/** 金额类字段默认最大小数位数 */
export const AMOUNT_DECIMAL_SCALE = 6

/**
 * 格式化数字：最多保留 scale 位小数，并去除末尾多余的 0
 */
export function formatDecimal(value, scale = AMOUNT_DECIMAL_SCALE, fallback = '0') {
  if (value === null || value === undefined || value === '') {
    return fallback
  }
  const num = Number(value)
  if (Number.isNaN(num)) {
    return fallback
  }
  return parseFloat(num.toFixed(scale)).toString()
}

/** 带货币符号的金额展示 */
export function formatCurrency(value, scale = AMOUNT_DECIMAL_SCALE) {
  return `¥${formatDecimal(value, scale)}`
}

/** el-table-column formatter */
export function tableAmountFormatter(row, column, cellValue) {
  return formatDecimal(cellValue)
}

/** 计算后保留指定位小数 */
export function roundAmount(value, scale = AMOUNT_DECIMAL_SCALE) {
  if (value === null || value === undefined || value === '') {
    return 0
  }
  const num = Number(value)
  if (Number.isNaN(num)) {
    return 0
  }
  return parseFloat(num.toFixed(scale))
}

/** 构建 summarizeTable 金额列格式配置 */
export function buildAmountSummaryFormat(fields, extraFormat = {}) {
  const format = { ...extraFormat }
  fields.forEach(field => {
    format[field] = { decimalPlaces: AMOUNT_DECIMAL_SCALE }
  })
  return format
}