var memcached = require('memcache');
var winston = require('winston');

// Create a new store with options
var MemcachedDocumentStore = function(options) {
  this.expire = options.expire;
  if (!MemcachedDocumentStore.client) {
    MemcachedDocumentStore.connect(options);
  }
};
MemcachedDocumentStore.secret = function() {
    return Math.random().toString(24).slice(-10);
};
// Create a connection
MemcachedDocumentStore.connect = function(options) {
  var host = options.host || '127.0.0.1';
  var port = options.port || 11211;
  this.client = new memcached.Client(port, host);
  this.client.connect();
  this.client.on('connect', function() {
    winston.info('connected to memcached on ' + host + ':' + port);
  });
  this.client.on('error', function(e) {
    winston.info('error connecting to memcached', { error: e });
  });
};

// Save file in a key
MemcachedDocumentStore.prototype.set =
function(key, data, callback, skipExpire) {
  MemcachedDocumentStore.client.set(key, data, function(err, reply) {
    if (!err) {
      var sc = MemcachedDocumentStore.secret();
      MemcachedDocumentStore.client.set(key + "-" + sc, "", function(err, reply) {
        if (!err) {
          callback(true, sc);
        }
      });
    }
    else {
      callback(false);
    }
  }, skipExpire ? 0 : this.expire);
};

// Get a file from a key
MemcachedDocumentStore.prototype.get = function(key, callback, skipExpire) {
  var _this = this;
  MemcachedDocumentStore.client.get(key, function(err, reply) {
    callback(err ? false : reply);
    if (_this.expire && !skipExpire) {
      winston.warn('store does not currently push forward expirations on GET');
    }
  });
};

MemcachedDocumentStore.prototype.remove = function(key, secret, callback) {
  MemcachedDocumentStore.client.get(key + "-" + secret, function(err, reply) {
    if (!err) {
      MemcachedDocumentStore.client.del(key, function(err, reply) {
        if (err) return callback(false);
        MemcachedDocumentStore.client.del(key + "-" + secret, function(err, reply) {
          if (err) return callback(false);
          callback(reply);
        });
      });
    }
    else {
      callback(false);
    }
  });
};

module.exports = MemcachedDocumentStore;