import "package:flutter/material.dart";

import "../main.dart";
import "../models.dart";
import "../format.dart";
import "../theme.dart";
import "car_form_sheet.dart";

/// Serializes a car to the full update payload. The API's updateCar rewrites
/// every column from the body, so partial payloads would blank omitted fields —
/// always send them all, overriding only what changed.
Map<String, dynamic> _carPayload(Car car, {int? currentKm}) => {
      "name": car.name,
      "make": car.make,
      "model": car.model,
      "year": car.year,
      "registration": car.registration,
      "registrationCountry": car.registrationCountry,
      "vin": car.vin,
      "oilSpec": car.oilSpec,
      "transmissionOilSpec": car.transmissionOilSpec,
      "differentialOilSpec": car.differentialOilSpec,
      "brakeFluidSpec": car.brakeFluidSpec,
      "coolantSpec": car.coolantSpec,
      "fuelType": car.fuelType,
      "buildDate": car.buildDate,
      "firstRegistrationDate": car.firstRegistrationDate,
      "serviceIntervalDays": car.serviceIntervalDays,
      "serviceIntervalKm": car.serviceIntervalKm,
      "currentKm": currentKm ?? car.currentKm,
    };

class CarDetailScreen extends StatefulWidget {
  final String carId;
  const CarDetailScreen({super.key, required this.carId});
  @override
  State<CarDetailScreen> createState() => _CarDetailScreenState();
}

class _CarDetailData {
  final Car car;
  final List<ServiceRecord> services;
  final List<Part> parts;
  _CarDetailData(this.car, this.services, this.parts);
}

class _CarDetailScreenState extends State<CarDetailScreen> {
  late Future<_CarDetailData> _future;

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

  Future<_CarDetailData> _load() async {
    final results = await Future.wait([
      apiClient.getCar(widget.carId),
      apiClient.listCarServices(widget.carId),
      apiClient.listCarParts(widget.carId),
    ]);
    return _CarDetailData(
      results[0] as Car,
      results[1] as List<ServiceRecord>,
      results[2] as List<Part>,
    );
  }

  void _reload() => setState(() => _future = _load());

  Future<void> _addService(Car car) async {
    final added = await showModalBottomSheet<bool>(
      context: context,
      isScrollControlled: true,
      builder: (_) => _ServiceSheet(carId: car.id, car: car),
    );
    if (added == true) _reload();
  }

  Future<void> _editService(Car car, ServiceRecord record) async {
    final saved = await showModalBottomSheet<bool>(
      context: context,
      isScrollControlled: true,
      builder: (_) => _ServiceSheet(carId: car.id, car: car, record: record),
    );
    if (saved == true) _reload();
  }

  Future<void> _deleteService(ServiceRecord record) async {
    final ok = await _confirm("Delete this service record?");
    if (!ok) return;
    try {
      await apiClient.deleteService(record.id);
      _reload();
    } catch (e) {
      _snack("Delete failed: $e");
    }
  }

  Future<void> _editCar(Car car) async {
    final updated = await showModalBottomSheet<Car?>(
      context: context,
      isScrollControlled: true,
      builder: (_) => CarFormSheet(car: car),
    );
    if (updated != null) _reload();
  }

  Future<void> _addPart(Car car) async {
    final saved = await showModalBottomSheet<bool>(
      context: context,
      isScrollControlled: true,
      builder: (_) => _PartSheet(carId: car.id),
    );
    if (saved == true) _reload();
  }

  Future<void> _editPart(Car car, Part part) async {
    final saved = await showModalBottomSheet<bool>(
      context: context,
      isScrollControlled: true,
      builder: (_) => _PartSheet(carId: car.id, part: part),
    );
    if (saved == true) _reload();
  }

  Future<void> _deletePart(Part part) async {
    final ok = await _confirm("Delete this part?");
    if (!ok) return;
    try {
      await apiClient.deletePart(part.id);
      _reload();
    } catch (e) {
      _snack("Delete failed: $e");
    }
  }

