/** 语句：random 生成随机数（仅 inVars[0]=min、inVars[1]=max，outVars[0]=目标变量名） */
const { assertStrictKeys } = require('../action-schema.js')
const types = ['random']

function parse (action, parseContext) {
  const { extractVarName } = parseContext
  const path = parseContext.actionPath || 'random'
  assertStrictKeys(action, ['type', 'inVars', 'outVars', 'integer'], path)
  if (!Array.isArray(action.inVars) || action.inVars.length !== 2) {
    throw new Error(`${path}: random 须 inVars 恰好 2 项 [min, max]`)
  }
  if (!Array.isArray(action.outVars) || action.outVars.length !== 1) {
    throw new Error(`${path}: random 须 outVars 恰好 1 项（写入变量名，如 "{x}"）`)
  }
  const integer = action.integer !== undefined ? action.integer : true
  return {
    type: 'random',
    integer,
    min: action.inVars[0],
    max: action.inVars[1],
    inVars: action.inVars.map((v) => extractVarName(v)),
    outVars: [extractVarName(action.outVars[0])],
    variable: extractVarName(action.outVars[0]),
  }
}

async function execute(action, ctx) {
  const { variableContext, extractVarName } = ctx
  let varName
  if (action.outVars && action.outVars.length > 0) {
    varName = extractVarName(action.outVars[0])
  } else if (action.variable) {
    varName = extractVarName(action.variable)
  } else {
    return { success: false, error: 'random 操作缺少 variable 或 outVars 参数' }
  }
  let min, max
  if (action.inVars && action.inVars.length >= 2) {
    min = Number(action.inVars[0])
    max = Number(action.inVars[1])
  } else {
    min = action.min !== undefined ? Number(action.min) : 0
    max = action.max !== undefined ? Number(action.max) : 100
  }
  const integer = action.integer !== undefined ? action.integer : true
  if (isNaN(min) || isNaN(max)) return { success: false, error: 'random 操作的 min 和 max 必须是数字' }
  if (min > max) return { success: false, error: 'random 操作的 min 不能大于 max' }
  const randomValue = integer
    ? Math.floor(Math.random() * (max - min + 1)) + min
    : Math.random() * (max - min) + min
  variableContext[varName] = randomValue
  return { success: true }
}

module.exports = { types, parse, execute }