'use strict';

var requiredDirective = function() {
  return {
    restrict: 'A',
    require: '?ngModel',
    link: function(scope, elm, attr, ctrl) {
      if (!ctrl) return;
      attr.required = true; // force truthy in case we are on non input element

      ctrl.$validators.required = function(modelValue, viewValue) {
        return !attr.required || !ctrl.$isEmpty(viewValue);
      };

      attr.$observe('required', function() {
        ctrl.$validate();
      });
    }
  };
};


var patternDirective = function() {
  return {
    restrict: 'A',
    require: '?ngModel',
    link: function(scope, elm, attr, ctrl) {
      if (!ctrl) return;

      var regexp, patternExp = attr.ngPattern || attr.pattern;
      attr.$observe('pattern', function(regex) {
        if (isString(regex) && regex.length > 0) {
          regex = new RegExp('^' + regex + '$');
        }

        if (regex && !regex.test) {
          throw minErr('ngPattern')('noregexp',
            'Expected {0} to be a RegExp but was {1}. Element: {2}', patternExp,
            regex, startingTag(elm));
        }

        regexp = regex || undefined;
        ctrl.$validate();
      });

      ctrl.$validators.pattern = function(value) {
        return ctrl.$isEmpty(value) || isUndefined(regexp) || regexp.test(value);
      };
    }
  };
};


var maxlengthDirective = function() {
  return {
    restrict: 'A',
    require: '?ngModel',
    link: function(scope, elm, attr, ctrl) {
      if (!ctrl) return;

      var maxlength = -1;
      attr.$observe('maxlength', function(value) {
        var intVal = int(value);
        maxlength = isNaN(intVal) ? -1 : intVal;
        ctrl.$validate();
      });
      ctrl.$validators.maxlength = function(modelValue, viewValue) {
        return (maxlength < 0) || ctrl.$isEmpty(modelValue) || (viewValue.length <= maxlength);
      };
    }
  };
};

var minlengthDirective = function() {
  return {
    restrict: 'A',
    require: '?ngModel',
    link: function(scope, elm, attr, ctrl) {
      if (!ctrl) return;

      var minlength = 0;
      attr.$observe('minlength', function(value) {
        minlength = int(value) || 0;
        ctrl.$validate();
      });
      ctrl.$validators.minlength = function(modelValue, viewValue) {
        return ctrl.$isEmpty(viewValue) || viewValue.length >= minlength;
      };
    }
  };
};
