import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:get_it/get_it.dart';
import 'package:superport/data/models/equipment/equipment_history_dto.dart';
import 'package:superport/services/equipment_service.dart';
import 'package:superport/screens/common/custom_widgets.dart';
import 'package:superport/core/errors/failures.dart';
import 'package:intl/intl.dart';

class EquipmentHistoryScreen extends StatefulWidget {
  final int equipmentId;
  final String equipmentName;

  const EquipmentHistoryScreen({
    Key? key,
    required this.equipmentId,
    required this.equipmentName,
  }) : super(key: key);

  @override
  State<EquipmentHistoryScreen> createState() => _EquipmentHistoryScreenState();
}

class _EquipmentHistoryScreenState extends State<EquipmentHistoryScreen> {
  final EquipmentService _equipmentService = GetIt.instance<EquipmentService>();
  List<EquipmentHistoryDto> _histories = [];
  bool _isLoading = false;  // 초기값을 false로 변경
  bool _isInitialLoad = true;  // 초기 로딩 상태 추가
  String? _error;
  int _currentPage = 1;
  final int _perPage = 20;
  bool _hasMore = true;
  final ScrollController _scrollController = ScrollController();

  @override
  void initState() {
    super.initState();
    print('[INIT] EquipmentHistoryScreen initialized for equipment ${widget.equipmentId}');
    _loadHistory(isInitialLoad: true);
    _scrollController.addListener(_onScroll);
  }

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

  void _onScroll() {
    if (_scrollController.position.pixels >= _scrollController.position.maxScrollExtent - 200) {
      _loadMoreHistory();
    }
  }

  Future<void> _loadHistory({bool isRefresh = false, bool isInitialLoad = false}) async {
    print('[_loadHistory] Called - isRefresh: $isRefresh, isInitialLoad: $isInitialLoad, _isLoading: $_isLoading');
    
    if (isRefresh) {
      _currentPage = 1;
      _hasMore = true;
      _histories.clear();
    }

    // 초기 로딩이 아닌 경우에만 중복 호출 방지
    if (!isInitialLoad && (!_hasMore || (!isRefresh && _isLoading))) {
      print('[_loadHistory] Skipping - hasMore: $_hasMore, isLoading: $_isLoading');
      return;
    }

    if (!mounted) return;
    
    setState(() {
      _isLoading = true;
      _error = null;
      if (isInitialLoad) _isInitialLoad = false;
    });

    try {
      print('[DEBUG] ==== STARTING HISTORY LOAD ====');
      print('[DEBUG] Equipment ID: ${widget.equipmentId}');
      print('[DEBUG] Equipment Name: ${widget.equipmentName}');
      print('[DEBUG] Page: $_currentPage, PerPage: $_perPage');
      print('[DEBUG] Current time: ${DateTime.now()}');
      
      // 타임아웃 설정
      final histories = await _equipmentService.getEquipmentHistory(
        widget.equipmentId,
        page: _currentPage,
        perPage: _perPage,
      ).timeout(
        const Duration(seconds: 10),
        onTimeout: () {
          print('[ERROR] API call timeout after 10 seconds');
          throw Exception('API 호출 시간 초과 (10초)');
        },
      );

      print('[DEBUG] API call completed successfully');
      print('[DEBUG] Received ${histories.length} history records');
      if (histories.isNotEmpty) {
        print('[DEBUG] First history record: ${histories.first.toJson()}');
      } else {
        print('[DEBUG] No history records found');
      }

      if (!mounted) {
        print('[WARNING] Widget not mounted, skipping setState');
        return;
      }

      setState(() {
        if (isRefresh) {
          _histories = histories;
        } else {
          _histories.addAll(histories);
        }
        _hasMore = histories.length == _perPage;
        if (_hasMore) _currentPage++;
        _isLoading = false;
        print('[DEBUG] State updated - Loading: false, Histories count: ${_histories.length}');
      });
    } on Failure catch (e) {
      print('[ERROR] Failure loading history: ${e.message}');
      if (!mounted) return;
      setState(() {
        _error = e.message;
        _isLoading = false;
      });
    } catch (e, stackTrace) {
      print('[ERROR] Unexpected error loading history: $e');
      print('[ERROR] Stack trace: $stackTrace');
      if (!mounted) return;
      setState(() {
        _error = '이력을 불러오는 중 오류가 발생했습니다: $e';
        _isLoading = false;
      });
    } finally {
      print('[DEBUG] ==== HISTORY LOAD COMPLETED ====');
    }
  }

  Future<void> _loadMoreHistory() async {
    await _loadHistory();
  }

  String _formatDate(DateTime? date) {
    if (date == null) return '-';
    return DateFormat('yyyy-MM-dd HH:mm').format(date);
  }