  Future<bool> _confirm(String message) async {
    final res = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        content: Text(message),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text("Cancel")),
          FilledButton(
            style: FilledButton.styleFrom(backgroundColor: DriverVault.danger),
            onPressed: () => Navigator.pop(ctx, true),
            child: const Text("Delete"),
          ),
        ],
      ),
    );
    return res == true;
  }

  void _snack(String msg) {
    if (mounted) ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(msg)));
  }

  Future<void> _shareCar(Car car) async {
    await showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      builder: (_) => _ShareSheet(car: car),
    );
  }

  Future<void> _editOdometer(Car car) async {
    final controller = TextEditingController(text: car.currentKm > 0 ? "${car.currentKm}" : "");
    final saved = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text("Current odometer"),
        content: TextField(
          controller: controller,
          keyboardType: TextInputType.number,
          decoration: const InputDecoration(suffixText: "km", border: OutlineInputBorder()),
          autofocus: true,
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text("Cancel")),
          FilledButton(
            onPressed: () async {
              await apiClient.updateCar(
                car.id,
                _carPayload(car, currentKm: int.tryParse(controller.text.trim()) ?? 0),
              );
              if (ctx.mounted) Navigator.pop(ctx, true);
            },
            child: const Text("Save"),
          ),
        ],
      ),
    );
    if (saved == true) _reload();
  }

  Future<void> _deleteCar(Car car, int serviceCount, int partCount) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (_) => _DeleteCarDialog(
        car: car,
        serviceCount: serviceCount,
        partCount: partCount,
      ),
    );
    if (confirmed != true) return;
    try {
      await apiClient.deleteCar(car.id);
      if (mounted) Navigator.pop(context); // back to dashboard (it refreshes)
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context)
            .showSnackBar(SnackBar(content: Text("Delete failed: $e")));
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: FutureBuilder<_CarDetailData>(
        future: _future,
        builder: (context, snap) {
          if (snap.connectionState == ConnectionState.waiting) {
            return const Scaffold(body: Center(child: CircularProgressIndicator()));
          }
          if (snap.hasError) {
            return Scaffold(
              appBar: AppBar(),
              body: Center(child: Text("${snap.error}")),
            );
          }
          final data = snap.data!;
          final car = data.car;
          final latest = data.services.isNotEmpty ? data.services.first : null;
          final status = serviceStatus(latest, car);

          return DefaultTabController(
            length: 3,
            child: Scaffold(
              appBar: AppBar(
                title: Text(car.name),
                actions: [
                  if (car.isOwner)
                    IconButton(
                      tooltip: "Share car",
                      icon: const Icon(Icons.person_add_alt),
                      onPressed: () => _shareCar(car),
                    ),
                  if (car.canWrite)
                    IconButton(
                      tooltip: "Edit car",
                      icon: const Icon(Icons.edit_outlined),
                      onPressed: () => _editCar(car),
                    ),
                  if (car.canWrite)
                    IconButton(
                      tooltip: "Update odometer",
                      icon: const Icon(Icons.speed),
                      onPressed: () => _editOdometer(car),
                    ),
                  if (car.isOwner)
                    IconButton(
                      tooltip: "Delete car",
                      icon: const Icon(Icons.delete_outline),
                      onPressed: () =>
                          _deleteCar(car, data.services.length, data.parts.length),
                    ),
                ],
                bottom: const TabBar(
                  isScrollable: true,
                  tabs: [
                    Tab(text: "Information"),
                    Tab(text: "Service history"),
                    Tab(text: "Parts catalog"),
                  ],
                ),
              ),
              body: Column(
                children: [
                  Padding(
                    padding: const EdgeInsets.fromLTRB(12, 12, 12, 0),
                    child: Column(
                      children: [
                        _StatusHeader(car: car, status: status),
                        if (car.isReadOnly) ...[
                          const SizedBox(height: 12),
                          const _ReadOnlyNotice(),
                        ],
                      ],
                    ),
                  ),
                  Expanded(
                    child: TabBarView(
                      children: [
                        // Information tab
                        _InfoTab(car: car, latest: latest),
                        // Service history tab
                        _TabList(
                          empty: data.services.isEmpty ? "No service records yet." : null,
                          onAdd: car.canWrite ? () => _addService(car) : null,
                          addLabel: "Add service",
                          children: data.services
                              .map((s) => _ServiceTile(
                                    record: s,
                                    onEdit: car.canWrite ? () => _editService(car, s) : null,
                                    onDelete: car.canWrite ? () => _deleteService(s) : null,
                                  ))
                              .toList(),
                        ),
                        // Parts catalog tab
                        _TabList(
                          empty: data.parts.isEmpty ? "No parts yet." : null,
                          onAdd: car.canWrite ? () => _addPart(car) : null,
                          addLabel: "Add part",
                          children: data.parts
                              .map((p) => _PartTile(
                                    part: p,
                                    onEdit: car.canWrite ? () => _editPart(car, p) : null,
                                    onDelete: car.canWrite ? () => _deletePart(p) : null,
                                  ))
                              .toList(),
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          );
        },
      ),
    );
  }
}

