import 'package:flutter/foundation.dart';

import 'package:miler/data/mock_backend.dart';
import 'package:miler/data/service_profile.dart';

/// ─────────────────────────────────────────────────────────────────────────
/// A MEAL DAY, WITH NO BACKEND BEHIND IT
///
/// The meal line has no endpoints. The Doormile backend serves parcel bookings
/// and consignments and knows nothing about kitchens, crates or subscribers, and
/// building against invented URLs would produce a flow that compiles, demos, and
/// is wrong the day a real contract arrives.
///
/// So the meal line runs on this: a complete day, held in memory, walked with
/// the real screens. Every status change the rider makes is recorded here
/// instead of being sent, which means the whole process — accept, arrive, load
/// the crate, deliver, skip, fail — can be designed, used and judged before a
/// single endpoint exists.
///
/// ── Why this is not the demo layer that was deleted ──
///
/// A mock layer was ripped out of this app for a good reason: it wrote rows into
/// the same SharedPreferences stores the real work uses, so demo stops surfaced
/// on a live rider's tabs weeks later, with nothing left in the repo to explain
/// them. Three rules keep this one from becoming that:
///
///  1. **It cannot reach a parcel rider.** [active] is false unless the signed-in
///     profile is the meal line, and an unrecognised tenant resolves to parcel.
///     There is no path from a normal login to this data.
///  2. **Its ids are self-identifying.** Every id is `MOCK-…`, which is exactly
///     what `purgeDemoRecords()` already looks for — so anything that does leak
///     into a store is removed at the next launch, by code that already ships.
///  3. **It has one switch.** [kMealMockEnabled] is the whole feature. When the
///     meal endpoints land, that constant goes false and the provider falls
///     through to the real call; nothing else in the app knows this file exists.
/// ─────────────────────────────────────────────────────────────────────────

/// Whether the day below is served instead of calling the API.
///
/// ── One switch for the whole app, not two ──
///
/// This used to be its own constant, and it was turned off on 2026-08-12 for a
/// real reason: while it was on, a meal rider tapped **Arrived** and **Picked
/// up**, watched the card advance, and the hub console never changed. Every
/// status write on this line was recorded in a `Map` on the phone and reported
/// as a success.
///
/// That failure mode has not gone away — it is simply what running without a
/// backend *means*, and it now applies to the whole app rather than to this
/// file alone. So the two switches became one: [kMockBackend] takes sign-in,
/// the day and every status write off the network together, and this follows
/// it. There is no state where the meal day is fictional but the statuses are
/// real, which is the confusing half of what used to be possible.
///
/// Turn the app back on to the real backend with:
///
///     flutter run --dart-define=MOCK_BACKEND=false
///
/// The meal line then falls through to the three booking routes it actually
/// depends on, all of which exist and are proven by the parcel line:
///
///   list      `GET  /miler/bookings`
///   arrived   `POST /miler/bookings/:id/reached`
///   picked up `POST /miler/bookings/:id/pickup-complete`
/// Follows the one mock switch at runtime rather than at compile time, so a
/// test (or a bench session) that turns the canned backend off turns this off
/// with it. See [MockBackend.enabled].
bool get kMealMockEnabled => MockBackend.enabled;

/// Wall-clock helper so the mock day always looks like *today's* shift rather
/// than a fixed date that reads as stale the moment anybody opens it.
String _slot(int hour, int minute) {
  final now = DateTime.now();
  final t = DateTime(now.year, now.month, now.day, hour, minute);
  return t.toIso8601String();
}

/// A meal run held in memory: two kitchens, seven subscribers, one rider.
///
/// Coordinates are real Coimbatore addresses in route order, because a route
/// that doubles back looks like a bug in the sequencing rather than what it is.
class MealRunMock {
  MealRunMock._();

  /// True when the app should serve this instead of calling the API.
  static bool get active =>
      kMealMockEnabled && ServiceProfile.active.sourceIsKitchen;

  /// Status overrides the rider has caused this session, keyed by order id.
  ///
  /// The mock's own rows are `assigned`; everything after that is something he
  /// did. Held separately rather than mutated into the rows so a reset is one
  /// `clear()` and the day itself stays declarative.
  static final Map<String, String> _status = <String, String>{};

