const { logActionError } = require('./actions/echo-parser.js')
const variableParser = require('./variable-parser.js')

/**
 * 执行操作序列（schedule/if/for/while + 普通步骤）
 * 规则：除 schedule 的定时间隔外，均为同步串行——上一步 await 结束才执行下一步；任一步失败立即 return，后续步骤不执行。
 * 根级 execute 数组之间可有 stepInterval；for/if/while/try 内部及 schedule 单次 tick 内步骤间隔为 0。
 */
function isOk(r) {
  return r && r.success === true
}

async function executeActionSequence(
  actions,
  device,
  folderPath,
  resolution,
  stepInterval,
  onStepComplete,
  shouldStop,
  depth,
  ctx
) {
  const { executeAction, logMessage, evaluateCondition, getActionName, parseDelayString, calculateWaitTime, replaceVariablesInString, state } = ctx
  const variableContext = state.variableContext
  const DEFAULT_STEP_INTERVAL = ctx.DEFAULT_STEP_INTERVAL ?? 1000
  /** 嵌套体内步骤紧接执行；仅根级兄弟结点之间用 stepInterval */
  const innerInterval = 0

  if (depth === 0) {
    state.globalStepCounter = 0
    state.variableContextInitialized = false
    state.currentWorkflowFolderPath = folderPath
  }

  let completedSteps = 0
  const interval = stepInterval ?? DEFAULT_STEP_INTERVAL

  for (let i = 0; i < actions.length; i++) {
    if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
    const action = actions[i]

    if (action.type === 'schedule') {
      const condition = action.condition || {}
      let intervalStr = condition.interval || '0s'
      if (replaceVariablesInString && typeof intervalStr === 'string') {
        intervalStr = replaceVariablesInString(intervalStr, variableContext)
      }
      let repeat = condition.repeat !== undefined ? condition.repeat : 1
      if (typeof repeat === 'string' && variableContext) {
        const varName = repeat.replace(/^\{|\}$/g, '').trim()
        const resolved = variableContext[varName]
        repeat = resolved !== undefined && resolved !== null && resolved !== '' ? (parseInt(resolved, 10) || 1) : 1
      }
      const actionsToExecute = action.interval || []
      const intervalMs = parseDelayString(intervalStr) || 0
      const maxIterations = repeat === -1 ? Infinity : (typeof repeat === 'number' ? repeat : 1)
      let iteration = 0

      while (iteration < maxIterations) {
        if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
        iteration++
        if (iteration > 1 && intervalMs > 0) {
          let remainingTime = intervalMs
          const countdownInterval = 100
          while (remainingTime > 0) {
            if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
            const waitTime = Math.min(countdownInterval, remainingTime)
            await new Promise(resolve => setTimeout(resolve, waitTime))
            remainingTime -= waitTime
          }
        }
        if (actionsToExecute.length > 0) {
          const result = await executeActionSequence(actionsToExecute, device, folderPath, resolution, innerInterval, onStepComplete, shouldStop, depth + 1, ctx)
          if (!isOk(result)) {
            return { success: false, error: (result && result.error != null) ? String(result.error) : 'failed', completedSteps: result && result.completedSteps != null ? result.completedSteps : completedSteps }
          }
          completedSteps += result.completedSteps || 0
        }
      }
      continue
    }

    if (action.type === 'if') {
      const conditionResult = evaluateCondition(action.condition, variableContext)
      const actionsToExecute = conditionResult ? (action.then || []) : (action.else || [])
      if (actionsToExecute.length > 0) {
        const result = await executeActionSequence(actionsToExecute, device, folderPath, resolution, innerInterval, onStepComplete, shouldStop, depth + 1, ctx)
        if (!isOk(result)) {
          return { success: false, error: (result && result.error != null) ? String(result.error) : 'failed', completedSteps: result && result.completedSteps != null ? result.completedSteps : completedSteps }
        }
        completedSteps += result.completedSteps || 0
      }
      continue
    }

