download-file.js

'use strict';
/**
 * MAC OSX ONLY
 */

// npm install request async
try{
  var request    = require('request');
  var async      = require('async');
  var Notification = require('node-notifier');
  var notifier = new Notification();
}catch(err){
  console.error("[Error] '%s' requires the 'request async node-notifier' packages to work", __filename);
  console.error("[Error] run 'cd %s && npm install request async node-notifier' and restart dot-clipboard (or edit download-file.js).", __dirname);
}
var exec       = require('child_process').exec;
var crypto     = require('crypto');
var os         = require('os');
var path       = require('path');
var fs         = require('fs');

module.exports = {
  options: {
    outputDir: path.resolve(process.env.HOME, 'Dropbox/Images'),
    tmpOutputDir: os.tmpdir(),
    fileExts: ['.png', '.jpg', '.jpeg', '.gif'],
    notify: true,

    askForTags: false,

    truncateSha1To: 1000,
    separator: '_'
  },
  run: function(link, f){
    link = link.trim();
    var parts, filext, filename, notifyMe = this.options.notify, tmp;

    parts = link.split(':');
    filext = path.extname(link);
    filename = path.basename(link);
    filename = filename.substr(0, filename.length - filext.length);
    tmp = filext.indexOf('?');
    if (tmp != -1) {
      filext = filext.substr(0, tmp);
    }

    if (this.options.fileExts.indexOf(filext) == -1 || !(parts[0] == 'http' || parts[0] == 'https')) {
      return f();
    }

    async.waterfall([
      downloadFileAndChecksum.bind(null, this.options, link, filext),
      checkIfFileExist.bind(null, fileNameComparator(this.options), this.options),
    ], function(err, tmpFile, fileSha1, alreadyExist){
      if(err || alreadyExist){
        return f(err);
      }

      async.waterfall([
        askForTags.bind(null, this.options, link),
        moveToOutputDir.bind(null, filename, tmpFile, fileSha1, this.options)
      ], function() {
        if (notifyMe) {
          notifier.notify({
            title: 'dot-clipboard',
            message: 'Saved ' + link
          });
        }
        f();
      });

    }.bind(this));
  }
};

function downloadFileAndChecksum(options, link, ext, f){
  var tmpFile = path.resolve(options.tmpOutputDir, + new Date() + ext);
  var hash    = crypto.createHash('sha1');
  hash.setEncoding('hex');

  var req = request(link)
  .on('error', function(err){
    f(err);
  })
  .on('end', function(){
    hash.end();
    f(null, tmpFile, hash.read());
  });
  req.pipe(hash, { end: false });
  req.pipe(fs.createWriteStream(tmpFile));
}

function checkIfFileExist(comparator, options, tmpFile, fileSha1, f){
  fs.readdir(options.outputDir, function(err, files){
    if(err){return f(err);}
    f(null, tmpFile, fileSha1, files.filter(comparator(fileSha1)).length > 0);
  });
}

function fileNameComparator(options){
  return function(fileSha1){
    return function(filename){
      var tmp = filename.split(options.separator);
      return tmp[tmp.length-1] === fileSha1.substring(0, options.truncateSha1To);
    };
  };
}

function askForTags(options, fileLink, f){
  if(!options.askForTags){
    return f(null, null);
  }

  var promptTitle = 'Enter tags (separated by \'-\') for file ('+fileLink+')';
  var cmd = "osascript -e 'Tell application \"System Events\" to display dialog \""+promptTitle+"\" default answer \"\"' -e 'text returned of result' 2>/dev/null";
  exec(cmd, function (error, stdout /*, stderr*/) {
    f(null, stdout);
  });
}

function moveToOutputDir(filename, tmpFile, fileSha1, options, tags, f){
  var file = path.resolve(options.outputDir, filename + options.separator + fileSha1.substring(0, options.truncateSha1To) + (tags ? options.separator + tags : '').trim() + path.extname(tmpFile)).trim();
  fs.rename(tmpFile, file, f);
}

eh hacky..