Must Have 코드팩토리의 플러터 프로그래밍 - 18 ~ 19

// lib/database/drift_database.dart
import 'package:calendar_scheduler/model/schedule.dart';
import 'package:drift/drift.dart';
import 'package:drift/native.dart';
import 'package:path_provider/path_provider.dart';
import 'package:path/path.dart' as p;
import 'dart:io';

part 'drift_database.g.dart';

@DriftDatabase(
  tables: [
    Schedules,
  ],
)
class LocalDatabase extends _$LocalDatabase {
  LocalDatabase() : super(_openConnection());

  Stream<List<Schedule>> watchSchedules(DateTime date) =>
      (select(schedules)..where((tbl) => tbl.date.equals(date))).watch();

  Future<int> createSchedule(SchedulesCompanion data) =>
      into(schedules).insert(data);

  Future<int> removeSchedule(int id) =>
      (delete(schedules)..where((tbl) => tbl.id.equals(id))).go();

  int get schemaVersion => 1;
}

LazyDatabase _openConnection() {
  return LazyDatabase(() async {
    final dbFolder = await getApplicationDocumentsDirectory();
    final file = File(p.join(dbFolder.path, 'db.sqlite'));
    return NativeDatabase(file);
  });
}

// lib/database/drift_database.g.dart
// GENERATED CODE - DO NOT MODIFY BY HAND

part of 'drift_database.dart';

// ignore_for_file: type=lint
class $SchedulesTable extends Schedules
    with TableInfo<$SchedulesTable, Schedule> {
  @override
  final GeneratedDatabase attachedDatabase;
  final String? _alias;
  $SchedulesTable(this.attachedDatabase, [this._alias]);
  static const VerificationMeta _idMeta = const VerificationMeta('id');
  @override
  late final GeneratedColumn<int> id = GeneratedColumn<int>(
      'id', aliasedName, false,
      hasAutoIncrement: true,
      type: DriftSqlType.int,
      requiredDuringInsert: false,
      defaultConstraints:
          GeneratedColumn.constraintIsAlways('PRIMARY KEY AUTOINCREMENT'));
  static const VerificationMeta _contentMeta =
      const VerificationMeta('content');
  @override
  late final GeneratedColumn<String> content = GeneratedColumn<String>(
      'content', aliasedName, false,
      type: DriftSqlType.string, requiredDuringInsert: true);
  static const VerificationMeta _dateMeta = const VerificationMeta('date');
  @override
  late final GeneratedColumn<DateTime> date = GeneratedColumn<DateTime>(
      'date', aliasedName, false,
      type: DriftSqlType.dateTime, requiredDuringInsert: true);
  static const VerificationMeta _startTimeMeta =
      const VerificationMeta('startTime');
  @override
  late final GeneratedColumn<int> startTime = GeneratedColumn<int>(
      'start_time', aliasedName, false,
      type: DriftSqlType.int, requiredDuringInsert: true);
  static const VerificationMeta _endTimeMeta =
      const VerificationMeta('endTime');
  @override
  late final GeneratedColumn<int> endTime = GeneratedColumn<int>(
      'end_time', aliasedName, false,
      type: DriftSqlType.int, requiredDuringInsert: true);
  @override
  List<GeneratedColumn> get $columns => [id, content, date, startTime, endTime];
  @override
  String get aliasedName => _alias ?? actualTableName;
  @override
  String get actualTableName => $name;
  static const String $name = 'schedules';
  @override
  VerificationContext validateIntegrity(Insertable<Schedule> instance,
      {bool isInserting = false}) {
    final context = VerificationContext();
    final data = instance.toColumns(true);
    if (data.containsKey('id')) {
      context.handle(_idMeta, id.isAcceptableOrUnknown(data['id']!, _idMeta));
    }
    if (data.containsKey('content')) {
      context.handle(_contentMeta,
          content.isAcceptableOrUnknown(data['content']!, _contentMeta));
    } else if (isInserting) {
      context.missing(_contentMeta);
    }
    if (data.containsKey('date')) {
      context.handle(
          _dateMeta, date.isAcceptableOrUnknown(data['date']!, _dateMeta));
    } else if (isInserting) {
      context.missing(_dateMeta);
    }
    if (data.containsKey('start_time')) {
      context.handle(_startTimeMeta,
          startTime.isAcceptableOrUnknown(data['start_time']!, _startTimeMeta));
    } else if (isInserting) {
      context.missing(_startTimeMeta);
    }
    if (data.containsKey('end_time')) {
      context.handle(_endTimeMeta,
          endTime.isAcceptableOrUnknown(data['end_time']!, _endTimeMeta));
    } else if (isInserting) {
      context.missing(_endTimeMeta);
    }
    return context;
  }

  @override
  Set<GeneratedColumn> get $primaryKey => {id};
  @override
  Schedule map(Map<String, dynamic> data, {String? tablePrefix}) {
    final effectivePrefix = tablePrefix != null ? '$tablePrefix.' : '';
    return Schedule(
      id: attachedDatabase.typeMapping
          .read(DriftSqlType.int, data['${effectivePrefix}id'])!,
      content: attachedDatabase.typeMapping
          .read(DriftSqlType.string, data['${effectivePrefix}content'])!,
      date: attachedDatabase.typeMapping
          .read(DriftSqlType.dateTime, data['${effectivePrefix}date'])!,
      startTime: attachedDatabase.typeMapping
          .read(DriftSqlType.int, data['${effectivePrefix}start_time'])!,
      endTime: attachedDatabase.typeMapping
          .read(DriftSqlType.int, data['${effectivePrefix}end_time'])!,
    );
  }

