500px

// Read down for what it does.
var laveshtien_strings = [
  "Photos in $in",
  "Photos near $in",
  "Photos by $user",
  "Photos tagged $tag",
  "Sort by $",
  "$term"
];

// DONT EVEN ASK ITS PORTED FROM SOME CODE
// WHICH WAS IN THIS FORM already :-(
function levDist(s, t) {
    var d = []; //2d matrix

    // Step 1
    var n = s.length;
    var m = t.length;

    if (n == 0) return m;
    if (m == 0) return n;

    //Create an array of arrays in javascript (a descending loop is quicker)
    for (var i = n; i >= 0; i--) d[i] = [];

    // Step 2
    for (var i = n; i >= 0; i--) d[i][0] = i;
    for (var j = m; j >= 0; j--) d[0][j] = j;

    // Step 3
    for (var i = 1; i <= n; i++) {
        var s_i = s.charAt(i - 1);

        // Step 4
        for (var j = 1; j <= m; j++) {

            //Check the jagged ld total so far
            if (i == j && d[i][j] > 4) return n;

            var t_j = t.charAt(j - 1);
            var cost = (s_i == t_j) ? 0 : 1; // Step 5

            //Calculate the minimum
            var mi = d[i - 1][j] + 1;
            var b = d[i][j - 1] + 1;
            var c = d[i - 1][j - 1] + cost;

            if (b < mi) mi = b;
            if (c < mi) mi = c;

            d[i][j] = mi; // Step 6

            //Damerau transposition
            if (i > 1 && j > 1 && s_i == t.charAt(j - 2) && s.charAt(i - 2) == t_j) {
                d[i][j] = Math.min(d[i][j], d[i - 2][j - 2] + cost);
            }
        }
    }

    // Step 7
    return d[n][m];
}

// So the other person wants to write code once in a while
// but reads most of it
// just to make sure she doesn't calls me asking whats going on in here
// wrote this amazing name
// Gotta love sublime for autoType
function removePossibleKeywordsAndCalculateLevDistanceUsing(lavQueryString, searchString){

  var tokens = lavQueryString.split(" "),
  inputWordArray = searchString.split(" "),
  tokensInputString = {},
  token = '',
  output = {
    score: Infinity,
    tokens:{}
  },
  shouldWeCallTheLev = true;

  for( var i = 0; i < tokens.length; i++ ){

    if( inputWordArray.length < tokens.length ){
      shouldWeCallTheLev = false;
      break;
    }

    if( tokens[i].indexOf("$") === -1){
      continue;
    }

    token = tokens[i].replace("$","");
    output.tokens[token] = inputWordArray[i];
    tokens[i] = inputWordArray[i] = '';

  }
  if( shouldWeCallTheLev ){
   output.score = levDist( tokens.join(" "), inputWordArray.join(" "));
  }

  return output;
}

function getBestLavMatch(string){
  var results = laveshtien_strings.map(function(lav){
    return removePossibleKeywordsAndCalculateLevDistanceUsing(lav, string);
  });

  results = results.sort(function(a, b){
    return a.score - b.score;
  });

  return results[0];
}


// path search
exports.search = function(req, res, next){
  if( req.service.allowsSearch === false){
    return res.json({
      status_code: 403,
      message: "Method Not Supported for this service",
    });
  }

  var lavResult = getBestLavMatch(req.query.q);

  if( levResult && levResult.score < 5 ){
    service.search(levResult.tokens).done(function(snResult){
      res.json({
        status_code: 200,
        message: 'Ok',
        data: snResult
      });
    }).fail(errorResponder(res));

    return;
  }

  // Implement suggestions here
  next ();
}


/// Read but didn't understood whats happening ?
// Takes strings like Photos in Jabalpur, etc
// Makes a kvp of them that i call later
// Dirty deeds done dirt cheap