search-query-parser/lib/search-query-parser.js

/*!
 * search-query-parser.js
 * Copyright(c) 2014-2019
 * MIT Licensed
 */

exports.parse = function (string, options) {
  // Set a default options object when none is provided
  if (!options) {
    options = { offsets: true };
  } else {
    // If options offsets was't passed, set it to true
    options.offsets =
      typeof options.offsets === "undefined" ? true : options.offsets;
  }

  if (!string) {
    string = "";
  }

  // When a simple string, return it
  if (-1 === string.indexOf(":") && !options.tokenize) {
    return string;
  }
  // When no keywords or ranges set, treat as a simple string
  else if (!options.keywords && !options.ranges && !options.tokenize) {
    return string;
  }
  // Otherwise parse the advanced query syntax
  else {
    // Our object to store the query object
    var query = { text: [] };
    // When offsets is true, create their array
    if (options.offsets) {
      query.offsets = [];
    }
    var exclusion = {};
    var terms = [];
    // Get a list of search terms respecting single and double quotes
    var regex = /(\S+:'(?:[^'\\]|\\.)*')|(\S+:"(?:[^"\\]|\\.)*")|(-?"(?:[^"\\]|\\.)*")|(-?'(?:[^'\\]|\\.)*')|\S+|\S+:\S+/g;
    var match;
    while ((match = regex.exec(string)) !== null) {
      var term = match[0];
      var sepIndex = term.indexOf(":");
      if (sepIndex !== -1) {
        var split = term.split(":"),
          key = term.slice(0, sepIndex),
          val = term.slice(sepIndex + 1);
        // Strip surrounding quotes
        val = val.replace(/^\"|\"$|^\'|\'$/g, "");
        // Strip backslashes respecting escapes
        val = (val + "").replace(/\\(.?)/g, function (s, n1) {
          switch (n1) {
            case "\\":
              return "\\";
            case "0":
              return "\u0000";
            case "":
              return "";
            default:
              return n1;
          }
        });
        terms.push({
          keyword: key,
          value: val,
          offsetStart: match.index,
          offsetEnd: match.index + term.length,
        });
      } else {
        var isExcludedTerm = false;
        if (term[0] === "-") {
          isExcludedTerm = true;
          term = term.slice(1);
        }

        // Strip surrounding quotes
        term = term.replace(/^\"|\"$|^\'|\'$/g, "");
        // Strip backslashes respecting escapes
        term = (term + "").replace(/\\(.?)/g, function (s, n1) {
          switch (n1) {
            case "\\":
              return "\\";
            case "0":
              return "\u0000";
            case "":
              return "";
            default:
              return n1;
          }
        });

        if (isExcludedTerm) {
          if (exclusion["text"]) {
            if (exclusion["text"] instanceof Array) {
              exclusion["text"].push(term);
            } else {
              exclusion["text"] = [exclusion["text"]];
              exclusion["text"].push(term);
            }
          } else {
            // First time seeing an excluded text term
            exclusion["text"] = term;
          }
        } else {
          terms.push({
            text: term,
            offsetStart: match.index,
            offsetEnd: match.index + term.length,
          });
        }
      }
    }
    // Reverse to ensure proper order when pop()'ing.
    terms.reverse();
    // For each search term
    var term;
    while ((term = terms.pop())) {
      // When just a simple term
      if (term.text) {
        // We add it as pure text
        query.text.push(term.text);
        // When offsets is true, push a new offset
        if (options.offsets) {
          query.offsets.push(term);
        }
      }
      // We got an advanced search syntax
      else {
        var key = term.keyword;
        // Check if the key is a registered keyword
        options.keywords = options.keywords || [];
        var isKeyword = false;
        var isExclusion = false;
        if (!/^-/.test(key)) {
          isKeyword = !(-1 === options.keywords.indexOf(key));
        } else if (key[0] === "-") {
          var _key = key.slice(1);
          isKeyword = !(-1 === options.keywords.indexOf(_key));
          if (isKeyword) {
            key = _key;
            isExclusion = true;
          }
        }

        // Check if the key is a registered range
        options.ranges = options.ranges || [];
        var isRange = !(-1 === options.ranges.indexOf(key));
        // When the key matches a keyword
        if (isKeyword) {
          // When offsets is true, push a new offset
          if (options.offsets) {
            query.offsets.push({
              keyword: key,
              value: term.value,
              offsetStart: isExclusion
                ? term.offsetStart + 1
                : term.offsetStart,
              offsetEnd: term.offsetEnd,
            });
          }

