'use strict';

/*!
 * Module dependencies.
 */

var Schema = require('./schema'),
    SchemaType = require('./schematype'),
    VirtualType = require('./virtualtype'),
    STATES = require('./connectionstate'),
    Types = require('./types'),
    Query = require('./query'),
    Model = require('./model'),
    Document = require('./document'),
    utils = require('./utils'),
    format = utils.toCollectionName,
    pkg = require('../package.json');

var querystring = require('querystring');

var Aggregate = require('./aggregate');
var PromiseProvider = require('./promise_provider');

/**
 * Mongoose constructor.
 *
 * The exports object of the `mongoose` module is an instance of this class.
 * Most apps will only use this one instance.
 *
 * @api public
 */

function Mongoose() {
  this.connections = [];
  this.plugins = [];
  this.models = {};
  this.modelSchemas = {};
  // default global options
  this.options = {
    pluralization: true
  };
  var conn = this.createConnection(); // default connection
  conn.models = this.models;
}

/**
 * Wraps the given Mongoose instance into a thenable (pseudo-promise). This
 * is so `connect()` and `disconnect()` can return a thenable while maintaining
 * backwards compatibility.
 *
 * @api private
 */

function MongooseThenable(mongoose, promise) {
  for (var key in mongoose) {
    if (typeof mongoose[key] === 'function') {
      this[key] = function() {
        return mongoose[key].apply(mongoose, arguments);
      };
    } else {
      this[key] = mongoose[key];
    }
  }
  this.$opPromise = promise;
}

/**
 * Ability to use mongoose object as a pseudo-promise so `.connect().then()`
 * and `.disconnect().then()` are viable.
 *
 * @param {Function} onFulfilled
 * @param {Function} onRejected
 * @return {Promise}
 * @api private
 */

MongooseThenable.prototype.then = function(onFulfilled, onRejected) {
  var Promise = PromiseProvider.get();
  if (!this.$opPromise) {
    return new Promise.ES6(function(resolve, reject) {
      reject(new Error('Can only call `.then()` if connect() or disconnect() ' +
        'has been called'));
    }).then(onFulfilled, onRejected);
  }
  return this.$opPromise.then(onFulfilled, onRejected);
};

/**
 * Ability to use mongoose object as a pseudo-promise so `.connect().then()`
 * and `.disconnect().then()` are viable.
 *
 * @param {Function} onFulfilled
 * @param {Function} onRejected
 * @return {Promise}
 * @api private
 */

MongooseThenable.prototype.catch = function(onRejected) {
  return this.then(null, onRejected);
};

/**
 * Expose connection states for user-land
 *
 */
Mongoose.prototype.STATES = STATES;

/**
 * Sets mongoose options
 *
 * ####Example:
 *
 *     mongoose.set('test', value) // sets the 'test' option to `value`
 *
 *     mongoose.set('debug', true) // enable logging collection methods + arguments to the console
 *
 *     mongoose.set('debug', function(collectionName, methodName, arg1, arg2...) {}); // use custom function to log collection methods + arguments
 *
 * @param {String} key
 * @param {String|Function} value
 * @api public
 */

Mongoose.prototype.set = function(key, value) {
  if (arguments.length === 1) {
    return this.options[key];
  }

  this.options[key] = value;
  return this;
};

/**
 * Gets mongoose options
 *
 * ####Example:
 *
 *     mongoose.get('test') // returns the 'test' value
 *
 * @param {String} key
 * @method get
 * @api public
 */

Mongoose.prototype.get = Mongoose.prototype.set;

/*!
 * ReplSet connection string check.
 */

var rgxReplSet = /^.+,.+$/;