  @override
  $SchedulesTable createAlias(String alias) {
    return $SchedulesTable(attachedDatabase, alias);
  }
}

class Schedule extends DataClass implements Insertable<Schedule> {
  final int id;
  final String content;
  final DateTime date;
  final int startTime;
  final int endTime;
  const Schedule(
      {required this.id,
      required this.content,
      required this.date,
      required this.startTime,
      required this.endTime});
  @override
  Map<String, Expression> toColumns(bool nullToAbsent) {
    final map = <String, Expression>{};
    map['id'] = Variable<int>(id);
    map['content'] = Variable<String>(content);
    map['date'] = Variable<DateTime>(date);
    map['start_time'] = Variable<int>(startTime);
    map['end_time'] = Variable<int>(endTime);
    return map;
  }

  SchedulesCompanion toCompanion(bool nullToAbsent) {
    return SchedulesCompanion(
      id: Value(id),
      content: Value(content),
      date: Value(date),
      startTime: Value(startTime),
      endTime: Value(endTime),
    );
  }

  factory Schedule.fromJson(Map<String, dynamic> json,
      {ValueSerializer? serializer}) {
    serializer ??= driftRuntimeOptions.defaultSerializer;
    return Schedule(
      id: serializer.fromJson<int>(json['id']),
      content: serializer.fromJson<String>(json['content']),
      date: serializer.fromJson<DateTime>(json['date']),
      startTime: serializer.fromJson<int>(json['startTime']),
      endTime: serializer.fromJson<int>(json['endTime']),
    );
  }
  @override
  Map<String, dynamic> toJson({ValueSerializer? serializer}) {
    serializer ??= driftRuntimeOptions.defaultSerializer;
    return <String, dynamic>{
      'id': serializer.toJson<int>(id),
      'content': serializer.toJson<String>(content),
      'date': serializer.toJson<DateTime>(date),
      'startTime': serializer.toJson<int>(startTime),
      'endTime': serializer.toJson<int>(endTime),
    };
  }

  Schedule copyWith(
          {int? id,
          String? content,
          DateTime? date,
          int? startTime,
          int? endTime}) =>
      Schedule(
        id: id ?? this.id,
        content: content ?? this.content,
        date: date ?? this.date,
        startTime: startTime ?? this.startTime,
        endTime: endTime ?? this.endTime,
      );
  @override
  String toString() {
    return (StringBuffer('Schedule(')
          ..write('id: $id, ')
          ..write('content: $content, ')
          ..write('date: $date, ')
          ..write('startTime: $startTime, ')
          ..write('endTime: $endTime')
          ..write(')'))
        .toString();
  }

  @override
  int get hashCode => Object.hash(id, content, date, startTime, endTime);
  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      (other is Schedule &&
          other.id == this.id &&
          other.content == this.content &&
          other.date == this.date &&
          other.startTime == this.startTime &&
          other.endTime == this.endTime);
}

class SchedulesCompanion extends UpdateCompanion<Schedule> {
  final Value<int> id;
  final Value<String> content;
  final Value<DateTime> date;
  final Value<int> startTime;
  final Value<int> endTime;
  const SchedulesCompanion({
    this.id = const Value.absent(),
    this.content = const Value.absent(),
    this.date = const Value.absent(),
    this.startTime = const Value.absent(),
    this.endTime = const Value.absent(),
  });
  SchedulesCompanion.insert({
    this.id = const Value.absent(),
    required String content,
    required DateTime date,
    required int startTime,
    required int endTime,
  })  : content = Value(content),
        date = Value(date),
        startTime = Value(startTime),
        endTime = Value(endTime);
  static Insertable<Schedule> custom({
    Expression<int>? id,
    Expression<String>? content,
    Expression<DateTime>? date,
    Expression<int>? startTime,
    Expression<int>? endTime,
  }) {
    return RawValuesInsertable({
      if (id != null) 'id': id,
      if (content != null) 'content': content,
      if (date != null) 'date': date,
      if (startTime != null) 'start_time': startTime,
      if (endTime != null) 'end_time': endTime,
    });
  }

  SchedulesCompanion copyWith(
      {Value<int>? id,
      Value<String>? content,
      Value<DateTime>? date,
      Value<int>? startTime,
      Value<int>? endTime}) {
    return SchedulesCompanion(
      id: id ?? this.id,
      content: content ?? this.content,
      date: date ?? this.date,
      startTime: startTime ?? this.startTime,
      endTime: endTime ?? this.endTime,
    );
  }

  @override
  Map<String, Expression> toColumns(bool nullToAbsent) {
    final map = <String, Expression>{};
    if (id.present) {
      map['id'] = Variable<int>(id.value);
    }
    if (content.present) {
      map['content'] = Variable<String>(content.value);
    }
    if (date.present) {
      map['date'] = Variable<DateTime>(date.value);
    }
    if (startTime.present) {
      map['start_time'] = Variable<int>(startTime.value);
    }
    if (endTime.present) {
      map['end_time'] = Variable<int>(endTime.value);
    }
    return map;
  }

  @override
  String toString() {
    return (StringBuffer('SchedulesCompanion(')
          ..write('id: $id, ')
          ..write('content: $content, ')
          ..write('date: $date, ')
          ..write('startTime: $startTime, ')
          ..write('endTime: $endTime')
          ..write(')'))
        .toString();
  }
}

abstract class _$LocalDatabase extends GeneratedDatabase {
  _$LocalDatabase(QueryExecutor e) : super(e);
  late final $SchedulesTable schedules = $SchedulesTable(this);
  @override
  Iterable<TableInfo<Table, Object?>> get allTables =>
      allSchemaEntities.whereType<TableInfo<Table, Object?>>();
  @override
  List<DatabaseSchemaEntity> get allSchemaEntities => [schedules];
}

// lib/model/schedule.dart
import 'package:drift/drift.dart';

class Schedules extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get content => text()();      
  DateTimeColumn get date => dateTime()(); 
  IntColumn get startTime => integer()();  
  IntColumn get endTime => integer()();    
}

// lib/main.dart
import 'package:calendar_scheduler/screen/home_screen.dart';
import 'package:flutter/material.dart';
import 'package:intl/date_symbol_data_local.dart';
import 'package:calendar_scheduler/database/drift_database.dart';
import 'package:get_it/get_it.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await initializeDateFormatting();

  final database = LocalDatabase();

