epdb.js

var MongoClient = require('mongodb').MongoClient; // Driver for connecting to MongoDB
var ObjectID =require('mongodb').ObjectID;
var async = require("async");

var dbConn;

//TODO
//var nconf = require('nconf');

MongoClient.connect('mongodb://localhost:40000/eposro', function(err, db) {
	if(!err){
		dbConn = db;
		console.log("Connected Successfully");
	}
    else{
        console.log(err);        
    }
});  

exports.saveProduct = function(product, cb){
	var pcollection = dbConn.collection('products');
	var idcollection=dbConn.collection('IDs');

	if(product._id===undefined)//read id from database
	{
        var query ={};
        var sort =[];
        var operator ={$inc:{"last_pdt_id":1}};
        var options ={new:true};
        idcollection.findAndModify(query,sort,operator,options,
        			function(err,doc){
        				if(!err)
        				{
        					id=doc.last_pdt_id;
							product._id=id;
							insert_product_internal(pcollection,product,cb);
        					
        				}
        				else
        				{
        					console.log(err);
        				}
        			});
	}
	else//directly insert the product
	{
		insert_product_internal(pcollection,product,cb);
	}
};

function insert_product_internal(collection,product,cb){
	collection.insert(product,function(err,result){
		if(!err){				
			cb(null,result);
			}
		else{console.log(err);}
		});
}


exports.findCategoryId =function(cat,cb){
	var category = dbConn.collection('category');
	category.findOne({"name":cat},function(err,result){
		if(!err){	
			var cids=[];
			if(result._id!=0){
				cids.unshift(result._id);
				category.findOne({_id:result.parent_id},function(err,res){
					if(!err){
						if(res._id!=0){
							cids.unshift(res._id);
							category.findOne({_id:res.parent_id},function(err,fres){
								if(!err){
									if(fres._id!=0){
										cids.unshift(fres._id);
										cb(null,cids);
										return;
									}
									else{
										cb(null,cids);
										return;
									}
								}
							});
						}
						else{
							cb(null,cids);
							return;
						}
					}
				});
			}
			else{
				cb(null,cids);
				return;
			}
		}
		else{
			console.log(err);
		}
	});
};

exports.findCityId = function(city,cb){
	var cities= dbConn.collection('cities');
	cities.findOne({"city":city.toLowerCase()},function(err,result){
		if(!err){
			cb(null,result._id);
		}
		else{
			console.log(err);
		}
	});
};

exports.getLastPdtId= function(cb){
	var IDs = dbConn.collection('IDs');
	IDs.findOne(function(err,res){
		if(!err){
			cb(null,res.last_pdt_id);
		}else{console.log(err);}
	});
};

exports.getProductVars = function(pname,brand,cb){
	var pcollection = dbConn.collection('products');
	pcollection.find({"pname":pname,"brand":brand}).toArray(function(err,result){
		if(!err){
			//build a pseudo product
			var vars=[];
			for(var i=0;i<result.length;i++){
				var product ={};
				product.vid = result[i]._id;
				product.vname = result[i].pname;
				product.facets =result[i].facets;
				vars.push(product);
			}
			cb(null,vars);
		}
		else{console.log(err);}
	});
};

exports.getRelatedPdts = function(last_pdt_id,cb){
	var pcollection = dbConn.collection('products');
	//generate random 2 products
	var rand = Math.floor(Math.random()*last_pdt_id),srand;
	var relPdts=[];
	pcollection.findOne({_id:rand},function(err,result){
		if(!err){
			if(result!=null){
			var pdt={};
			pdt.id=result._id;
			pdt.pname=result.pname;
			pdt.img=result.img;
			relPdts.push(pdt);
			}
			srand = Math.floor(Math.random()*last_pdt_id);
			pcollection.findOne({_id:srand},function(err,result){
			if(!err){
				if(result!=null){
					pdt={};
					pdt.id=result._id;
					pdt.pname=result.pname;
					pdt.img=result.img;
					relPdts.push(pdt);
					}
				cb(null,relPdts);
				}
				else{console.log(err);}
				});
		}else{console.log(err);}
	});
};

