// FaiSettingsDialog — modal for changing the hub endpoint.
// Reads current values from HubService, persists on save via
// HubService.reconnect.

import 'package:fai_dart_sdk/fai_dart_sdk.dart';
import 'package:flutter/material.dart';

import '../data/hub.dart';
import '../theme/theme.dart';
import '../theme/tokens.dart';

class FaiSettingsDialog extends StatefulWidget {
  const FaiSettingsDialog({super.key});

  /// Convenience launcher used from the sidebar gear icon.
  static Future<bool> show(BuildContext context) async {
    final ok = await showDialog<bool>(
      context: context,
      builder: (_) => const FaiSettingsDialog(),
    );
    return ok ?? false;
  }

  @override
  State<FaiSettingsDialog> createState() => _FaiSettingsDialogState();
}

class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
  late final TextEditingController _host;
  late final TextEditingController _port;
  bool _secure = false;
  bool _saving = false;
  String? _error;
  ChannelStatusSnapshot? _channels;

  @override
  void initState() {
    super.initState();
    final ep = HubService.instance.currentEndpoint;
    _host = TextEditingController(text: ep.host);
    _port = TextEditingController(text: ep.port.toString());
    _secure = ep.secure;
    _loadChannels();
  }

  Future<void> _loadChannels() async {
    try {
      final snap = await HubService.instance.channelStatus();
      if (!mounted) return;
      setState(() => _channels = snap);
    } catch (_) {
      // Silent: channels block stays hidden when the hub is
      // unreachable (the endpoint section is the operator's
      // path back to a working connection).
    }
  }

  Future<void> _connectToChannel(ChannelInfo ch) async {
    setState(() {
      _host.text = '127.0.0.1';
      _port.text = ch.port.toString();
      _secure = false;
    });
    await _save();
  }

  @override
  void dispose() {
    _host.dispose();
    _port.dispose();
    super.dispose();
  }

  Future<void> _save() async {
    setState(() {
      _saving = true;
      _error = null;
    });
    final port = int.tryParse(_port.text.trim());
    if (port == null || port <= 0 || port > 65535) {
      setState(() {
        _saving = false;
        _error = 'port must be 1–65535';
      });
      return;
    }
    final endpoint = HubEndpoint(
      host: _host.text.trim().isEmpty ? '127.0.0.1' : _host.text.trim(),
      port: port,
      secure: _secure,
    );
    try {
      await HubService.instance.reconnect(endpoint);
      if (!mounted) return;
      Navigator.pop(context, true);
    } catch (e) {
      setState(() {
        _saving = false;
        _error = e.toString();
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return AlertDialog(
      title: const Text('Hub endpoint'),
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(FaiRadius.md),
      ),
      contentPadding: const EdgeInsets.symmetric(
        horizontal: FaiSpace.xl,
        vertical: FaiSpace.lg,
      ),
      content: ConstrainedBox(
        constraints: const BoxConstraints(maxWidth: 380),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              'Where should Studio connect? Default is the local hub at 127.0.0.1:50051.',
              style: theme.textTheme.bodySmall?.copyWith(
                color: theme.colorScheme.onSurfaceVariant,
              ),
            ),
            const SizedBox(height: FaiSpace.lg),
            TextField(
              controller: _host,
              decoration: const InputDecoration(
                labelText: 'Host',
                border: OutlineInputBorder(),
                isDense: true,
              ),
              autofocus: true,
            ),
            const SizedBox(height: FaiSpace.md),
            Row(
              children: [
                Expanded(
                  flex: 2,
                  child: TextField(
                    controller: _port,
                    decoration: const InputDecoration(
                      labelText: 'Port',
                      border: OutlineInputBorder(),
                      isDense: true,
                    ),
                    keyboardType: TextInputType.number,
                  ),
                ),
                const SizedBox(width: FaiSpace.md),
                Expanded(
                  flex: 3,
                  child: SwitchListTile(
                    contentPadding: EdgeInsets.zero,
                    dense: true,
                    title: const Text('TLS'),
                    subtitle: Text(
                      'https/grpc-secure',
                      style: theme.textTheme.bodySmall?.copyWith(
                        color: theme.colorScheme.onSurfaceVariant,
                      ),
                    ),
                    value: _secure,
                    onChanged: (v) => setState(() => _secure = v),
                  ),
                ),
              ],
            ),
            if (_error != null) ...[
              const SizedBox(height: FaiSpace.md),
              Text(
                _error!,
                style: theme.textTheme.bodySmall?.copyWith(
                  color: theme.colorScheme.error,
                ),
              ),
            ],
            const SizedBox(height: FaiSpace.md),
            Container(
              padding: const EdgeInsets.all(FaiSpace.sm),
              decoration: BoxDecoration(
                color: theme.colorScheme.surfaceContainerHigh,
                borderRadius: BorderRadius.circular(FaiRadius.sm),
              ),
              child: Row(
                children: [
                  Icon(
                    Icons.link,
                    size: 14,
                    color: theme.colorScheme.onSurfaceVariant,
                  ),
                  const SizedBox(width: FaiSpace.sm),
                  Text(
                    _previewUrl(),
                    style: FaiTheme.mono(
                      size: 11,
                      color: theme.colorScheme.onSurface,
                    ),
                  ),
                ],
              ),
            ),
            if (_channels != null) ...[
              const SizedBox(height: FaiSpace.lg),
              Text(
                'CHANNELS',
                style: theme.textTheme.labelSmall?.copyWith(
                  color: theme.colorScheme.onSurfaceVariant,
                  letterSpacing: 0.6,
                  fontSize: 10,
                ),
              ),
              const SizedBox(height: 4),
              for (final ch in _channels!.channels)
                _ChannelRow(
                  channel: ch,
                  active: ch.name == _channels!.active,
                  onConnect: _saving ? null : () => _connectToChannel(ch),
                ),
            ],
          ],
        ),
      ),
      actions: [
        TextButton(
          onPressed: _saving ? null : () => Navigator.pop(context, false),
          child: const Text('Cancel'),
        ),
        FilledButton(
          onPressed: _saving ? null : _save,
          child: _saving
              ? const SizedBox(
                  width: 16,
                  height: 16,
                  child: CircularProgressIndicator(strokeWidth: 2),
                )
              : const Text('Save & connect'),
        ),
      ],
    );
  }