  String _getTransactionTypeText(String? type) {
    switch (type) {
      case 'I':
        return '입고';
      case 'O':
        return '출고';
      case 'R':
        return '대여';
      case 'T':
        return '반납';
      case 'D':
        return '폐기';
      default:
        return type ?? '-';
    }
  }

  Color _getTransactionTypeColor(String? type) {
    switch (type) {
      case 'I':
        return Colors.green;
      case 'O':
        return Colors.blue;
      case 'R':
        return Colors.orange;
      case 'T':
        return Colors.teal;
      case 'D':
        return Colors.red;
      default:
        return Colors.grey;
    }
  }

  Widget _buildHistoryItem(EquipmentHistoryDto history) {
    final typeColor = _getTransactionTypeColor(history.transactionType);
    return Card(
      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
      child: ListTile(
        leading: CircleAvatar(
          backgroundColor: typeColor.withOpacity(0.2),
          child: Text(
            _getTransactionTypeText(history.transactionType),
            style: TextStyle(
              color: typeColor,
              fontWeight: FontWeight.bold,
              fontSize: 12,
            ),
          ),
        ),
        title: Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Expanded(
              child: Text(
                history.remarks ?? '비고 없음',
                overflow: TextOverflow.ellipsis,
              ),
            ),
            Text(
              '수량: ${history.quantity}',
              style: const TextStyle(fontSize: 14),
            ),
          ],
        ),
        subtitle: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const SizedBox(height: 4),
            Text(_formatDate(history.transactionDate)),
            if (history.userName != null)
              Text('담당자: ${history.userName}'),
          ],
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    print('[BUILD] EquipmentHistoryScreen - Loading: $_isLoading, InitialLoad: $_isInitialLoad, Error: $_error, Histories: ${_histories.length}');
    
    return Scaffold(
      appBar: AppBar(
        title: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text('장비 이력'),
            Text(
              widget.equipmentName,
              style: const TextStyle(fontSize: 14, fontWeight: FontWeight.normal),
            ),
          ],
        ),
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh),
            onPressed: () => _loadHistory(isRefresh: true),
            tooltip: '새로고침',
          ),
        ],
      ),
      body: Builder(
        builder: (context) {
          print('[UI] Building body - Loading: $_isLoading, InitialLoad: $_isInitialLoad, Error: $_error, Histories: ${_histories.length}');
          
          // 초기 로딩 또는 일반 로딩 중
          if ((_isInitialLoad || _isLoading) && _histories.isEmpty) {
            return Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  const CircularProgressIndicator(),
                  const SizedBox(height: 16),
                  Text('장비 ID ${widget.equipmentId}의 이력을 불러오는 중...'),
                  const SizedBox(height: 8),
                  TextButton(
                    onPressed: () {
                      print('[USER] Cancel loading clicked');
                      setState(() {
                        _isLoading = false;
                        _error = '사용자가 로딩을 취소했습니다';
                      });
                    },
                    child: const Text('로딩 취소'),
                  ),
                ],
              ),
            );
          }
          
          if (_error != null && _histories.isEmpty) {
            return Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  const Icon(Icons.error_outline, size: 48, color: Colors.red),
                  const SizedBox(height: 16),
                  Text('오류 발생', style: Theme.of(context).textTheme.titleLarge),
                  const SizedBox(height: 8),
                  Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 32),
                    child: Text(
                      _error!,
                      textAlign: TextAlign.center,
                      style: const TextStyle(color: Colors.red),
                    ),
                  ),
                  const SizedBox(height: 16),
                  ElevatedButton.icon(
                    icon: const Icon(Icons.refresh),
                    label: const Text('다시 시도'),
                    onPressed: () => _loadHistory(isRefresh: true),
                  ),
                ],
              ),
            );
          }
          
          return RefreshIndicator(
            onRefresh: () => _loadHistory(isRefresh: true),
            child: _histories.isEmpty
                ? ListView(
                    children: [
                      const SizedBox(height: 200),
                      const Icon(Icons.history, size: 48, color: Colors.grey),
                      const SizedBox(height: 16),
                      const Center(
                        child: Text(
                          '이력이 없습니다.',
                          style: TextStyle(fontSize: 16, color: Colors.grey),
                        ),
                      ),
                      const SizedBox(height: 8),
                      Center(
                        child: TextButton(
                          onPressed: () => _loadHistory(isRefresh: true),
                          child: const Text('새로고침'),
                        ),
                      ),
                    ],
                  )
                : ListView.builder(
                    controller: _scrollController,
                    itemCount: _histories.length + (_hasMore ? 1 : 0),
                    itemBuilder: (context, index) {
                      if (index == _histories.length) {
                        return const Padding(
                          padding: EdgeInsets.all(16.0),
                          child: Center(child: CircularProgressIndicator()),
                        );
                      }
                      return _buildHistoryItem(_histories[index]);
                    },
                  ),
          );
        },
      ),
    );
  }
}