import 'package:flutter/material.dart';
import 'package:medora/controllers/doctor_controller.dart';
import '../../../route/route_names.dart';

class QualificationsScreen extends StatefulWidget {
  final DoctorController? controller;

  const QualificationsScreen({
    super.key,
    required this.controller,
  });

  @override
  State<QualificationsScreen> createState() => _QualificationsScreenState();
}

class _QualificationsScreenState extends State<QualificationsScreen> {
  late DoctorController _controller;
  late TextEditingController _qualificationsController;
  late List<String> qualifications;
  bool _isEditing = false;
  bool _showOthersField = false;
  final _formKey = GlobalKey<FormState>();

  // Predefined popular qualifications
  final List<String> popularQualifications = [
    'MBBS',
    'MD',
    'MS',
    'BDS',
    'DNB',
    'DM',
    'MCh',
    'PhD',
    'MPH',
    'Others'
  ];

  @override
  void initState() {
    super.initState();
    _controller = widget.controller ?? DoctorController();
    _controller.model.qualifications ??= [];
    _qualificationsController = TextEditingController();
    qualifications = List<String>.from(_controller.model.qualifications ?? []);
  }

  bool _validateBeforeNextPage() {
    if (qualifications.isEmpty) {
      _showError('Please add at least one qualification');
      return false;
    }
    return true;
  }

  bool _validateQualification(String value) {
    if (value.isEmpty) {
      _showError('Please enter a qualification');
      return false;
    }

    if (qualifications.any((q) => q.toLowerCase() == value.toLowerCase())) {
      _showError('This qualification has already been added');
      return false;
    }

    if (!RegExp(r'^[a-zA-Z0-9\s.,]+$').hasMatch(value)) {
      _showError('Please enter valid qualification text');
      return false;
    }

    if (value.length < 2) {
      _showError('Qualification must be at least 2 characters long');
      return false;
    }

    return true;
  }

  void _newQualification() {
    final qualification = _qualificationsController.text.trim();

    if (_formKey.currentState!.validate() &&
        _validateQualification(qualification)) {
      // Check if qualification already exists (case-insensitive)
      bool isDuplicate = qualifications
          .any((q) => q.toLowerCase() == qualification.toLowerCase());

      if (!isDuplicate) {
        setState(() {
          qualifications.add(qualification);
          _isEditing = true;
          _qualificationsController.clear();
        });
        _controller.addQualification(qualification);
      } else {
        // Show error message for duplicate qualification
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('This qualification has already been added'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  void _toggleQualification(String qualification) {
    setState(() {
      if (qualification == 'Others') {
        _showOthersField = !_showOthersField;
        return;
      }

      if (qualifications.contains(qualification)) {
        qualifications.remove(qualification);
        _controller.removeQualification(qualification);
      } else {
        // Check if qualification already exists (case-insensitive)
        bool isDuplicate = qualifications
            .any((q) => q.toLowerCase() == qualification.toLowerCase());

        if (!isDuplicate) {
          qualifications.add(qualification);
          _controller.addQualification(qualification);
        } else {
          // Show error message for duplicate qualification
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('This qualification has already been added'),
              backgroundColor: Colors.red,
            ),
          );
        }
      }
    });
  }

  void _removeQualification(int index) {
    setState(() {
      qualifications.removeAt(index);
      _isEditing = true;
    });
    _controller.removeQualification(_qualificationsController.text);
  }

