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

import '../../data/sources/ble/ble_provisioner.dart';

// Shared bottom sheet used by onboarding and the main sensor screens.
// Flow: scan → select device → enter WiFi credentials → provision → place on map.
class BleProvisionSheet extends ConsumerStatefulWidget {
  const BleProvisionSheet({super.key});

  @override
  ConsumerState<BleProvisionSheet> createState() => _BleProvisionSheetState();
}

class _BleProvisionSheetState extends ConsumerState<BleProvisionSheet> {
  final _provisioner = BleProvisioner();
  final _ssidController = TextEditingController();
  final _wifiPasswordController = TextEditingController();

  BleScanResult? _selected;
  bool _provisioning = false;
  String? _error;

  @override
  void dispose() {
    _provisioner.dispose();
    _ssidController.dispose();
    _wifiPasswordController.dispose();
    super.dispose();
  }

  Future<void> _provision() async {
    if (_selected == null) return;
    setState(() {
      _provisioning = true;
      _error = null;
    });
    try {
      await _provisioner.provision(
        _selected!.deviceId,
        ssid: _ssidController.text.trim(),
        wifiPassword: _wifiPasswordController.text,
      );
      // TODO: poll localiserd until sensor appears, then prompt placement on map.
      if (mounted) Navigator.of(context).pop();
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      if (mounted) setState(() => _provisioning = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return DraggableScrollableSheet(
      expand: false,
      initialChildSize: 0.6,
      maxChildSize: 0.9,
      builder: (context, scrollController) => Padding(
        padding: EdgeInsets.fromLTRB(
          24,
          16,
          24,
          MediaQuery.of(context).viewInsets.bottom + 24,
        ),
        child: ListView(
          controller: scrollController,
          children: [
            Text('Add sensor',
                style: Theme.of(context).textTheme.titleLarge),
            const SizedBox(height: 16),

            // Scan results
            // TODO: StreamBuilder on _provisioner.scan() — show a list of
            //       BleScanResult tiles; tapping one sets _selected.
            const Text('Nearby ESP32 devices'),
            const SizedBox(height: 8),
            const Placeholder(fallbackHeight: 120),
            const SizedBox(height: 24),

            if (_selected != null) ...[
              Text('Selected: ${_selected!.name}'),
              const SizedBox(height: 16),
              TextField(
                controller: _ssidController,
                decoration: const InputDecoration(
                  labelText: 'WiFi SSID',
                  border: OutlineInputBorder(),
                ),
              ),
              const SizedBox(height: 12),
              TextField(
                controller: _wifiPasswordController,
                decoration: const InputDecoration(
                  labelText: 'WiFi password',
                  border: OutlineInputBorder(),
                ),
                obscureText: true,
              ),
              const SizedBox(height: 16),
            ],

            if (_error != null)
              Padding(
                padding: const EdgeInsets.only(bottom: 12),
                child: Text(_error!,
                    style: TextStyle(
                        color: Theme.of(context).colorScheme.error)),
              ),

            FilledButton(
              onPressed: (_selected == null || _provisioning) ? null : _provision,
              child: _provisioning
                  ? const SizedBox.square(
                      dimension: 20,
                      child: CircularProgressIndicator(strokeWidth: 2))
                  : const Text('Provision & add'),
            ),
          ],
        ),
      ),
    );
  }
}