import 'package:diameter/components/dialogs.dart';
import 'package:diameter/components/dropdown.dart';
import 'package:diameter/components/forms.dart';
import 'package:diameter/config.dart';
import 'package:diameter/navigation.dart';
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';

enum GlucoseDisplayMode { activeOnly, bothForList, bothForDetail, both }

enum GlucoseMeasurement {
  mgPerDl,
  mmolPerL,
}

enum NutritionMeasurement {
  grams,
  ounces,
  cups,
}

class Settings {
  static void loadSettingsIntoConfig() async {
    nutritionMeasurement = await getNutritionMeasurement();
    glucoseMeasurement = await getGlucoseMeasurement();
    glucoseDisplayMode = await getGlucoseDisplayMode();
  }

  static Future<GlucoseDisplayMode> getGlucoseDisplayMode() async {
    final settings = await SharedPreferences.getInstance();
    int? index = settings.getInt('glucoseDisplayMode');
    return index != null && index < GlucoseDisplayMode.values.length
        ? GlucoseDisplayMode.values[index]
        : GlucoseDisplayMode.bothForList;
  }

  static Future<GlucoseMeasurement> getGlucoseMeasurement() async {
    final settings = await SharedPreferences.getInstance();
    int? index = settings.getInt('glucoseMeasurement');
    return index != null && index < GlucoseMeasurement.values.length
        ? GlucoseMeasurement.values[index]
        : GlucoseMeasurement.mgPerDl;
  }

  static Future<NutritionMeasurement> getNutritionMeasurement() async {
    final settings = await SharedPreferences.getInstance();
    int? index = settings.getInt('nutritionMeasurement');
    return index != null && index < NutritionMeasurement.values.length
        ? NutritionMeasurement.values[index]
        : NutritionMeasurement.grams;
  }

  static void setGlucoseDisplayMode(
      GlucoseDisplayMode? glucoseDisplayMode) async {
    final settings = await SharedPreferences.getInstance();
    if (glucoseDisplayMode != null) {
      settings.setInt('glucoseDisplayMode', glucoseDisplayMode.index);
    }
  }

  static void setGlucoseMeasurement(
      GlucoseMeasurement? glucoseMeasurement) async {
    final settings = await SharedPreferences.getInstance();
    if (glucoseMeasurement != null) {
      settings.setInt('preferredGlucoseMeasurement', glucoseMeasurement.index);
    }
  }

  static void setNutritionMeasurement(
      NutritionMeasurement? nutritionMeasurement) async {
    final settings = await SharedPreferences.getInstance();
    if (nutritionMeasurement != null) {
      settings.setInt(
          'preferredNutritionMeasurement', nutritionMeasurement.index);
    }
  }

  static void resetAll() async {
    final settings = await SharedPreferences.getInstance();

    settings.remove('glucoseDisplayMode');
    settings.remove('preferredGlucoseMeasurement');
    settings.remove('preferredNutritionMeasurement');
  }
}

class SettingsScreen extends StatefulWidget {
  static const String routeName = '/settings';

  const SettingsScreen({Key? key}) : super(key: key);

  @override
  _SettingsScreenState createState() => _SettingsScreenState();
}

class _SettingsScreenState extends State<SettingsScreen> {
  final GlobalKey<FormState> _settingsForm = GlobalKey<FormState>();

  void onReset() {
    Settings.resetAll();
    setState(() {
      Settings.loadSettingsIntoConfig();
    });
  }

  void handleResetAction() async {
    Dialogs.showConfirmationDialog(
      context: context,
      onConfirm: onReset,
      message: 'Are you sure you want to reset all settings?',
    );
  }

  @override
  initState() {
    super.initState();
    Settings.loadSettingsIntoConfig();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Application Settings'),
      ),
      drawer: const Navigation(currentLocation: SettingsScreen.routeName),
      body: SingleChildScrollView(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            FormWrapper(
              formState: _settingsForm,
              fields: [
                AutoCompleteDropdownButton<NutritionMeasurement>(
                  selectedItem: nutritionMeasurement,
                  label: 'Preferred Nutrition Measurement',
                  items: NutritionMeasurement.values,
                  onChanged: (value) {
                    if (value != null) {
                      Settings.setNutritionMeasurement(value);
                      setState(() {
                        nutritionMeasurement = value;
                      });
                    }
                  },
                ),
                AutoCompleteDropdownButton<GlucoseMeasurement>(
                  selectedItem: glucoseMeasurement,
                  label: 'Preferred Glucose Measurement',
                  items: GlucoseMeasurement.values,
                  onChanged: (value) {
                    if (value != null) {
                      Settings.setGlucoseMeasurement(value);
                      setState(() {
                        glucoseMeasurement = value;
                      });
                    }
                  },
                ),
                BooleanFormField(
                  value: glucoseDisplayMode == GlucoseDisplayMode.activeOnly,
                  label: 'only display active glucose measurement',
                  onChanged: (_) {
                    GlucoseDisplayMode mode =
                        glucoseDisplayMode == GlucoseDisplayMode.activeOnly
                            ? GlucoseDisplayMode.both
                            : GlucoseDisplayMode.activeOnly;
                    Settings.setGlucoseDisplayMode(mode);
                    setState(() {
                      glucoseDisplayMode = mode;
                    });
                  },
                ),
                BooleanFormField(
                  value: glucoseDisplayMode == GlucoseDisplayMode.both ||
                      glucoseDisplayMode == GlucoseDisplayMode.bothForDetail,
                  enabled: glucoseDisplayMode != GlucoseDisplayMode.activeOnly,
                  label: 'display both glucose measurements in detail view',
                  onChanged: (_) {
                    GlucoseDisplayMode mode = glucoseDisplayMode ==
                            GlucoseDisplayMode.both
                        ? GlucoseDisplayMode.bothForList
                        : glucoseDisplayMode == GlucoseDisplayMode.bothForList
                            ? GlucoseDisplayMode.both
                            : GlucoseDisplayMode.activeOnly;
                    Settings.setGlucoseDisplayMode(mode);
                    setState(() {
                      glucoseDisplayMode = mode;
                    });
                  },
                ),
                BooleanFormField(
                  value: glucoseDisplayMode == GlucoseDisplayMode.both ||
                      glucoseDisplayMode == GlucoseDisplayMode.bothForList,
                  enabled: glucoseDisplayMode != GlucoseDisplayMode.activeOnly,
                  label: 'display both glucose measurements in list view',
                  onChanged: (_) {
                    GlucoseDisplayMode mode = glucoseDisplayMode ==
                            GlucoseDisplayMode.both
                        ? GlucoseDisplayMode.bothForDetail
                        : glucoseDisplayMode == GlucoseDisplayMode.bothForDetail
                            ? GlucoseDisplayMode.both
                            : GlucoseDisplayMode.activeOnly;
                    Settings.setGlucoseDisplayMode(mode);
                    setState(() {
                      glucoseDisplayMode = mode;
                    });
                  },
                ),
              ],
            ),
          ],
        ),
      ),
      bottomNavigationBar: BottomAppBar(
        child: Padding(
          padding: const EdgeInsets.all(10.0),
          child: Row(
            children: [
              ElevatedButton.icon(
                onPressed: handleResetAction,
                icon: const Icon(
                  Icons.settings_backup_restore,
                  size: 18.0,
                ),
                label: const Text('RESET ALL'),
              ),
              const Spacer(),
            ],
          ),
        ),
      ),
    );
  }
}