import 'package:flutter/foundation.dart';
import 'package:shared_preferences/shared_preferences.dart';

import 'package:miler/data/api_config.dart';
import 'package:miler/data/miler_api.dart';

/// ─────────────────────────────────────────────────────────────────────────
/// DUTY, BREAKS AND THE LOCATION HEARTBEAT
///
/// ── What was deleted here ──
///
/// A `_buildSslBypassClient()` that returned an `IOClient` whose
/// `badCertificateCallback` returned `true` for every certificate, pinned a
/// hardcoded IP for the retired backend's host, and hand-rolled its own
/// `SecureSocket` upgrade. It existed to work around a carrier's broken DNS on
/// a backend that is no longer deployed — and it meant every request it carried
/// could be read and rewritten by anything on the path, including a rider's GPS
/// track and his duty state.
///
/// It is gone along with the rest of the legacy path. `api.doormile.com` is
/// reached over ordinary, verified TLS.
///
/// ── The class names survive their implementations ──
///
/// `RiderLogController` drives duty through create/update/get "rider log"
/// calls, which is the legacy shape. Rather than rewrite that controller, these
/// four classes keep their names and map the intent onto the real endpoints:
/// the first log of a session starts duty, later ones are location heartbeats,
/// and an off-duty payload ends it.
/// ─────────────────────────────────────────────────────────────────────────

String _s(dynamic v) => v == null ? '' : v.toString();

double? _d(dynamic v) => double.tryParse(_s(v));

/// ─────────────────────────────────────────────────────────────────────────
/// WHY THE CONSOLE'S DEVICE PANEL WAS EMPTY
///
/// Not the telemetry. [DeviceTelemetry] reads the handset correctly, its
/// payload carries every field the console draws, and every caller spreads it
/// into the heartbeat. The reading was right and it never left the phone.
///
/// [_heartbeat] is the only thing that posts `POST /miler/logs`, and it is also
/// the only thing that writes `PUT /miler/location`. Both were unreachable,
/// because the two entry points below gate on one locally cached number:
///
/// ```
///   if ((prefs.getInt('dutylogid') ?? 0) <= 0) return _startDuty(data);
///   return _heartbeat(data);
/// ```
///
/// `dutylogid` is written in exactly one place — a successful
/// `POST /miler/duty/start` — and it is zeroed on going off duty. So there are
/// two ordinary ways to end up on duty with a zero, and both are permanent:
///
///  • **The server already has the rider on duty.** `duty/start` answers 400,
///    which [_startDuty] correctly treats as a reconciliation rather than a
///    failure and delegates to [_currentDuty] — which read `dutylogid` out of
///    the response and wrote it to `logid` and `logId` **and not to
///    `dutylogid`**. The gate stayed shut. Next tick: `duty/start` again, 400
///    again, reconcile again, still shut. Forever, and silently, because
///    nothing in that loop is an error. It happens after a reinstall, after
///    cleared storage, after an `endDuty` that never landed, and on any fresh
///    login for a rider the backend still has on shift.
///
///  • **The response spells the id differently.** [_startDuty] read one key on
///    one level. Anything else — `logid`, `id`, a top-level field rather than
///    one under `data` — parsed to zero and was *stored* as zero, which puts a
///    rider into the same permanent loop on his very first shift. This codebase
///    has been bitten by exactly this before; see `AuthProvider._tokenIn`,
///    which looks in nine places for the bearer for precisely this reason.
///
/// ── The design error underneath both ──
///
/// `POST /miler/logs` does not take a duty log id. Its contract is
/// `{logdate, latitude, longitude, battery, is_charging, connection,
/// location_service, accuracy, is_background}` — nothing about duty. Gating
/// telemetry on an identifier the endpoint does not want, that the backend is
/// not obliged to return, is what turned one unmapped field into total
/// silence on both writes.
///
/// So the gate is now *"has duty been established"* — a fact — rather than
/// *"do we happen to hold a non-zero id"*, which is an artefact. The id is
/// still stored when it arrives, because [_dutyEnvelope] and the legacy duty
/// readers want it; it simply no longer decides whether a rider reports.
/// ─────────────────────────────────────────────────────────────────────────

