import { BaseExtension, ExtensionTypeEnum } from '../extension'
import type { MCPTool, MCPToolCallResult } from '../../types'
import type { AttachmentFileInfo } from './vector-db'

export interface AttachmentInput {
  path: string
  name?: string
  type?: string
  size?: number
}

export interface IngestAttachmentsResult {
  filesProcessed: number
  chunksInserted: number
  files: AttachmentFileInfo[]
}

export const RAG_INTERNAL_SERVER = 'rag-internal'

/**
 * RAG extension base: exposes RAG tools and orchestration API.
 */
export abstract class RAGExtension extends BaseExtension {
  type(): ExtensionTypeEnum | undefined {
    return ExtensionTypeEnum.RAG
  }

  abstract getTools(): Promise<MCPTool[]>
  /**
   * Lightweight list of tool names for quick routing/lookup.
   */
  abstract getToolNames(): Promise<string[]>
  abstract callTool(toolName: string, args: Record<string, unknown>): Promise<MCPToolCallResult>

  abstract ingestAttachments(threadId: string, files: AttachmentInput[]): Promise<IngestAttachmentsResult>
}