  GetIt.I.registerSingleton<LocalDatabase>(database);

  runApp(
    MaterialApp(
      home: HomeScreen(),
    ),
  );
}

// lib/screen/home_screen.dart
import 'package:flutter/material.dart';
import 'package:calendar_scheduler/component/main_calendar.dart';
import 'package:calendar_scheduler/component/schedule_card.dart';
import 'package:calendar_scheduler/component/today_banner.dart';
import 'package:calendar_scheduler/component/schedule_bottom_sheet.dart';
import 'package:calendar_scheduler/const/colors.dart';
import 'package:get_it/get_it.dart';
import 'package:calendar_scheduler/database/drift_database.dart';

class HomeScreen extends StatefulWidget {
  const HomeScreen({Key? key}) : super(key: key);

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  DateTime selectedDate = DateTime.utc(
    DateTime.now().year,
    DateTime.now().month,
    DateTime.now().day,
  );

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      floatingActionButton: FloatingActionButton(
        backgroundColor: PRIMARY_COLOR,
        onPressed: () {
          showModalBottomSheet(
            context: context,
            isDismissible: true,
            isScrollControlled: true,
            builder: (_) => ScheduleBottomSheet(
              selectedDate: selectedDate,
            ),
          );
        },
        child: Icon(
          Icons.add,
        ),
      ),
      body: SafeArea(
        child: Column(
          children: [
            MainCalendar(
              selectedDate: selectedDate,
              onDaySelected: onDaySelected,
            ),
            SizedBox(height: 8.0),
            StreamBuilder<List<Schedule>>(
                stream: GetIt.I<LocalDatabase>().watchSchedules(selectedDate),
                builder: (context, snapshot) {
                  return TodayBanner(
                    selectedDate: selectedDate,
                    count: snapshot.data?.length ?? 0,
                  );
                }
            ),
            SizedBox(height: 8.0),
            Expanded(
              child: StreamBuilder<List<Schedule>>(
                stream: GetIt.I<LocalDatabase>().watchSchedules(selectedDate),
                builder: (context, snapshot) {
                  if (!snapshot.hasData) {
                    return Container();
                  }

                  return ListView.builder(
                    itemCount: snapshot.data!.length,
                    itemBuilder: (context, index) {
                      final schedule =
                          snapshot.data![index];
                      return Dismissible(
                        key: ObjectKey(schedule.id),
                        direction: DismissDirection.startToEnd,
                        onDismissed: (DismissDirection direction) {
                          GetIt.I<LocalDatabase>().removeSchedule(schedule.id);
                        },
                        child: Padding(
                          padding: const EdgeInsets.only(
                              bottom: 8.0, left: 8.0, right: 8.0),
                          child: ScheduleCard(
                            startTime: schedule.startTime,
                            endTime: schedule.endTime,
                            content: schedule.content,
                          ),
                        ),
                      );
                    },
                  );
                },
              ),
            ),
          ],
        ),
      ),
    );
  }

  void onDaySelected(DateTime selectedDate, DateTime focusedDate) {
    setState(() {
      this.selectedDate = selectedDate;
    });
  }
}

// lib/const/color.dart
import 'package:flutter/material.dart';

const PRIMARY_COLOR = Color(0xff0DB2B2);
final LIGHT_GREY_COLOR = Colors.grey[200]!;
final DARK_GREY_COLOR = Colors.grey[600]!;
final TEXT_FIELD_FILL_COLOR = Colors.grey[300]!;

// lib/component/custom_text_field.dart
import 'package:calendar_scheduler/const/colors.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

class CustomTextField extends StatelessWidget {
  final String label;
  final bool isTime;
  final FormFieldSetter<String> onSaved;
  final FormFieldValidator<String> validator;

  const CustomTextField({
    required this.label,
    required this.isTime,
    required this.onSaved,
    required this.validator,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          label,
          style: TextStyle(
            color: PRIMARY_COLOR,
            fontWeight: FontWeight.w600,
          ),
        ),
        Expanded(
          flex: isTime ? 0 : 1,
          child: TextFormField(
            onSaved: onSaved,
            validator: validator,
            cursorColor: Colors.grey,
            maxLines: isTime ? 1 : null,
            expands: !isTime,
            keyboardType: isTime ? TextInputType.number : TextInputType.multiline,
            inputFormatters: isTime
                ? [
              FilteringTextInputFormatter.digitsOnly,
            ]
                : [],
            decoration: InputDecoration(
              border: InputBorder.none,
              filled: true,
              fillColor: Colors.grey[300],
              suffixText: isTime ? '시' : null,
            ),
          ),
        ),
      ],
    );
  }
}

// lib/component/main_calendar.dart
import 'package:flutter/material.dart';
import 'package:table_calendar/table_calendar.dart';
import 'package:calendar_scheduler/const/colors.dart';

class MainCalendar extends StatelessWidget {
  final OnDaySelected onDaySelected;
  final DateTime selectedDate;

  MainCalendar({
    required this.onDaySelected,
    required this.selectedDate,
  });

