// lib/screens/restaurant_select_screen.dart

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

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

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

  @override
  State<RestaurantSelectScreen> createState() => _RestaurantSelectScreenState();
}

class _RestaurantSelectScreenState extends State<RestaurantSelectScreen> {
  late Future<List<Restaurant>> _future;
  String? _debugLastRaw;
  int? _debugLastStatus;

  @override
  void initState() {
    super.initState();
    _future = _load();
  }

  Future<List<Restaurant>> _load() async {
    final raw = await Api.listRestaurantsRaw();
    _debugLastRaw = raw.rawBody;
    _debugLastStatus = raw.statusCode;
    return Api.listRestaurants();
  }

  Future<void> _selectBusinessAndContinue(Restaurant r) async {
    final appState = context.read<AppState>();

    // You MUST have a userId for ordering.
    final userId = appState.userId;
    if (userId == null || userId <= 0) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text("Missing UserID (not logged in).")),
      );
      return;
    }

    // Set selected business
    appState.setBusiness(r.businessId);

    // Go pick service point, and WAIT for a selection.
    final sp = await Navigator.of(context).pushNamed(
      AppRoutes.servicePointSelect,
      arguments: {
        "BusinessID": r.businessId,
        "UserID": userId,
      },
    );

    if (!mounted) return;

    if (sp is ServicePoint) {
      // Store selection in AppState
      appState.setServicePoint(sp.servicePointId);

      // Navigate to Menu Browse
      Navigator.of(context).pushNamed(
        AppRoutes.menuBrowse,
        arguments: {
          "BusinessID": r.businessId,
          "ServicePointID": sp.servicePointId,
          "UserID": userId,
        },
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Select Business"),
      ),
      body: FutureBuilder<List<Restaurant>>(
        future: _future,
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return const Center(child: CircularProgressIndicator());
          }

          if (snapshot.hasError) {
            return _ErrorPane(
              title: "Businesses Load Failed",
              message: snapshot.error.toString(),
              statusCode: _debugLastStatus,
              raw: _debugLastRaw,
              onRetry: () => setState(() => _future = _load()),
            );
          }

          final items = snapshot.data ?? const <Restaurant>[];
          if (items.isEmpty) {
            return _ErrorPane(
              title: "No Businesses Returned",
              message: "The API returned an empty list.",
              statusCode: _debugLastStatus,
              raw: _debugLastRaw,
              onRetry: () => setState(() => _future = _load()),
            );
          }

          return ListView.builder(
            padding: const EdgeInsets.all(16),
            itemCount: items.length,
            itemBuilder: (context, i) {
              final r = items[i];
              return Container(
                margin: const EdgeInsets.only(bottom: 12),
                decoration: BoxDecoration(
                  borderRadius: BorderRadius.circular(16),
                  boxShadow: [
                    BoxShadow(
                      color: Colors.black.withAlpha(15),
                      blurRadius: 8,
                      offset: const Offset(0, 2),
                    ),
                  ],
                ),
                child: Material(
                  borderRadius: BorderRadius.circular(16),
                  color: Theme.of(context).colorScheme.surface,
                  child: InkWell(
                    borderRadius: BorderRadius.circular(16),
                    onTap: () => _selectBusinessAndContinue(r),
                    child: Padding(
                      padding: const EdgeInsets.all(20),
                      child: Row(
                        children: [
                          Container(
                            width: 56,
                            height: 56,
                            decoration: BoxDecoration(
                              color: Theme.of(context).colorScheme.primaryContainer,
                              borderRadius: BorderRadius.circular(12),
                            ),
                            child: Icon(
                              Icons.store,
                              size: 32,
                              color: Theme.of(context).colorScheme.onPrimaryContainer,
                            ),
                          ),
                          const SizedBox(width: 16),
                          Expanded(
                            child: Column(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                Text(
                                  r.name,
                                  style: Theme.of(context).textTheme.titleLarge?.copyWith(
                                        fontWeight: FontWeight.w600,
                                      ),
                                ),
                                const SizedBox(height: 4),
                                Text(
                                  "Tap to view menu",
                                  style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                                        color: Theme.of(context).colorScheme.onSurfaceVariant,
                                      ),
                                ),
                              ],
                            ),
                          ),
                          Icon(
                            Icons.arrow_forward_ios,
                            color: Theme.of(context).colorScheme.onSurfaceVariant,
                            size: 20,
                          ),
                        ],
                      ),
                    ),
                  ),
                ),
              );
            },
          );
        },
      ),
    );
  }
}

class _ErrorPane extends StatelessWidget {
  final String title;
  final String message;
  final int? statusCode;
  final String? raw;
  final VoidCallback onRetry;

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

  @override
  Widget build(BuildContext context) {
    return Center(
      child: SingleChildScrollView(
        padding: const EdgeInsets.all(18),
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 720),
          child: Card(
            child: Padding(
              padding: const EdgeInsets.all(18),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(title, style: Theme.of(context).textTheme.titleLarge),
                  const SizedBox(height: 10),
                  Text(message),
                  const SizedBox(height: 14),
                  if (statusCode != null) Text("HTTP: $statusCode"),
                  if (raw != null && raw!.trim().isNotEmpty) ...[
                    const SizedBox(height: 10),
                    const Text("Raw response:"),
                    const SizedBox(height: 6),
                    Text(raw!),
                  ],
                  const SizedBox(height: 14),
                  FilledButton(
                    onPressed: onRetry,
                    child: const Text("Retry"),
                  ),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}