    if (action.type === 'for') {
      if (action.times != null) {
        let count = action.times
        if (typeof count === 'string') {
          const varName = count.replace(/^\{|\}$/g, '').trim()
          count = Math.max(0, parseInt(variableContext[varName], 10) || 0)
        } else {
          count = Math.max(0, parseInt(count, 10) || 0)
        }
        const timesVarKey = action.variable != null ? String(action.variable).replace(/^\{|\}$/g, '').trim() : null
        const originalDeclaredForTimes = state.declaredVariableNames
        if (timesVarKey) state.declaredVariableNames = (originalDeclaredForTimes || []).concat(timesVarKey)
        for (let i = 0; i < count; i++) {
          if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
          if (action.variable) variableContext[action.variable.replace(/^\{|\}$/g, '').trim()] = i
          if (action.body && action.body.length > 0) {
            const result = await executeActionSequence(action.body, device, folderPath, resolution, innerInterval, onStepComplete, shouldStop, depth + 1, ctx)
            if (!isOk(result)) {
              return { success: false, error: (result && result.error != null) ? String(result.error) : 'failed', completedSteps: result && result.completedSteps != null ? result.completedSteps : completedSteps }
            }
            completedSteps += result.completedSteps || 0
          }
        }
        if (timesVarKey) state.declaredVariableNames = originalDeclaredForTimes
      } else {
        let items = action.array
        if (typeof items === 'string' && items.startsWith('{') && items.endsWith('}')) {
          const varName = items.slice(1, -1).trim()
          items = variableContext[varName]
        }
        items = Array.isArray(items) ? items : []
        const indexKey = action.indexVariable != null ? String(action.indexVariable).replace(/^\{|\}$/g, '').trim() : null
        const variableKey = action.variable != null ? String(action.variable).replace(/^\{|\}$/g, '').trim() : null
        const originalDeclared = state.declaredVariableNames
        const forLocals = [indexKey, variableKey].filter(Boolean)
        if (forLocals.length > 0) state.declaredVariableNames = (originalDeclared || []).concat(forLocals)
        // 每次进入 for 都先重置索引变量，避免沿用上一个 for 循环的 idx 等（多个 for 共用同一 variableContext）
        if (indexKey !== null) variableContext[indexKey] = 0
        for (let i = 0; i < items.length; i++) {
          if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
          if (indexKey !== null) variableContext[indexKey] = i
          if (variableKey !== null) variableContext[variableKey] = items[i]
          if (action.body && action.body.length > 0) {
            const result = await executeActionSequence(action.body, device, folderPath, resolution, innerInterval, onStepComplete, shouldStop, depth + 1, ctx)
            if (!isOk(result)) {
              return { success: false, error: (result && result.error != null) ? String(result.error) : 'failed', completedSteps: result && result.completedSteps != null ? result.completedSteps : completedSteps }
            }
            completedSteps += result.completedSteps || 0
          }
        }
        if (forLocals.length > 0) state.declaredVariableNames = originalDeclared
      }
      continue
    }

    if (action.type === 'while') {
      while (evaluateCondition(action.condition, variableContext)) {
        if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
        if (action.body && action.body.length > 0) {
          const result = await executeActionSequence(action.body, device, folderPath, resolution, innerInterval, onStepComplete, shouldStop, depth + 1, ctx)
          if (!isOk(result)) {
            return { success: false, error: (result && result.error != null) ? String(result.error) : 'failed', completedSteps: result && result.completedSteps != null ? result.completedSteps : completedSteps }
          }
          completedSteps += result.completedSteps || 0
        }
      }
      continue
    }