  void _showError(String message) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(message),
        backgroundColor: Colors.red,
        behavior: SnackBarBehavior.floating,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        actions: [
          IconButton(
            onPressed: () {
              if (_validateBeforeNextPage()) {
                Navigator.pushNamed(
                  context,
                  RouteNames.doctorAddressScreen,
                  arguments: _controller,
                );
              }
            },
            icon: const Icon(Icons.arrow_forward),
          ),
        ],
        title: const Text('Qualifications'),
      ),
      body: SingleChildScrollView(
        child: Padding(
          padding: const EdgeInsets.all(16.0),
          child: Container(
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(16),
              boxShadow: [
                BoxShadow(
                  color: Colors.grey.withOpacity(0.1),
                  spreadRadius: 5,
                  blurRadius: 10,
                  offset: const Offset(0, 3),
                ),
              ],
            ),
            child: Form(
              key: _formKey,
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Padding(
                    padding: const EdgeInsets.all(20),
                    child: GridView.builder(
                      shrinkWrap: true,
                      physics: const NeverScrollableScrollPhysics(),
                      gridDelegate:
                          const SliverGridDelegateWithFixedCrossAxisCount(
                        crossAxisCount: 3,
                        childAspectRatio: 2.5,
                        crossAxisSpacing: 10,
                        mainAxisSpacing: 10,
                      ),
                      itemCount: popularQualifications.length,
                      itemBuilder: (context, index) {
                        final qualification = popularQualifications[index];
                        final isSelected = qualification != 'Others' &&
                            qualifications.contains(qualification);
                        final isOthers = qualification == 'Others';

                        return Material(
                          color: Colors.transparent,
                          child: InkWell(
                            onTap: () => _toggleQualification(qualification),
                            borderRadius: BorderRadius.circular(25),
                            child: Container(
                              decoration: BoxDecoration(
                                color:
                                    isSelected || (isOthers && _showOthersField)
                                        ? Colors.blue.withOpacity(0.2)
                                        : Colors.grey.withOpacity(0.1),
                                borderRadius: BorderRadius.circular(25),
                                border: Border.all(
                                  color: isSelected ||
                                          (isOthers && _showOthersField)
                                      ? Colors.blue
                                      : Colors.transparent,
                                ),
                              ),
                              alignment: Alignment.center,
                              child: Text(
                                qualification,
                                style: TextStyle(
                                  color: isSelected ||
                                          (isOthers && _showOthersField)
                                      ? Colors.blue
                                      : Colors.black87,
                                  fontWeight: FontWeight.w500,
                                ),
                              ),
                            ),
                          ),
                        );
                      },
                    ),
                  ),
                  if (_showOthersField) ...[
                    Container(
                      margin: const EdgeInsets.symmetric(horizontal: 20),
                      decoration: BoxDecoration(
                        color: Colors.white,
                        borderRadius: BorderRadius.circular(12),
                        border: Border.all(color: Colors.blue.shade100),
                      ),
                      child: Padding(
                        padding: const EdgeInsets.symmetric(horizontal: 12),
                        child: TextFormField(
                          controller: _qualificationsController,
                          decoration: InputDecoration(
                            hintText: 'Enter your qualification',
                            border: InputBorder.none,
                            suffixIcon: IconButton(
                              icon: const Icon(Icons.add_circle_outline,
                                  color: Colors.blue),
                              onPressed: _newQualification,
                            ),
                          ),
                          onFieldSubmitted: (_) => _newQualification(),
                        ),
                      ),
                    ),
                    const SizedBox(height: 20),
                  ],
                  if (qualifications.isNotEmpty) ...[
                    Padding(
                      padding: const EdgeInsets.symmetric(horizontal: 20),
                      child: Text(
                        'Selected Qualifications',
                        style: TextStyle(
                          fontSize: 16,
                          fontWeight: FontWeight.w500,
                          color: Colors.grey[700],
                        ),
                      ),
                    ),
                    const SizedBox(height: 10),
                    ListView.builder(
                      shrinkWrap: true,
                      physics: const NeverScrollableScrollPhysics(),
                      itemCount: qualifications.length,
                      padding: const EdgeInsets.symmetric(horizontal: 20),
                      itemBuilder: (context, index) {
                        return Card(
                          elevation: 0,
                          color: Colors.blue.withOpacity(0.1),
                          margin: const EdgeInsets.only(bottom: 8),
                          shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(12),
                          ),
                          child: ListTile(
                            title: Text(
                              qualifications[index],
                              style: const TextStyle(
                                fontWeight: FontWeight.w500,
                              ),
                            ),
                            trailing: IconButton(
                              icon: const Icon(
                                Icons.delete,
                                color: Colors.red,
                                size: 20,
                              ),
                              onPressed: () => _removeQualification(index),
                            ),
                          ),
                        );
                      },
                    ),
                  ],
                  const SizedBox(height: 20),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }

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