import "package:flutter/material.dart";
import "package:provider/provider.dart";

import "../app/app_router.dart";
import "../app/app_state.dart";
import "../models/service_point.dart";
import "../services/api.dart";

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

  @override
  State<ServicePointSelectScreen> createState() => _ServicePointSelectScreenState();
}

class _ServicePointSelectScreenState extends State<ServicePointSelectScreen> {
  Future<List<ServicePoint>>? _future;

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    final businessId = context.read<AppState>().selectedBusinessId;
    if (businessId == null) return;
    _future ??= Api.listServicePoints(businessId: businessId);
  }

  @override
  Widget build(BuildContext context) {
    final businessId = context.watch<AppState>().selectedBusinessId;

    if (businessId == null) {
      return Scaffold(
        appBar: AppBar(title: const Text("Select Service Point")),
        body: const Center(child: Text("No restaurant selected.")),
      );
    }

    return Scaffold(
      appBar: AppBar(
        title: const Text("Select Service Point"),
      ),
      body: FutureBuilder<List<ServicePoint>>(
        future: _future,
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return const Center(child: CircularProgressIndicator());
          }
          if (snapshot.hasError) {
            return _ErrorPane(
              message: "Failed to load service points.\n${snapshot.error}",
              onRetry: () => setState(() => _future = Api.listServicePoints(businessId: businessId)),
            );
          }

          final items = snapshot.data ?? const <ServicePoint>[];
          if (items.isEmpty) {
            return _ErrorPane(
              message: "No service points returned.",
              onRetry: () => setState(() => _future = Api.listServicePoints(businessId: businessId)),
            );
          }

          return ListView.separated(
            itemCount: items.length,
            separatorBuilder: (_, __) => const Divider(height: 1),
            itemBuilder: (context, i) {
              final sp = items[i];
              return ListTile(
                title: Text(sp.name),
                trailing: const Icon(Icons.chevron_right),
                onTap: () {
                  context.read<AppState>().setServicePoint(sp.servicePointId);
                  Navigator.of(context).pushNamedAndRemoveUntil(
                    AppRoutes.orderHome,
                    (route) => false,
                  );
                },
              );
            },
          );
        },
      ),
    );
  }
}

class _ErrorPane extends StatelessWidget {
  final String message;
  final VoidCallback onRetry;

  const _ErrorPane({required this.message, required this.onRetry});

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Padding(
        padding: const EdgeInsets.all(18),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(message, textAlign: TextAlign.center),
            const SizedBox(height: 12),
            FilledButton(
              onPressed: onRetry,
              child: const Text("Retry"),
            ),
          ],
        ),
      ),
    );
  }
}