/**
 * 计算百分比变化
 * @param a
 * @param b
 */
export const calculatePercentageChange = (cur: number, prev: number) => {
  // 计算差值
  const diff = cur - prev

  if (diff === 0)
    return {
      diff,
      percentage: "0",
    }

  // 计算百分比
  const percentage = Math.abs((diff / prev) * 100).toFixed(1)

  return {
    diff,
    percentage,
  }
}

/**
 * 计算周同比
 * @param cur
 * @param prev
 * @param needCN
 */
export const calculateWeeklyRate = (
  cur: string | number,
  prev: string | number,
  needCN = true
) => {
  const { diff, percentage } = calculatePercentageChange(
    Number(cur),
    Number(prev)
  )
  if (diff > 0)
    return {
      text: `<font color='red'>${
        needCN ? "较上周 " : ""
      }↑${percentage}%</font>`,
      diff,
      percentage,
    }
  if (diff < 0)
    return {
      text: `<font color='green'>${
        needCN ? "较上周 " : ""
      }↓${percentage}%</font>`,
      diff,
      percentage,
    }
  return {
    text: `<font color='gray'>${needCN ? "较上周 " : ""}0%</font>`,
    diff,
    percentage,
  }
}