State-transition Diagram

The pottery items in the online store will have different states depending on where they are in the customer's purchasing and pick-up process. The states are 'For Sale', 'Pending', 'Sold', and 'Available Upon Request'. A state-transition diagram to show the inputs/actions that cause these state changes based on the following information:

• 'Available Upon Request' means that the item is not for sale, but if a customer requests, the artist can make a similar item for them.
• Whether an item is listed as 'For Sale' or 'Available Upon Request' is up to the artist, and they can change their mind at any time.
• When a customer purchases a 'For Sale' item online and pays with their credit card, that item is considered 'Sold'.
• When a customer would rather pay in person at the store, the item is listed as 'Pending' until payment is received. If the item isn't picked up within 3 days, the item goes back for sale.
• The store accepts returns for online purchases and could then list them for sale again.