const MUTATION_INTENT =
  /(?:设计|创建|生成|添加|增加|新增|修改|调整|编辑|删除|移动|旋转|缩放|布置|装修|建造|搭建|修复|design|create|generate|add|modify|update|edit|delete|remove|move|rotate|scale|furnish|build|repair|fix)/i

export function requiresPascalMutation(messages: unknown[]): boolean {
  const latestUserMessage = [...messages]
    .reverse()
    .find(
      (message) =>
        Boolean(message) &&
        typeof message === 'object' &&
        (message as { role?: unknown }).role === 'user',
    ) as { parts?: unknown } | undefined

  if (!Array.isArray(latestUserMessage?.parts)) return false
  const text = latestUserMessage.parts
    .filter((part): part is { text: string; type: 'text' } =>
      Boolean(
        part &&
          typeof part === 'object' &&
          (part as { type?: unknown }).type === 'text' &&
          typeof (part as { text?: unknown }).text === 'string',
      ),
    )
    .map((part) => part.text)
    .join(' ')

  return MUTATION_INTENT.test(text)
}

export function pascalAgentStepPolicy(params: {
  hasMutation: boolean
  mutationRequired: boolean
  mutationToolNames: string[]
  stepNumber: number
}): { activeTools?: string[]; toolChoice: 'auto' | 'required' } {
  if (!(params.mutationRequired && !params.hasMutation)) return { toolChoice: 'auto' }
  if (params.stepNumber < 2) return { toolChoice: 'required' }
  return {
    activeTools: params.mutationToolNames,
    toolChoice: 'required',
  }
}