'use strict';

module.exports = function defFunc(ajv) {
  defFunc.definition = {
    type: 'object',
    macro: function (schema) {
      if (schema.length == 0) return {};
      if (schema.length == 1) return { not: { required: schema } };
      var schemas = schema.map(function (prop) {
        return { required: [prop] };
      });
      return { not: { anyOf: schemas } };
    },
    metaSchema: {
      type: 'array',
      items: {
        type: 'string'
      }
    }
  };

  ajv.addKeyword('prohibited', defFunc.definition);
  return ajv;
};