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

final emailsProvider = FutureProvider.autoDispose<List<Map<String, dynamic>>>((ref) async {
  final apiClient = ref.watch(apiClientProvider);
  return apiClient.getEmails();
});

class EmailsScreen extends ConsumerWidget {
  const EmailsScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final emailsAsync = ref.watch(emailsProvider);
    
    return Scaffold(
      appBar: AppBar(
        title: const Text('Emails'),
      ),
      body: emailsAsync.when(
        data: (emails) {
          if (emails.isEmpty) {
            return Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Icon(
                    Icons.email_outlined,
                    size: 64,
                    color: Colors.grey.shade400,
                  ),
                  const SizedBox(height: 16),
                  Text(
                    'No emails yet',
                    style: Theme.of(context).textTheme.titleMedium?.copyWith(
                      color: Colors.grey,
                    ),
                  ),
                  const SizedBox(height: 8),
                  Text(
                    'Generate an email from a client profile',
                    style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                      color: Colors.grey,
                    ),
                  ),
                ],
              ),
            );
          }
          
          final drafts = emails.where((e) => e['status'] == 'draft').toList();
          final sent = emails.where((e) => e['status'] == 'sent').toList();
          
          return DefaultTabController(
            length: 2,
            child: Column(
              children: [
                const TabBar(
                  tabs: [
                    Tab(text: 'Drafts'),
                    Tab(text: 'Sent'),
                  ],
                ),
                Expanded(
                  child: TabBarView(
                    children: [
                      _EmailList(emails: drafts, isDraft: true, ref: ref),
                      _EmailList(emails: sent, isDraft: false, ref: ref),
                    ],
                  ),
                ),
              ],
            ),
          );
        },
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (e, s) => Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Icon(Icons.error_outline, size: 64, color: Colors.red.shade300),
              const SizedBox(height: 16),
              const Text('Failed to load emails'),
              TextButton(
                onPressed: () => ref.invalidate(emailsProvider),
                child: const Text('Retry'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _EmailList extends StatelessWidget {
  final List<Map<String, dynamic>> emails;
  final bool isDraft;
  final WidgetRef ref;
  
  const _EmailList({
    required this.emails,
    required this.isDraft,
    required this.ref,
  });
  
  @override
  Widget build(BuildContext context) {
    if (emails.isEmpty) {
      return Center(
        child: Text(
          isDraft ? 'No drafts' : 'No sent emails',
          style: TextStyle(color: Colors.grey.shade600),
        ),
      );
    }
    
    return ListView.builder(
      padding: const EdgeInsets.all(16),
      itemCount: emails.length,
      itemBuilder: (context, index) {
        final email = emails[index];
        final dateFormat = DateFormat.yMMMd().add_jm();
        final date = email['sentAt'] ?? email['createdAt'];
        
        return Card(
          margin: const EdgeInsets.only(bottom: 12),
          child: ListTile(
            title: Text(
              email['subject'] ?? 'No subject',
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
            ),
            subtitle: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  email['content']?.toString().substring(0, 
                    email['content'].toString().length > 100 ? 100 : email['content'].toString().length) ?? '',
                  maxLines: 2,
                  overflow: TextOverflow.ellipsis,
                  style: TextStyle(color: Colors.grey.shade600),
                ),
                const SizedBox(height: 4),
                Text(
                  date != null ? dateFormat.format(DateTime.parse(date)) : '',
                  style: Theme.of(context).textTheme.bodySmall?.copyWith(
                    color: Colors.grey,
                  ),
                ),
              ],
            ),
            trailing: isDraft
                ? Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      IconButton(
                        icon: const Icon(Icons.send),
                        onPressed: () async {
                          try {
                            await ref.read(apiClientProvider).sendEmail(email['id']);
                            ref.invalidate(emailsProvider);
                          } catch (e) {
                            if (context.mounted) {
                              ScaffoldMessenger.of(context).showSnackBar(
                                SnackBar(content: Text('Failed to send: $e')),
                              );
                            }
                          }
                        },
                      ),
                      IconButton(
                        icon: const Icon(Icons.delete_outline),
                        onPressed: () async {
                          final confirm = await showDialog<bool>(
                            context: context,
                            builder: (ctx) => AlertDialog(
                              title: const Text('Delete Draft'),
                              content: const Text('Are you sure?'),
                              actions: [
                                TextButton(
                                  onPressed: () => Navigator.pop(ctx, false),
                                  child: const Text('Cancel'),
                                ),
                                TextButton(
                                  onPressed: () => Navigator.pop(ctx, true),
                                  child: const Text('Delete'),
                                ),
                              ],
                            ),
                          );
                          if (confirm == true) {
                            await ref.read(apiClientProvider).deleteEmail(email['id']);
                            ref.invalidate(emailsProvider);
                          }
                        },
                      ),
                    ],
                  )
                : email['aiGenerated'] == true
                    ? const Chip(
                        label: Text('AI'),
                        visualDensity: VisualDensity.compact,
                      )
                    : null,
            isThreeLine: true,
          ),
        );
      },
    );
  }
}