import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:superport/models/company_model.dart';
import 'package:superport/models/user_model.dart';
import 'package:superport/screens/common/theme_tailwind.dart';
import 'package:superport/screens/common/custom_widgets.dart';
import 'package:superport/services/mock_data_service.dart';
import 'package:superport/utils/constants.dart';
import 'package:superport/utils/validators.dart';
import 'package:flutter/services.dart';
import 'package:superport/screens/user/controllers/user_form_controller.dart';
import 'package:superport/models/user_phone_field.dart';
import 'package:superport/screens/common/widgets/company_branch_dropdown.dart';

// 사용자 등록/수정 화면 (UI만 담당, 상태/로직 분리)
class UserFormScreen extends StatefulWidget {
  final int? userId;
  const UserFormScreen({super.key, this.userId});

  @override
  State<UserFormScreen> createState() => _UserFormScreenState();
}

class _UserFormScreenState extends State<UserFormScreen> {
  final TextEditingController _passwordController = TextEditingController();
  final TextEditingController _confirmPasswordController = TextEditingController();
  bool _showPassword = false;
  bool _showConfirmPassword = false;

  @override
  void dispose() {
    _passwordController.dispose();
    _confirmPasswordController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
      create: (_) => UserFormController(
        dataService: MockDataService(),
        userId: widget.userId,
      ),
      child: Consumer<UserFormController>(
        builder: (context, controller, child) {
          return Scaffold(
            appBar: AppBar(
              title: Text(controller.isEditMode ? '사용자 수정' : '사용자 등록'),
            ),
            body: controller.isLoading
                ? const Center(child: CircularProgressIndicator())
                : Padding(
                    padding: const EdgeInsets.all(16.0),
                    child: Form(
                      key: controller.formKey,
                      child: SingleChildScrollView(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            // 이름
                            _buildTextField(
                              label: '이름',
                              initialValue: controller.name,
                              hintText: '사용자 이름을 입력하세요',
                              validator: (value) => validateRequired(value, '이름'),
                              onSaved: (value) => controller.name = value!,
                            ),
                            
                            // 사용자명 (신규 등록 시만)
                            if (!controller.isEditMode) ...[                              
                              _buildTextField(
                                label: '사용자명',
                                initialValue: controller.username,
                                hintText: '로그인에 사용할 사용자명',
                                validator: (value) {
                                  if (value == null || value.isEmpty) {
                                    return '사용자명을 입력해주세요';
                                  }
                                  if (value.length < 3) {
                                    return '사용자명은 3자 이상이어야 합니다';
                                  }
                                  if (controller.isUsernameAvailable == false) {
                                    return '이미 사용 중인 사용자명입니다';
                                  }
                                  return null;
                                },
                                onChanged: (value) {
                                  controller.username = value;
                                  controller.checkUsernameAvailability(value);
                                },
                                onSaved: (value) => controller.username = value!,
                                suffixIcon: controller.isCheckingUsername
                                    ? const SizedBox(
                                        width: 20,
                                        height: 20,
                                        child: Padding(
                                          padding: EdgeInsets.all(12.0),
                                          child: CircularProgressIndicator(
                                            strokeWidth: 2,
                                          ),
                                        ),
                                      )
                                    : controller.isUsernameAvailable != null
                                        ? Icon(
                                            controller.isUsernameAvailable!
                                                ? Icons.check_circle
                                                : Icons.cancel,
                                            color: controller.isUsernameAvailable!
                                                ? Colors.green
                                                : Colors.red,
                                          )
                                        : null,
                              ),
                              
                              // 비밀번호
                              _buildPasswordField(
                                label: '비밀번호',
                                controller: _passwordController,
                                hintText: '비밀번호를 입력하세요',
                                obscureText: !_showPassword,
                                onToggleVisibility: () {
                                  setState(() {
                                    _showPassword = !_showPassword;
                                  });
                                },
                                validator: (value) {
                                  if (value == null || value.isEmpty) {
                                    return '비밀번호를 입력해주세요';
                                  }
                                  if (value.length < 6) {
                                    return '비밀번호는 6자 이상이어야 합니다';
                                  }
                                  return null;
                                },
                                onSaved: (value) => controller.password = value!,
                              ),
                              
                              // 비밀번호 확인
                              _buildPasswordField(
                                label: '비밀번호 확인',
                                controller: _confirmPasswordController,
                                hintText: '비밀번호를 다시 입력하세요',
                                obscureText: !_showConfirmPassword,
                                onToggleVisibility: () {
                                  setState(() {
                                    _showConfirmPassword = !_showConfirmPassword;
                                  });
                                },
                                validator: (value) {
                                  if (value == null || value.isEmpty) {
                                    return '비밀번호를 다시 입력해주세요';
                                  }
                                  if (value != _passwordController.text) {
                                    return '비밀번호가 일치하지 않습니다';
                                  }
                                  return null;
                                },
                              ),
                            ],
                            