    if (action.type === 'try') {
      const tryActions = action.try || []
      const successActions = action.success || []
      const failActions = action.fail || []
      /** try 主路径失败后：即使 fail 分支执行成功，默认仍向上返回失败，避免 for 进入下一轮或继续执行后续兄弟步骤。需继续时请设 continueAfterFail: true */
      const continueAfterFail = action.continueAfterFail === true
      const result = tryActions.length > 0
        ? await executeActionSequence(tryActions, device, folderPath, resolution, innerInterval, onStepComplete, shouldStop, depth + 1, ctx)
        : { success: true, completedSteps: 0 }
      if (isOk(result) && successActions.length > 0) {
        const successResult = await executeActionSequence(successActions, device, folderPath, resolution, innerInterval, onStepComplete, shouldStop, depth + 1, ctx)
        if (!isOk(successResult)) {
          return { success: false, error: (successResult && successResult.error != null) ? String(successResult.error) : 'failed', completedSteps }
        }
        completedSteps += (result.completedSteps || 0) + (successResult.completedSteps || 0)
      } else if (isOk(result)) {
        completedSteps += result.completedSteps || 0
      } else {
        const errMsg = (result.error != null && result.error !== '') ? String(result.error) : 'Unknown error'
        const timeStr = new Date().toISOString().replace('T', ' ').slice(0, 19)
        await logMessage(`[sequence-runner] [try failed] ${timeStr} ${errMsg}`, folderPath).catch(() => {})
        if (failActions.length > 0) {
          const failResult = await executeActionSequence(failActions, device, folderPath, resolution, innerInterval, onStepComplete, shouldStop, depth + 1, ctx)
          if (!isOk(failResult)) return failResult
          completedSteps += (result.completedSteps || 0) + (failResult.completedSteps || 0)
          if (!continueAfterFail) {
            return { success: false, error: errMsg, completedSteps }
          }
        } else {
          return result
        }
      }
      continue
    }

    const times = action.times || 1
    if (onStepComplete) onStepComplete(i + 1, actions.length, getActionName(action), 0, times, 0)

    const waitTime = calculateWaitTime(action.data, action.delay)
    if (waitTime > 0) {
      let remainingTime = waitTime
      const countdownInterval = 100
      const stepName = getActionName(action)
      while (remainingTime > 0) {
        if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
        if (onStepComplete) onStepComplete(i + 1, actions.length, stepName, remainingTime, times, 0)
        const waitTimeChunk = Math.min(countdownInterval, remainingTime)
        await new Promise(resolve => setTimeout(resolve, waitTimeChunk))
        remainingTime -= waitTimeChunk
      }
    }

    for (let t = 0; t < times; t++) {
      if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
      if (onStepComplete) onStepComplete(i + 1, actions.length, getActionName(action), 0, times, t + 1)

      state.globalStepCounter++
      const typeName = getActionName(action)

      // inVars/outVars 引用的变量必须在 workflow.variables 中声明，否则写 log 并失败
      if ((action.inVars && action.inVars.length > 0) || (action.outVars && action.outVars.length > 0)) {
        const declared = state.declaredVariableNames || []
        const validation = variableParser.validateInOutVars(action, declared)
        if (!validation.valid) {
          const errMsg = `inVars/outVars 引用了未在 variables 中声明的变量: ${validation.undeclared.join(', ')}`
          await logActionError(action, { success: false, error: errMsg }, { getActionName, logMessage, folderPath }).catch(() => {})
          return { success: false, error: errMsg, completedSteps: i }
        }
      }

      const result = await executeAction(action, device, folderPath, resolution)

      if (isOk(result) && result.skipped) { /* 步骤跳过不写 log */ }

      // 统一由 echo-parser.logActionError 打印结点报错，各结点只需 return { success: false, error } 即可
      if (!isOk(result)) {
        await logActionError(action, result, { getActionName, logMessage, folderPath }).catch(() => {})
        const errDetail = result && result.error != null && result.error !== '' ? String(result.error) : 'unknown'
        return { success: false, error: errDetail, completedSteps: i }
      }

      if (t < times - 1) await new Promise(resolve => setTimeout(resolve, 500))
    }

    completedSteps++
    if (onStepComplete) onStepComplete(i + 1, actions.length, getActionName(action), 0, times, times)

    if (i < actions.length - 1) {
      let remainingTime = interval
      const countdownInterval = 100
      const nextStepName = getActionName(actions[i + 1])
      const nextTimes = actions[i + 1].times || 1
      while (remainingTime > 0) {
        if (shouldStop && shouldStop()) return { success: false, error: 'Execution stopped', completedSteps }
        if (onStepComplete) onStepComplete(i + 1, actions.length, nextStepName, remainingTime, nextTimes, 0)
        const waitTime = Math.min(countdownInterval, remainingTime)
        await new Promise(resolve => setTimeout(resolve, waitTime))
        remainingTime -= waitTime
      }
    }
  }

  return { success: true, completedSteps }
}

module.exports = { executeActionSequence }