第 15 章：循环的终点与起点

// → src/query.ts 的 State 类型（简化版）
let state: State = {
  messages: params.messages,          // 对话历史
  toolUseContext: params.toolUseContext,
  maxOutputTokensOverride: undefined,  // 输出 token 覆盖
  autoCompactTracking: undefined,      // 压缩追踪
  stopHookActive: undefined,           // stop hook 是否激活
  maxOutputTokensRecoveryCount: 0,     // max-output 恢复次数
  hasAttemptedReactiveCompact: false,  // 是否已尝试响应式压缩
  turnCount: 1,                        // 当前轮次
  pendingToolUseSummary: undefined,    // 待处理的工具摘要
  transition: undefined,               // 上一轮的转换原因
}

// → src/query.ts 的 queryLoop() 函数（简化版）
if (!needsFollowUp) {
  // 模型没有请求工具调用 → 对话可以结束
  // ... 但先检查是否有错误需要恢复 ...
  return { reason: 'completed' }
}

// → src/query.ts 的 queryLoop() 函数（简化版）
if (isPromptTooLongError(lastMessage)) {
  const drainResult = await drainCollapsedMessages(messages)
  if (drainResult.freedSpace > 0) {
    state = {
      ...state,
      messages: drainResult.trimmedMessages,
      transition: { reason: 'collapse_drain_retry' },
    }
    continue  // 回到 while(true) 开头，重新调用 API
  }
  // drain 不够 → 进入阶段 2
}

// → src/query.ts 的 queryLoop() 函数（简化版）
if (shouldAttemptReactiveCompact) {
  const compactResult = await reactiveCompact(messages, systemPrompt, model)

  if (compactResult.success) {
    state = {
      ...state,
      messages: compactResult.compactedMessages,
      hasAttemptedReactiveCompact: true,  // 标记已尝试，不再重复
      transition: { reason: 'reactive_compact_retry' },
    }
    continue  // 回到 while(true) 开头
  }
  // 压缩也失败了 → 暴露错误给用户
}

// → src/query.ts 的 queryLoop() 函数（简化版）
if (isWithheldMaxOutputTokens(lastMessage)) {
  // 第一次遇到：从默认 8K 升级到 64K
  if (maxOutputTokensOverride === undefined) {
    state = {
      ...state,
      maxOutputTokensOverride: ESCALATED_MAX_TOKENS,  // 64K
      transition: { reason: 'max_tokens_escalation' },
    }
    continue
  }

  // 升级后仍不够：注入恢复消息让模型继续
  if (maxOutputTokensRecoveryCount < MAX_OUTPUT_TOKENS_RECOVERY_LIMIT) {
    const recoveryMessage = createUserMessage({
      content: 'Output token limit hit. Resume directly where you left off...',
      isMeta: true,  // 对用户隐藏
    })
    state = {
      ...state,
      messages: [...messages, recoveryMessage],
      maxOutputTokensRecoveryCount: count + 1,
      transition: { reason: 'max_tokens_resume' },
    }
    continue
  }

  // 恢复次数耗尽 → 暴露错误
  yield lastMessage
}

const stopHookResult = yield* handleStopHooks(...)

if (stopHookResult.preventContinuation) {
  return { reason: 'stop_hook_prevented' }
}

if (stopHookResult.blockingErrors.length > 0) {
  // 注入错误消息后继续循环（不是退出！）
  state = {
    ...state,
    messages: [...messages, ...assistantMessages, ...blockingErrors],
    stopHookActive: true,
    transition: { reason: 'stop_hook_blocking' },
  }
  continue
}

if (turnCount > 3 && lastOutputTokenCount < DIMINISHING_RETURN_THRESHOLD) {
  consecutiveLowOutputTurns++
  if (consecutiveLowOutputTurns >= 3) {
    return { reason: 'completed' }
  }
}

state = {
  messages: [...messages, ...assistantMessages, ...toolResults],
  toolUseContext,
  turnCount: turnCount + 1,
  pendingToolUseSummary: undefined,       // 重置
  maxOutputTokensRecoveryCount: 0,        // 重置恢复计数
  hasAttemptedReactiveCompact: false,      // 重置压缩标记
  stopHookActive: undefined,              // 重置
  transition: undefined,                  // 重置
}
continue  // 回到 while(true) 开头

console.log('[DEBUG] State transition:', state.transition?.reason, 'turn:', state.turnCount)

const ORIGINAL_MAX_TOKENS = 200  // 临时极小值

console.log('[DEBUG] Output tokens this turn:', outputTokenCount)