import { tool } from 'ai';
import { z } from 'zod';
import { AiApiError } from '../ai-shared/AiError';
import type { KnowledgeRepository } from './KnowledgeRepository';

export function createKnowledgeTools(repository: KnowledgeRepository) {
  return {
    listKnowledgeFiles: tool({
      description: '列出企业知识库中的可用文件。回答需要知识库事实的问题前先查看可用文件。',
      inputSchema: z.object({
        dir: z.string().optional().describe('相对知识库根的目录；省略时列出全部根'),
      }),
      execute: ({ dir }, { abortSignal }) => safeToolResult(() => (
        repository.listFiles(dir, abortSignal)
      )),
    }),
    readKnowledgeFile: tool({
      description: '按相对路径读取知识库文件；文件较大时根据 nextOffset 分块续读。',
      inputSchema: z.object({
        path: z.string().min(1).describe('listKnowledgeFiles 返回的相对路径'),
        offset: z.number().int().nonnegative().optional().describe('UTF-8 字节偏移'),
      }),
      execute: ({ path, offset }, { abortSignal }) => safeToolResult(() => (
        repository.readFile(path, offset, abortSignal)
      )),
    }),
    searchKnowledge: tool({
      description: '在企业知识库中搜索关键词，返回文件、行号和片段。',
      inputSchema: z.object({
        keyword: z.string().min(2).max(64).describe('要搜索的关键词'),
      }),
      execute: ({ keyword }, { abortSignal }) => safeToolResult(() => (
        repository.search(keyword, abortSignal)
      )),
    }),
  };
}

function safeToolResult<T>(operation: () => T): T | { error: { code: number; message: string } } {
  try {
    return operation();
  } catch (error) {
    if (error instanceof AiApiError) {
      return { error: { code: error.code, message: error.message } };
    }
    return { error: { code: 4505, message: '知识库工具执行失败' } };
  }
}