过滤日期数组中的空白

Question

我有一个包含约会和花名册的数组。它们由类型分隔。

如何过滤只返回名单中空白的日期范围

除了总的“块”似乎不正确外，它似乎部分起作用。另外，块的最后一部分没有正确的开始和结束日期。

const appointments = [
  {
    "start": 1549953000000,
    "end": 1549985400000,
    "id": "roster-item-1",
    "type": "background",
    "className": "timeline-background__regular"
  },
  {
    "start": 1549959300000,
    "end": 1549971000000,
    "id": "range-1",
    "type": "range",
    "className": "timeline-range__regular"
  },
  {
    "start": 1549978200000,
    "end": 1549996200000,
    "id": "range-1",
    "type": "range",
    "className": "timeline-range__regular"
  },
  {
    "start": 1550125800000,
    "end": 1550158200000,
    "id": "roster-item-2",
    "type": "background",
    "className": "timeline-background__regular"
  },
  {
    "start": 1550471400000,
    "end": 1550503800000,
    "id": "roster-item-3",
    "type": "background",
    "className": "timeline-background__regular"
  },
  {
    "start": 1550557800000,
    "end": 1550590200000,
    "id": "roster-item-4",
    "type": "background",
    "className": "timeline-background__regular"
  },
  {
    "start": 1550644200000,
    "end": 1550676600000,
    "id": "roster-item-5",
    "type": "background",
    "className": "timeline-background__regular"
  }
]


const draggedAppointment = {
  "type": "range",
  "id": "1fe94e2d-59e6-4dbd-a9e7-bcc3f92e7b84",
  "start": 1549959300000,
  "end": 1550169000000,
};

appointments
  .reduce((accumulator, currAppointment, currentIndex, array) => {
    const currStart = currAppointment.start;
    const currEnd = currAppointment.end;

    const prevAppointment = array[currentIndex - 1];

    // Only add roster items
    if (prevAppointment && prevAppointment.type === 'background') {

      const prevStart = prevAppointment.start;
      const prevEnd = prevAppointment.end;

      // All of previous
      if (currStart > prevEnd || currStart < prevStart) {
        accumulator.push({
          type: currAppointment.type,
          id: `${draggedAppointment.id}-${currentIndex}-${currStart}`,
          start: prevStart,
          end: prevEnd
        });

        return accumulator;
      }

      // Start of previous and end of current
      if (currStart > prevStart) {
        accumulator.push({
          type: currAppointment.type,
          id: `${draggedAppointment.id}-${currentIndex}-${currEnd}`,
          start: prevStart,
          end: currStart
        });
      }

      // Beginning of current and end of previous
      if (currEnd < prevEnd && currStart < prevEnd) {
        accumulator.push({
          type: currAppointment.type,
          id: `${draggedAppointment.id}-${currStart}-${currentIndex}`,
          start: currEnd,
          end: prevEnd
        });
      }
    }

    // If no previous appointment, push current without id
    if (!prevAppointment) {
      accumulator.push({
        type: currAppointment.type,
        start: currStart,
        end: currEnd
      });
    }

    return accumulator;
  }, [])
  .filter(app => app.id)
  .map(app => ({
        ...app,
        start: new Date(app.start).toLocaleString(),
        end: new Date(app.end).toLocaleString(),
  }));

我希望将draggedAppointment划分为“块”，其中名册中有可用空间。