/// Set once duty is known to be on, and cleared when it goes off.
///
/// Deliberately separate from `dutylogid`: this answers "should the heartbeat
/// run", which is a question about duty, and the id answers "which duty log
/// row", which is a question about the backend's bookkeeping. Conflating them
/// is the bug above.
const String _kDutyEstablished = 'duty_established';

/// Every spelling and nesting the duty endpoints have used for the log id.
///
/// Ordered by how the current contract answers, then by what deployments have
/// been seen to send. A miss is no longer fatal — see [_dutyEstablished] — but
/// finding the id keeps the legacy `logid` readers correct.
const List<String> _dutyLogIdKeys = [
  'dutylogid',
  'dutyLogId',
  'duty_log_id',
  'logid',
  'logId',
  'log_id',
  'id',
];

/// The duty log id anywhere in [res], or `0`.
///
/// Looks in the envelope's `data` and in the undecorated body, because a
/// handler that returns `{success, dutylogid}` and one that returns
/// `{success, data:{dutylogid}}` are both shapes this contract has worn.
int _dutyLogIdIn(ApiResult res) {
  final sources = <Map>[res.map, if (res.raw is Map) res.raw as Map];
  for (final source in sources) {
    for (final key in _dutyLogIdKeys) {
      final v = source[key];
      if (v == null) continue;
      final n = int.tryParse(v.toString().trim());
      if (n != null && n > 0) return n;
    }
  }
  return 0;
}

/// Records that the rider is on duty, and the id if the backend sent one.
///
/// The flag is set whether or not there is an id, which is the whole fix: a
/// rider whose duty the server has confirmed reports, even when the response
/// did not name the row.
Future<void> _rememberDuty(int dutyLogId) async {
  final prefs = await SharedPreferences.getInstance();
  if (dutyLogId > 0) {
    await prefs.setInt('logid', dutyLogId);
    await prefs.setInt('logId', dutyLogId);
    await prefs.setInt('dutylogid', dutyLogId);
  }
  await prefs.setBool(_kDutyEstablished, true);
  await prefs.setInt('onduty', 1);
}

/// Forgets duty, on the way off shift.
Future<void> _forgetDuty() async {
  final prefs = await SharedPreferences.getInstance();
  await prefs.setInt('dutylogid', 0);
  await prefs.setBool(_kDutyEstablished, false);
}

/// Whether duty has been established, so the heartbeat should run.
Future<bool> _dutyEstablished() async {
  final prefs = await SharedPreferences.getInstance();
  if (prefs.getBool(_kDutyEstablished) == true) return true;
  // An install that predates the flag: a stored id means duty was started by
  // an earlier build, and that rider must not have to go off and on again to
  // start reporting.
  return (prefs.getInt('dutylogid') ?? 0) > 0;
}

/// Legacy `{status, details}` for the duty-state readers.
Map<String, dynamic> _dutyEnvelope(Map data) {
  final bool on = data['onduty'] == true;
  final dutylogid = data['dutylogid'] ?? 0;
  return {
    'status': true,
    'code': 200,
    'details': {
      'logid': dutylogid,
      'onduty': on ? 1 : 0,
      'login': data['loginat'],
    },
  };
}

Future<Map<String, dynamic>?> _startDuty(Map data) async {
  final res = await MilerApi.startDuty(
    lat: _d(data['latitude']),
    lon: _d(data['longitude']),
  );
  if (res.ok) {
    // Looked at one key on one level and stored whatever it found, including
    // a zero — which shut the heartbeat's gate permanently on a response that
    // had merely spelled the id differently. See [_dutyLogIdIn].
    final id = _dutyLogIdIn(res);
    await _rememberDuty(id);
    return {
      'status': true,
      'code': 200,
      'details': {'logid': id, 'login': res.map['loginat'], 'onduty': 1},
    };
  }
  // "Already on duty" is a 400 and is not a failure — it is the app and the
  // server disagreeing about state, which the current duty answers.
  if (res.status == 400) return _currentDuty();
  return {'status': false, 'code': res.status};
}

