/**
 * 识图传方报价：请求侧增量组装
 * 首次全量 drugs；同味数下只传 quote_token + drugs_patch（改了的下标），省流量
 */

/**
 * 比较两味报价药品是否等价（用于算 patch）
 * @param {Record<string, any>|null|undefined} a
 * @param {Record<string, any>|null|undefined} b
 */
export function isSameQuoteDrug(a, b) {
  if (!a || !b) return false
  return (
    Number(a.drug_id || 0) === Number(b.drug_id || 0) &&
    Number(a.number || 0) === Number(b.number || 0) &&
    Number(a.price || 0) === Number(b.price || 0) &&
    String(a.name || '') === String(b.name || '') &&
    Number(a.way_id || 0) === Number(b.way_id || 0)
  )
}

/**
 * 组装增量报价入参
 * @param {{
 *   scalars: Record<string, any>,
 *   drugs: Array<Record<string, any>>,
 *   quoteToken?: string,
 *   lastQuoteDrugs?: Array<Record<string, any>>|null
 * }} opts
 * @returns {{ payload: Record<string, any>, nextLastDrugs: Array<Record<string, any>> }}
 */
export function buildIncrementalQuotePayload(opts) {
  const scalars = opts.scalars || {}
  const drugs = Array.isArray(opts.drugs) ? opts.drugs : []
  const quoteToken = String(opts.quoteToken || '').trim()
  const prev = Array.isArray(opts.lastQuoteDrugs) ? opts.lastQuoteDrugs : null
  const payload = Object.assign({}, scalars)
  if (quoteToken) {
    payload.quote_token = quoteToken
  }
  // 无 token、味数变化、或上次快照缺失 → 全量
  if (!quoteToken || !prev || prev.length !== drugs.length) {
    payload.drugs = drugs
    return { payload, nextLastDrugs: drugs }
  }
  const patches = []
  for (let i = 0; i < drugs.length; i++) {
    if (!isSameQuoteDrug(prev[i], drugs[i])) {
      patches.push({ index: i, drug: drugs[i] })
    }
  }
  if (patches.length === 0) {
    // 只改了地址/剂数/煎法，不带 drugs
    return { payload, nextLastDrugs: prev }
  }
  if (patches.length >= drugs.length) {
    payload.drugs = drugs
  } else {
    payload.drugs_patch = patches
  }
  return { payload, nextLastDrugs: drugs }
}