// lib/screens/order_home_screen.dart

import "package:flutter/material.dart";
import "../services/api.dart";

class OrderHomeScreen extends StatefulWidget {
  // OPTIONAL so routes that call `const OrderHomeScreen()` compile.
  // You can wire real values later.
  final int? businessId;
  final int? servicePointId;
  final int? userId;

  const OrderHomeScreen({
    super.key,
    this.businessId,
    this.servicePointId,
    this.userId,
  });

  @override
  State<OrderHomeScreen> createState() => _OrderHomeScreenState();
}

class _OrderHomeScreenState extends State<OrderHomeScreen> {
  final _businessCtl = TextEditingController();
  final _servicePointCtl = TextEditingController();
  final _userCtl = TextEditingController();

  bool _busy = false;
  String? _error;

  int? _orderId;

  @override
  void initState() {
    super.initState();
    _businessCtl.text = (widget.businessId ?? 0).toString();
    _servicePointCtl.text = (widget.servicePointId ?? 0).toString();
    _userCtl.text = (widget.userId ?? 0).toString();
  }

  @override
  void dispose() {
    _businessCtl.dispose();
    _servicePointCtl.dispose();
    _userCtl.dispose();
    super.dispose();
  }

  int _parseInt(TextEditingController c) {
    final s = c.text.trim();
    return int.tryParse(s) ?? 0;
  }

  Future<void> _run(Future<void> Function() fn) async {
    if (_busy) return;
    setState(() {
      _busy = true;
      _error = null;
    });
    try {
      await fn();
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  Future<void> _createOrLoadCart() async {
    await _run(() async {
      final businessId = _parseInt(_businessCtl);
      final servicePointId = _parseInt(_servicePointCtl);
      final userId = _parseInt(_userCtl);

      final cartData = await Api.getOrCreateCart(
        userId: userId,
        businessId: businessId,
        servicePointId: servicePointId,
        orderTypeId: 1, // MVP default: dine-in
      );

      final oid = _asInt(cartData is Map ? cartData["OrderID"] : null);
      setState(() => _orderId = oid == 0 ? null : oid);
    });
  }

  Future<void> _refreshCart() async {
    if (_orderId == null) return;
    await _run(() async {
      await Api.getCart(orderId: _orderId!);
    });
  }

  Future<void> _addDemoItem(int itemId) async {
    if (_orderId == null) {
      setState(() => _error = "No cart yet. Tap 'Create/Load Cart' first.");
      return;
    }

    await _run(() async {
      await Api.setLineItem(
        orderId: _orderId!,
        parentOrderLineItemId: 0,
        itemId: itemId,
        qty: 1,
        selectedChildItemIds: const <int>[],
      );
    });
  }

  Future<void> _submit() async {
    if (_orderId == null) {
      setState(() => _error = "No cart yet.");
      return;
    }

    await _run(() async {
      await Api.submitOrder(orderId: _orderId!);
    });
  }

  @override
  Widget build(BuildContext context) {
    final orderId = _orderId;

    return Scaffold(
      appBar: AppBar(title: const Text("Order (Compile-Only MVP)")),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          const Text(
            "This screen exists only to compile cleanly against Api.dart.\n"
            "No menu, no models, no polish.",
          ),
          const SizedBox(height: 16),

          _LabeledField(label: "BusinessID", controller: _businessCtl, enabled: !_busy),
          const SizedBox(height: 10),
          _LabeledField(label: "ServicePointID", controller: _servicePointCtl, enabled: !_busy),
          const SizedBox(height: 10),
          _LabeledField(label: "UserID", controller: _userCtl, enabled: !_busy),

          const SizedBox(height: 16),

          Row(
            children: [
              Expanded(
                child: ElevatedButton(
                  onPressed: _busy ? null : _createOrLoadCart,
                  child: const Text("Create/Load Cart"),
                ),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: OutlinedButton(
                  onPressed: (_busy || orderId == null) ? null : _refreshCart,
                  child: const Text("Refresh Cart"),
                ),
              ),
            ],
          ),

          const SizedBox(height: 16),

          Card(
            child: Padding(
              padding: const EdgeInsets.all(12),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text("Cart OrderID: ${orderId ?? "(none)"}"),
                  const SizedBox(height: 10),
                  Wrap(
                    spacing: 10,
                    runSpacing: 10,
                    children: [
                      ElevatedButton(
                        onPressed: _busy ? null : () => _addDemoItem(101),
                        child: const Text("Add Demo Item 101"),
                      ),
                      ElevatedButton(
                        onPressed: _busy ? null : () => _addDemoItem(102),
                        child: const Text("Add Demo Item 102"),
                      ),
                      ElevatedButton(
                        onPressed: _busy ? null : () => _addDemoItem(103),
                        child: const Text("Add Demo Item 103"),
                      ),
                    ],
                  ),
                  const SizedBox(height: 12),
                  ElevatedButton(
                    onPressed: (_busy || orderId == null) ? null : _submit,
                    child: const Text("Submit Order"),
                  ),
                ],
              ),
            ),
          ),

          const SizedBox(height: 16),

          if (_busy) ...[
            const Center(child: CircularProgressIndicator()),
            const SizedBox(height: 16),
          ],

          if (_error != null)
            Card(
              child: Padding(
                padding: const EdgeInsets.all(12),
                child: Text(_error!),
              ),
            ),
        ],
      ),
    );
  }
}

class _LabeledField extends StatelessWidget {
  final String label;
  final TextEditingController controller;
  final bool enabled;

  const _LabeledField({
    required this.label,
    required this.controller,
    required this.enabled,
  });

  @override
  Widget build(BuildContext context) {
    return TextField(
      controller: controller,
      enabled: enabled,
      keyboardType: TextInputType.number,
      decoration: InputDecoration(
        labelText: label,
        border: const OutlineInputBorder(),
      ),
    );
  }
}

int _asInt(dynamic v) {
  if (v is int) return v;
  if (v is double) return v.toInt();
  if (v is String) return int.tryParse(v) ?? 0;
  return 0;
}