import fs from 'fs';
import { v4 } from 'uuid';
import os from 'os';
import { exec } from 'child_process';
import path from 'path';

import IPdfToTextProvider from '../IPdfToTextProvider';
import IOptionsPdfParseDTO from '../dto/IOptionsPdfParseDTO';

export default class LinuxPdfToText implements IPdfToTextProvider {
  public async extract(filePath: string, options: IOptionsPdfParseDTO = {}): Promise<string> {
    const tempTextFile = path.resolve(os.tmpdir(), v4());
    const { pageNumber } = options;

    const pageNumberOption = pageNumber !== undefined ? `-f ${pageNumber} -l ${pageNumber}` : '';

    const command = `pdftotext -layout  ${pageNumberOption} ${filePath} ${tempTextFile}`;

    return new Promise((resolve, reject) => {
      exec(command, async err => {
        if (err) {
          return reject(err);
        }

        const contentFile = await fs.promises.readFile(tempTextFile);

        await fs.promises.unlink(tempTextFile);
        return resolve(contentFile.toString());
      });
    });
  }
}