exports.writeLastPdtId = function(last_id,cb){
	var IDs = dbConn.collection('IDs');
	IDs.findOne(function(err,res){
		if(!err){
			IDs.update({_id:res._id},{ $set: { "last_pdt_id":last_id}},function(err,res){
				if(!err){
					cb(null,res);
				}
				else{console.log(err);}
			});
		}
		else{console.log(err);}
	});
};

exports.getCategories =function(id,cb){
	var category=dbConn.collection("category");
	category.find({parent_id:parseInt(id)}).toArray(function(err,res){
		if(!err){
			var cats =[];
			for(var i=0;i<res.length;i++){
				cats.push({
					catID:res[i]._id,
					title:res[i].name
				});
			}
			cb(cats);
		}
	});
};

exports.checkForProduct = function(gtin,cb){
	
	var products = dbConn.collection("products");
	products.find({"gtin":gtin}).toArray(function(err,res){
		if(!err){
			if(res.length==0){
				cb(null,0);
			}
			else{
				cb(null,1);
			}
		}
		else{
			console.log(err);
		}
	});
};

exports.updateProdVars =function(vars,product,cb){
	var products=dbConn.collection("products");
	var variant={};
	variant.vid = product._id;
	variant.vname = product.pname;
	variant.facets =product.facets;
	var count=0;
	if(JSON.stringify(vars)!="[]"){
		for(var i=0;i<vars.length;i++){
		products.update({_id:vars[i].vid},{$push:{"vars":variant}},function(err,res){	
			if(!err){
				console.log("Variant "+i);
				count++;
				if(count==vars.length){
					cb(null,1);
				}
			else{
				console.log(err);
				}
			}
		});
	 	}
	}
	else{
		cb(null,0);
	}
};
exports.addToCart = function(userId,pid,current_city,cb)
{
	var cart={};
	var users = dbConn.collection("users");
	var products = dbConn.collection("products");
	var cities = dbConn.collection("cities");

	async.waterfall([
	//functions to be executed in order
	function(callback){//find the user with the user id
		var users = dbConn.collection("users");
		users.findOne({_id:userId,cart:{$exists:true}},function(err,res){
			if(!err){
				callback(null,res);
			}
		});
	},
	function(user,callback){
		if(user!=undefined){//cart field exits
			var flag=0,price=0;
			user.cart.products.forEach(function(product){
				if(product.pid==pid){
					flag=1;
					price=product.price;
					return;
				}
			});
			callback(null,flag,price);
		}
		else{
			//create the cart subdocument and add product
			cart.products=[];
			cart.estimated_cost=0;
			users.update({_id:userId},{$set:{"cart":cart}},function(err,res){
				if(!err){
					callback(null,0,null);
					return;
				}
				else{
					console.log(err);
				}
			});
		}
	},function(flag,price){
		if(flag==1){
			users.update({_id:userId,"cart.products.pid":pid},{$inc:{"cart.products.$.count":1,"cart.estimated_cost":parseInt(price)}},function(err,res){
					
					if(!err){
						cb("product Incremented");
						return;
					}
					else{
						console.log(err);
						return;
					}
			});
		}
		else{
			//create product
			var prod ={};
			prod.pid =pid;
			cities.findOne({city:current_city},function(err,res){
				if(!err){
					var city_id=res._id;
					products.findOne({_id:pid,"price.mrp.city":city_id},{"price.mrp.$":1,"pname":1},function(err,res){
						if(!err){
							if(res!=null){
								prod.name=res.pname;
								prod.price=res.price.mrp[0].mrp;//add this product to the database now
								prod.count=1;
								users.update({_id:userId},{$push:{"cart.products":prod},$inc:{"cart.estimated_cost":parseInt(prod.price)}},function(err,res){
								if(!err){
									cb("Product Added successfully");
									return;
									}
								else{
									console.log(err);
									return;
									}
								});
							}
							else{
								cb("No Product Exists");
								return;
							}
						}
					});
				}
			});
		}
	}
	],function(err,res){
	if(!err){
		console.log("All the functions executed properly");
	}
});
};