  @override
  Widget build(BuildContext context) {
    return TableCalendar(
      locale: 'ko_kr',
      onDaySelected: onDaySelected,
      selectedDayPredicate: (date) =>
      date.year == selectedDate.year &&
          date.month == selectedDate.month &&
          date.day == selectedDate.day,
      firstDay: DateTime(1800, 1, 1),
      lastDay: DateTime(3000, 1, 1),
      focusedDay: DateTime.now(),
      headerStyle: HeaderStyle(
        titleCentered: true,
        formatButtonVisible: false,
        titleTextStyle: TextStyle(
          fontWeight: FontWeight.w700,
          fontSize: 16.0,
        ),
      ),
      calendarStyle: CalendarStyle(
        isTodayHighlighted: false,
        defaultDecoration: BoxDecoration(
          borderRadius: BorderRadius.circular(6.0),
          color: LIGHT_GREY_COLOR,
        ),
        weekendDecoration: BoxDecoration(
          borderRadius: BorderRadius.circular(6.0),
          color: LIGHT_GREY_COLOR,
        ),
        selectedDecoration: BoxDecoration(
          borderRadius: BorderRadius.circular(6.0),
          border: Border.all(
            color: PRIMARY_COLOR,
            width: 1.0,
          ),
        ),
        defaultTextStyle: TextStyle(
          fontWeight: FontWeight.w600,
          color: DARK_GREY_COLOR,
        ),
        weekendTextStyle: TextStyle(
          fontWeight: FontWeight.w600,
          color: DARK_GREY_COLOR,
        ),
        selectedTextStyle: TextStyle(
          fontWeight: FontWeight.w600,
          color: PRIMARY_COLOR,
        ),
      ),
    );
  }
}

// lib/component/schedule_bottom_sheet.dart
import 'package:flutter/material.dart';
import 'package:calendar_scheduler/component/custom_text_field.dart';
import 'package:calendar_scheduler/const/colors.dart';
import 'package:drift/drift.dart' hide Column;
import 'package:get_it/get_it.dart';
import 'package:calendar_scheduler/database/drift_database.dart';

class ScheduleBottomSheet extends StatefulWidget {
  final DateTime selectedDate;

  const ScheduleBottomSheet({
    required this.selectedDate,
    Key? key,
  }) : super(key: key);

  @override
  State<ScheduleBottomSheet> createState() => _ScheduleBottomSheetState();
}

class _ScheduleBottomSheetState extends State<ScheduleBottomSheet> {
  final GlobalKey<FormState> formKey = GlobalKey();

  int? startTime;
  int? endTime;
  String? content;

  @override
  Widget build(BuildContext context) {
    final bottomInset = MediaQuery.of(context).viewInsets.bottom;

    return Form(
      key: formKey,
      child: SafeArea(
        child: Container(
          height: MediaQuery.of(context).size.height / 2 +
              bottomInset,
          color: Colors.white,
          child: Padding(
            padding:
                EdgeInsets.only(left: 8, right: 8, top: 8, bottom: bottomInset),
            child: Column(
              children: [
                Row(
                  children: [
                    Expanded(
                      child: CustomTextField(
                        label: '시작 시간',
                        isTime: true,
                        onSaved: (String? val) {
                          startTime = int.parse(val!);
                        },
                        validator: timeValidator,
                      ),
                    ),
                    const SizedBox(width: 16.0),
                    Expanded(
                      child: CustomTextField(
                        label: '종료 시간',
                        isTime: true,
                        onSaved: (String? val) {
                          endTime = int.parse(val!);
                        },
                        validator: timeValidator,
                      ),
                    ),
                  ],
                ),
                SizedBox(height: 8.0),
                Expanded(
                  child: CustomTextField(
                    label: '내용',
                    isTime: false,
                    onSaved: (String? val) {
                      content = val;
                    },
                    validator: contentValidator,
                  ),
                ),
                SizedBox(
                  width: double.infinity,
                  child: ElevatedButton(
                    onPressed: onSavePressed,
                    style: ElevatedButton.styleFrom(
                      primary: PRIMARY_COLOR,
                    ),
                    child: Text('저장'),
                  ),
                ),
              ],
            ),
          ),
        ),
      ),  
    );
  }

  void onSavePressed() async {
    if (formKey.currentState!.validate()) {
      formKey.currentState!.save();

      await GetIt.I<LocalDatabase>().createSchedule(
        SchedulesCompanion(
          startTime: Value(startTime!),
          endTime: Value(endTime!),
          content: Value(content!),
          date: Value(widget.selectedDate),
        ),
      );

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

  String? timeValidator(String? val) {
    if (val == null) {
      return '값을 입력해주세요';
    }

    int? number;

    try {
      number = int.parse(val);
    } catch (e) {
      return '숫자를 입력해주세요';
    }

    if (number < 0 || number > 24) {
      return '0시부터 24시 사이를 입력해주세요';
    }

    return null;
  }

  String? contentValidator(String? val) {
    if (val == null || val.length == 0) {
      return '값을 입력해주세요';
    }

    return null;
  }
}

// lib/component/schedule_card.dart
import 'package:calendar_scheduler/const/colors.dart';
import 'package:flutter/material.dart';

class ScheduleCard extends StatelessWidget {
  final int startTime;
  final int endTime;
  final String content;

  const ScheduleCard({
    required this.startTime,
    required this.endTime,
    required this.content,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
        border: Border.all(
          width: 1.0,
          color: PRIMARY_COLOR,
        ),
        borderRadius: BorderRadius.circular(8.0),
      ),
      child: Padding(
        padding: const EdgeInsets.all(16.0),
        child: IntrinsicHeight(  
          child: Row(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              _Time(   
                startTime: startTime,
                endTime: endTime,
              ),
              SizedBox(width: 16.0),
              _Content(   
                content: content,
              ),
              SizedBox(width: 16.0),
            ],
          ),
        ),
      ),
    );
  }
}

class _Time extends StatelessWidget {
  final int startTime;  
  final int endTime;    

  const _Time({
    required this.startTime,
    required this.endTime,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final textStyle = TextStyle(
      fontWeight: FontWeight.w600,
      color: PRIMARY_COLOR,
      fontSize: 16.0,
    );

    return Column(  
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          '${startTime.toString().padLeft(2, '0')}:00',  
          style: textStyle,
        ),
        Text(
          '${endTime.toString().padLeft(2, '0')}:00', 
          style: textStyle.copyWith(
            fontSize: 10.0,
          ),
        ),
      ],
    );
  }
}

class _Content extends StatelessWidget {
  final String content;  

  const _Content({
    required this.content,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Expanded(  
      child: Text(
        content,
      ),
    );
  }
}

