var ConfigLoader = require('./lib/config-loader');
var compile = require('./lib/compiler');
var execute = require('./lib/executor');

/**
 * Initialize an application from an options object or
 * a set of JSON and JavaScript files.
 *
 * This function takes an optional argument that is either a string
 * or an object.
 *
 * If the argument is a string, then it sets the application root directory
 * based on the string value. Then it:
 *
 *  1. Creates DataSources from the `datasources.json` file in the application
 *   root directory.
 *
 *  2. Creates Models from the `models.json` file in the application
 *    root directory.
 *
 * If the argument is an object, then it looks for `model`, `dataSources`,
 * and `appRootDir` properties of the object.
 * If the object has no `appRootDir` property then it sets the current working
 * directory as the application root directory.
 * Then it:
 *
 * 1. Creates DataSources from the `options.dataSources` object.
 *
 * 2. Creates Models from the `options.models` object.
 *
 * In both cases, the function loads JavaScript files in the `/models` and
 * `/boot` subdirectories of the application root directory with `require()`.
 *
 *  **NOTE:** mixing `app.boot()` and `app.model(name, config)` in multiple
 *  files may result in models being **undefined** due to race conditions.
 *  To avoid this when using `app.boot()` make sure all models are passed
 *  as part of the `models` definition.
 *
 * Throws an error if the config object is not valid or if boot fails.
 *
 * @param app LoopBack application created by `loopback()`.
 * @options {String|Object} options Boot options; If String, this is
 * the application root directory; if object, has below properties.
 * @property {String} appRootDir Directory to use when loading JSON and
 * JavaScript files (optional).
 * Defaults to the current directory (`process.cwd()`).
 * @property {Object} models Object containing `Model` definitions (optional).
 * @property {Object} dataSources Object containing `DataSource`
 * definitions (optional).
 * @property {String} modelsRootDir Directory to use when loading `models.json`
 * and `models/*.js`. Defaults to `appRootDir`.
 * @property {String} datasourcesRootDir Directory to use when loading
 * `datasources.json`. Defaults to `appRootDir`.
 * @property {String} env Environment type, defaults to `process.env.NODE_ENV`
 * or `development`. Common values are `development`, `staging` and
 * `production`; however the applications are free to use any names.
 * @end
 *
 * @header bootLoopBackApp(app, [options])
 */

exports = module.exports = function bootLoopBackApp(app, options) {
  // backwards compatibility with loopback's app.boot
  options.env = options.env || app.get('env');

  var instructions = compile(options);
  execute(app, instructions);
};

exports.ConfigLoader = ConfigLoader;
exports.compile = compile;
exports.execute = execute;