import 'package:flutter/material.dart';
import 'relay_management_controller.dart';
import '../../data/nostr/models/nostr_relay.dart';

/// Screen for managing Nostr relays.
/// 
/// Allows users to view, add, remove, and monitor relay health,
/// and trigger manual syncs.
class RelayManagementScreen extends StatefulWidget {
  /// Controller for managing relay state.
  final RelayManagementController controller;

  /// Creates a [RelayManagementScreen] instance.
  const RelayManagementScreen({
    super.key,
    required this.controller,
  });

  @override
  State<RelayManagementScreen> createState() => _RelayManagementScreenState();
}

class _RelayManagementScreenState extends State<RelayManagementScreen> {
  final TextEditingController _urlController = TextEditingController();

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Nostr Relay Management'),
      ),
      body: ListenableBuilder(
        listenable: widget.controller,
        builder: (context, child) {
          return Column(
            children: [
              // Error message
              if (widget.controller.error != null)
                Container(
                  width: double.infinity,
                  padding: const EdgeInsets.all(16),
                  color: Colors.red.shade100,
                  child: Row(
                    children: [
                      Icon(Icons.error, color: Colors.red.shade700),
                      const SizedBox(width: 8),
                      Expanded(
                        child: Text(
                          widget.controller.error!,
                          style: TextStyle(color: Colors.red.shade700),
                        ),
                      ),
                      IconButton(
                        icon: const Icon(Icons.close),
                        onPressed: widget.controller.clearError,
                        color: Colors.red.shade700,
                      ),
                    ],
                  ),
                ),

              // Actions section
              Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    // Add relay input
                    Row(
                      children: [
                        Expanded(
                          child: TextField(
                            controller: _urlController,
                            decoration: InputDecoration(
                              labelText: 'Relay URL',
                              hintText: widget.controller.relays.isNotEmpty
                                  ? widget.controller.relays.first.url
                                  : 'wss://nostrum.satoshinakamoto.win',
                              border: const OutlineInputBorder(),
                            ),
                            keyboardType: TextInputType.url,
                          ),
                        ),
                        const SizedBox(width: 8),
                        ElevatedButton.icon(
                          onPressed: () {
                            final url = _urlController.text.trim();
                            if (url.isNotEmpty) {
                              if (widget.controller.addRelay(url)) {
                                _urlController.clear();
                                ScaffoldMessenger.of(context).showSnackBar(
                                  const SnackBar(
                                    content: Text('Relay added successfully'),
                                    duration: Duration(seconds: 2),
                                  ),
                                );
                              }
                            }
                          },
                          icon: const Icon(Icons.add),
                          label: const Text('Add'),
                        ),
                      ],
                    ),
                    const SizedBox(height: 16),

                    // Action buttons
                    Wrap(
                      spacing: 8,
                      runSpacing: 8,
                      children: [
                        ElevatedButton.icon(
                          onPressed: widget.controller.isCheckingHealth
                              ? null
                              : widget.controller.checkRelayHealth,
                          icon: widget.controller.isCheckingHealth
                              ? const SizedBox(
                                  width: 16,
                                  height: 16,
                                  child: CircularProgressIndicator(strokeWidth: 2),
                                )
                              : const Icon(Icons.health_and_safety),
                          label: const Text('Check Health'),
                        ),
                        if (widget.controller.syncEngine != null)
                          ElevatedButton.icon(
                            onPressed: widget.controller.isSyncing
                                ? null
                                : () async {
                                    final success = await widget.controller.triggerManualSync();
                                    if (mounted) {
                                      ScaffoldMessenger.of(context).showSnackBar(
                                        SnackBar(
                                          content: Text(
                                            success
                                                ? 'Sync triggered successfully'
                                                : 'Sync failed: ${widget.controller.error ?? "Unknown error"}',
                                          ),
                                          duration: const Duration(seconds: 2),
                                        ),
                                      );
                                    }
                                  },
                            icon: widget.controller.isSyncing
                                ? const SizedBox(
                                    width: 16,
                                    height: 16,
                                    child: CircularProgressIndicator(strokeWidth: 2),
                                  )
                                : const Icon(Icons.sync),
                            label: const Text('Manual Sync'),
                          ),
                      ],
                    ),
                  ],
                ),
              ),

              const Divider(),

              // Relay list
              Expanded(
                child: widget.controller.relays.isEmpty
                    ? Center(
                        child: Column(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: [
                            Icon(
                              Icons.cloud_off,
                              size: 64,
                              color: Colors.grey.shade400,
                            ),
                            const SizedBox(height: 16),
                            Text(
                              'No relays configured',
                              style: Theme.of(context).textTheme.titleLarge?.copyWith(
                                    color: Colors.grey,
                                  ),
                            ),
                            const SizedBox(height: 8),
                            Text(
                              'Add a relay to get started',
                              style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                                    color: Colors.grey,
                                  ),
                            ),
                          ],
                        ),
                      )
                    : ListView.builder(
                        itemCount: widget.controller.relays.length,
                        itemBuilder: (context, index) {
                          final relay = widget.controller.relays[index];
                          return _RelayListItem(
                            relay: relay,
                            onConnect: () => widget.controller.connectRelay(relay.url),
                            onDisconnect: () => widget.controller.disconnectRelay(relay.url),
                            onRemove: () {
                              widget.controller.removeRelay(relay.url);
                              ScaffoldMessenger.of(context).showSnackBar(
                                SnackBar(
                                  content: Text('Relay ${relay.url} removed'),
                                  duration: const Duration(seconds: 2),
                                ),
                              );
                            },
                          );
                        },
                      ),
              ),
            ],
          );
        },
      ),
    );
  }
}

/// Widget for displaying a single relay in the list.
class _RelayListItem extends StatelessWidget {
  /// The relay to display.
  final NostrRelay relay;

  /// Callback when connect is pressed.
  final VoidCallback onConnect;

  /// Callback when disconnect is pressed.
  final VoidCallback onDisconnect;

  /// Callback when remove is pressed.
  final VoidCallback onRemove;

  const _RelayListItem({
    required this.relay,
    required this.onConnect,
    required this.onDisconnect,
    required this.onRemove,
  });

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
      child: ListTile(
        leading: CircleAvatar(
          backgroundColor: relay.isConnected ? Colors.green : Colors.grey,
          child: Icon(
            relay.isConnected ? Icons.check : Icons.close,
            color: Colors.white,
            size: 20,
          ),
        ),
        title: Text(
          relay.url,
          style: const TextStyle(fontWeight: FontWeight.bold),
        ),
        subtitle: Text(
          relay.isConnected ? 'Connected' : 'Disconnected',
          style: TextStyle(
            color: relay.isConnected ? Colors.green : Colors.grey,
          ),
        ),
        trailing: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            IconButton(
              icon: Icon(
                relay.isConnected ? Icons.link_off : Icons.link,
                color: relay.isConnected ? Colors.orange : Colors.green,
              ),
              tooltip: relay.isConnected ? 'Disconnect' : 'Connect',
              onPressed: relay.isConnected ? onDisconnect : onConnect,
            ),
            IconButton(
              icon: const Icon(Icons.delete, color: Colors.red),
              tooltip: 'Remove',
              onPressed: onRemove,
            ),
          ],
        ),
      ),
    );
  }
}