var MongoClient = require('mongodb').MongoClient;
var ObjectID = require('mongodb').ObjectID;


module.exports = function (config) {

	function getMongoContent(options, callback) {
		config.debug && console.log('getMongoContent options', options);
		MongoClient.connect(config.mongo.server, config.mongo.options, function (err, db) {
			if (err) {
				config.debug && console.log('ERR1 getMongoContent',err);
				return callback(err);
			}
			db.collection(options.collection, function (err, col) {
				if (err) {
					config.debug && console.log('ERR2 getMongoContent',err);
					return callback(err);
				}
				if (options.query._id && !(options.query._id instanceof Object)) {
					options.query._id = new ObjectID.createFromHexString(options.query._id);
				}
				col.findOne(options.query, function (err, result) {
					if (err) {
						config.debug && console.log('ERR3 getMongoContent',err);
						return callback(err);
					}
					if (!result) {
						return callback(new Error('Data not found ' + options.collection + '/' + JSON.stringify(options.query)));
					}
					return callback(null, result, col);
				});
			});
		});
	}

	function getMongoAttribute(options, callback) {
		config.debug && console.log('getMongoAttribute options', options);
		return getMongoContent(options, function (err, result) {
			if (err) {
				config.errors && console.log('ERR1 getMongoAttribute',err);
				return callback(err);
			}
			var attribute_options = null;
				config.debug && console.log('getMongoAttribute result', result);
			if (result && result.hasOwnProperty(options.attribute)) {
				attribute_options = {
					collection: options.collection,
					query: {_id: result[options.attribute].guid}
				};
				config.debug && console.log('getMongoAttribute attribute_options', attribute_options);

				return getMongoContent(attribute_options, function (err, attribute_result) {
					if (err) {
						config.errors && console.log('ERR2 getMongoAttribute',err);
						return callback(err);
					}
					config.debug && console.log('getMongoAttribute attribute_result', attribute_result);
					return callback(err, attribute_result);
				});
			} else {
				config.debug && console.log('getMongoAttribute try direct lookup');
				attribute_options = {
					collection: options.collection,
					query: {
						parent: result._id,
						name: result.name+'.'+options.attribute
					}
				};
				config.debug && console.log('getMongoAttribute attribute_options', attribute_options);

				return getMongoContent(attribute_options, function (err, attribute_result) {
					if (err) {
						config.errors && console.log('ERR3 getMongoAttribute',err);
						return callback(err);
					}
					if (attribute_result) {
						config.debug && console.log('getMongoAttribute direct attribute_result', attribute_result);
						return callback(err, attribute_result);
					} else {
						if (options.type) {
							if (options.type == 'json') {
								config.errors && console.log('ERR4 getMongoAttribute empty json {}');

								return callback(null, '{}');
							}
							if (options.type == 'text') {
								config.errors && console.log('ERR5 getMongoAttribute empty string');
								return callback(null, '');
							}
						}
						return callback(new Error('Data not found ' + options.collection + '/' + JSON.stringify(options.query) + '.' + options.attribute));
					}
				});

			}
		})
	}
	function saveData(collection, data, callback) {
		if (data._id && !(data._id instanceof Object)) {
			data._id = new ObjectID.createFromHexString(data._id);
		}
		config.debug && console.log('saving', data._id);
		collection.save(data, {safe:true}, callback);
	}

	function setMongoContent(data, options, callback) {
		config.debug && console.log('setMongoContent options', options);
		MongoClient.connect(config.mongo.server, config.mongo.options,  function (err, db) {
			if (err) {
				config.errors && console.log('ERR1 setMongoContent',err);
				return callback(err);
			}
			db.collection(options.collection, function (err, col) {
				if (err) {
					config.errors && console.log('ERR2 setMongoContent',err);
					return callback(err);
				}
				if (options.operation) {
					data.version = options.operation.v;
				}
				if (!data._id) {
					config.debug && console.log('setMongoContent lookup by query',options.query);
					col.findOne(options.query, function (err, result) {
						if (result){
							data._id=result._id;
						}
						return saveData(col, data, callback);
					})
				} else {
					return saveData(col, data, callback);
				}
			});
		});
	}

	function setMongoAttribute(data, options, callback) {
		config.debug && console.log('setMongoAttribute options', options);
		getMongoContent(options, function (err, result, col) {
			if (err) {
				config.errors && console.log('ERR1 setMongoAttribute',err);
				return callback(err);
			}
			var attribute_options = {
				collection: options.collection
			};
			if (result.hasOwnProperty(options.attribute)) {
				config.debug && console.log('getMongoAttribute parent found, get child and save');
				attribute_options.query = {_id: result[options.attribute].guid};
				getMongoContent(attribute_options, function (err, attribute_result, col) {
					if (err) {
						config.errors && console.log('ERR2 setMongoAttribute',err);
						return callback(err);
					}
					attribute_result[options.attribute] = data;
					if (options.operation) {
						attribute_result.version = options.operation.v;
					}
					attribute_result.parent = result._id;
					return saveData(col, attribute_result, callback);
				});
			} else {
				config.debug && console.log('getMongoAttribute try direct lookup');
				attribute_options = {
					collection: options.collection,
					query: {
						parent: result._id,
						name: result.name+'.'+options.attribute
					}
				};
				config.debug && console.log('getMongoAttribute attribute_options', attribute_options);
				return getMongoContent(attribute_options, function (err, attribute_result) {
					if (attribute_result) {
						config.debug && console.log('getMongoAttribute found lost attribute, reconnect');
						result[options.attribute] = { guid: attribute_result._id };
						return saveData(col, result, callback);

					} else {
						config.debug && console.log('getMongoAttribute field does not exist yet. need to create doc first.');
						var attribute_data = {
							name: result.name + '.' + options.attribute,
							parent: result._id
						};
						attribute_data[options.attribute] = data;
						if (options.operation) {
							attribute_data.version = options.operation.v;
						}

						return saveData(col, attribute_data, function (err, attribute_result) {
							if(err){
								config.errors && console.log('ERR3 setMongoAttribute',err);
							}
							result[options.attribute] = { guid: attribute_result._id };
							return saveData(col, result, callback);
						})
					}
				});
			}
		})
	}

	return {
		getMongoAttribute: getMongoAttribute,
		getMongoContent: getMongoContent,
		setMongoAttribute: setMongoAttribute,
		setMongoContent: setMongoContent
	};
};