import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:uuid/uuid.dart';
import 'package:worldhopper/models/opds_server.dart';
import 'package:worldhopper/providers/server_provider.dart';
import 'package:worldhopper/services/server_software_detector.dart';

/// Screen for adding a new OPDS server
class AddServerScreen extends ConsumerStatefulWidget {
  const AddServerScreen({super.key});

  @override
  ConsumerState<AddServerScreen> createState() => _AddServerScreenState();
}

class _AddServerScreenState extends ConsumerState<AddServerScreen> {
  final _formKey = GlobalKey<FormState>();
  final _nameController = TextEditingController();
  final _urlController = TextEditingController();
  final _usernameController = TextEditingController();
  final _passwordController = TextEditingController();
  bool _requiresAuth = false;
  bool _obscurePassword = true;
  bool _isLoading = false;

  @override
  void dispose() {
    _nameController.dispose();
    _urlController.dispose();
    _usernameController.dispose();
    _passwordController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Add Server'),
      ),
      body: Form(
        key: _formKey,
        child: ListView(
          padding: const EdgeInsets.all(16),
          children: [
            // Name field
            TextFormField(
              controller: _nameController,
              decoration: const InputDecoration(
                labelText: 'Server Name',
                hintText: 'My Library',
                prefixIcon: Icon(Icons.label),
              ),
              textInputAction: TextInputAction.next,
              validator: (value) {
                if (value == null || value.trim().isEmpty) {
                  return 'Please enter a server name';
                }
                return null;
              },
            ),
            const SizedBox(height: 16),

            // URL field
            TextFormField(
              controller: _urlController,
              decoration: const InputDecoration(
                labelText: 'Server URL',
                hintText: 'https://example.com/opds',
                prefixIcon: Icon(Icons.link),
              ),
              keyboardType: TextInputType.url,
              textInputAction: TextInputAction.next,
              validator: (value) {
                if (value == null || value.trim().isEmpty) {
                  return 'Please enter a server URL';
                }
                final uri = Uri.tryParse(value.trim());
                if (uri == null || !uri.hasScheme || !uri.hasAuthority) {
                  return 'Please enter a valid URL';
                }
                if (uri.scheme != 'http' && uri.scheme != 'https') {
                  return 'URL must start with http:// or https://';
                }
                return null;
              },
            ),
            const SizedBox(height: 24),

            // Authentication toggle
            SwitchListTile(
              title: const Text('Requires Authentication'),
              subtitle: const Text('Enable if server requires login'),
              value: _requiresAuth,
              onChanged: (value) {
                setState(() {
                  _requiresAuth = value;
                  if (!value) {
                    _usernameController.clear();
                    _passwordController.clear();
                  }
                });
              },
            ),
            const SizedBox(height: 16),

            // Authentication fields (conditionally shown)
            if (_requiresAuth) ...[
              TextFormField(
                controller: _usernameController,
                decoration: const InputDecoration(
                  labelText: 'Username',
                  prefixIcon: Icon(Icons.person),
                ),
                textInputAction: TextInputAction.next,
                validator: (value) {
                  if (_requiresAuth && (value == null || value.trim().isEmpty)) {
                    return 'Please enter a username';
                  }
                  return null;
                },
              ),
              const SizedBox(height: 16),
              TextFormField(
                controller: _passwordController,
                decoration: InputDecoration(
                  labelText: 'Password',
                  prefixIcon: const Icon(Icons.lock),
                  suffixIcon: IconButton(
                    icon: Icon(
                      _obscurePassword ? Icons.visibility : Icons.visibility_off,
                    ),
                    onPressed: () {
                      setState(() {
                        _obscurePassword = !_obscurePassword;
                      });
                    },
                  ),
                ),
                obscureText: _obscurePassword,
                textInputAction: TextInputAction.done,
                validator: (value) {
                  if (_requiresAuth && (value == null || value.isEmpty)) {
                    return 'Please enter a password';
                  }
                  return null;
                },
                onFieldSubmitted: (_) => _saveServer(),
              ),
              const SizedBox(height: 24),
            ],

            // Help text
            Card(
              color: Theme.of(context).colorScheme.surfaceContainerHighest,
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Row(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Icon(
                      Icons.info_outline,
                      color: Theme.of(context).colorScheme.primary,
                    ),
                    const SizedBox(width: 12),
                    Expanded(
                      child: Text(
                        'Enter the root URL of your OPDS server. Credentials will be securely stored on your device.',
                        style: Theme.of(context).textTheme.bodySmall,
                      ),
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 32),

            // Save button
            FilledButton(
              onPressed: _isLoading ? null : _saveServer,
              child: _isLoading
                  ? const SizedBox(
                      height: 20,
                      width: 20,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    )
                  : const Text('Add Server'),
            ),
          ],
        ),
      ),
    );
  }

  Future<void> _saveServer() async {
    if (!_formKey.currentState!.validate()) {
      return;
    }

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

    try {
      final url = _urlController.text.trim();

      // Check if server already exists
      final exists = await ref
          .read(serverNotifierProvider.notifier)
          .serverExists(url);

      if (exists) {
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('A server with this URL already exists'),
              backgroundColor: Colors.orange,
            ),
          );
        }
        setState(() {
          _isLoading = false;
        });
        return;
      }

      // Create new server
      var server = OPDSServer(
        id: const Uuid().v4(),
        name: _nameController.text.trim(),
        url: url,
        username: _requiresAuth ? _usernameController.text.trim() : null,
        password: _requiresAuth ? _passwordController.text : null,
        createdAt: DateTime.now(),
      );

      // Detect server software
      final detectedSoftware = await ServerSoftwareDetector().detect(server);
      if (detectedSoftware != null) {
        server = server.copyWith(serverSoftware: detectedSoftware);
      }

      // Save server
      await ref.read(serverNotifierProvider.notifier).addServer(server);

      if (mounted) {
        // Show success message
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('${server.name} added successfully'),
            backgroundColor: Colors.green,
          ),
        );

        // Navigate back
        context.pop();
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Error adding server: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    } finally {
      if (mounted) {
        setState(() {
          _isLoading = false;
        });
      }
    }
  }
}