// lib/component/today_banner.dart
import 'package:calendar_scheduler/const/colors.dart';
import 'package:flutter/material.dart';

class TodayBanner extends StatelessWidget {
  final DateTime selectedDate; 
  final int count; 

  const TodayBanner({
    required this.selectedDate,
    required this.count,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final textStyle = TextStyle( 
      fontWeight: FontWeight.w600,
      color: Colors.white,
    );

    return Container(
      color: PRIMARY_COLOR,
      child: Padding(
        padding: EdgeInsets.symmetric(horizontal: 16.0, vertical: 8.0),
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Text(
              '${selectedDate.year}년 ${selectedDate.month}월 ${selectedDate.day}일', 
              style: textStyle,
            ),
            Text(
              '$count개', 
              style: textStyle,
            ),
          ],
        ),
      ),
    );
  }
}

// lib/repository/schedule_repository.dart
import 'dart:async';
import 'dart:io';

import 'package:calendar_scheduler/model/schedule_model.dart';
import 'package:dio/dio.dart';

class ScheduleRepository {
  final _dio = Dio();
  final _targetUrl = 'http://${Platform.isAndroid ? '10.0.2.2' : 'localhost'}:3000/schedule'; 

  Future<List<ScheduleModel>> getSchedules({
    required DateTime date,
  }) async {
    final resp = await _dio.get(
      _targetUrl,
      queryParameters: { 
        'date':
        '${date.year}${date.month.toString().padLeft(2, '0')}${date.day.toString().padLeft(2, '0')}',
      },
    );

    return resp.data 
        .map<ScheduleModel>(
          (x) => ScheduleModel.fromJson(
        json: x,
      ),
    )
        .toList();
  }

  Future<String> createSchedule({
    required ScheduleModel schedule,
  }) async {
    final json = schedule.toJson();

    final resp = await _dio.post(_targetUrl, data: json);

    return resp.data?['id'];
  }

  Future<String> deleteSchedule({
    required String id,
  }) async {
    final resp = await _dio.delete(_targetUrl, data: {
      'id': id, 
    });

    return resp.data?['id']; 
  }
}

// lib/provider/schedule_provider.dart
import 'package:calendar_scheduler/model/schedule_model.dart';
import 'package:calendar_scheduler/repository/schedule_repository.dart';
import 'package:flutter/material.dart';
import 'package:uuid/uuid.dart';

class ScheduleProvider extends ChangeNotifier {
  final ScheduleRepository repository; 

  DateTime selectedDate = DateTime.utc( 
    DateTime.now().year,
    DateTime.now().month,
    DateTime.now().day,
  );
  Map<DateTime, List<ScheduleModel>> cache = {}; 

  ScheduleProvider({
    required this.repository,
  }) : super() {
    getSchedules(date: selectedDate);
  }

  void getSchedules({
    required DateTime date,
  }) async {
    final resp = await repository.getSchedules(date: date); 

    cache.update(date, (value) => resp, ifAbsent: () => resp); 

    notifyListeners(); 
  }

  void createSchedule({
    required ScheduleModel schedule,
  }) async {
    final targetDate = schedule.date;
    final uuid = Uuid();

    final tempId = uuid.v4(); 
    final newSchedule = schedule.copyWith(
      id: tempId, 
    );

    cache.update( 
      targetDate,
          (value) => [
        ...value,
        newSchedule,
      ]..sort(
            (a, b) => a.startTime.compareTo(
          b.startTime,
        ),
      ),
      ifAbsent: () => [newSchedule],
    );

    notifyListeners(); 

    try {
      final savedSchedule = await repository.createSchedule(schedule: schedule); 

      cache.update( 
        targetDate,
            (value) => value
            .map((e) => e.id == tempId
            ? e.copyWith(
          id: savedSchedule,
        )
            : e)
            .toList(),
      );
    } catch (e) {
      cache.update( 
        targetDate,
            (value) => value.where((e) => e.id != tempId).toList(),
      );
    }
  }

  void deleteSchedule({
    required DateTime date,
    required String id,
  }) async {
    final targetSchedule = cache[date]!.firstWhere(
          (e) => e.id == id,
    ); 

    cache.update(
      date,
          (value) => value.where((e) => e.id != id).toList(),
      ifAbsent: () => [],
    );

    notifyListeners(); 

    try {
      await repository.deleteSchedule(id: id);
    } catch (e) {
      cache.update(
        date,
            (value) => [...value, targetSchedule]..sort(
              (a, b) => a.startTime.compareTo(
            b.startTime,
          ),
        ),
      );
    }

    notifyListeners();
  }

  void changeSelectedDate({
    required DateTime date,
  }) {
    selectedDate = date;
    notifyListeners();
  }
}

// lib/model/schedule_model.dart
class ScheduleModel {
  final String id;
  final String content;
  final DateTime date;
  final int startTime;
  final int endTime;

  ScheduleModel({
    required this.id,
    required this.content,
    required this.date,
    required this.startTime,
    required this.endTime,
  });

  ScheduleModel.fromJson({
    required Map<String, dynamic> json,
  })  : id = json['id'],
        content = json['content'],
        date = DateTime.parse(json['date']),
        startTime = json['startTime'],
        endTime = json['endTime'];

  Map<String, dynamic> toJson() {
    return {
      'id': id,
      'content': content,
      'date':
      '${date.year}${date.month.toString().padLeft(2, '0')}${date.day.toString().padLeft(2, '0')}',
      'startTime': startTime,
      'endTime': endTime,
    };
  }

  ScheduleModel copyWith({
    String? id,
    String? content,
    DateTime? date,
    int? startTime,
    int? endTime,
  }) {
    return ScheduleModel(
      id: id ?? this.id,
      content: content ?? this.content,
      date: date ?? this.date,
      startTime: startTime ?? this.startTime,
      endTime: endTime ?? this.endTime,
    );
  }
}

// lib/model/schedule.dart
// ... 18장과 동일 ...