Future<Map<String, dynamic>?> _currentDuty() async {
  final res = await MilerApi.dutyCurrent();
  if (!res.ok) return {'status': false, 'code': res.status};

  final on = res.map['onduty'] == true;
  if (on) {
    // ── The line that was missing ──
    //
    // This wrote the id to `logid` and `logId` and stopped, leaving
    // `dutylogid` — the only key the heartbeat's gate reads — at zero. So the
    // reconciliation that exists to recover from "the server already has you
    // on duty" recovered the duty state and not the ability to report it, and
    // the next tick came straight back here. See the note at the top.
    await _rememberDuty(_dutyLogIdIn(res));
  } else {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setInt('onduty', 0);
    await _forgetDuty();
  }
  return _dutyEnvelope(res.map);
}

/// The GPS heartbeat, which is two writes with different lifetimes:
///
///  • `PUT /miler/location` — Redis, and the index dispatch searches. This is
///    the one that decides whether the rider is findable.
///  • `POST /miler/logs` — the telemetry trail, for reconstructing a shift
///    afterwards.
///
/// Both are best-effort and neither blocks the rider. The location write is
/// reported back because duty state depends on it; the log is fire-and-forget.
Future<Map<String, dynamic>?> _heartbeat(Map data) async {
  final lat = _d(data['latitude']);
  final lon = _d(data['longitude']);
  if (lat == null || lon == null) return ApiConfig.okEnvelope('no fix');

  final res = await MilerApi.pushLocation(
    latitude: lat,
    longitude: lon,
    pincode: _s(data['pincode']).isEmpty ? null : _s(data['pincode']),
    speed: _d(data['speed']),
    heading: _d(data['heading']),
  );

  // ── Awaited, but its outcome is still discarded ──
  //
  // This was `unawaited(...)`, for a good reason that turned out to be the
  // wrong mechanism: a telemetry failure must never read as a location failure,
  // because the caller treats the latter as duty state going wrong. `unawaited`
  // achieves that by never looking at the result — and also by not waiting for
  // the request to finish.
  //
  // On Android this heartbeat runs inside `flutter_foreground_task`'s **own
  // Flutter engine**, spun up per tick. When the callback returns, that engine
  // can be suspended before an in-flight future completes. So the awaited
  // `PUT /miler/location` above landed on every tick and this `POST /miler/logs`
  // was killed mid-flight — which is exactly what the backend saw: a rider with
  // a live position in Redis and no new telemetry row behind it, while the app
  // logged a successful heartbeat.
  //
  // Awaiting it costs one round trip on a call that already had to happen and
  // guarantees the request outlives the tick. The isolation the `unawaited` was
  // protecting is kept by the `try`: the result is logged and thrown away, and
  // nothing below branches on it.
  try {
    final logRes = await MilerApi.postLog(
      latitude: lat,
      longitude: lon,
      speed: _d(data['speed']),
      heading: _d(data['heading']),
      accuracy: _d(data['accuracy']),
      status: _s(data['status']).isEmpty ? null : _s(data['status']),
      orderId: data['orderid'],
      battery: int.tryParse(_s(data['battery'])),
      isCharging: data['is_charging'] == true,
      connection: _s(data['connection']).isEmpty
          ? null
          : _s(data['connection']),
      // ── This was being dropped on the floor ──
      //
      // Every other device field on the heartbeat was forwarded and this one
      // was not, so `location_service` could never reach `/miler/logs` however
      // faithfully the caller supplied it — and the console's Location Service
      // column had no field to read. It is the single most useful thing on
      // that panel: a rider who has turned location off explains his own
      // silence, and nothing else on the row can.
      locationService: _s(data['location_service']).isEmpty
          ? null
          : _s(data['location_service']),
      isBackground: data['is_background'] == true,
    );
    // The one line that says whether telemetry reached the console. It was
    // silent on success *and* on failure, which is why a dropped post took
    // several rounds of backend archaeology to find.
    debugPrint(
      '[RIDERLOG][LOGS] POST /miler/logs -> ${logRes.status} '
      'ok=${logRes.ok} battery=${_s(data['battery'])} '
      'connection=${_s(data['connection'])}',
    );
  } catch (e) {
    debugPrint('[RIDERLOG][LOGS] POST /miler/logs failed: $e');
  }

  return res.ok
      ? ApiConfig.okEnvelope()
      : {'status': false, 'code': res.status};
}

