functions selling any item at a fix price

[mubarak23]

PR for issue: #83

The function implements a Cairo contract named StrategySaleAnyItemAtFixedPrice This contract manages the sale of items (identified by token_id) at a fixed price, with specific features such as setting prices, handling bids, and upgrading the contract.

Key functionalities:

1. Initialization (constructor):

   • Initializes the contract with the owner's address and a protocol fee.

2. Updating Protocol Fee (update_protocol_fee):

   • Allows the owner to update the protocol fee, which is the fee applied to transactions.

3. Getting Protocol Fee (protocol_fee):

   • Retrieves the current protocol fee.

4. Setting an Item for Sale (set_item_sale):

   • Allows the owner of a specific token_id to list it for sale. It checks if the caller is the token owner and emits an event once the item is listed.

5. Setting Price for an Item (set_price_for_item):

   • Allows a buyer to set a price for a listed item. It verifies that the buyer is not the token owner, checks if the bid price is different from any existing bids by the buyer, and then records the bid, emitting an event for the action.

6. Executing Buyer Bids (can_execute_buyer_bid):

   • Checks if a buyer's bid can be executed. It verifies that the token has been listed by the seller and compares the buyer's bid price against the existing bid to determine if the bid is executable.

7. Contract Upgrading (upgrade):

   • Allows the contract owner to upgrade the contract implementation using a new ClassHash, ensuring only the owner can perform this action.

Events:

• ItemForSaleAdded: Emitted when a new item is listed for sale.
• SetPriceForItemByBuyer: Emitted when a buyer sets a price for a listed item.

This contract integrates with StarkNet's components for ownership (OwnableComponent) and upgradability (UpgradeableComponent), ensuring that only authorized users can perform sensitive operations like updating the protocol fee and upgrading the contract.

[mubarak23]

@0xandee This PR is available for Review

[0xandee]

Can you adding comments or quick docs so I can have better understanding how it works @mubarak23

[mubarak23]

sure, i will add it

[mubarak23]

Can you adding comments or quick docs so I can have better understanding how it works @mubarak23

i added description on how the contract work