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

/// Screen for editing an existing OPDS server
class EditServerScreen extends ConsumerStatefulWidget {
  final String serverId;

  const EditServerScreen({
    super.key,
    required this.serverId,
  });

  @override
  ConsumerState<EditServerScreen> createState() => _EditServerScreenState();
}

class _EditServerScreenState extends ConsumerState<EditServerScreen> {
  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;
  OPDSServer? _originalServer;

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

  @override
  Widget build(BuildContext context) {
    final serverAsync = ref.watch(serverProvider(widget.serverId));

    return Scaffold(
      appBar: AppBar(
        title: const Text('Edit Server'),
      ),
      body: serverAsync.when(
        data: (server) {
          if (server == null) {
            return const Center(
              child: Text('Server not found'),
            );
          }

          // Initialize form fields if not already done
          if (_originalServer == null) {
            _originalServer = server;
            _nameController.text = server.name;
            _urlController.text = server.url;
            _requiresAuth = server.requiresAuth;
            if (server.username != null) {
              _usernameController.text = server.username!;
            }
            if (server.password != null) {
              _passwordController.text = server.password!;
            }
          }

          return Form(
            key: _formKey,
            child: ListView(
              padding: const EdgeInsets.all(16),
              children: [
                // Name field
                TextFormField(
                  controller: _nameController,
                  decoration: const InputDecoration(
                    labelText: 'Server Name',
                    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',
                    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),
                ],

                // Server metadata
                Card(
                  color: Theme.of(context).colorScheme.surfaceContainerHighest,
                  child: Padding(
                    padding: const EdgeInsets.all(16),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          'Server Information',
                          style: Theme.of(context)
                              .textTheme
                              .titleSmall
                              ?.copyWith(
                                fontWeight: FontWeight.bold,
                              ),
                        ),
                        const SizedBox(height: 8),
                        _buildInfoRow(
                          'Added',
                          _formatDateTime(server.createdAt),
                        ),
                        if (server.lastSyncedAt != null)
                          _buildInfoRow(
                            'Last Synced',
                            _formatDateTime(server.lastSyncedAt!),
                          ),
                      ],
                    ),
                  ),
                ),
                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('Save Changes'),
                ),
              ],
            ),
          );
        },
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (error, stack) => Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              const Icon(Icons.error_outline, size: 48, color: Colors.red),
              const SizedBox(height: 16),
              Text('Error loading server: $error'),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildInfoRow(String label, String value) {
    return Padding(
      padding: const EdgeInsets.only(top: 4),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Text(
            label,
            style: Theme.of(context).textTheme.bodySmall?.copyWith(
                  color: Theme.of(context)
                      .colorScheme
                      .onSurface
                      .withOpacity(0.6),
                ),
          ),
          Text(
            value,
            style: Theme.of(context).textTheme.bodySmall,
          ),
        ],
      ),
    );
  }

  String _formatDateTime(DateTime dateTime) {
    return '${dateTime.year}-${dateTime.month.toString().padLeft(2, '0')}-${dateTime.day.toString().padLeft(2, '0')} '
        '${dateTime.hour.toString().padLeft(2, '0')}:${dateTime.minute.toString().padLeft(2, '0')}';
  }

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

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

    try {
      // Create updated server
      final updatedServer = _originalServer!.copyWith(
        name: _nameController.text.trim(),
        url: _urlController.text.trim(),
        username: _requiresAuth ? _usernameController.text.trim() : null,
        password: _requiresAuth ? _passwordController.text : null,
      );

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

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

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