import type { RingCalculatorInput, RingCalculatorResult } from '../types/calculator'

/**
 * 校验计算器输入，所有数值字段必须为非负数
 * @throws Error 如果任意字段为负数
 */
export function validateInput(input: RingCalculatorInput): void {
  const fields: Array<[keyof RingCalculatorInput, string]> = [
    ['goldWeight', '金重'],
    ['mainStoneWeight', '主石重'],
    ['sideStoneWeight', '副石重'],
    ['lossRate', '损耗'],
    ['moldGoldPrice', '倒模金价'],
    ['mainStoneUnitPrice', '主石单价'],
    ['sideStoneUnitPrice', '副石单价'],
    ['sideStoneCount', '副石粒数'],
    ['microSettingFee', '微镶费'],
    ['mainStoneSettingFee', '主石镶费'],
    ['threeDFee', '3D起板费'],
    ['basicLaborCost', '基本工费'],
    ['otherCost', '其他费用'],
  ]

  for (const [key, label] of fields) {
    if (input[key] < 0) {
      throw new Error(`${label}不能为负数`)
    }
  }
}

/**
 * 钻戒计算器核心计算函数
 *
 * 公式：
 * - 净金重(g) = 金重(g) - 主石重(ct)×0.2 - 副石重(ct)×0.2
 * - 含耗重(g) = 净金重(g) × 损耗
 * - 金值(元) = 含耗重(g) × 倒模金价(元)
 * - 主石总价(元) = 主石重(ct) × 主石单价(元)
 * - 副石总价(元) = 副石重(ct) × 副石单价(元)
 * - 微镶总价(元) = 副石粒数(p) × 微镶费(元)
 * - 总价 = 金值 + 主石总价 + 副石总价 + 主石镶费 + 微镶总价 + 3D起板费 + 基本工费 + 其他费用
 */
export function calculateRing(input: RingCalculatorInput): RingCalculatorResult {
  validateInput(input)

  const netGoldWeight = input.goldWeight - input.mainStoneWeight * 0.2 - input.sideStoneWeight * 0.2
  const weightWithLoss = netGoldWeight * input.lossRate
  const goldValue = weightWithLoss * input.moldGoldPrice
  const mainStoneTotal = input.mainStoneWeight * input.mainStoneUnitPrice
  const sideStoneTotal = input.sideStoneWeight * input.sideStoneUnitPrice
  const microSettingTotal = input.sideStoneCount * input.microSettingFee
  const totalPrice = goldValue + mainStoneTotal + sideStoneTotal
    + input.mainStoneSettingFee + microSettingTotal
    + input.threeDFee + input.basicLaborCost + input.otherCost

  return {
    netGoldWeight,
    weightWithLoss,
    goldValue,
    mainStoneTotal,
    sideStoneTotal,
    microSettingTotal,
    totalPrice,
  }
}