var Q = require('q');
var joi = require('joi');
var OKRestEndpoint = require('okrest');

/**
 * Creates an OKResource types
 * Takes a resource name and a spec defining the resources attributes.
 */
function createResourceClass(name, spec, options) {
  options = options || {};
  spec = spec || {};
  // All resources have the same default CRUD endpoint
  var viewClass = options.endpoint || OKRestEndpoint;
  // Id determines specific resource referenced.
  // Defaults to set of all resources of this type.
  var id = options.id || '*';
  if (viewClass !== OKRestEndpoint && !(viewClass instanceof OKRestEndpoint))
    throw new Error('Resource view not descendent of OKRestEndpoint');

  /**
   * OKResource!
   */
  function OKResource(options) {
    if (!(this instanceof OKResource)) return new OKResource(options);
    options = options || {};
    this.name = name;
    if (!name)
      throw new Error('No resource type provided to resource!')
    var db = this._db = options.db;
    if (!db)
      throw new Error('No DB provided to resource!');
    this._validator = compileValidator(spec);
  }

  /**
   * Returns the resource's CRUD view
   * This allows us to specify custom views per resource if need be
   */
  OKResource.prototype.view = function(options) {
    return viewClass(this, options);
  };

  // OKResource.prototype.get = function() {
  //   return this._query();
  // };

  // Expose the resource type on the class constructor
  OKResource.type = name;

  return OKResource;
}

/**
 * Compiles our schema spec into a schema validator function
 */
function compileValidator(spec) {
  // Skip validation for now
  var schema = joi.any();
  return schema.validate.bind(schema);
}

module.exports = createResourceClass;