/**
 * Checks if ?replicaSet query parameter is specified in URI
 *
 * ####Example:
 *
 *     checkReplicaSetInUri('localhost:27000?replicaSet=rs0'); // true
 *
 * @param {String} uri
 * @return {boolean}
 * @api private
 */

var checkReplicaSetInUri = function(uri) {
  if (!uri) {
    return false;
  }

  var queryStringStart = uri.indexOf('?');
  var isReplicaSet = false;
  if (queryStringStart !== -1) {
    try {
      var obj = querystring.parse(uri.substr(queryStringStart + 1));
      if (obj && obj.replicaSet) {
        isReplicaSet = true;
      }
    } catch (e) {
      return false;
    }
  }

  return isReplicaSet;
};

/**
 * Creates a Connection instance.
 *
 * Each `connection` instance maps to a single database. This method is helpful when mangaging multiple db connections.
 *
 * If arguments are passed, they are proxied to either [Connection#open](#connection_Connection-open) or [Connection#openSet](#connection_Connection-openSet) appropriately. This means we can pass `db`, `server`, and `replset` options to the driver. _Note that the `safe` option specified in your schema will overwrite the `safe` db option specified here unless you set your schemas `safe` option to `undefined`. See [this](/docs/guide.html#safe) for more information._
 *
 * _Options passed take precedence over options included in connection strings._
 *
 * ####Example:
 *
 *     // with mongodb:// URI
 *     db = mongoose.createConnection('mongodb://user:pass@localhost:port/database');
 *
 *     // and options
 *     var opts = { db: { native_parser: true }}
 *     db = mongoose.createConnection('mongodb://user:pass@localhost:port/database', opts);
 *
 *     // replica sets
 *     db = mongoose.createConnection('mongodb://user:pass@localhost:port,anotherhost:port,yetanother:port/database');
 *
 *     // and options
 *     var opts = { replset: { strategy: 'ping', rs_name: 'testSet' }}
 *     db = mongoose.createConnection('mongodb://user:pass@localhost:port,anotherhost:port,yetanother:port/database', opts);
 *
 *     // with [host, database_name[, port] signature
 *     db = mongoose.createConnection('localhost', 'database', port)
 *
 *     // and options
 *     var opts = { server: { auto_reconnect: false }, user: 'username', pass: 'mypassword' }
 *     db = mongoose.createConnection('localhost', 'database', port, opts)
 *
 *     // initialize now, connect later
 *     db = mongoose.createConnection();
 *     db.open('localhost', 'database', port, [opts]);
 *
 * @param {String} [uri] a mongodb:// URI
 * @param {Object} [options] options to pass to the driver
 * @param {Object} [options.config] mongoose-specific options
 * @param {Boolean} [options.config.autoIndex] set to false to disable automatic index creation for all models associated with this connection.
 * @see Connection#open #connection_Connection-open
 * @see Connection#openSet #connection_Connection-openSet
 * @return {Connection} the created Connection object
 * @api public
 */

Mongoose.prototype.createConnection = function(uri, options) {
  var conn = new Connection(this);
  this.connections.push(conn);

  if (arguments.length) {
    if (rgxReplSet.test(arguments[0]) || checkReplicaSetInUri(arguments[0])) {
      conn.openSet.apply(conn, arguments);
    } else if (options && options.replset &&
        (options.replset.replicaSet || options.replset.rs_name)) {
      conn.openSet.apply(conn, arguments);
    } else {
      conn.open.apply(conn, arguments);
    }
  }

  return conn;
};

