wbyoung/maguey

'use strict';

var _ = require('lodash');
var Class = require('corazon/class');

/**
 * Helper method for creating a chainable method that alters column options.
 *
 * @private
 * @function Column~opt
 * @param {String} name The name of the option to set.
 * @param {Boolean} arg Whether or not the option accepts an argument. If so,
 * the value will be stored as the column's option value. If not, it will
 * simply be flagged as enabled (set to a value of `true`).
 */
var opt = function(name, arg) {
  return function() {
    this.options[name] = arg ? arguments[0] : true;
    return this;
  };
};

/**
 * @class Column
 * @classdesc
 *
 * An object that can update column options via chainable methods.
 */
var Column = Class.extend(/** @lends Column# */ {

  /**
   * Create a column.
   *
   *
   * @protected
   * @constructor Column
   * @param {Object} column The column on which to alter options.
   * @param {String} column.name The name of the column.
   * @param {String} column.type The type of the column.
   * @param {Object} column.options Options that have been enabled for this
   * column.
   */
  init: function(column) {
    _.extend(this, column);
  },

  /**
   * Alias of {@link Column#primaryKey}.
   *
   * @method
   * @public
   * @see {@link Column#primaryKey}
   */
  pk: opt('primaryKey'),

  /**
   * Mark this column as being a primary key column.
   *
   * @method
   * @public
   */
  primaryKey: opt('primaryKey'),

  /**
   * Mark this column as not accepting null values.
   *
   * @method
   * @public
   */
  notNull: opt('notNull'),

  /**
   * Mark this column as containing unique values.
   *
   * @method
   * @public
   */
  unique: opt('unique'),

  /**
   * Set the default value for this column.
   *
   * Note that this value will be escaped before being handed off to the
   * database. Because of this, we recommend against sending user-input to this
   * method.
   *
   * @method
   * @public
   * @param {String|Number} value The value for the default.
   */
  default: opt('default', true),

  /**
   * Set the column that this column references.
   *
   * @method
   * @public
   * @param {String} reference The table & column that this column references.
   * For instance, `user.id`.
   */
  references: opt('references', true),

  /**
   * Action for delete. Only used for columns that have used
   * {@link Column#references}.
   *
   * @method
   * @public
   * @param {String} action The action. One of `cascade`, `restrict`, or
   * `nullify`.
   */
  onDelete: opt('onDelete', true),

  /**
   * Action for update. Only used for columns that have used
   * {@link Column#references}.
   *
   * @method
   * @public
   * @param {String} action The action. One of `cascade`, `restrict`, or
   * `nullify`.
   */
  onUpdate: opt('onUpdate', true),

});

module.exports = Column.reopenClass({
  __name__: 'Table~Column',
});