  /// Records what a status call *would* have sent. Always succeeds — there is
  /// nothing to fail.
  static bool setStatus(String orderId, String status) {
    if (orderId.isEmpty) return true;
    _status[orderId] = status;
    debugPrint('[MEAL_MOCK] $orderId → $status');
    return true;
  }

  /// Same, keyed by the numeric booking id the controllers carry.
  static bool setStatusByPickupId(int pickupId, String status) {
    if (pickupId <= 0) return true;
    final row = _day.firstWhere(
      (r) => r['pickupid'] == pickupId,
      orElse: () => const <String, dynamic>{},
    );
    final id = (row['orderid'] ?? '').toString();
    return setStatus(id, status);
  }

  /// Puts the day back to the top. Wired to nothing yet — it exists so a
  /// demo can be run twice without reinstalling the app.
  static void reset() => _status.clear();

  /// The day as the cards read it, with whatever the rider has done applied.
  ///
  /// A fresh copy every call: the screens mutate stop maps in place (compliance
  /// stamps, proof blocks), and handing out the master rows would let one run's
  /// leftovers show up in the next.
  static List<Map<String, dynamic>> stops() => [
    for (final row in _day)
      {...row, 'orderstatus': _status[row['orderid']] ?? row['orderstatus']},
  ];

  // ── The day itself ──────────────────────────────────────────────────────
  //
  // Two kitchens is deliberate rather than decorative: a single-kitchen day
  // hides every question the grouping exists to answer — which crate is this,
  // which bags belong to it, what happens when the second load is still at a
  // counter he has not reached.
  //
  // Five orders on the first counter and four on the second, because the whole
  // pickup flow is a claim about a *set*: `5 orders · 5 bags`, five names on the
  // confirmation, five deliveries afterwards. A day of ones would let every one
  // of those read correctly while being wrong.
  static final List<Map<String, dynamic>> _day = [
    // ── Vidhya Kitchen · Gandhi Nagar, Peelamedu ──
    _drop(
      id: 1001,
      step: 1,
      name: 'Joe Mathew',
      phone: '9840012001',
      address: '12, SNS Colony, Peelamedu',
      lat: 11.0271,
      lng: 76.9962,
      kitchen: _vidhya,
      bag: 'DG-1001',
      meals: 1,
    ),
    _drop(
      id: 1002,
      step: 2,
      name: 'Arun Prakash',
      phone: '9840012002',
      address: '21, New Street, Peelamedu',
      lat: 11.0248,
      lng: 76.9941,
      kitchen: _vidhya,
      bag: 'DG-1002',
      meals: 1,
    ),
    _drop(
      id: 1003,
      step: 3,
      name: 'Priya Venkatesh',
      phone: '9840012003',
      address: '45, West Avenue, RS Puram',
      lat: 11.0043,
      lng: 76.9518,
      kitchen: _vidhya,
      bag: 'DG-1003',
      meals: 1,
    ),
    _drop(
      id: 1004,
      step: 4,
      name: 'Kumar Selvam',
      phone: '9840012004',
      address: 'Flat 3C, Lakshmi Towers, 100 Feet Road, Gandhipuram',
      lat: 11.0168,
      lng: 76.9558,
      kitchen: _vidhya,
      bag: 'DG-1004',
      meals: 1,
    ),
    _drop(
      id: 1005,
      step: 5,
      name: 'Ravi Shankar',
      phone: '9840012005',
      address: '8, Krishna Colony, 2nd Street, Singanallur',
      lat: 10.9925,
      lng: 77.0289,
      kitchen: _vidhya,
      bag: 'DG-1005',
      meals: 1,
    ),

