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

import '../models/vehicle.dart';
import '../services/app_state.dart';

/// Add/edit form for a vehicle. Pass an existing [vehicle] to edit it, or
/// omit it to create a new one.
class AddEditVehicleScreen extends StatefulWidget {
  final Vehicle? vehicle;

  const AddEditVehicleScreen({super.key, this.vehicle});

  @override
  State<AddEditVehicleScreen> createState() => _AddEditVehicleScreenState();
}

class _AddEditVehicleScreenState extends State<AddEditVehicleScreen> {
  final _formKey = GlobalKey<FormState>();
  late final TextEditingController _makeController;
  late final TextEditingController _modelController;
  late final TextEditingController _colorController;
  late final TextEditingController _plateController;

  bool get _isEditing => widget.vehicle != null;

  @override
  void initState() {
    super.initState();
    _makeController = TextEditingController(text: widget.vehicle?.make ?? '');
    _modelController = TextEditingController(text: widget.vehicle?.model ?? '');
    _colorController = TextEditingController(text: widget.vehicle?.color ?? '');
    _plateController = TextEditingController(text: widget.vehicle?.licensePlate ?? '');
  }

  @override
  void dispose() {
    _makeController.dispose();
    _modelController.dispose();
    _colorController.dispose();
    _plateController.dispose();
    super.dispose();
  }

  Future<void> _save() async {
    if (!_formKey.currentState!.validate()) return;

    final appState = context.read<AppState>();
    if (_isEditing) {
      await appState.updateVehicle(widget.vehicle!.copyWith(
        make: _makeController.text.trim(),
        model: _modelController.text.trim(),
        color: _colorController.text.trim(),
        licensePlate: _plateController.text.trim(),
      ));
    } else {
      await appState.addVehicle(
        make: _makeController.text.trim(),
        model: _modelController.text.trim(),
        color: _colorController.text.trim(),
        licensePlate: _plateController.text.trim(),
      );
    }

    if (mounted) Navigator.of(context).pop();
  }

  Future<void> _confirmDelete() async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Delete vehicle?'),
        content: Text(
          'This will also delete all fuel entries and receipt photos logged for '
          '${widget.vehicle!.displayName}. This cannot be undone.',
        ),
        actions: [
          TextButton(onPressed: () => Navigator.of(context).pop(false), child: const Text('Cancel')),
          TextButton(
            onPressed: () => Navigator.of(context).pop(true),
            child: const Text('Delete', style: TextStyle(color: Colors.red)),
          ),
        ],
      ),
    );

    if (confirmed == true && mounted) {
      await context.read<AppState>().deleteVehicle(widget.vehicle!.id);
      if (mounted) {
        Navigator.of(context)
          ..pop()
          ..pop();
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(_isEditing ? 'Edit Vehicle' : 'Add Vehicle'),
        actions: [
          if (_isEditing)
            IconButton(
              icon: const Icon(Icons.delete_outline),
              tooltip: 'Delete vehicle',
              onPressed: _confirmDelete,
            ),
        ],
      ),
      body: Form(
        key: _formKey,
        child: ListView(
          padding: const EdgeInsets.all(16),
          children: [
            TextFormField(
              controller: _makeController,
              decoration: const InputDecoration(labelText: 'Make', hintText: 'e.g. Ford'),
              textCapitalization: TextCapitalization.words,
              validator: (v) => (v == null || v.trim().isEmpty) ? 'Required' : null,
            ),
            const SizedBox(height: 12),
            TextFormField(
              controller: _modelController,
              decoration: const InputDecoration(labelText: 'Model', hintText: 'e.g. F-150'),
              textCapitalization: TextCapitalization.words,
              validator: (v) => (v == null || v.trim().isEmpty) ? 'Required' : null,
            ),
            const SizedBox(height: 12),
            TextFormField(
              controller: _colorController,
              decoration: const InputDecoration(labelText: 'Color', hintText: 'e.g. Red'),
              textCapitalization: TextCapitalization.words,
              validator: (v) => (v == null || v.trim().isEmpty) ? 'Required' : null,
            ),
            const SizedBox(height: 12),
            TextFormField(
              controller: _plateController,
              decoration: const InputDecoration(labelText: 'License Plate'),
              textCapitalization: TextCapitalization.characters,
              validator: (v) => (v == null || v.trim().isEmpty) ? 'Required' : null,
            ),
            const SizedBox(height: 24),
            FilledButton(
              onPressed: _save,
              child: Text(_isEditing ? 'Save Changes' : 'Add Vehicle'),
            ),
          ],
        ),
      ),
    );
  }
}