const CHINESE_MUTATION_ACTIONS =
  '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'
const ENGLISH_MUTATION_ACTIONS =
  'design|create|generate|add|modify|change|update|edit|delete|remove|move|rotate|scale|furnish|build|repair|fix'

const MUTATION_INTENT = new RegExp(
  `(?:${CHINESE_MUTATION_ACTIONS}|${ENGLISH_MUTATION_ACTIONS})`,
  'i',
)

const NEGATED_CHINESE_MUTATION = new RegExp(
  `(?:不要|请勿|勿|无需|不需要|不用|禁止|避免|不(?:再)?)[^，。；;,.!?！？]{0,32}(?:${CHINESE_MUTATION_ACTIONS})`,
  'gi',
)
const NEGATED_ENGLISH_MUTATION = new RegExp(
  `(?:do\\s+not|don't|dont|please\\s+do\\s+not|please\\s+don't|without|avoid)\\s+[^,.!?;]{0,48}(?:${ENGLISH_MUTATION_ACTIONS})`,
  'gi',
)

function actionableIntentText(text: string): string {
  return text.replace(NEGATED_CHINESE_MUTATION, ' ').replace(NEGATED_ENGLISH_MUTATION, ' ')
}

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(actionableIntentText(text))
}

export function pascalAgentStepPolicy(params: {
  hasMutation: boolean
  mutationRequired: boolean
  mutationToolNames: string[]
  readOnlyToolNames: string[]
  stepNumber: number
}): { activeTools?: string[]; toolChoice: 'auto' | 'required' } {
  if (!params.mutationRequired) {
    return { activeTools: params.readOnlyToolNames, toolChoice: 'auto' }
  }
  if (!(params.mutationRequired && !params.hasMutation)) return { toolChoice: 'auto' }
  if (params.stepNumber < 1) return { toolChoice: 'required' }
  return {
    activeTools: params.mutationToolNames,
    toolChoice: 'required',
  }
}