import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import '../../../shared/services/api_client.dart';
import 'clients_screen.dart';
import 'client_detail_screen.dart';

class ClientFormScreen extends ConsumerStatefulWidget {
  final String? clientId;
  
  const ClientFormScreen({super.key, this.clientId});

  @override
  ConsumerState<ClientFormScreen> createState() => _ClientFormScreenState();
}

class _ClientFormScreenState extends ConsumerState<ClientFormScreen> {
  final _formKey = GlobalKey<FormState>();
  bool _isLoading = false;
  bool _isInitialized = false;
  
  // Form controllers
  final _firstNameController = TextEditingController();
  final _lastNameController = TextEditingController();
  final _emailController = TextEditingController();
  final _phoneController = TextEditingController();
  final _companyController = TextEditingController();
  final _roleController = TextEditingController();
  final _industryController = TextEditingController();
  final _notesController = TextEditingController();
  final _interestsController = TextEditingController();
  final _tagsController = TextEditingController();
  
  DateTime? _birthday;
  DateTime? _anniversary;

  bool get isEditing => widget.clientId != null;

  @override
  void dispose() {
    _firstNameController.dispose();
    _lastNameController.dispose();
    _emailController.dispose();
    _phoneController.dispose();
    _companyController.dispose();
    _roleController.dispose();
    _industryController.dispose();
    _notesController.dispose();
    _interestsController.dispose();
    _tagsController.dispose();
    super.dispose();
  }

  void _initializeFromClient(Map<String, dynamic> client) {
    if (_isInitialized) return;
    _isInitialized = true;
    
    _firstNameController.text = client['firstName'] ?? '';
    _lastNameController.text = client['lastName'] ?? '';
    _emailController.text = client['email'] ?? '';
    _phoneController.text = client['phone'] ?? '';
    _companyController.text = client['company'] ?? '';
    _roleController.text = client['role'] ?? '';
    _industryController.text = client['industry'] ?? '';
    _notesController.text = client['notes'] ?? '';
    _interestsController.text = (client['interests'] as List?)?.join(', ') ?? '';
    _tagsController.text = (client['tags'] as List?)?.join(', ') ?? '';
    
    if (client['birthday'] != null) {
      _birthday = DateTime.tryParse(client['birthday']);
    }
    if (client['anniversary'] != null) {
      _anniversary = DateTime.tryParse(client['anniversary']);
    }
  }

  Future<void> _handleSubmit() async {
    if (!_formKey.currentState!.validate()) return;
    
    setState(() => _isLoading = true);
    
    try {
      final data = {
        'firstName': _firstNameController.text.trim(),
        'lastName': _lastNameController.text.trim(),
        if (_emailController.text.isNotEmpty) 'email': _emailController.text.trim(),
        if (_phoneController.text.isNotEmpty) 'phone': _phoneController.text.trim(),
        if (_companyController.text.isNotEmpty) 'company': _companyController.text.trim(),
        if (_roleController.text.isNotEmpty) 'role': _roleController.text.trim(),
        if (_industryController.text.isNotEmpty) 'industry': _industryController.text.trim(),
        if (_notesController.text.isNotEmpty) 'notes': _notesController.text.trim(),
        if (_interestsController.text.isNotEmpty)
          'interests': _interestsController.text.split(',').map((e) => e.trim()).where((e) => e.isNotEmpty).toList(),
        if (_tagsController.text.isNotEmpty)
          'tags': _tagsController.text.split(',').map((e) => e.trim()).where((e) => e.isNotEmpty).toList(),
        if (_birthday != null) 'birthday': _birthday!.toIso8601String(),
        if (_anniversary != null) 'anniversary': _anniversary!.toIso8601String(),
      };
      
      final apiClient = ref.read(apiClientProvider);
      
      if (isEditing) {
        await apiClient.updateClient(widget.clientId!, data);
        ref.invalidate(clientDetailProvider(widget.clientId!));
      } else {
        final client = await apiClient.createClient(data);
        widget.clientId ?? client['id'];
      }
      
      ref.invalidate(clientsProvider(null));
      
      if (mounted) {
        context.go(isEditing ? '/clients/${widget.clientId}' : '/');
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Failed to save: $e')),
        );
      }
    } finally {
      if (mounted) {
        setState(() => _isLoading = false);
      }
    }
  }