// lib/database/drift_database.dart
// ... 18장과 동일 ...

// lib/database/drift_database.g.dart
// GENERATED CODE - DO NOT MODIFY BY HAND

part of 'drift_database.dart';

// **************************************************************************
// DriftDatabaseGenerator
// **************************************************************************

// ignore_for_file: type=lint
class Schedule extends DataClass implements Insertable<Schedule> {
  final int id;
  final String content;
  final DateTime date;
  final int startTime;
  final int endTime;
  const Schedule(
      {required this.id,
      required this.content,
      required this.date,
      required this.startTime,
      required this.endTime});
  @override
  Map<String, Expression> toColumns(bool nullToAbsent) {
    final map = <String, Expression>{};
    map['id'] = Variable<int>(id);
    map['content'] = Variable<String>(content);
    map['date'] = Variable<DateTime>(date);
    map['start_time'] = Variable<int>(startTime);
    map['end_time'] = Variable<int>(endTime);
    return map;
  }

  SchedulesCompanion toCompanion(bool nullToAbsent) {
    return SchedulesCompanion(
      id: Value(id),
      content: Value(content),
      date: Value(date),
      startTime: Value(startTime),
      endTime: Value(endTime),
    );
  }

  factory Schedule.fromJson(Map<String, dynamic> json,
      {ValueSerializer? serializer}) {
    serializer ??= driftRuntimeOptions.defaultSerializer;
    return Schedule(
      id: serializer.fromJson<int>(json['id']),
      content: serializer.fromJson<String>(json['content']),
      date: serializer.fromJson<DateTime>(json['date']),
      startTime: serializer.fromJson<int>(json['startTime']),
      endTime: serializer.fromJson<int>(json['endTime']),
    );
  }
  @override
  Map<String, dynamic> toJson({ValueSerializer? serializer}) {
    serializer ??= driftRuntimeOptions.defaultSerializer;
    return <String, dynamic>{
      'id': serializer.toJson<int>(id),
      'content': serializer.toJson<String>(content),
      'date': serializer.toJson<DateTime>(date),
      'startTime': serializer.toJson<int>(startTime),
      'endTime': serializer.toJson<int>(endTime),
    };
  }

  Schedule copyWith(
          {int? id,
          String? content,
          DateTime? date,
          int? startTime,
          int? endTime}) =>
      Schedule(
        id: id ?? this.id,
        content: content ?? this.content,
        date: date ?? this.date,
        startTime: startTime ?? this.startTime,
        endTime: endTime ?? this.endTime,
      );
  @override
  String toString() {
    return (StringBuffer('Schedule(')
          ..write('id: $id, ')
          ..write('content: $content, ')
          ..write('date: $date, ')
          ..write('startTime: $startTime, ')
          ..write('endTime: $endTime')
          ..write(')'))
        .toString();
  }

  @override
  int get hashCode => Object.hash(id, content, date, startTime, endTime);
  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      (other is Schedule &&
          other.id == this.id &&
          other.content == this.content &&
          other.date == this.date &&
          other.startTime == this.startTime &&
          other.endTime == this.endTime);
}

class SchedulesCompanion extends UpdateCompanion<Schedule> {
  final Value<int> id;
  final Value<String> content;
  final Value<DateTime> date;
  final Value<int> startTime;
  final Value<int> endTime;
  const SchedulesCompanion({
    this.id = const Value.absent(),
    this.content = const Value.absent(),
    this.date = const Value.absent(),
    this.startTime = const Value.absent(),
    this.endTime = const Value.absent(),
  });
  SchedulesCompanion.insert({
    this.id = const Value.absent(),
    required String content,
    required DateTime date,
    required int startTime,
    required int endTime,
  })  : content = Value(content),
        date = Value(date),
        startTime = Value(startTime),
        endTime = Value(endTime);
  static Insertable<Schedule> custom({
    Expression<int>? id,
    Expression<String>? content,
    Expression<DateTime>? date,
    Expression<int>? startTime,
    Expression<int>? endTime,
  }) {
    return RawValuesInsertable({
      if (id != null) 'id': id,
      if (content != null) 'content': content,
      if (date != null) 'date': date,
      if (startTime != null) 'start_time': startTime,
      if (endTime != null) 'end_time': endTime,
    });
  }

  SchedulesCompanion copyWith(
      {Value<int>? id,
      Value<String>? content,
      Value<DateTime>? date,
      Value<int>? startTime,
      Value<int>? endTime}) {
    return SchedulesCompanion(
      id: id ?? this.id,
      content: content ?? this.content,
      date: date ?? this.date,
      startTime: startTime ?? this.startTime,
      endTime: endTime ?? this.endTime,
    );
  }

  @override
  Map<String, Expression> toColumns(bool nullToAbsent) {
    final map = <String, Expression>{};
    if (id.present) {
      map['id'] = Variable<int>(id.value);
    }
    if (content.present) {
      map['content'] = Variable<String>(content.value);
    }
    if (date.present) {
      map['date'] = Variable<DateTime>(date.value);
    }
    if (startTime.present) {
      map['start_time'] = Variable<int>(startTime.value);
    }
    if (endTime.present) {
      map['end_time'] = Variable<int>(endTime.value);
    }
    return map;
  }