/// A scrollable tab body: an optional "+ Add" button, an empty-state message, or
/// the list of tiles.
class _TabList extends StatelessWidget {
  final String? empty;
  final VoidCallback? onAdd;
  final String addLabel;
  final List<Widget> children;
  const _TabList({
    required this.empty,
    required this.onAdd,
    required this.addLabel,
    required this.children,
  });

  @override
  Widget build(BuildContext context) {
    return ListView(
      padding: const EdgeInsets.fromLTRB(12, 12, 12, 80),
      children: [
        if (onAdd != null)
          Align(
            alignment: Alignment.centerRight,
            child: FilledButton.icon(
              onPressed: onAdd,
              icon: const Icon(Icons.add, size: 18),
              label: Text(addLabel),
            ),
          ),
        const SizedBox(height: 8),
        if (empty != null) _Empty(empty!) else ...children,
      ],
    );
  }
}

/// Slim header shown above the tabs: car subtitle (make/model) plus the
/// service-status badge. The car's spec details now live in the Information tab.
class _StatusHeader extends StatelessWidget {
  final Car car;
  final Status status;
  const _StatusHeader({required this.car, required this.status});

  @override
  Widget build(BuildContext context) {
    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
        side: BorderSide(color: DriverVault.isDark(context) ? DriverVault.darkBorder : DriverVault.ink100),
      ),
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
        child: Row(
          children: [
            Expanded(
              child: Text(car.subtitle.isEmpty ? car.name : car.subtitle,
                  style: TextStyle(color: DriverVault.muted(context))),
            ),
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
              decoration: BoxDecoration(
                  color: status.bg(DriverVault.isDark(context)), borderRadius: BorderRadius.circular(999)),
              child: Text(status.label,
                  style: TextStyle(color: status.fg(DriverVault.isDark(context)), fontWeight: FontWeight.w600)),
            ),
          ],
        ),
      ),
    );
  }
}

/// Information tab: the car's spec details (oil specs, odometer, interval, next
/// due, VIN) in a scrollable card.
class _InfoTab extends StatelessWidget {
  final Car car;
  final ServiceRecord? latest;
  const _InfoTab({required this.car, required this.latest});

  @override
  Widget build(BuildContext context) {
    return ListView(
      padding: const EdgeInsets.fromLTRB(12, 12, 12, 80),
      children: [
        Card(
          elevation: 0,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(12),
            side: BorderSide(color: DriverVault.isDark(context) ? DriverVault.darkBorder : DriverVault.ink100),
          ),
          child: Padding(
            padding: const EdgeInsets.all(14),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                _kv(context, "Engine oil spec", _orDash(car.oilSpec)),
                _kv(context, "Transmission oil spec", _orDash(car.transmissionOilSpec)),
                _kv(context, "Differential oil spec", _orDash(car.differentialOilSpec)),
                _kv(context, "Brake fluid spec", _orDash(car.brakeFluidSpec)),
                _kv(context, "Coolant spec", _orDash(car.coolantSpec)),
                _kv(context, "Current odometer", formatKm(car.currentKm)),
                _kv(context, "Service interval", "${car.serviceIntervalDays} days · ${formatKm(car.serviceIntervalKm)}"),
                _kv(context, "Next due", "${formatDate(latest?.nextServiceDate)} · ${formatKm(latest?.nextServiceKm)}"),
                _kv(context, "Registration plate", _orDash(car.registration)),
                _kv(context, "Registration country", _orDash(car.registrationCountry)),
                _kv(context, "VIN", _orDash(car.vin)),
                _kv(context, "Fuel type", _fuelLabel(car.fuelType)),
                _kv(context, "Build date", _dateOrDash(car.buildDate)),
                _kv(context, "First registration", _dateOrDash(car.firstRegistrationDate)),
              ],
            ),
          ),
        ),
      ],
    );
  }

