/*!
 * Module dependencies.
 */

var EventEmitter = require('events').EventEmitter;
var STATES = require('./connectionstate');

/**
 * Abstract Collection constructor
 *
 * This is the base class that drivers inherit from and implement.
 *
 * @param {String} name name of the collection
 * @param {Connection} conn A MongooseConnection instance
 * @param {Object} opts optional collection options
 * @api public
 */

function Collection(name, conn, opts) {
  if (opts === void 0) {
    opts = {};
  }
  if (opts.capped === void 0) {
    opts.capped = {};
  }

  opts.bufferCommands = undefined === opts.bufferCommands
      ? true
      : opts.bufferCommands;

  if (typeof opts.capped === 'number') {
    opts.capped = {size: opts.capped};
  }

  this.opts = opts;
  this.name = name;
  this.collectionName = name;
  this.conn = conn;
  this.queue = [];
  this.buffer = this.opts.bufferCommands;
  this.emitter = new EventEmitter();

  if (STATES.connected === this.conn.readyState) {
    this.onOpen();
  }
}

/**
 * The collection name
 *
 * @api public
 * @property name
 */

Collection.prototype.name;

/**
 * The collection name
 *
 * @api public
 * @property collectionName
 */

Collection.prototype.collectionName;

/**
 * The Connection instance
 *
 * @api public
 * @property conn
 */

Collection.prototype.conn;

/**
 * Called when the database connects
 *
 * @api private
 */

Collection.prototype.onOpen = function() {
  this.buffer = false;
  this.doQueue();
};

/**
 * Called when the database disconnects
 *
 * @api private
 */

Collection.prototype.onClose = function() {
  if (this.opts.bufferCommands) {
    this.buffer = true;
  }
};

/**
 * Queues a method for later execution when its
 * database connection opens.
 *
 * @param {String} name name of the method to queue
 * @param {Array} args arguments to pass to the method when executed
 * @api private
 */

Collection.prototype.addQueue = function(name, args) {
  this.queue.push([name, args]);
  return this;
};

/**
 * Executes all queued methods and clears the queue.
 *
 * @api private
 */

Collection.prototype.doQueue = function() {
  for (var i = 0, l = this.queue.length; i < l; i++) {
    this[this.queue[i][0]].apply(this, this.queue[i][1]);
  }
  this.queue = [];
  var _this = this;
  process.nextTick(function() {
    _this.emitter.emit('queue');
  });
  return this;
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.ensureIndex = function() {
  throw new Error('Collection#ensureIndex unimplemented by driver');
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.findAndModify = function() {
  throw new Error('Collection#findAndModify unimplemented by driver');
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.findOne = function() {
  throw new Error('Collection#findOne unimplemented by driver');
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.find = function() {
  throw new Error('Collection#find unimplemented by driver');
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.insert = function() {
  throw new Error('Collection#insert unimplemented by driver');
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.save = function() {
  throw new Error('Collection#save unimplemented by driver');
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.update = function() {
  throw new Error('Collection#update unimplemented by driver');
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.getIndexes = function() {
  throw new Error('Collection#getIndexes unimplemented by driver');
};

/**
 * Abstract method that drivers must implement.
 */

Collection.prototype.mapReduce = function() {
  throw new Error('Collection#mapReduce unimplemented by driver');
};

/*!
 * Module exports.
 */

module.exports = Collection;