  @override
  String toString() {
    return (StringBuffer('SchedulesCompanion(')
          ..write('id: $id, ')
          ..write('content: $content, ')
          ..write('date: $date, ')
          ..write('startTime: $startTime, ')
          ..write('endTime: $endTime')
          ..write(')'))
        .toString();
  }
}

class $SchedulesTable extends Schedules
    with TableInfo<$SchedulesTable, Schedule> {
  @override
  final GeneratedDatabase attachedDatabase;
  final String? _alias;
  $SchedulesTable(this.attachedDatabase, [this._alias]);
  final VerificationMeta _idMeta = const VerificationMeta('id');
  @override
  late final GeneratedColumn<int> id = GeneratedColumn<int>(
      'id', aliasedName, false,
      type: DriftSqlType.int,
      requiredDuringInsert: false,
      defaultConstraints: 'PRIMARY KEY AUTOINCREMENT');
  final VerificationMeta _contentMeta = const VerificationMeta('content');
  @override
  late final GeneratedColumn<String> content = GeneratedColumn<String>(
      'content', aliasedName, false,
      type: DriftSqlType.string, requiredDuringInsert: true);
  final VerificationMeta _dateMeta = const VerificationMeta('date');
  @override
  late final GeneratedColumn<DateTime> date = GeneratedColumn<DateTime>(
      'date', aliasedName, false,
      type: DriftSqlType.dateTime, requiredDuringInsert: true);
  final VerificationMeta _startTimeMeta = const VerificationMeta('startTime');
  @override
  late final GeneratedColumn<int> startTime = GeneratedColumn<int>(
      'start_time', aliasedName, false,
      type: DriftSqlType.int, requiredDuringInsert: true);
  final VerificationMeta _endTimeMeta = const VerificationMeta('endTime');
  @override
  late final GeneratedColumn<int> endTime = GeneratedColumn<int>(
      'end_time', aliasedName, false,
      type: DriftSqlType.int, requiredDuringInsert: true);
  @override
  List<GeneratedColumn> get $columns => [id, content, date, startTime, endTime];
  @override
  String get aliasedName => _alias ?? 'schedules';
  @override
  String get actualTableName => 'schedules';
  @override
  VerificationContext validateIntegrity(Insertable<Schedule> instance,
      {bool isInserting = false}) {
    final context = VerificationContext();
    final data = instance.toColumns(true);
    if (data.containsKey('id')) {
      context.handle(_idMeta, id.isAcceptableOrUnknown(data['id']!, _idMeta));
    }
    if (data.containsKey('content')) {
      context.handle(_contentMeta,
          content.isAcceptableOrUnknown(data['content']!, _contentMeta));
    } else if (isInserting) {
      context.missing(_contentMeta);
    }
    if (data.containsKey('date')) {
      context.handle(
          _dateMeta, date.isAcceptableOrUnknown(data['date']!, _dateMeta));
    } else if (isInserting) {
      context.missing(_dateMeta);
    }
    if (data.containsKey('start_time')) {
      context.handle(_startTimeMeta,
          startTime.isAcceptableOrUnknown(data['start_time']!, _startTimeMeta));
    } else if (isInserting) {
      context.missing(_startTimeMeta);
    }
    if (data.containsKey('end_time')) {
      context.handle(_endTimeMeta,
          endTime.isAcceptableOrUnknown(data['end_time']!, _endTimeMeta));
    } else if (isInserting) {
      context.missing(_endTimeMeta);
    }
    return context;
  }

  @override
  Set<GeneratedColumn> get $primaryKey => {id};
  @override
  Schedule map(Map<String, dynamic> data, {String? tablePrefix}) {
    final effectivePrefix = tablePrefix != null ? '$tablePrefix.' : '';
    return Schedule(
      id: attachedDatabase.options.types
          .read(DriftSqlType.int, data['${effectivePrefix}id'])!,
      content: attachedDatabase.options.types
          .read(DriftSqlType.string, data['${effectivePrefix}content'])!,
      date: attachedDatabase.options.types
          .read(DriftSqlType.dateTime, data['${effectivePrefix}date'])!,
      startTime: attachedDatabase.options.types
          .read(DriftSqlType.int, data['${effectivePrefix}start_time'])!,
      endTime: attachedDatabase.options.types
          .read(DriftSqlType.int, data['${effectivePrefix}end_time'])!,
    );
  }

  @override
  $SchedulesTable createAlias(String alias) {
    return $SchedulesTable(attachedDatabase, alias);
  }
}

abstract class _$LocalDatabase extends GeneratedDatabase {
  _$LocalDatabase(QueryExecutor e) : super(e);
  late final $SchedulesTable schedules = $SchedulesTable(this);
  @override
  Iterable<TableInfo<Table, dynamic>> get allTables =>
      allSchemaEntities.whereType<TableInfo<Table, Object?>>();
  @override
  List<DatabaseSchemaEntity> get allSchemaEntities => [schedules];
}

// lib/main.dart
import 'package:calendar_scheduler/screen/home_screen.dart';
import 'package:flutter/material.dart';
import 'package:intl/date_symbol_data_local.dart';
import 'package:calendar_scheduler/database/drift_database.dart';
import 'package:get_it/get_it.dart';
import 'package:calendar_scheduler/provider/schedule_provider.dart';
import 'package:calendar_scheduler/repository/schedule_repository.dart';
import 'package:provider/provider.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await initializeDateFormatting();

  final database = LocalDatabase();

  final repository = ScheduleRepository();
  final scheduleProvider = ScheduleProvider(repository: repository);

  GetIt.I.registerSingleton<LocalDatabase>(database);

  runApp(
    ChangeNotifierProvider(
      create: (_) => scheduleProvider,
      child: MaterialApp(
        home: HomeScreen(),
      ),
    ),
  );
}

// lib/screen/home_screen.dart
import 'package:flutter/material.dart';
import 'package:calendar_scheduler/component/main_calendar.dart';
import 'package:calendar_scheduler/component/schedule_card.dart';
import 'package:calendar_scheduler/component/today_banner.dart';
import 'package:calendar_scheduler/component/schedule_bottom_sheet.dart';
import 'package:calendar_scheduler/const/colors.dart';
import 'package:get_it/get_it.dart';
import 'package:calendar_scheduler/database/drift_database.dart';
import 'package:provider/provider.dart';
import 'package:calendar_scheduler/provider/schedule_provider.dart';

class HomeScreen extends StatelessWidget {
  DateTime selectedDate = DateTime.utc(
    DateTime.now().year,
    DateTime.now().month,
    DateTime.now().day,
  );

