Event Calendar

import 'dart:convert';

void main(){
  var json = '''
  [
    {
    "descricao" : "deskripsi 1",
    "data_acao" : "2021-11-09",
    "hora_inicial_acao" : "08:00:00",
    "hora_final_acao" : "12:00:00"
},
{
    "descricao" : "deskripsi 2",
    "data_acao" : "2021-12-09",
    "hora_inicial_acao" : "08:00:00",
    "hora_final_acao" : "12:00:00"
},
{
    "descricao" : "deskripsi 3",
    "data_acao" : "2021-12-09",
    "hora_inicial_acao" : "13:00:00",
    "hora_final_acao" : "18:00:00"
}
]
  ''';
  final List<dynamic> responseJson = jsonDecode(json);

      final events = responseJson.map((e) => EventModel.fromMap(e)).toList();

      var map = <DateTime, List<EventModel>>{};
      for (final event in events) {
        final date = event.dataAcao;
        var original = map[date];
        if (original == null) {
          map[date] = [event];
        } else {
          map[date] = [...original, event];
        }
      }

      map.forEach((key,value){
         print('Key : $key | Value : $value');
      });
}



class EventModel {
  EventModel({
    required this.descricao,
    required this.dataAcao,
    required this.horaInicialAcao,
    required this.horaFinalAcao,
  });

  final String descricao;
  final DateTime dataAcao;
  final String horaInicialAcao;
  final String horaFinalAcao;

  EventModel copyWith({
    String? descricao,
    DateTime? dataAcao,
    String? horaInicialAcao,
    String? horaFinalAcao,
  }) {
    return EventModel(
      descricao: descricao ?? this.descricao,
      dataAcao: dataAcao ?? this.dataAcao,
      horaInicialAcao: horaInicialAcao ?? this.horaInicialAcao,
      horaFinalAcao: horaFinalAcao ?? this.horaFinalAcao,
    );
  }

  Map<String, dynamic> toMap() {
    return {
      'descricao': descricao,
      'data_acao': dataAcao.millisecondsSinceEpoch,
      'hora_inicial_acao': horaInicialAcao,
      'hora_final_acao': horaFinalAcao,
    };
  }

  factory EventModel.fromMap(Map<String, dynamic> map) {
    return EventModel(
      descricao: map['descricao'],
      dataAcao: DateTime.parse(map['data_acao']),
      horaInicialAcao: map['hora_inicial_acao'],
      horaFinalAcao: map['hora_final_acao'],
    );
  }

  String toJson() => json.encode(toMap());

  factory EventModel.fromJson(String source) => EventModel.fromMap(json.decode(source));

  @override
  String toString() {
    return 'EventModel(descricao: $descricao, dataAcao: $dataAcao, horaInicialAcao: $horaInicialAcao, horaFinalAcao: $horaFinalAcao)';
  }
}