  static String _orDash(String v) => v.isEmpty ? "—" : v;

  static const Map<String, String> _fuelLabels = {
    "petrol": "Petrol (gasoline)",
    "diesel": "Diesel",
    "hybrid": "Hybrid",
    "electric": "Electric",
  };
  static String _fuelLabel(String v) => _fuelLabels[v] ?? "—";

  static String _dateOrDash(String iso) {
    final d = DateTime.tryParse(iso);
    return d == null ? "—" : formatDate(d);
  }

  Widget _kv(BuildContext context, String k, String v) => Padding(
        padding: const EdgeInsets.symmetric(vertical: 3),
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            SizedBox(width: 150, child: Text(k, style: TextStyle(color: DriverVault.muted(context)))),
            Expanded(child: Text(v, style: DriverVault.mono(context, size: 13, weight: FontWeight.w500,
                color: Theme.of(context).colorScheme.onSurface))),
          ],
        ),
      );
}

class _ServiceTile extends StatelessWidget {
  final ServiceRecord record;
  final VoidCallback? onEdit;
  final VoidCallback? onDelete;
  const _ServiceTile({required this.record, this.onEdit, this.onDelete});

  @override
  Widget build(BuildContext context) {
    final chips = <Widget>[
      if (record.changedOil) _chip(context, "Oil & filter"),
      if (record.changedEngineAirFilter) _chip(context, "Engine air"),
      if (record.changedCabinAirFilter) _chip(context, "Cabin air"),
    ];
    return Card(
      elevation: 0,
      margin: const EdgeInsets.only(bottom: 8),
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(10),
        side: BorderSide(color: DriverVault.isDark(context) ? DriverVault.darkBorder : DriverVault.ink100),
      ),
      child: Padding(
        padding: const EdgeInsets.all(12),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(formatDate(record.date), style: const TextStyle(fontWeight: FontWeight.w600)),
                Row(children: [
                  Text(formatKm(record.km)),
                  if (onEdit != null || onDelete != null)
                    _RowMenu(onEdit: onEdit, onDelete: onDelete),
                ]),
              ],
            ),
            const SizedBox(height: 4),
            Text("Next: ${formatDate(record.nextServiceDate)} · ${formatKm(record.nextServiceKm)}",
                style: const TextStyle(color: Colors.grey, fontSize: 12)),
            if (chips.isNotEmpty) ...[
              const SizedBox(height: 8),
              Wrap(spacing: 6, runSpacing: 6, children: chips),
            ],
            if (record.notes.isNotEmpty) ...[
              const SizedBox(height: 6),
              Text(record.notes, style: const TextStyle(fontSize: 12, fontStyle: FontStyle.italic)),
            ],
          ],
        ),
      ),
    );
  }

  Widget _chip(BuildContext context, String label) => Container(
        padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
        decoration: BoxDecoration(
          color: DriverVault.isDark(context) ? DriverVault.successSoftDark : DriverVault.successSoft,
          borderRadius: BorderRadius.circular(6),
        ),
        child: Text(label, style: const TextStyle(color: DriverVault.success, fontSize: 11, fontWeight: FontWeight.w500)),
      );
}

class _PartTile extends StatelessWidget {
  final Part part;
  final VoidCallback? onEdit;
  final VoidCallback? onDelete;
  const _PartTile({required this.part, this.onEdit, this.onDelete});
  @override
  Widget build(BuildContext context) {
    return Card(
      elevation: 0,
      margin: const EdgeInsets.only(bottom: 6),
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(10),
        side: BorderSide(color: DriverVault.isDark(context) ? DriverVault.darkBorder : DriverVault.ink100),
      ),
      child: ListTile(
        dense: true,
        title: Text(part.name, style: const TextStyle(fontWeight: FontWeight.w600)),
        subtitle: Text(part.partNumber.isEmpty ? "—" : part.partNumber,
            style: DriverVault.mono(context, size: 12, weight: FontWeight.w400, color: DriverVault.muted(context))),
        trailing: (onEdit != null || onDelete != null)
            ? _RowMenu(onEdit: onEdit, onDelete: onDelete)
            : null,
      ),
    );
  }
}

