const os = require('os');
const path = require('path');
const fs = require('fs');

exports.download_file_id = async function (axios, file_id, filename_override) {
  console.log('Downloading file...');
  const url = '/event/file/'+file_id+'/download';
  
  const data = await axios({
    method: "get",
    url: url,
    responseType: "stream"
  })
    .then(function (response) {
      //console.log(response);
      //console.log(response.data);
      
      let filename = 'default.txt';
      
      if (typeof filename_override === 'undefined' || filename_override == null) {
        let headerLine = response.data.headers['content-disposition'];
        
        console.log(headerLine);
        console.log(headerLine.indexOf('="'));
        console.log(headerLine.indexOf('='));
        if (headerLine.indexOf('="') != -1) {
          let startFileNameIndex = headerLine.indexOf('="') + 2;
          let endFileNameIndex = headerLine.lastIndexOf('"');
          filename = headerLine.substring(startFileNameIndex, endFileNameIndex);
        } else if (headerLine.indexOf('=') != -1) {
          let startFileNameIndex = headerLine.indexOf('=') + 1;
          let endFileNameIndex = headerLine.length;
          filename = headerLine.substring(startFileNameIndex, endFileNameIndex);
        } else {
          filename = 'filename_not_found_in_header.txt';
        }
      } else {
        filename = filename_override;
      }

      let directory = 'file_cache/';
      
      directory_and_filename = path.join(directory, filename);
      
      //console.log(directory_and_filename);
      
      if (fs.existsSync(directory_and_filename)) {
        console.log('File already exists: '+directory_and_filename);
      } else {
        console.log('Starting file download: '+directory_and_filename);
        response.data.pipe(fs.createWriteStream(directory_and_filename));
      }
      //data = response.data;
      return true;
      //return response.data;
    })
    .catch(function (error) {
      console.log(error);
      return error;
    });
  
  return data;
}