  String _previewUrl() {
    final scheme = _secure ? 'https' : 'http';
    final host =
        _host.text.trim().isEmpty ? '127.0.0.1' : _host.text.trim();
    final port = _port.text.trim().isEmpty ? '50051' : _port.text.trim();
    return '$scheme://$host:$port';
  }
}

class _ChannelRow extends StatelessWidget {
  final ChannelInfo channel;
  final bool active;
  final VoidCallback? onConnect;

  const _ChannelRow({
    required this.channel,
    required this.active,
    required this.onConnect,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 2),
      child: Row(
        children: [
          Icon(
            channel.running ? Icons.circle : Icons.circle_outlined,
            size: 10,
            color: channel.running
                ? FaiColors.success
                : theme.colorScheme.outline,
          ),
          const SizedBox(width: FaiSpace.sm),
          SizedBox(
            width: 88,
            child: Text(
              channel.name,
              style: FaiTheme.mono(
                size: 11,
                weight: active ? FontWeight.w600 : FontWeight.w400,
                color: theme.colorScheme.onSurface,
              ),
            ),
          ),
          SizedBox(
            width: 64,
            child: Text(
              ':${channel.port}',
              style: FaiTheme.mono(
                size: 11,
                color: theme.colorScheme.onSurfaceVariant,
              ),
            ),
          ),
          Expanded(
            child: Text(
              channel.running ? 'running' : 'stopped',
              style: theme.textTheme.bodySmall?.copyWith(
                color: theme.colorScheme.onSurfaceVariant,
              ),
            ),
          ),
          if (active)
            Padding(
              padding: const EdgeInsets.only(right: FaiSpace.sm),
              child: Text(
                'active',
                style: theme.textTheme.labelSmall?.copyWith(
                  color: theme.colorScheme.primary,
                ),
              ),
            ),
          TextButton(
            onPressed: channel.running ? onConnect : null,
            child: const Text('Connect'),
          ),
        ],
      ),
    );
  }
}