  @override
  Widget build(BuildContext context) {
    final provider = context.watch<ScheduleProvider>();
    final selectedDate = provider.selectedDate;
    final schedules = provider.cache[selectedDate] ?? [];

    return Scaffold(
      floatingActionButton: FloatingActionButton(
        backgroundColor: PRIMARY_COLOR,
        onPressed: () {
          showModalBottomSheet(
            context: context,
            isDismissible: true,
            isScrollControlled: true,
            builder: (_) => ScheduleBottomSheet(
              selectedDate: selectedDate,
            ),
          );
        },
        child: Icon(
          Icons.add,
        ),
      ),
      body: SafeArea(
        child: Column(
          children: [
            MainCalendar(
              selectedDate: selectedDate,
              onDaySelected: (selectedDate, focusedDate) =>
                  onDaySelected(selectedDate, focusedDate, context),
            ),
            SizedBox(height: 8.0),
            TodayBanner(
              selectedDate: selectedDate,
              count: 0,
            ),
            SizedBox(height: 8.0),
            Expanded(
              child: ListView.builder(
                itemCount: schedules.length,
                itemBuilder: (context, index) {
                  final schedule = schedules[index];

                  return Dismissible(
                    key: ObjectKey(schedule.id),
                    direction: DismissDirection.startToEnd,
                    onDismissed: (DismissDirection direction) {
                      provider.deleteSchedule(date: selectedDate, id: schedule.id);  // ➊
                    },
                    child: Padding(
                      padding: const EdgeInsets.only(
                          bottom: 8.0, left: 8.0, right: 8.0),
                      child: ScheduleCard(
                        startTime: schedule.startTime,
                        endTime: schedule.endTime,
                        content: schedule.content,
                      ),
                    ),
                  );
                },
              ),
            ),
          ],
        ),
      ),
    );
  }

  void onDaySelected(
      DateTime selectedDate,
      DateTime focusedDate,
      BuildContext context,
      ) {
    final provider = context.read<ScheduleProvider>();
    provider.changeSelectedDate(
      date: selectedDate,
    );
    provider.getSchedules(date: selectedDate);
  }
}

// lib/const/colors.dart
// ... 18장과 동일 ...

// lib/component/custom_text_field.dart
// ... 18장과 동일 ...

// lib/component/main_calendar.dart
// ... 18장과 동일 ...

// lib/component/schedule_bottom_sheet.dart
import 'package:flutter/material.dart';
import 'package:calendar_scheduler/component/custom_text_field.dart';
import 'package:calendar_scheduler/const/colors.dart';
import 'package:drift/drift.dart' hide Column;
import 'package:get_it/get_it.dart';
import 'package:calendar_scheduler/database/drift_database.dart';
import 'package:calendar_scheduler/model/schedule_model.dart';
import 'package:provider/provider.dart';
import 'package:calendar_scheduler/provider/schedule_provider.dart';

class ScheduleBottomSheet extends StatefulWidget {
  final DateTime selectedDate;

  const ScheduleBottomSheet({
    required this.selectedDate,
    Key? key,
  }) : super(key: key);

  @override
  State<ScheduleBottomSheet> createState() => _ScheduleBottomSheetState();
}

class _ScheduleBottomSheetState extends State<ScheduleBottomSheet> {
  final GlobalKey<FormState> formKey = GlobalKey();

  int? startTime;
  int? endTime;
  String? content;

  @override
  Widget build(BuildContext context) {
    final bottomInset = MediaQuery.of(context).viewInsets.bottom;

    return Form(
      key: formKey,
      child: SafeArea(
        child: Container(
          height: MediaQuery.of(context).size.height / 2 +
              bottomInset,
          color: Colors.white,
          child: Padding(
            padding:
                EdgeInsets.only(left: 8, right: 8, top: 8, bottom: bottomInset),
            child: Column(
              children: [
                Row(
                  children: [
                    Expanded(
                      child: CustomTextField(
                        label: '시작 시간',
                        isTime: true,
                        onSaved: (String? val) {
                          startTime = int.parse(val!);
                        },
                        validator: timeValidator,
                      ),
                    ),
                    const SizedBox(width: 16.0),
                    Expanded(
                      child: CustomTextField(
                        label: '종료 시간',
                        isTime: true,
                        onSaved: (String? val) {
                          endTime = int.parse(val!);
                        },
                        validator: timeValidator,
                      ),
                    ),
                  ],
                ),
                SizedBox(height: 8.0),
                Expanded(
                  child: CustomTextField(
                    label: '내용',
                    isTime: false,
                    onSaved: (String? val) {
                      content = val;
                    },
                    validator: contentValidator,
                  ),
                ),
                SizedBox(
                  width: double.infinity,
                  child: ElevatedButton(
                    onPressed: () => onSavePressed(context),
                    style: ElevatedButton.styleFrom(
                      primary: PRIMARY_COLOR,
                    ),
                    child: Text('저장'),
                  ),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  void onSavePressed(BuildContext context) async { if (formKey.currentState!.validate()) {
      formKey.currentState!.save();

      context.read<ScheduleProvider>().createSchedule(
        schedule: ScheduleModel(
          id: 'new_model',
          content: content!,
          date: widget.selectedDate,
          startTime: startTime!,
          endTime: endTime!,
        ),
      );

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

  String? timeValidator(String? val) {
    if (val == null) {
      return '값을 입력해주세요';
    }

    int? number;

    try {
      number = int.parse(val);
    } catch (e) {
      return '숫자를 입력해주세요';
    }

    if (number < 0 || number > 24) {
      return '0시부터 24시 사이를 입력해주세요';
    }

    return null;

  String? contentValidator(String? val) {
    if (val == null || val.length == 0) {
      return '값을 입력해주세요';
    }

    return null;
  }
}

// lib/component/schedule_card.dart
// ... 18장과 동일 ...

// lib/component/today_banner.dart
// ... 18장과 동일 ...