// Service for checking the availability of a given word

Splitter.module('Checkers', function(Checkers, Splitter) {

  var LocalChecker = {
    comKeyFor: function(compound) {
      return 'avail/.com/' + compound;
    },

    check: function(compound) {
      return $.jStorage.get(this.comKeyFor(compound));
    },

    store: function(compound, availability) {
      var key = '';

      // Don't want to store error states.
      if (availability === 'available' || availability === 'unavailable') {
        key = this.comKeyFor(compound);
        // Expire the value in 10 mins.
        return $.jStorage.set(key, availability, { TTL: 600000 })
      };

      return false;
    }
  };

  // Class which can check the availability of a word.
  var Checker = {
    check: function(compound, options) {
      options || (options = {});
      // console.log("Checking availability of", compound);
      // No-op if the word is blank.
      if ($.trim(compound).length === 0) { return; };

      var localAvailability = LocalChecker.check(compound);

      if (localAvailability) {
        // console.log("Local availability of", compound + ".com", localAvailability);
        options.success(localAvailability);
      } else {
        $.ajax({
          url: '/availabilities/' + encodeURIComponent(compound),
          dataType: 'json',
          success: function(json) {
            var availability = json.status;
            // console.log("Remote availability of", compound + ".com", availability);
            LocalChecker.store(compound, availability);
            options.success(availability);
          },
          error: options.error
        });
      }
    }
  };

  Checkers.check = function(word, success) {
    Checker.check(word, success);
  };

  // Create a debounced version of the checking method.
  Checkers.debouncedCheck = _.debounce(Checkers.check, 300);
});