/// Overflow menu with Edit/Delete for a service/part row (write-gated).
class _RowMenu extends StatelessWidget {
  final VoidCallback? onEdit;
  final VoidCallback? onDelete;
  const _RowMenu({this.onEdit, this.onDelete});
  @override
  Widget build(BuildContext context) {
    return PopupMenuButton<String>(
      padding: EdgeInsets.zero,
      icon: const Icon(Icons.more_vert, size: 18),
      onSelected: (v) {
        if (v == "edit") onEdit?.call();
        if (v == "delete") onDelete?.call();
      },
      itemBuilder: (_) => [
        if (onEdit != null) const PopupMenuItem(value: "edit", child: Text("Edit")),
        if (onDelete != null)
          const PopupMenuItem(
              value: "delete", child: Text("Delete", style: TextStyle(color: DriverVault.danger))),
      ],
    );
  }
}

class _Empty extends StatelessWidget {
  final String text;
  const _Empty(this.text);
  @override
  Widget build(BuildContext context) => Padding(
        padding: const EdgeInsets.symmetric(vertical: 16),
        child: Center(child: Text(text, style: const TextStyle(color: Colors.grey))),
      );
}

/// Shown on a car that was shared with the current user read-only.
class _ReadOnlyNotice extends StatelessWidget {
  const _ReadOnlyNotice();
  @override
  Widget build(BuildContext context) {
    final onTint = DriverVault.brandOnTint(context);
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
      decoration: BoxDecoration(
        color: DriverVault.brandTint(context),
        borderRadius: BorderRadius.circular(10),
      ),
      child: Row(
        children: [
          Icon(Icons.visibility_outlined, size: 18, color: onTint),
          const SizedBox(width: 8),
          Expanded(
            child: Text(
              "Shared with you (read-only). You can't make changes.",
              style: TextStyle(color: onTint, fontSize: 13),
            ),
          ),
        ],
      ),
    );
  }
}

/// Owner-only bottom sheet to manage who a car is shared with: list current
/// grants, add one by email at a chosen permission, or remove one.
class _ShareSheet extends StatefulWidget {
  final Car car;
  const _ShareSheet({required this.car});
  @override
  State<_ShareSheet> createState() => _ShareSheetState();
}

class _ShareSheetState extends State<_ShareSheet> {
  late Future<List<CarShare>> _future;
  final _email = TextEditingController();
  String _permission = "read";
  bool _submitting = false;
  String? _error;

  @override
  void initState() {
    super.initState();
    _future = apiClient.listCarShares(widget.car.id);
  }

  @override
  void dispose() {
    _email.dispose();
    super.dispose();
  }

  void _reload() => setState(() => _future = apiClient.listCarShares(widget.car.id));

  Future<void> _add() async {
    final email = _email.text.trim();
    if (email.isEmpty) return;
    setState(() {
      _submitting = true;
      _error = null;
    });
    try {
      await apiClient.addCarShare(widget.car.id, email, _permission);
      _email.clear();
      _permission = "read";
      _reload();
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      if (mounted) setState(() => _submitting = false);
    }
  }

  Future<void> _setPermission(CarShare s, String value) async {
    try {
      await apiClient.addCarShare(widget.car.id, s.email, value);
      _reload();
    } catch (e) {
      setState(() => _error = e.toString());
    }
  }