                            // 수정 모드에서 비밀번호 변경 (선택사항)
                            if (controller.isEditMode) ...[                              
                              ExpansionTile(
                                title: const Text('비밀번호 변경'),
                                children: [
                                  _buildPasswordField(
                                    label: '새 비밀번호',
                                    controller: _passwordController,
                                    hintText: '변경할 경우만 입력하세요',
                                    obscureText: !_showPassword,
                                    onToggleVisibility: () {
                                      setState(() {
                                        _showPassword = !_showPassword;
                                      });
                                    },
                                    validator: (value) {
                                      if (value != null && value.isNotEmpty && value.length < 6) {
                                        return '비밀번호는 6자 이상이어야 합니다';
                                      }
                                      return null;
                                    },
                                    onSaved: (value) => controller.password = value ?? '',
                                  ),
                                  
                                  _buildPasswordField(
                                    label: '새 비밀번호 확인',
                                    controller: _confirmPasswordController,
                                    hintText: '비밀번호를 다시 입력하세요',
                                    obscureText: !_showConfirmPassword,
                                    onToggleVisibility: () {
                                      setState(() {
                                        _showConfirmPassword = !_showConfirmPassword;
                                      });
                                    },
                                    validator: (value) {
                                      if (_passwordController.text.isNotEmpty && value != _passwordController.text) {
                                        return '비밀번호가 일치하지 않습니다';
                                      }
                                      return null;
                                    },
                                  ),
                                ],
                              ),
                            ],
                            
                            // 직급
                            _buildTextField(
                              label: '직급',
                              initialValue: controller.position,
                              hintText: '직급을 입력하세요',
                              onSaved: (value) => controller.position = value ?? '',
                            ),
                            
                            // 소속 회사/지점
                            CompanyBranchDropdown(
                              companies: controller.companies,
                              selectedCompanyId: controller.companyId,
                              selectedBranchId: controller.branchId,
                              branches: controller.branches,
                              onCompanyChanged: (value) {
                                controller.companyId = value;
                                controller.branchId = null;
                                if (value != null) {
                                  controller.loadBranches(value);
                                } else {
                                  controller.branches = [];
                                }
                              },
                              onBranchChanged: (value) {
                                controller.branchId = value;
                              },
                            ),
                            
                            // 이메일
                            _buildTextField(
                              label: '이메일',
                              initialValue: controller.email,
                              hintText: '이메일을 입력하세요',
                              keyboardType: TextInputType.emailAddress,
                              validator: (value) {
                                if (value == null || value.isEmpty) return null;
                                return validateEmail(value);
                              },
                              onSaved: (value) => controller.email = value ?? '',
                            ),
                            // 전화번호
                            _buildPhoneFieldsSection(controller),
                            // 권한
                            _buildRoleRadio(controller),
                            const SizedBox(height: 24),
                            // 오류 메시지 표시
                            if (controller.error != null)
                              Container(
                                padding: const EdgeInsets.all(12),
                                margin: const EdgeInsets.only(bottom: 16),
                                decoration: BoxDecoration(
                                  color: Colors.red.shade50,
                                  borderRadius: BorderRadius.circular(8),
                                  border: Border.all(color: Colors.red.shade200),
                                ),
                                child: Row(
                                  children: [
                                    Icon(Icons.error_outline, color: Colors.red.shade700),
                                    const SizedBox(width: 8),
                                    Expanded(
                                      child: Text(
                                        controller.error!,
                                        style: TextStyle(color: Colors.red.shade700),
                                      ),
                                    ),
                                  ],
                                ),
                              ),
                            // 저장 버튼
                            SizedBox(
                              width: double.infinity,
                              child: ElevatedButton(
                                onPressed: controller.isLoading
                                    ? null
                                    : () => _onSaveUser(controller),
                                style: AppThemeTailwind.primaryButtonStyle,
                                child: Padding(
                                  padding: const EdgeInsets.all(12.0),
                                  child: controller.isLoading
                                      ? const SizedBox(
                                          height: 20,
                                          width: 20,
                                          child: CircularProgressIndicator(
                                            strokeWidth: 2,
                                            valueColor: AlwaysStoppedAnimation<Color>(Colors.white),
                                          ),
                                        )
                                      : Text(
                                          controller.isEditMode ? '수정하기' : '등록하기',
                                          style: const TextStyle(fontSize: 16),
                                        ),
                                ),
                              ),
                            ),
                          ],
                        ),
                      ),
                    ),
                  ),
          );
        },
      ),
    );
  }

