import { Document } from "../types";
import { PDFDocumentLoader } from "./pdf";
import { DocxDocumentLoader } from "./docx";
import { TextDocumentLoader } from "./text";
import * as path from "path";

export class DocumentLoaderFactory {
  private pdfLoader = new PDFDocumentLoader();
  private docxLoader = new DocxDocumentLoader();
  private textLoader = new TextDocumentLoader();

  private supportedExtensions = new Map<string, string>([
    ["pdf", "pdf"],
    ["docx", "docx"],
    ["doc", "docx"], // Treat .doc files as docx
    ["txt", "text"],
    ["text", "text"],
    ["md", "text"],
    ["markdown", "text"],
  ]);

  async loadDocument(filePath: string, content: Buffer): Promise<Document> {
    const extension = this.getFileExtension(filePath);
    const loaderType = this.supportedExtensions.get(extension);

    if (!loaderType) {
      throw new Error(`Unsupported file type: ${extension}`);
    }

    console.log(`[DocumentLoaderFactory] Loading ${filePath} as ${loaderType}`);

    switch (loaderType) {
      case "pdf":
        return await this.pdfLoader.load(filePath, content);
      case "docx":
        return await this.docxLoader.load(filePath, content);
      case "text":
        return await this.textLoader.load(filePath, content);
      default:
        throw new Error(`Unsupported loader type: ${loaderType}`);
    }
  }

  private getFileExtension(filePath: string): string {
    return path.extname(filePath).toLowerCase().slice(1);
  }

  getSupportedExtensions(): string[] {
    return Array.from(this.supportedExtensions.keys());
  }

  isSupported(filePath: string): boolean {
    const extension = this.getFileExtension(filePath);
    return this.supportedExtensions.has(extension);
  }
}