  Future<void> _remove(CarShare s) async {
    try {
      await apiClient.removeCarShare(widget.car.id, s.userId);
      _reload();
    } catch (e) {
      setState(() => _error = e.toString());
    }
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.only(
        left: 16,
        right: 16,
        top: 16,
        bottom: MediaQuery.of(context).viewInsets.bottom + 16,
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text("Share ${widget.car.name}",
              style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w600)),
          const SizedBox(height: 4),
          const Text(
            "Read-only lets them view; read & write also lets them edit the car and its records.",
            style: TextStyle(color: Colors.grey, fontSize: 12),
          ),
          const SizedBox(height: 12),
          if (_error != null)
            Padding(
              padding: const EdgeInsets.only(bottom: 8),
              child: Text(_error!, style: const TextStyle(color: DriverVault.danger)),
            ),
          Row(
            children: [
              Expanded(
                child: TextField(
                  controller: _email,
                  keyboardType: TextInputType.emailAddress,
                  decoration: const InputDecoration(
                    labelText: "User email",
                    border: OutlineInputBorder(),
                    isDense: true,
                  ),
                ),
              ),
              const SizedBox(width: 8),
              DropdownButton<String>(
                value: _permission,
                onChanged: (v) => setState(() => _permission = v ?? "read"),
                items: const [
                  DropdownMenuItem(value: "read", child: Text("Read")),
                  DropdownMenuItem(value: "write", child: Text("Write")),
                ],
              ),
            ],
          ),
          const SizedBox(height: 8),
          SizedBox(
            width: double.infinity,
            child: FilledButton(
              onPressed: _submitting ? null : _add,
              child: Text(_submitting ? "Sharing…" : "Share"),
            ),
          ),
          const SizedBox(height: 16),
          const Text("People with access",
              style: TextStyle(fontWeight: FontWeight.w600)),
          const SizedBox(height: 4),
          FutureBuilder<List<CarShare>>(
            future: _future,
            builder: (context, snap) {
              if (snap.connectionState == ConnectionState.waiting) {
                return const Padding(
                  padding: EdgeInsets.all(12),
                  child: Center(child: CircularProgressIndicator()),
                );
              }
              final shares = snap.data ?? [];
              if (shares.isEmpty) {
                return const Padding(
                  padding: EdgeInsets.symmetric(vertical: 12),
                  child: Text("Not shared with anyone yet.",
                      style: TextStyle(color: Colors.grey)),
                );
              }
              return Column(
                children: shares
                    .map((s) => ListTile(
                          contentPadding: EdgeInsets.zero,
                          dense: true,
                          title: Text(s.label),
                          subtitle: s.name.isNotEmpty ? Text(s.email) : null,
                          trailing: Row(
                            mainAxisSize: MainAxisSize.min,
                            children: [
                              DropdownButton<String>(
                                value: s.permission,
                                underline: const SizedBox.shrink(),
                                onChanged: (v) => v == null ? null : _setPermission(s, v),
                                items: const [
                                  DropdownMenuItem(value: "read", child: Text("Read")),
                                  DropdownMenuItem(value: "write", child: Text("Write")),
                                ],
                              ),
                              IconButton(
                                tooltip: "Remove",
                                icon: const Icon(Icons.close, size: 18),
                                onPressed: () => _remove(s),
                              ),
                            ],
                          ),
                        ))
                    .toList(),
              );
            },
          ),
        ],
      ),
    );
  }
}

/// Type-to-confirm dialog for deleting a car. The delete button is enabled only
/// once the user types the car's exact name — guarding this cascade delete
/// (which also removes all of the car's service records and parts).
class _DeleteCarDialog extends StatefulWidget {
  final Car car;
  final int serviceCount;
  final int partCount;
  const _DeleteCarDialog({
    required this.car,
    required this.serviceCount,
    required this.partCount,
  });
  @override
  State<_DeleteCarDialog> createState() => _DeleteCarDialogState();
}

class _DeleteCarDialogState extends State<_DeleteCarDialog> {
  final _confirm = TextEditingController();
  bool _deleting = false;

  @override
  void dispose() {
    _confirm.dispose();
    super.dispose();
  }

  bool get _canDelete => _confirm.text.trim() == widget.car.name;

  String _plural(int n, String noun) => "$n $noun${n == 1 ? '' : 's'}";

