentAs(endDate));
        }).toList();

    if (dateMaintenances.isEmpty) return;

    showModalBottomSheet(
      context: context,
      builder:
          (context) => Container(
            padding: const EdgeInsets.all(16),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  '${DateFormat('yyyy년 MM월 dd일').format(date)} 유지보수',
                  style: Theme.of(context).textTheme.titleLarge,
                ),
                const SizedBox(height: 16),
                ...dateMaintenances.map(
                  (m) => ListTile(
                    title: Text('Equipment History #${m.equipmentHistoryId}'),
                    subtitle: Text(
                      '${m.maintenanceType == "O" ? "현장" : "원격"} | ${m.periodMonth}개월 주기',
                    ),
                    trailing: Text(
                      DateFormat('yyyy-MM-dd').format(m.endedAt), // 종료일로 대체
                    ),
                    onTap: () {
                      Navigator.of(context).pop();
                      _showMaintenanceDetails(m);
                    },
                  ),
                ),
              ],
            ),
          ),
    );
  }
}