This is a node and mongo based rest application that has exposed crud operations for items, inventories and orders.
items are the food products
inventory is the quantity available for the items
orders contains items and their quantities

Node (https://nodejs.org/en/download/)
MongoDB (https://docs.mongodb.com/manual/installation/)

starts mongodb server -> mongo_db_path\bin\mongod
installs all node dependencies -> npm install
starts the node server and hosts the API -> node ./bin/www
All the APIs are listed in orders.api.json (it can be imported into postman)

3 collections - items, inventory, orders
items document = ["name", "type", "course", "price"]
inventory document = ["itemId", "itemName", "quantity"]
order document = [items : ["itemId", "itemName", "quantity"]]

4 modules - config, items, inventory, orders

GET /config/reload : api takes care of collection creation and filling up the items table via csv

GET /items : gets all items
GET /item/:itemId : gets an item by id
PUT /item/:itemId {} : replaces an item based on id
DELETE /item/:itemId : deletes an item by id
POST /item {}: creates a new item
POST /item/query {} : search for specific items, sort on keys, paginated results

GET /inventory : gets all inventories
GET /inventory/:inventoryId : gets an inventory by id
DELETE /inventory/:inventoryId : deletes an inventoryId by id
POST /inventory {}: creates a new inventory

GET /orders : gets all orders
GET /orders/:orderId : gets an order by id
DELETE /orders/:orderId : deletes an orderId by id
POST /orders {}: creates a new order

User can query the items to find the items of their choice.
User can place order for multiple items along with its quantities.
When user places an order, if inventory is available for the items, inventory of these items is decreased by the quantity in the order.
If atleast one item does not have sufficent inventory, then the items in the order that are already processed are reverted by adding back the item quantity to the inventory.
The user is notified which item was out of stock.
Otherwise, user is notified that order is placed.

For loops could be replaced with workers
Validations on the APIs \ save failed orders \ ability to store historical data
mongoose?
add users \ simple UI