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: const Text("Delete this car?", style: TextStyle(color: DriverVault.danger, fontWeight: FontWeight.w700)),
      content: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(
            "This permanently deletes ${widget.car.name} and all of its "
            "${_plural(widget.serviceCount, 'service record')} and "
            "${_plural(widget.partCount, 'part')}. This cannot be undone.",
          ),
          const SizedBox(height: 16),
          Text("Type “${widget.car.name}” to confirm",
              style: const TextStyle(fontSize: 13, color: Colors.grey)),
          const SizedBox(height: 6),
          TextField(
            controller: _confirm,
            autofocus: true,
            decoration: InputDecoration(hintText: widget.car.name, border: const OutlineInputBorder()),
            onChanged: (_) => setState(() {}),
          ),
        ],
      ),
      actions: [
        TextButton(
          onPressed: _deleting ? null : () => Navigator.pop(context, false),
          child: const Text("Cancel"),
        ),
        FilledButton(
          style: FilledButton.styleFrom(backgroundColor: const Color(0xFFDC2626)),
          onPressed: (!_canDelete || _deleting)
              ? null
              : () {
                  setState(() => _deleting = true);
                  Navigator.pop(context, true);
                },
          child: Text(_deleting ? "Deleting…" : "Delete permanently"),
        ),
      ],
    );
  }
}

/// Bottom sheet for adding or editing a service record.
class _ServiceSheet extends StatefulWidget {
  final String carId;
  final Car car;
  final ServiceRecord? record; // null => create
  const _ServiceSheet({required this.carId, required this.car, this.record});
  @override
  State<_ServiceSheet> createState() => _ServiceSheetState();
}

class _ServiceSheetState extends State<_ServiceSheet> {
  late DateTime _date;
  late final TextEditingController _km;
  late final TextEditingController _notes;
  late bool _oil, _engine, _cabin;
  bool _saving = false;
  String? _error;

  bool get _isEdit => widget.record != null;

  @override
  void initState() {
    super.initState();
    final r = widget.record;
    _date = r?.date ?? DateTime.now();
    _km = TextEditingController(text: (r != null && r.km > 0) ? "${r.km}" : "");
    _notes = TextEditingController(text: r?.notes ?? "");
    _oil = r?.changedOil ?? true;
    _engine = r?.changedEngineAirFilter ?? false;
    _cabin = r?.changedCabinAirFilter ?? false;
  }

  @override
  void dispose() {
    _km.dispose();
    _notes.dispose();
    super.dispose();
  }

  Future<void> _save() async {
    setState(() {
      _saving = true;
      _error = null;
    });
    final payload = {
      "car": widget.carId,
      "date": _date.toUtc().toIso8601String(),
      "km": int.tryParse(_km.text.trim()) ?? 0,
      "changedOil": _oil,
      "changedEngineAirFilter": _engine,
      "changedCabinAirFilter": _cabin,
      "notes": _notes.text.trim(),
    };
    try {
      if (_isEdit) {
        await apiClient.updateService(widget.record!.id, payload);
      } else {
        await apiClient.createService(payload);
      }
      if (mounted) Navigator.pop(context, true);
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      if (mounted) setState(() => _saving = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.only(
        left: 16,
        right: 16,
        top: 16,
        bottom: MediaQuery.of(context).viewInsets.bottom + 16,
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(_isEdit ? "Edit service record" : "Add service record",
              style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w600)),
          const SizedBox(height: 12),
          if (_error != null)
            Padding(
              padding: const EdgeInsets.only(bottom: 8),
              child: Text(_error!, style: const TextStyle(color: DriverVault.danger)),
            ),
          Row(
            children: [
              Expanded(
                child: OutlinedButton.icon(
                  icon: const Icon(Icons.calendar_today, size: 16),
                  label: Text(formatDate(_date)),
                  onPressed: () async {
                    final picked = await showDatePicker(
                      context: context,
                      initialDate: _date,
                      firstDate: DateTime(2000),
                      lastDate: DateTime.now().add(const Duration(days: 365)),
                    );
                    if (picked != null) setState(() => _date = picked);
                  },
                ),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: TextField(
                  controller: _km,
                  keyboardType: TextInputType.number,
                  decoration: const InputDecoration(labelText: "Odometer (km)", border: OutlineInputBorder()),
                ),
              ),
            ],
          ),
          const SizedBox(height: 8),
          CheckboxListTile(
            value: _oil,
            onChanged: (v) => setState(() => _oil = v ?? false),
            title: const Text("Oil & oil filter"),
            contentPadding: EdgeInsets.zero,
            controlAffinity: ListTileControlAffinity.leading,
          ),
          CheckboxListTile(
            value: _engine,
            onChanged: (v) => setState(() => _engine = v ?? false),
            title: const Text("Engine air filter"),
            contentPadding: EdgeInsets.zero,
            controlAffinity: ListTileControlAffinity.leading,
          ),
          CheckboxListTile(
            value: _cabin,
            onChanged: (v) => setState(() => _cabin = v ?? false),
            title: const Text("Cabin air filter"),
            contentPadding: EdgeInsets.zero,
            controlAffinity: ListTileControlAffinity.leading,
          ),
          TextField(
            controller: _notes,
            decoration: const InputDecoration(labelText: "Notes", border: OutlineInputBorder()),
          ),
          const SizedBox(height: 8),
          Text(
            "Next service (+${widget.car.serviceIntervalDays}d / +${formatKm(widget.car.serviceIntervalKm)}) is computed automatically.",
            style: const TextStyle(color: Colors.grey, fontSize: 12),
          ),
          const SizedBox(height: 12),
          SizedBox(
            width: double.infinity,
            child: FilledButton(
              onPressed: _saving ? null : _save,
              child: Padding(
                padding: const EdgeInsets.symmetric(vertical: 12),
                child: Text(_saving ? "Saving…" : (_isEdit ? "Save changes" : "Add service")),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