  // 이름/직급/이메일 등 공통 텍스트 필드 위젯
  Widget _buildTextField({
    required String label,
    required String initialValue,
    required String hintText,
    TextInputType? keyboardType,
    List<TextInputFormatter>? inputFormatters,
    String? Function(String?)? validator,
    void Function(String?)? onSaved,
    void Function(String)? onChanged,
    Widget? suffixIcon,
  }) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 16.0),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(label, style: const TextStyle(fontWeight: FontWeight.bold)),
          const SizedBox(height: 4),
          TextFormField(
            initialValue: initialValue,
            decoration: InputDecoration(
              hintText: hintText,
              suffixIcon: suffixIcon,
            ),
            keyboardType: keyboardType,
            inputFormatters: inputFormatters,
            validator: validator,
            onSaved: onSaved,
            onChanged: onChanged,
          ),
        ],
      ),
    );
  }

  // 비밀번호 필드 위젯
  Widget _buildPasswordField({
    required String label,
    required TextEditingController controller,
    required String hintText,
    required bool obscureText,
    required VoidCallback onToggleVisibility,
    String? Function(String?)? validator,
    void Function(String?)? onSaved,
  }) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 16.0),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(label, style: const TextStyle(fontWeight: FontWeight.bold)),
          const SizedBox(height: 4),
          TextFormField(
            controller: controller,
            obscureText: obscureText,
            decoration: InputDecoration(
              hintText: hintText,
              suffixIcon: IconButton(
                icon: Icon(
                  obscureText ? Icons.visibility : Icons.visibility_off,
                ),
                onPressed: onToggleVisibility,
              ),
            ),
            validator: validator,
            onSaved: onSaved,
          ),
        ],
      ),
    );
  }
  
  // 전화번호 입력 필드 섹션 위젯 (UserPhoneField 기반)
  Widget _buildPhoneFieldsSection(UserFormController controller) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const Text('전화번호', style: TextStyle(fontWeight: FontWeight.bold)),
        const SizedBox(height: 4),
        ...controller.phoneFields.asMap().entries.map((entry) {
          final i = entry.key;
          final phoneField = entry.value;
          return Row(
            children: [
              // 종류 드롭다운
              DropdownButton<String>(
                value: phoneField.type,
                items: controller.phoneTypes
                    .map((type) => DropdownMenuItem(value: type, child: Text(type)))
                    .toList(),
                onChanged: (value) {
                  phoneField.type = value!;
                },
              ),
              const SizedBox(width: 8),
              // 번호 입력
              Expanded(
                child: TextFormField(
                  controller: phoneField.controller,
                  keyboardType: TextInputType.phone,
                  decoration: const InputDecoration(hintText: '전화번호'),
                  onSaved: (value) {}, // 값은 controller에서 직접 추출
                ),
              ),
              IconButton(
                icon: const Icon(Icons.remove_circle, color: Colors.red),
                onPressed: controller.phoneFields.length > 1
                    ? () => controller.removePhoneField(i)
                    : null,
              ),
            ],
          );
        }),
        // 추가 버튼
        Align(
          alignment: Alignment.centerLeft,
          child: TextButton.icon(
            onPressed: () => controller.addPhoneField(),
            icon: const Icon(Icons.add),
            label: const Text('전화번호 추가'),
          ),
        ),
      ],
    );
  }

  // 권한(관리등급) 라디오 위젯
  Widget _buildRoleRadio(UserFormController controller) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 16.0),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          const Text('권한', style: TextStyle(fontWeight: FontWeight.bold)),
          const SizedBox(height: 4),
          Row(
            children: [
              Expanded(
                child: RadioListTile<String>(
                  title: const Text('관리자'),
                  value: UserRoles.admin,
                  groupValue: controller.role,
                  onChanged: (value) {
                    controller.role = value!;
                  },
                ),
              ),
              Expanded(
                child: RadioListTile<String>(
                  title: const Text('일반 사용자'),
                  value: UserRoles.member,
                  groupValue: controller.role,
                  onChanged: (value) {
                    controller.role = value!;
                  },
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }

  // 저장 버튼 클릭 시 사용자 저장
  void _onSaveUser(UserFormController controller) async {
    await controller.saveUser((error) {
      if (error != null) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(error),
            backgroundColor: Colors.red,
          ),
        );
      } else {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(controller.isEditMode ? '사용자 정보가 수정되었습니다' : '사용자가 등록되었습니다'),
            backgroundColor: Colors.green,
          ),
        );
        Navigator.pop(context, true);
      }
    });
  }
}