/**
 * Opens the default mongoose connection.
 *
 * If arguments are passed, they are proxied to either
 * [Connection#open](#connection_Connection-open) or
 * [Connection#openSet](#connection_Connection-openSet) appropriately.
 *
 * _Options passed take precedence over options included in connection strings._
 *
 * ####Example:
 *
 *     mongoose.connect('mongodb://user:pass@localhost:port/database');
 *
 *     // replica sets
 *     var uri = 'mongodb://user:pass@localhost:port,anotherhost:port,yetanother:port/mydatabase';
 *     mongoose.connect(uri);
 *
 *     // with options
 *     mongoose.connect(uri, options);
 *
 *     // connecting to multiple mongos
 *     var uri = 'mongodb://hostA:27501,hostB:27501';
 *     var opts = { mongos: true };
 *     mongoose.connect(uri, opts);
 *
 *     // optional callback that gets fired when initial connection completed
 *     var uri = 'mongodb://nonexistent.domain:27000';
 *     mongoose.connect(uri, function(error) {
 *       // if error is truthy, the initial connection failed.
 *     })
 *
 * @param {String} uri(s)
 * @param {Object} [options]
 * @param {Function} [callback]
 * @see Mongoose#createConnection #index_Mongoose-createConnection
 * @api public
 * @return {MongooseThenable} pseudo-promise wrapper around this
 */

Mongoose.prototype.connect = function() {
  var conn = this.connection;
  if (rgxReplSet.test(arguments[0]) || checkReplicaSetInUri(arguments[0])) {
    return new MongooseThenable(this, conn.openSet.apply(conn, arguments));
  }

  return new MongooseThenable(this, conn.open.apply(conn, arguments));
};

/**
 * Disconnects all connections.
 *
 * @param {Function} [fn] called after all connection close.
 * @return {MongooseThenable} pseudo-promise wrapper around this
 * @api public
 */

Mongoose.prototype.disconnect = function(fn) {
  var error;
  this.connections.forEach(function(conn) {
    conn.close(function(err) {
      if (error) {
        return;
      }
      if (err) {
        error = err;
      }
    });
  });

  var Promise = PromiseProvider.get();
  return new MongooseThenable(this, new Promise.ES6(function(resolve, reject) {
    fn && fn(error);
    if (error) {
      reject(error);
      return;
    }
    resolve();
  }));
};

/**
 * Defines a model or retrieves it.
 *
 * Models defined on the `mongoose` instance are available to all connection created by the same `mongoose` instance.
 *
 * ####Example:
 *
 *     var mongoose = require('mongoose');
 *
 *     // define an Actor model with this mongoose instance
 *     mongoose.model('Actor', new Schema({ name: String }));
 *
 *     // create a new connection
 *     var conn = mongoose.createConnection(..);
 *
 *     // retrieve the Actor model
 *     var Actor = conn.model('Actor');
 *
 * _When no `collection` argument is passed, Mongoose produces a collection name by passing the model `name` to the [utils.toCollectionName](#utils_exports.toCollectionName) method. This method pluralizes the name. If you don't like this behavior, either pass a collection name or set your schemas collection name option._
 *
 * ####Example:
 *
 *     var schema = new Schema({ name: String }, { collection: 'actor' });
 *
 *     // or
 *
 *     schema.set('collection', 'actor');
 *
 *     // or
 *
 *     var collectionName = 'actor'
 *     var M = mongoose.model('Actor', schema, collectionName)
 *
 * @param {String} name model name
 * @param {Schema} [schema]
 * @param {String} [collection] name (optional, induced from model name)
 * @param {Boolean} [skipInit] whether to skip initialization (defaults to false)
 * @api public
 */

Mongoose.prototype.model = function(name, schema, collection, skipInit) {
  if (typeof schema === 'string') {
    collection = schema;
    schema = false;
  }

  if (utils.isObject(schema) && !(schema.instanceOfSchema)) {
    schema = new Schema(schema);
  }

  if (typeof collection === 'boolean') {
    skipInit = collection;
    collection = null;
  }

  // handle internal options from connection.model()
  var options;
  if (skipInit && utils.isObject(skipInit)) {
    options = skipInit;
    skipInit = true;
  } else {
    options = {};
  }

  // look up schema for the collection.
  if (!this.modelSchemas[name]) {
    if (schema) {
      // cache it so we only apply plugins once
      this.modelSchemas[name] = schema;
      this._applyPlugins(schema);
    } else {
      throw new mongoose.Error.MissingSchemaError(name);
    }
  }

  var model;
  var sub;