/// Bottom sheet for adding or editing a part.
class _PartSheet extends StatefulWidget {
  final String carId;
  final Part? part; // null => create
  const _PartSheet({required this.carId, this.part});
  @override
  State<_PartSheet> createState() => _PartSheetState();
}

class _PartSheetState extends State<_PartSheet> {
  late final TextEditingController _name;
  late final TextEditingController _partNumber;
  bool _saving = false;
  String? _error;

  bool get _isEdit => widget.part != null;

  @override
  void initState() {
    super.initState();
    _name = TextEditingController(text: widget.part?.name ?? "");
    _partNumber = TextEditingController(text: widget.part?.partNumber ?? "");
  }

  @override
  void dispose() {
    _name.dispose();
    _partNumber.dispose();
    super.dispose();
  }

  Future<void> _save() async {
    final name = _name.text.trim();
    if (name.isEmpty) {
      setState(() => _error = "Part name is required.");
      return;
    }
    setState(() {
      _saving = true;
      _error = null;
    });
    final payload = {
      "car": widget.carId,
      "name": name,
      "partNumber": _partNumber.text.trim(),
    };
    try {
      if (_isEdit) {
        await apiClient.updatePart(widget.part!.id, payload);
      } else {
        await apiClient.createPart(payload);
      }
      if (mounted) Navigator.pop(context, true);
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      if (mounted) setState(() => _saving = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.only(
        left: 16,
        right: 16,
        top: 16,
        bottom: MediaQuery.of(context).viewInsets.bottom + 16,
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(_isEdit ? "Edit part" : "Add part",
              style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w600)),
          const SizedBox(height: 12),
          if (_error != null)
            Padding(
              padding: const EdgeInsets.only(bottom: 8),
              child: Text(_error!, style: const TextStyle(color: DriverVault.danger)),
            ),
          TextField(
            controller: _name,
            textCapitalization: TextCapitalization.words,
            decoration: const InputDecoration(labelText: "Part name *", border: OutlineInputBorder()),
          ),
          const SizedBox(height: 8),
          TextField(
            controller: _partNumber,
            decoration: const InputDecoration(labelText: "Part number", border: OutlineInputBorder()),
          ),
          const SizedBox(height: 12),
          SizedBox(
            width: double.infinity,
            child: FilledButton(
              onPressed: _saving ? null : _save,
              child: Padding(
                padding: const EdgeInsets.symmetric(vertical: 12),
                child: Text(_saving ? "Saving…" : (_isEdit ? "Save changes" : "Add part")),
              ),
            ),
          ),
        ],
      ),
    );
  }
}