          var value = term.value;
          // When value is a thing
          if (value.length) {
            // Get an array of values when several are there
            var values = value.split(",");
            if (isExclusion) {
              if (exclusion[key]) {
                // ...many times...
                if (exclusion[key] instanceof Array) {
                  // ...and got several values this time...
                  if (values.length > 1) {
                    // ... concatenate both arrays.
                    exclusion[key] = exclusion[key].concat(values);
                  } else {
                    // ... append the current single value.
                    exclusion[key].push(value);
                  }
                }
                // We saw that keyword only once before
                else {
                  // Put both the current value and the new
                  // value in an array
                  exclusion[key] = [exclusion[key]];
                  exclusion[key].push(value);
                }
              }
              // First time we see that keyword
              else {
                // ...and got several values this time...
                if (values.length > 1) {
                  // ...add all values seen.
                  exclusion[key] = values;
                }
                // Got only a single value this time
                else {
                  // Record its value as a string
                  if (options.alwaysArray) {
                    // ...but we always return an array if option alwaysArray is true
                    exclusion[key] = [value];
                  } else {
                    // Record its value as a string
                    exclusion[key] = value;
                  }
                }
              }
            } else {
              // If we already have seen that keyword...
              if (query[key]) {
                // ...many times...
                if (query[key] instanceof Array) {
                  // ...and got several values this time...
                  if (values.length > 1) {
                    // ... concatenate both arrays.
                    query[key] = query[key].concat(values);
                  } else {
                    // ... append the current single value.
                    query[key].push(value);
                  }
                }
                // We saw that keyword only once before
                else {
                  // Put both the current value and the new
                  // value in an array
                  query[key] = [query[key]];
                  query[key].push(value);
                }
              }
              // First time we see that keyword
              else {
                // ...and got several values this time...
                if (values.length > 1) {
                  // ...add all values seen.
                  query[key] = values;
                }
                // Got only a single value this time
                else {
                  if (options.alwaysArray) {
                    // ...but we always return an array if option alwaysArray is true
                    query[key] = [value];
                  } else {
                    // Record its value as a string
                    query[key] = value;
                  }
                }
              }
            }
          }
        }
        // The key allows a range
        else if (isRange) {
          // When offsets is true, push a new offset
          if (options.offsets) {
            query.offsets.push(term);
          }

          var value = term.value;
          // Range are separated with a dash
          var rangeValues = value.split("-");
          // When both end of the range are specified
          // keyword:XXXX-YYYY
          query[key] = {};
          if (2 === rangeValues.length) {
            query[key].from = rangeValues[0];
            query[key].to = rangeValues[1];
          }
          // When pairs of ranges are specified
          // keyword:XXXX-YYYY,AAAA-BBBB
          else if (!rangeValues.length % 2) {
          }
          // When only getting a single value,
          // or an odd number of values
          else {
            query[key].from = value;
          }
        } else {
          // We add it as pure text
          var text = term.keyword + ":" + term.value;
          query.text.push(text);

          // When offsets is true, push a new offset
          if (options.offsets) {
            query.offsets.push({
              text: text,
              offsetStart: term.offsetStart,
              offsetEnd: term.offsetEnd,
            });
          }
        }
      }
    }

    // Concatenate all text terms if any
    if (query.text.length) {
      if (!options.tokenize) {
        query.text = query.text.join(" ").trim();
      }
    }
    // Just remove the attribute text when it's empty
    else {
      delete query.text;
    }

    // Return forged query object
    query.exclude = exclusion;
    return query;
  }
};

exports.stringify = function (queryObject, options, prefix) {
  // Set a default options object when none is provided
  if (!options) {
    options = { offsets: true };
  }

  // If the query object is falsy we can just return an empty string
  if (!queryObject) {
    return "";
  }

  // If the query object is already a string, we can return it immediately
  if (typeof queryObject === "string") {
    return queryObject;
  }

  // If the query object is an array, we can return it concatenated with a space
  if (Array.isArray(queryObject)) {
    return queryObject.join(" ");
  }

  // If the query object does not have any keys, we can return an empty string
  if (!Object.keys(queryObject).length) {
    return "";
  }

  // If the query object contains only text which is a string, we can return it immediately
  if (
    Object.keys(queryObject).length === 3 &&
    !!queryObject.text &&
    !!queryObject.offsets &&
    !!queryObject.exclude &&
    typeof queryObject.text === "string"
  ) {
    return queryObject.text;
  }

  // We will use a prefix for the exclude syntax later one
  if (!prefix) {
    prefix = "";
  }

  // Helpers
  var addQuotes = function (string) {
    return string.indexOf(" ") > -1 ? JSON.stringify(string) : string;
  };
  var addPrefix = function (string) {
    return prefix + string;
  };

  // Keep track of all single parts in this array
  var parts = [];

  // Text
  if (queryObject.text) {
    var value = [];
    if (typeof queryObject.text === "string") {
      value.push(queryObject.text);
    } else {
      value.push.apply(value, queryObject.text);
    }

    if (value.length > 0) {
      parts.push(value.map(addQuotes).map(addPrefix).join(" "));
    }
  }

  // Keywords
  if (options.keywords) {
    options.keywords.forEach(function (keyword) {
      if (!queryObject[keyword]) {
        return;
      }

      var value = [];
      if (typeof queryObject[keyword] === "string") {
        value.push(queryObject[keyword]);
      } else {
        value.push.apply(value, queryObject[keyword]);
      }

      if (value.length > 0) {
        parts.push(addPrefix(keyword + ":" + value.map(addQuotes).join(",")));
      }
    });
  }

  // Ranges
  if (options.ranges) {
    options.ranges.forEach(function (range) {
      if (!queryObject[range]) {
        return;
      }

      var value = queryObject[range].from;
      var to = queryObject[range].to;
      if (to) {
        value = value + "-" + to;
      }

      if (value) {
        parts.push(addPrefix(range + ":" + value));
      }
    });
  }

  // Exclude
  if (queryObject.exclude) {
    if (Object.keys(queryObject.exclude).length > 0) {
      parts.push(exports.stringify(queryObject.exclude, options, "-"));
    }
  }

  return parts.join(" ");
};