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/presentation/clients_screen.dart';

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

  @override
  ConsumerState<EmailComposeScreen> createState() => _EmailComposeScreenState();
}

class _EmailComposeScreenState extends ConsumerState<EmailComposeScreen> {
  final _purposeController = TextEditingController();
  final _subjectController = TextEditingController();
  final _contentController = TextEditingController();
  
  String? _selectedClientId;
  bool _isGenerating = false;
  bool _hasGenerated = false;

  @override
  void initState() {
    super.initState();
    _selectedClientId = widget.clientId;
  }

  @override
  void dispose() {
    _purposeController.dispose();
    _subjectController.dispose();
    _contentController.dispose();
    super.dispose();
  }

  Future<void> _generateEmail() async {
    if (_selectedClientId == null) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Please select a client')),
      );
      return;
    }
    
    if (_purposeController.text.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Please enter a purpose')),
      );
      return;
    }
    
    setState(() => _isGenerating = true);
    
    try {
      final result = await ref.read(apiClientProvider).generateEmail(
        clientId: _selectedClientId!,
        purpose: _purposeController.text.trim(),
      );
      
      setState(() {
        _subjectController.text = result['subject'] ?? '';
        _contentController.text = result['content'] ?? '';
        _hasGenerated = true;
      });
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Failed to generate: $e')),
        );
      }
    } finally {
      if (mounted) {
        setState(() => _isGenerating = false);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final clientsAsync = ref.watch(clientsProvider(null));
    
    return Scaffold(
      appBar: AppBar(
        title: const Text('Compose Email'),
        actions: [
          if (_hasGenerated)
            TextButton(
              onPressed: () {
                // Email was already saved as draft during generation
                context.go('/emails');
              },
              child: const Text('Done'),
            ),
        ],
      ),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          // Client selector
          Text(
            'Select Client',
            style: Theme.of(context).textTheme.titleMedium?.copyWith(
              fontWeight: FontWeight.bold,
            ),
          ),
          const SizedBox(height: 8),
          clientsAsync.when(
            data: (clients) => DropdownButtonFormField<String>(
              value: _selectedClientId,
              decoration: const InputDecoration(
                hintText: 'Choose a client',
              ),
              items: clients.map((client) => DropdownMenuItem(
                value: client['id'] as String,
                child: Text('${client['firstName']} ${client['lastName']}'),
              )).toList(),
              onChanged: (value) {
                setState(() {
                  _selectedClientId = value;
                  _hasGenerated = false;
                });
              },
            ),
            loading: () => const LinearProgressIndicator(),
            error: (e, s) => Text('Error loading clients: $e'),
          ),
          
          const SizedBox(height: 24),
          
          // Purpose input
          Text(
            'Email Purpose',
            style: Theme.of(context).textTheme.titleMedium?.copyWith(
              fontWeight: FontWeight.bold,
            ),
          ),
          const SizedBox(height: 8),
          TextFormField(
            controller: _purposeController,
            decoration: const InputDecoration(
              hintText: 'e.g., Follow up after meeting, Birthday wishes, Market update',
            ),
            maxLines: 2,
          ),
          
          const SizedBox(height: 16),
          
          // Generate button
          FilledButton.icon(
            onPressed: _isGenerating ? null : _generateEmail,
            icon: _isGenerating 
                ? const SizedBox(
                    width: 20,
                    height: 20,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  )
                : const Icon(Icons.auto_awesome),
            label: Text(_isGenerating ? 'Generating...' : 'Generate with AI'),
          ),
          
          if (_hasGenerated) ...[
            const SizedBox(height: 32),
            const Divider(),
            const SizedBox(height: 16),
            
            // Subject
            Text(
              'Subject',
              style: Theme.of(context).textTheme.titleMedium?.copyWith(
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 8),
            TextFormField(
              controller: _subjectController,
              decoration: const InputDecoration(
                hintText: 'Email subject',
              ),
            ),
            
            const SizedBox(height: 16),
            
            // Content
            Text(
              'Content',
              style: Theme.of(context).textTheme.titleMedium?.copyWith(
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 8),
            TextFormField(
              controller: _contentController,
              decoration: const InputDecoration(
                hintText: 'Email content',
              ),
              maxLines: 12,
            ),
            
            const SizedBox(height: 16),
            
            Row(
              children: [
                Expanded(
                  child: OutlinedButton.icon(
                    onPressed: _generateEmail,
                    icon: const Icon(Icons.refresh),
                    label: const Text('Regenerate'),
                  ),
                ),
              ],
            ),
          ],
        ],
      ),
    );
  }
}