import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import 'controllers/equipment_history_controller.dart';

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

  @override
  State<InventoryDashboard> createState() => _InventoryDashboardState();
}

class _InventoryDashboardState extends State<InventoryDashboard> {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final controller = context.read<EquipmentHistoryController>();
      controller.loadStockStatus(); // 재고 현황 로드
    });
  }
  
  @override
  Widget build(BuildContext context) {
    final theme = ShadTheme.of(context);
    
    return Scaffold(
      backgroundColor: theme.colorScheme.background,
      body: Consumer<EquipmentHistoryController>(
        builder: (context, controller, child) {
          if (controller.isLoading) {
            return const Center(
              child: CircularProgressIndicator(),
            );
          }
          
          return SingleChildScrollView(
            padding: const EdgeInsets.all(24),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // 헤더
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          '재고 대시보드',
                          style: theme.textTheme.h2,
                        ),
                        const SizedBox(height: 4),
                        Text(
                          '실시간 재고 현황 및 경고 알림',
                          style: theme.textTheme.muted,
                        ),
                      ],
                    ),
                    Row(
                      children: [
                        ShadButton.outline(
                          child: const Row(
                            children: [
                              Icon(Icons.refresh, size: 16),
                              SizedBox(width: 8),
                              Text('새로고침'),
                            ],
                          ),
                          onPressed: () {
                            controller.loadStockStatus();
                            controller.loadHistories();
                          },
                        ),
                        const SizedBox(width: 8),
                        ShadButton(
                          child: const Row(
                            children: [
                              Icon(Icons.download, size: 16),
                              SizedBox(width: 8),
                              Text('보고서 다운로드'),
                            ],
                          ),
                          onPressed: () {
                            // 보고서 다운로드 기능
                          },
                        ),
                      ],
                    ),
                  ],
                ),
                const SizedBox(height: 24),
                
                // 통계 카드
                GridView.count(
                  shrinkWrap: true,
                  physics: const NeverScrollableScrollPhysics(),
                  crossAxisCount: MediaQuery.of(context).size.width > 1200 ? 4 : 2,
                  mainAxisSpacing: 16,
                  crossAxisSpacing: 16,
                  childAspectRatio: 1.5,
                  children: [
                    _buildStatCard(
                      theme,
                      title: '총 입고',
                      value: '${controller.getStockSummary()['totalIn']}',
                      unit: '개',
                      icon: Icons.input,
                      color: Colors.green,
                    ),
                    _buildStatCard(
                      theme,
                      title: '총 출고',
                      value: '${controller.getStockSummary()['totalOut']}',
                      unit: '개',
                      icon: Icons.output,
                      color: Colors.red,
                    ),
                    _buildStatCard(
                      theme,
                      title: '현재 재고',
                      value: '${controller.getStockSummary()['totalStock']}',
                      unit: '개',
                      icon: Icons.inventory_2,
                      color: theme.colorScheme.primary,
                    ),
                    _buildStatCard(
                      theme,
                      title: '총 거래',
                      value: '${controller.histories.length}',
                      unit: '건',
                      icon: Icons.history,
                      color: Colors.blue,
                    ),
                  ],
                ),
                const SizedBox(height: 32),
                
                // 최근 거래 이력 (백엔드 스키마 기반)
                Text(
                  '최근 거래 이력',
                  style: theme.textTheme.h3,
                ),
                const SizedBox(height: 16),
                ShadCard(
                  child: Padding(
                    padding: const EdgeInsets.all(16),
                    child: controller.histories.isEmpty
                        ? const Center(
                            child: Text('거래 이력이 없습니다.'),
                          )
                        : Column(
                            children: controller.histories.take(10).map((history) {
                              return Padding(
                                padding: const EdgeInsets.symmetric(vertical: 8),
                                child: Row(
                                  children: [
                                    Expanded(
                                      flex: 2,
                                      child: Text(
                                        DateFormat('MM/dd HH:mm').format(history.transactedAt),
                                        style: theme.textTheme.small,
                                      ),
                                    ),
                                    Expanded(
                                      flex: 1,
                                      child: Container(
                                        padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                                        decoration: BoxDecoration(
                                          color: history.transactionType == 'I' ? Colors.green : Colors.red,
                                          borderRadius: BorderRadius.circular(4),
                                        ),
                                        child: Text(
                                          history.transactionType == 'I' ? '입고' : '출고',
                                          style: const TextStyle(color: Colors.white, fontSize: 12),
                                          textAlign: TextAlign.center,
                                        ),
                                      ),
                                    ),
                                    Expanded(
                                      flex: 1,
                                      child: Text(
                                        '${history.quantity}개',
                                        style: theme.textTheme.small,
                                        textAlign: TextAlign.right,
                                      ),
                                    ),
                                    Expanded(
                                      flex: 2,
                                      child: Text(
                                        history.remark ?? '-',
                                        style: theme.textTheme.small,
                                        textAlign: TextAlign.right,
                                        overflow: TextOverflow.ellipsis,
                                      ),
                                    ),
                                  ],
                                ),
                              );
                            }).toList(),
                          ),
                  ),
                ),
                const SizedBox(height: 24),
              ],
            ),
          );
        },
      ),
    );
  }
  
  Widget _buildStatCard(
    ShadThemeData theme, {
    required String title,
    required String value,
    required String unit,
    required IconData icon,
    required Color color,
  }) {
    return ShadCard(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Icon(icon, color: color, size: 24),
                Text(
                  unit,
                  style: theme.textTheme.muted,
                ),
              ],
            ),
            Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  value,
                  style: theme.textTheme.h2,
                ),
                Text(
                  title,
                  style: theme.textTheme.small.copyWith(
                    color: theme.colorScheme.mutedForeground,
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}