exports.removeFromCart=function(userId,pid,cb){
	//decrement count of the product from cart
	var users =dbConn.collection("users");
	var products=dbConn.collection("products");
	users.findOne({_id:userId,"cart.products.pid":pid},{"cart.products":1},function(err,res){
		if(!err){
			//search the products with given pid
			if(res==null){
				cb("Product does not exist in cart");
				return;
			}
			var price,count,total_prod=res.cart.products.length;
			for(var i=0;i<total_prod;i++){
				if(res.cart.products[i].pid===pid){
					price = res.cart.products[i].price;
					count = res.cart.products[i].count;
					break;
				}
			}
			if(count!=1){
				users.update({_id:userId,"cart.products.pid":pid},{$inc:{"cart.estimated_cost":-parseInt(price),"cart.products.$.count":-1}},function(err,res){
					if(!err){
							cb("Product Count decremented");
							return;
					}
					else{
							console.log(err);
							return;
					}
				});
			}
			else{
				users.update({_id:userId},{$pull:{"cart.products":{"pid":pid}},$inc:{"cart.estimated_cost":-parseInt(price)}},function(err,res){
					if(!err){
							if(total_prod==1){
								users.update({_id:userId},{$unset:{cart:true}},function(err,res){
									if(!err){
										cb("cart removed from user "+ userId);
										return;
									}
									else{
										console.log(err);
									}
								});
							}
							else{
								
								cb("product removed from cart");
								return;
							}
					}
					else{
							console.log(err);
					}
				});
			}
		}
	});
};

exports.checkOut = function(userId,cb){
	//read the last order id used from IDs collection
	var IDs = dbConn.collection('IDs');
	var orders =dbConn.collection('orders');
	var users=dbConn.collection("users");
	async.waterfall([
		function(callback){
			IDs.findOne({},function(err,res){
				if(!err){
					callback(null,res.last_order_id);
					return;
				}
				else{
					console.log(err);
					return;
				}
			});
		},
		function(last_order_id,callback){
			if(last_order_id!=null){
				users.findOne({_id:userId},function(err,res){
				if(!err){
					callback(null,last_order_id,res);
					return;
				}
				});
			}
		},
		function(last_order_id,user,callback){
			//create order
			if(user!=null){
				var order={};
				order._id=++last_order_id;
				order.ordered_by=userId;
				order.vendors_serving=[];
				order.selected_vendors=[];
				order.items=user.cart.products;
				order.estimated_cost=user.cart.estimated_cost;
				order.processing_status=0;
				if(user.cart.order_mode!=undefined){
					order.order_mode=user.cart.order_mode;
				}
				else{
					order.order_mode=user.default_delivery_preference;
				}
				//write this to order collection
				orders.insert(order,function(err,res){
					if(!err){
						//update last order_id
						IDs.update({},{$set:{"last_order_id":last_order_id}},function(err,res){
							if(!err){
							//update the user collection to contain that order id
								callback(null,order._id);
								return;
							}
						});
					}
				});
			}
		},
		function(current_order,callback){
			if(current_order!=null){
				users.update({_id:userId},{$push:{orderIDs:current_order},$unset:{cart:true}},function(err,res){
				if(!err){
					cb("Successfully added the order "+current_order);
					return;
				}
				else{
					console.log(err);
					return;
				}
				});
			}
		}
		],function(err,result){
		if(!err){
			console.log("All functions are executed");
			return;
		}
	});
};

exports.fetchCart = function(userId,cb){
	var users = dbConn.collection("users");
	users.findOne({_id:userId},function(err,res){
		if(!err){
			if(res.cart!=undefined){
				console.log("Sending response in epdb as :"+res);
				cb(res.cart);
			    return;
			}
			else{
				res = null;
				console.log("Sending resp in epdb as : "+res);
				cb(res);
				return;
			}
		}
		else{
			console.log(err);
		}
	});
};
exports.saveBrand=function(cbrand,cgln,cb){
	var brands=dbConn.collection("brands");
	brands.insert({brand:cbrand,gln:cgln},function(err,res){
		if(!err){
			console.log("Added brand");
			cb(null,res);
			return;
		}
	});
};
exports.clearCollections = function(table,cb){
	setTimeout(function(){
		var coll = dbConn.collection(table);
		coll.remove({});
		cb();
	},5000);
	
	
}