将Firestore数据分组为不同的数组格式

Question

我需要将收到的“原始” Firestore数据分组为可用于适当显示的数组格式。

我从Firestore收到了此邮件：

{
 activityName: "BFG",
 comment: "Roger is naughty",
 mark: 86,
 subject: "English",
 task: "reading",
 term:1,
 year: 2019
}, {
 activityName: "The Twits",
 comment: "Roger is really good",
 mark: 99,
 subject: "English",
 task: "reading",
 term:2,
 year: 2019
},
{
 activityName: "Basic sums",
 comment: "Roger is average",
 mark: 19,
 subject: "Maths",
 task: "Addition",
 term:2,
 year: 2019
}

并且我希望以手风琴形式将其作为分组数据呈现

年份->任期->主题->任务-> activityName->标记（和注释）

因此，我认为最好/最简单的方法是将数据转换为以下格式，以简化用于显示分组数据的循环。

{
 year:2019,
 terms: [
        {term: 1,
         subjects: [
             {subject: "English",
              tasks: [
                     {task: "reading",
                      activities: [
                                  {activityName: "BFG",
                                   result: [
                                           {comment: "Roger is naughty",
                                            mark: 86
                                           }]
                                  }]
                      }]
              }]
         },
         {term: 2,
         subjects: [
             {subject: "English",
              tasks: [
                     {task: "reading",
                      activities: [
                                  {activityName: "The Twits",
                                   result: [
                                           {comment: "Roger is really good",
                                            mark: 99
                                           }]
                                  }]
                      }]
              }]
         },
         {term: 2,
         subjects: [
             {subject: "Maths",
              tasks: [
                     {task: "Addition",
                      activities: [
                                  {activityName: "Basic sums",
                                   result: [
                                           {comment: "Roger is average",
                                            mark: 19
                                           }]
                                  }]
                      }]
              }]
         }
 ]
}

为使这种新结构发生而对循环或想法的任何建议将不胜感激。