import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../providers/auth_provider.dart';
import '../services/api_service.dart';
import '../models/conversation.dart';

class HistoryScreen extends StatefulWidget {
  final Function(String) onSelectConversation;

  const HistoryScreen({
    super.key,
    required this.onSelectConversation,
  });

  @override
  State<HistoryScreen> createState() => _HistoryScreenState();
}

class _HistoryScreenState extends State<HistoryScreen> {
  final ApiService _apiService = ApiService();
  List<Conversation> _conversations = [];
  bool _isLoading = true;
  String? _error;

  @override
  void initState() {
    super.initState();
    _loadConversations();
  }

  Future<void> _loadConversations() async {
    final auth = context.read<AuthProvider>();
    _apiService.setToken(auth.token);

    setState(() {
      _isLoading = true;
      _error = null;
    });

    try {
      final conversations = await _apiService.getConversations();
      setState(() {
        _conversations = conversations;
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _error = e.toString();
        _isLoading = false;
      });
    }
  }

  Future<void> _deleteConversation(String id) async {
    try {
      await _apiService.deleteConversation(id);
      setState(() {
        _conversations.removeWhere((c) => c.id == id);
      });
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Failed to delete: $e'),
            backgroundColor: Colors.red.shade700,
          ),
        );
      }
    }
  }

  IconData _getTitleIcon(String title) {
    final lower = title.toLowerCase();
    if (lower.contains('error') || lower.contains('fix') || lower.contains('bug')) {
      return Icons.bug_report;
    }
    if (lower.contains('test')) {
      return Icons.science;
    }
    if (lower.contains('backup') || lower.contains('restore')) {
      return Icons.backup;
    }
    if (lower.contains('deploy') || lower.contains('build')) {
      return Icons.rocket_launch;
    }
    if (lower.contains('install') || lower.contains('setup')) {
      return Icons.download;
    }
    return Icons.chat_bubble_outline;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFF1A1A1A),
      appBar: AppBar(
        backgroundColor: const Color(0xFF2D2D2D),
        title: const Text('Conversations'),
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh),
            onPressed: _loadConversations,
          ),
        ],
      ),
      body: _buildBody(),
    );
  }

  Widget _buildBody() {
    if (_isLoading) {
      return const Center(
        child: CircularProgressIndicator(color: Colors.orange),
      );
    }

    if (_error != null) {
      return Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(Icons.error_outline, size: 48, color: Colors.red.shade400),
            const SizedBox(height: 16),
            Text(
              _error!,
              style: TextStyle(color: Colors.grey.shade400),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 16),
            ElevatedButton(
              onPressed: _loadConversations,
              style: ElevatedButton.styleFrom(
                backgroundColor: Colors.orange.shade700,
              ),
              child: const Text('Retry'),
            ),
          ],
        ),
      );
    }

    if (_conversations.isEmpty) {
      return Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(Icons.chat_bubble_outline, size: 64, color: Colors.grey.shade700),
            const SizedBox(height: 16),
            Text(
              'No conversations yet',
              style: TextStyle(
                color: Colors.grey.shade400,
                fontSize: 18,
              ),
            ),
            const SizedBox(height: 8),
            Text(
              'Start a new chat to get started',
              style: TextStyle(
                color: Colors.grey.shade600,
                fontSize: 14,
              ),
            ),
          ],
        ),
      );
    }

    return RefreshIndicator(
      onRefresh: _loadConversations,
      color: Colors.orange,
      child: ListView.builder(
        padding: const EdgeInsets.symmetric(vertical: 8),
        itemCount: _conversations.length,
        itemBuilder: (context, index) {
          final conv = _conversations[index];
          return Dismissible(
            key: Key(conv.id),
            direction: DismissDirection.endToStart,
            background: Container(
              alignment: Alignment.centerRight,
              padding: const EdgeInsets.only(right: 20),
              color: Colors.red.shade700,
              child: const Icon(Icons.delete, color: Colors.white),
            ),
            confirmDismiss: (_) async {
              return await showDialog<bool>(
                context: context,
                builder: (context) => AlertDialog(
                  backgroundColor: const Color(0xFF2D2D2D),
                  title: const Text(
                    'Delete Conversation?',
                    style: TextStyle(color: Colors.white),
                  ),
                  content: const Text(
                    'This action cannot be undone.',
                    style: TextStyle(color: Colors.white70),
                  ),
                  actions: [
                    TextButton(
                      onPressed: () => Navigator.pop(context, false),
                      child: const Text('Cancel'),
                    ),
                    TextButton(
                      onPressed: () => Navigator.pop(context, true),
                      style: TextButton.styleFrom(
                        foregroundColor: Colors.red.shade400,
                      ),
                      child: const Text('Delete'),
                    ),
                  ],
                ),
              );
            },
            onDismissed: (_) => _deleteConversation(conv.id),
            child: ListTile(
              leading: CircleAvatar(
                backgroundColor: const Color(0xFF3D3D3D),
                child: Icon(
                  _getTitleIcon(conv.displayTitle),
                  color: Colors.orange.shade400,
                  size: 20,
                ),
              ),
              title: Text(
                conv.displayTitle,
                style: const TextStyle(
                  color: Colors.white,
                  fontWeight: FontWeight.w500,
                ),
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
              ),
              subtitle: Text(
                '${conv.timeAgo} • ${conv.messageCount} messages',
                style: TextStyle(
                  color: Colors.grey.shade500,
                  fontSize: 12,
                ),
              ),
              trailing: Icon(
                Icons.chevron_right,
                color: Colors.grey.shade600,
              ),
              onTap: () {
                widget.onSelectConversation(conv.id);
                Navigator.pop(context);
              },
            ),
          );
        },
      ),
    );
  }
}