    // ── Annapoorna Mess · Thadagam Road ──
    _drop(
      id: 2001,
      step: 6,
      name: 'Meena Krishnan',
      phone: '9840012006',
      address: '31, Sarojini Street, Gandhipuram',
      lat: 11.0181,
      lng: 76.9603,
      kitchen: _annapoorna,
      bag: 'AM-2001',
      meals: 1,
    ),
    _drop(
      id: 2002,
      step: 7,
      name: 'Sai Ganesh',
      phone: '9840012007',
      address: '14, Trichy Road, above the pharmacy, Ramanathapuram',
      lat: 10.9871,
      lng: 76.9931,
      kitchen: _annapoorna,
      bag: 'AM-2002',
      meals: 1,
    ),
    _drop(
      id: 2003,
      step: 8,
      name: 'Devi Lakshmi',
      phone: '9840012008',
      address: '22, Kamarajar Road, near the school gate, Uppilipalayam',
      lat: 10.9903,
      lng: 76.9977,
      kitchen: _annapoorna,
      bag: 'AM-2003',
      meals: 1,
    ),
    _drop(
      id: 2004,
      step: 9,
      name: 'Karthik Raja',
      phone: '9840012009',
      address: '5B, Thadagam Road, opposite the water tank',
      lat: 11.0221,
      lng: 76.9391,
      kitchen: _annapoorna,
      bag: 'AM-2004',
      meals: 1,
    ),
  ];

  /// A counter the rider collects from: what it is called, where it is, and the
  /// id everything groups on.
  static const _vidhya = (
    id: 'K1',
    name: 'Vidhya Kitchen',
    address: 'Gandhi Nagar, Peelamedu, Coimbatore - 641004',
    lat: 11.0261,
    lng: 76.9931,
    locationId: 901,
  );

  static const _annapoorna = (
    id: 'K2',
    name: 'Annapoorna Mess',
    address: '19, Thadagam Road, RS Puram, Coimbatore - 641002',
    lat: 11.0195,
    lng: 76.9412,
    locationId: 902,
  );

  /// One subscriber drop, in the legacy stop shape every card in the app reads.
  ///
  /// ── Both ends, in the right fields ──
  ///
  /// The `pickup*` fields are the **kitchen** and the `drop*` fields are the
  /// **customer**, because that is what the app navigates on: before collection
  /// `navigationTarget` reads `pickuplat/pickuplon`, and after it reads
  /// `droplat/droplon` — see [MilkRun]. This fixture used to put the customer in
  /// both, which sent a rider to a subscriber's flat to collect a lunch that was
  /// still at a counter three kilometres away.
  ///
  /// `type: delivery` is stated rather than inferred: the app would reach the
  /// same answer from the profile, but a fixture that relies on a fallback is
  /// testing the fallback rather than the screen.
  static Map<String, dynamic> _drop({
    required int id,
    required int step,
    required String name,
    required String phone,
    required String address,
    required double lat,
    required double lng,
    required ({
      String id,
      String name,
      String address,
      double lat,
      double lng,
      int locationId,
    })
    kitchen,
    required String bag,
    required int meals,
  }) => <String, dynamic>{
    // `MOCK-` so `purgeDemoRecords()` recognises anything that leaks into a
    // store. See the note at the top of this file.
    'orderid': 'MOCK-M-$id',
    'pickupid': id,
    'orderheaderid': id,
    'pickuplocationid': kitchen.locationId,
    'orderstatus': 'assigned',
    'step': step,

    // Who is being handed food.
    'pickupcustomer': name,
    'pickupcontactno': phone,

    // Where he collects: the counter.
    'pickupaddress': kitchen.address,
    'pickuplat': kitchen.lat,
    'pickuplon': kitchen.lng,
    'pickuplong': kitchen.lng,

    // Where it goes: the door.
    'dropaddress': '$address, Coimbatore, Tamil Nadu 641004',
    'droplat': lat,
    'droplon': lng,

    // The counter itself. The grouping, the headings, the manifest and the
    // bag identity all key off these.
    'kitchenid': kitchen.id,
    'kitchenname': kitchen.name,
    'baglabel': bag,

    // A drop, and how many boxes are in it. One order is one bag — the count
    // here is the *meal* count inside that bag, and nothing reads it as a bag
    // count. See [BagManifest].
    'type': 'delivery',
    'deliveryqty': meals,
    'quantity': meals,

    // Nothing is owed at any door — a subscriber paid the client by the month.
    // Stated as zero rather than omitted so a payload reader cannot mistake a
    // missing field for an unknown amount.
    'collectionamt': 0,
    'pickupamt': 0,

    // The lunch slot the whole run belongs to.
    'starttime': _slot(11, 30),
    'endtime': _slot(13, 30),
    'eta': '8',
    'kms': '2.4',
  };
}