/// True when the payload means "go off duty".
bool _isOffDutyIntent(Map data) {
  final status = _s(data['status']).toLowerCase();
  final onduty = data['onduty'];
  final bool ondutyZero = onduty == 0 || _s(onduty) == '0';
  return status.contains('offline') ||
      status.contains('logout') ||
      data.containsKey('logout') ||
      (data.containsKey('onduty') && ondutyZero);
}

class CreateRiderLogProvider {
  /// The first call of a session starts duty; every later one is a heartbeat.
  ///
  /// ── The start is no longer a tick the rider loses ──
  ///
  /// This returned [_startDuty]'s envelope and stopped, so the tick that opened
  /// the shift carried no telemetry and no position — the console had nothing
  /// until the next one, thirty seconds later. Worse, when `duty/start`
  /// reconciled a rider the server already had on duty, the old gate never
  /// opened at all and *every* tick ended here. See the note at the top of this
  /// file.
  ///
  /// Duty is established first, then the same payload beats immediately. The
  /// heartbeat is best-effort and its result is not merged into the duty
  /// envelope, because the caller reads that envelope for duty state and a
  /// telemetry failure is not a duty failure.
  Future<Map<String, dynamic>?> createRiderLog(
    Map<String, dynamic> data,
  ) async {
    if (await _dutyEstablished()) return _heartbeat(data);

    final started = await _startDuty(data);
    if (await _dutyEstablished()) await _heartbeat(data);
    return started;
  }
}

class UpdateRiderLogProvider {
  Future<Map<String, dynamic>?> updateRiderLog(
    Map<String, dynamic> data,
  ) async {
    if (_isOffDutyIntent(data)) {
      await _forgetDuty();
      final res = await MilerApi.endDuty();
      if (res.ok) {
        final prefs = await SharedPreferences.getInstance();
        await prefs.setInt('onduty', 0);
      }
      return res.ok
          ? ApiConfig.toLegacyEnvelope(res.raw ?? {'success': true})
          : {'status': false, 'code': res.status};
    }

    final onduty = data['onduty'];
    if ((onduty == 1 || _s(onduty) == '1') && !await _dutyEstablished()) {
      // Same shape as [CreateRiderLogProvider.createRiderLog]: establish duty,
      // then beat on the same tick rather than returning and leaving the
      // console with nothing for another interval.
      final started = await _startDuty(data);
      if (await _dutyEstablished()) await _heartbeat(data);
      return started;
    }
    return _heartbeat(data);
  }
}

class GetRiderLogProvider {
  Future<Map<String, dynamic>?> getRiderLog() => _currentDuty();

  /// There is no rider-count endpoint in the contract, and no screen that needs
  /// one — the dashboard figures come from bookings and earnings. Kept as a
  /// zero so the one legacy caller does not have to branch.
  Future<Map<String, dynamic>?> getRiderCount() async {
    ApiConfig.logGap('getRiderCount', 'No count endpoint in v1.');
    return {'status': true, 'count': 0};
  }
}

class BreakRiderLogProvider {
  Future<Map<String, dynamic>?> createBreakRiderLog(
    Map<String, dynamic> data,
  ) async {
    final bt = _s(data['breaktype'] ?? data['reason'] ?? 'Personal');
    final res = await MilerApi.startBreak(bt);
    if (res.ok) {
      final prefs = await SharedPreferences.getInstance();
      await prefs.setInt(
        'breaklogid',
        int.tryParse('${res.map['breaklogid'] ?? 0}') ?? 0,
      );
      // The availability enum's break value is `Break`, not `On_Break` — the
      // obvious guess is the wrong one and is silently rejected.
      unawaited(MilerApi.setAvailability('Break'));
      return ApiConfig.toLegacyEnvelope(res.raw ?? {'success': true});
    }
    return {'status': false, 'code': res.status};
  }

  Future<Map<String, dynamic>?> updateBreakRiderLog() async {
    final res = await MilerApi.endBreak();
    if (res.ok) unawaited(MilerApi.setAvailability('Available'));
    return res.ok
        ? ApiConfig.toLegacyEnvelope(res.raw ?? {'success': true})
        : {'status': false, 'code': res.status};
  }
}

/// Local `unawaited`, so a fire-and-forget call reads as deliberate rather than
/// as a missing `await`.
void unawaited(Future<void> future) {
  future.catchError((Object e) {
    debugPrint('[RIDERLOG] background call failed: $e');
  });
}