// ===== 工具箱：交易计算 =====
const calcState = {
  direction: 'up'
}

const updateCalcSign = () => {
  const signEl = document.getElementById('calc-sign-display')
  if (!signEl) return
  const radios = document.querySelectorAll('input[name="calc-direction"]')
  radios.forEach(r => {
    if (r.checked) calcState.direction = r.value
  })
  if (calcState.direction === 'up') {
    signEl.textContent = '+'
    signEl.className = 'calc-sign-display is-up'
  } else {
    signEl.textContent = '-'
    signEl.className = 'calc-sign-display is-down'
  }
}

const getCalcAmount = () => {
  const inputEl = document.getElementById('calc-amount-input')
  const selectEl = document.getElementById('calc-amount-select')
  const inputValue = inputEl ? parseFloat(inputEl.value) : NaN
  if (Number.isFinite(inputValue) && inputValue > 0) return inputValue
  const selectValue = selectEl ? parseFloat(selectEl.value) : NaN
  return Number.isFinite(selectValue) ? selectValue : 0
}

// A 股费率：佣金万 1.0，最低 5 元
const calcCommission = amount => {
  const rate = 0.0001
  const fee = amount * rate
  return Math.max(fee, 5)
}

// 过户费：万 0.1
const calcTransferFee = amount => {
  return amount * 0.00001
}

// 印花税：卖出 0.1%
const calcStampTax = amount => {
  return amount * 0.001
}

const doTradeCalc = () => {
  const priceEl = document.getElementById('calc-price')
  const sharesEl = document.getElementById('calc-shares')
  const resultPriceEl = document.getElementById('calc-result-price')
  const resultFeeEl = document.getElementById('calc-result-fee')
  const resultSharesEl = document.getElementById('calc-result-shares')
  const buyAmountEl = document.getElementById('calc-buy-amount')
  const sellAmountEl = document.getElementById('calc-sell-amount')
  const diffEl = document.getElementById('calc-diff')

  const price = priceEl ? parseFloat(priceEl.value) : NaN
  const shares = sharesEl ? parseFloat(sharesEl.value) : NaN

  if (!Number.isFinite(price) || price <= 0 || !Number.isFinite(shares) || shares <= 0) {
    if (resultPriceEl) resultPriceEl.value = ''
    if (resultFeeEl) resultFeeEl.value = ''
    if (resultSharesEl) resultSharesEl.value = ''
    if (buyAmountEl) buyAmountEl.value = ''
    if (sellAmountEl) sellAmountEl.value = ''
    if (diffEl) diffEl.value = ''
    return
  }

  const amount = getCalcAmount()
  if (amount <= 0) return

  const sign = calcState.direction === 'up' ? 1 : -1
  const theoreticalPrice = price * (1 + sign * amount / 100)

  if (theoreticalPrice <= 0) {
    if (resultPriceEl) resultPriceEl.value = ''
    if (resultFeeEl) resultFeeEl.value = ''
    if (resultSharesEl) resultSharesEl.value = ''
    if (buyAmountEl) buyAmountEl.value = ''
    if (sellAmountEl) sellAmountEl.value = ''
    if (diffEl) diffEl.value = ''
    return
  }

  const buyAmountVal = price * shares
  const sellAmountVal = theoreticalPrice * shares

  const buyCommission = calcCommission(buyAmountVal)
  const buyTransferFee = calcTransferFee(buyAmountVal)

  const sellCommission = calcCommission(sellAmountVal)
  const sellTransferFee = calcTransferFee(sellAmountVal)
  const sellStampTax = calcStampTax(sellAmountVal)

  const totalFees = buyCommission + buyTransferFee + sellCommission + sellTransferFee + sellStampTax

  // 差额 = 卖出金额 - 买入金额 - 交易费
  const diff = sellAmountVal - buyAmountVal - totalFees

  if (resultPriceEl) resultPriceEl.value = theoreticalPrice.toFixed(3)
  if (resultFeeEl) resultFeeEl.value = totalFees.toFixed(2)
  if (resultSharesEl) resultSharesEl.value = shares
  if (buyAmountEl) buyAmountEl.value = buyAmountVal.toFixed(2)
  if (sellAmountEl) sellAmountEl.value = sellAmountVal.toFixed(2)
  if (diffEl) diffEl.value = diff.toFixed(2)
}

// ===== 工具箱初始化 =====
document.addEventListener('DOMContentLoaded', () => {
  // 幅度符号更新
  const amountSelect = document.getElementById('calc-amount-select')
  const amountInput = document.getElementById('calc-amount-input')
  if (amountSelect) amountSelect.addEventListener('change', updateCalcSign)
  if (amountInput) amountInput.addEventListener('input', updateCalcSign)
  const directionRadios = document.querySelectorAll('input[name="calc-direction"]')
  directionRadios.forEach(r => r.addEventListener('change', updateCalcSign))
  updateCalcSign()

  // 计算按钮
  const btnCalc = document.getElementById('btn-calc')
  if (btnCalc) btnCalc.addEventListener('click', doTradeCalc)
})