  // connection.model() may be passing a different schema for
  // an existing model name. in this case don't read from cache.
  if (this.models[name] && options.cache !== false) {
    if (schema && schema.instanceOfSchema && schema !== this.models[name].schema) {
      throw new mongoose.Error.OverwriteModelError(name);
    }

    if (collection) {
      // subclass current model with alternate collection
      model = this.models[name];
      schema = model.prototype.schema;
      sub = model.__subclass(this.connection, schema, collection);
      // do not cache the sub model
      return sub;
    }

    return this.models[name];
  }

  // ensure a schema exists
  if (!schema) {
    schema = this.modelSchemas[name];
    if (!schema) {
      throw new mongoose.Error.MissingSchemaError(name);
    }
  }

  // Apply relevant "global" options to the schema
  if (!('pluralization' in schema.options)) schema.options.pluralization = this.options.pluralization;


  if (!collection) {
    collection = schema.get('collection') || format(name, schema.options);
  }

  var connection = options.connection || this.connection;
  model = Model.compile(name, schema, collection, connection, this);

  if (!skipInit) {
    model.init();
  }

  if (options.cache === false) {
    return model;
  }

  this.models[name] = model;
  return this.models[name];
};

/**
 * Returns an array of model names created on this instance of Mongoose.
 *
 * ####Note:
 *
 * _Does not include names of models created using `connection.model()`._
 *
 * @api public
 * @return {Array}
 */

Mongoose.prototype.modelNames = function() {
  var names = Object.keys(this.models);
  return names;
};

/**
 * Applies global plugins to `schema`.
 *
 * @param {Schema} schema
 * @api private
 */

Mongoose.prototype._applyPlugins = function(schema) {
  for (var i = 0, l = this.plugins.length; i < l; i++) {
    schema.plugin(this.plugins[i][0], this.plugins[i][1]);
  }
};

/**
 * Declares a global plugin executed on all Schemas.
 *
 * Equivalent to calling `.plugin(fn)` on each Schema you create.
 *
 * @param {Function} fn plugin callback
 * @param {Object} [opts] optional options
 * @return {Mongoose} this
 * @see plugins ./plugins.html
 * @api public
 */

Mongoose.prototype.plugin = function(fn, opts) {
  this.plugins.push([fn, opts]);
  return this;
};

/**
 * The default connection of the mongoose module.
 *
 * ####Example:
 *
 *     var mongoose = require('mongoose');
 *     mongoose.connect(...);
 *     mongoose.connection.on('error', cb);
 *
 * This is the connection used by default for every model created using [mongoose.model](#index_Mongoose-model).
 *
 * @property connection
 * @return {Connection}
 * @api public
 */

Mongoose.prototype.__defineGetter__('connection', function() {
  return this.connections[0];
});

/*!
 * Driver depentend APIs
 */

var driver = global.MONGOOSE_DRIVER_PATH || './drivers/node-mongodb-native';

/*!
 * Connection
 */

var Connection = require(driver + '/connection');

/*!
 * Collection
 */

var Collection = require(driver + '/collection');

/**
 * The Mongoose Aggregate constructor
 *
 * @method Aggregate
 * @api public
 */

Mongoose.prototype.Aggregate = Aggregate;

/**
 * The Mongoose Collection constructor
 *
 * @method Collection
 * @api public
 */

Mongoose.prototype.Collection = Collection;

/**
 * The Mongoose [Connection](#connection_Connection) constructor
 *
 * @method Connection
 * @api public
 */

Mongoose.prototype.Connection = Connection;

/**
 * The Mongoose version
 *
 * @property version
 * @api public
 */

Mongoose.prototype.version = pkg.version;

/**
 * The Mongoose constructor
 *
 * The exports of the mongoose module is an instance of this class.
 *
 * ####Example:
 *
 *     var mongoose = require('mongoose');
 *     var mongoose2 = new mongoose.Mongoose();
 *
 * @method Mongoose
 * @api public
 */