  Future<void> _selectDate(BuildContext context, bool isBirthday) async {
    final initialDate = isBirthday ? _birthday : _anniversary;
    final picked = await showDatePicker(
      context: context,
      initialDate: initialDate ?? DateTime.now(),
      firstDate: DateTime(1900),
      lastDate: DateTime.now().add(const Duration(days: 365)),
    );
    
    if (picked != null) {
      setState(() {
        if (isBirthday) {
          _birthday = picked;
        } else {
          _anniversary = picked;
        }
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    // Load existing client data if editing
    if (isEditing) {
      final clientAsync = ref.watch(clientDetailProvider(widget.clientId!));
      return clientAsync.when(
        data: (client) {
          _initializeFromClient(client);
          return _buildForm(context);
        },
        loading: () => Scaffold(
          appBar: AppBar(title: const Text('Edit Client')),
          body: const Center(child: CircularProgressIndicator()),
        ),
        error: (e, s) => Scaffold(
          appBar: AppBar(title: const Text('Edit Client')),
          body: Center(child: Text('Error: $e')),
        ),
      );
    }
    
    return _buildForm(context);
  }

  Widget _buildForm(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(isEditing ? 'Edit Client' : 'New Client'),
        actions: [
          TextButton(
            onPressed: _isLoading ? null : _handleSubmit,
            child: _isLoading
                ? const SizedBox(
                    width: 20,
                    height: 20,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  )
                : const Text('Save'),
          ),
        ],
      ),
      body: Form(
        key: _formKey,
        child: ListView(
          padding: const EdgeInsets.all(16),
          children: [
            // Basic info
            Text(
              'Basic Information',
              style: Theme.of(context).textTheme.titleMedium?.copyWith(
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 16),
            Row(
              children: [
                Expanded(
                  child: TextFormField(
                    controller: _firstNameController,
                    decoration: const InputDecoration(labelText: 'First Name *'),
                    validator: (v) => v?.isEmpty == true ? 'Required' : null,
                  ),
                ),
                const SizedBox(width: 16),
                Expanded(
                  child: TextFormField(
                    controller: _lastNameController,
                    decoration: const InputDecoration(labelText: 'Last Name *'),
                    validator: (v) => v?.isEmpty == true ? 'Required' : null,
                  ),
                ),
              ],
            ),
            const SizedBox(height: 16),
            TextFormField(
              controller: _emailController,
              decoration: const InputDecoration(labelText: 'Email'),
              keyboardType: TextInputType.emailAddress,
            ),
            const SizedBox(height: 16),
            TextFormField(
              controller: _phoneController,
              decoration: const InputDecoration(labelText: 'Phone'),
              keyboardType: TextInputType.phone,
            ),
            
            const SizedBox(height: 32),
            Text(
              'Professional',
              style: Theme.of(context).textTheme.titleMedium?.copyWith(
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 16),
            TextFormField(
              controller: _companyController,
              decoration: const InputDecoration(labelText: 'Company'),
            ),
            const SizedBox(height: 16),
            TextFormField(
              controller: _roleController,
              decoration: const InputDecoration(labelText: 'Role'),
            ),
            const SizedBox(height: 16),
            TextFormField(
              controller: _industryController,
              decoration: const InputDecoration(labelText: 'Industry'),
            ),
            
            const SizedBox(height: 32),
            Text(
              'Personal',
              style: Theme.of(context).textTheme.titleMedium?.copyWith(
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 16),
            Row(
              children: [
                Expanded(
                  child: InkWell(
                    onTap: () => _selectDate(context, true),
                    child: InputDecorator(
                      decoration: const InputDecoration(labelText: 'Birthday'),
                      child: Text(
                        _birthday != null
                            ? '${_birthday!.month}/${_birthday!.day}/${_birthday!.year}'
                            : 'Select date',
                        style: TextStyle(
                          color: _birthday != null ? null : Colors.grey,
                        ),
                      ),
                    ),
                  ),
                ),
                const SizedBox(width: 16),
                Expanded(
                  child: InkWell(
                    onTap: () => _selectDate(context, false),
                    child: InputDecorator(
                      decoration: const InputDecoration(labelText: 'Anniversary'),
                      child: Text(
                        _anniversary != null
                            ? '${_anniversary!.month}/${_anniversary!.day}/${_anniversary!.year}'
                            : 'Select date',
                        style: TextStyle(
                          color: _anniversary != null ? null : Colors.grey,
                        ),
                      ),
                    ),
                  ),
                ),
              ],
            ),
            const SizedBox(height: 16),
            TextFormField(
              controller: _interestsController,
              decoration: const InputDecoration(
                labelText: 'Interests',
                hintText: 'Golf, Wine, Travel (comma separated)',
              ),
            ),
            
            const SizedBox(height: 32),
            Text(
              'Notes & Tags',
              style: Theme.of(context).textTheme.titleMedium?.copyWith(
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 16),
            TextFormField(
              controller: _notesController,
              decoration: const InputDecoration(labelText: 'Notes'),
              maxLines: 4,
            ),
            const SizedBox(height: 16),
            TextFormField(
              controller: _tagsController,
              decoration: const InputDecoration(
                labelText: 'Tags',
                hintText: 'VIP, Referral Source (comma separated)',
              ),
            ),
            
            const SizedBox(height: 32),
          ],
        ),
      ),
    );
  }
}