Mongoose.prototype.Mongoose = Mongoose;

/**
 * The Mongoose [Schema](#schema_Schema) constructor
 *
 * ####Example:
 *
 *     var mongoose = require('mongoose');
 *     var Schema = mongoose.Schema;
 *     var CatSchema = new Schema(..);
 *
 * @method Schema
 * @api public
 */

Mongoose.prototype.Schema = Schema;

/**
 * The Mongoose [SchemaType](#schematype_SchemaType) constructor
 *
 * @method SchemaType
 * @api public
 */

Mongoose.prototype.SchemaType = SchemaType;

/**
 * The various Mongoose SchemaTypes.
 *
 * ####Note:
 *
 * _Alias of mongoose.Schema.Types for backwards compatibility._
 *
 * @property SchemaTypes
 * @see Schema.SchemaTypes #schema_Schema.Types
 * @api public
 */

Mongoose.prototype.SchemaTypes = Schema.Types;

/**
 * The Mongoose [VirtualType](#virtualtype_VirtualType) constructor
 *
 * @method VirtualType
 * @api public
 */

Mongoose.prototype.VirtualType = VirtualType;

/**
 * The various Mongoose Types.
 *
 * ####Example:
 *
 *     var mongoose = require('mongoose');
 *     var array = mongoose.Types.Array;
 *
 * ####Types:
 *
 * - [ObjectId](#types-objectid-js)
 * - [Buffer](#types-buffer-js)
 * - [SubDocument](#types-embedded-js)
 * - [Array](#types-array-js)
 * - [DocumentArray](#types-documentarray-js)
 *
 * Using this exposed access to the `ObjectId` type, we can construct ids on demand.
 *
 *     var ObjectId = mongoose.Types.ObjectId;
 *     var id1 = new ObjectId;
 *
 * @property Types
 * @api public
 */

Mongoose.prototype.Types = Types;

/**
 * The Mongoose [Query](#query_Query) constructor.
 *
 * @method Query
 * @api public
 */

Mongoose.prototype.Query = Query;

/**
 * The Mongoose [Promise](#promise_Promise) constructor.
 *
 * @method Promise
 * @api public
 */

Object.defineProperty(Mongoose.prototype, 'Promise', {
  get: function() {
    return PromiseProvider.get();
  },
  set: function(lib) {
    PromiseProvider.set(lib);
  }
});

/**
 * Storage layer for mongoose promises
 *
 * @method PromiseProvider
 * @api public
 */

Mongoose.prototype.PromiseProvider = PromiseProvider;

/**
 * The Mongoose [Model](#model_Model) constructor.
 *
 * @method Model
 * @api public
 */

Mongoose.prototype.Model = Model;

/**
 * The Mongoose [Document](#document-js) constructor.
 *
 * @method Document
 * @api public
 */

Mongoose.prototype.Document = Document;

/**
 * The Mongoose DocumentProvider constructor.
 *
 * @method DocumentProvider
 * @api public
 */

Mongoose.prototype.DocumentProvider = require('./document_provider');

/**
 * The [MongooseError](#error_MongooseError) constructor.
 *
 * @method Error
 * @api public
 */

Mongoose.prototype.Error = require('./error');

/**
 * The Mongoose CastError constructor
 *
 * @method Error
 * @api public
 */

Mongoose.prototype.CastError = require('./error/cast');

/**
 * The [node-mongodb-native](https://github.com/mongodb/node-mongodb-native) driver Mongoose uses.
 *
 * @property mongo
 * @api public
 */

Mongoose.prototype.mongo = require('mongodb');

/**
 * The [mquery](https://github.com/aheckmann/mquery) query builder Mongoose uses.
 *
 * @property mquery
 * @api public
 */

Mongoose.prototype.mquery = require('mquery');

/*!
 * The exports object is an instance of Mongoose.
 *
 * @api public
 */

var mongoose = module.exports = exports = new Mongoose;
