fixes

[nahss]

Hey skaunov, lovely submission I went through your dapp and noticed a few issues and optimizations. Below are some of the changes I made:

Key Concepts and Components:

LockObject Struct:

This is the core structure representing the HTLC. It includes fields like the creation timestamp, deadline, hashed secret, refund and target addresses, and the coin being locked.

Events:

The module defines several events to signal state changes in the HTLC:

• NewLockEvent: Emitted when a new lock is created.
• LockClaimedEvent: Emitted when a lock is redeemed using the correct secret.
• LockRefundedEvent: Emitted when a lock is refunded after the deadline.

Error Codes:

Constants to represent various error conditions:

• ESecretPreimageWrong: Thrown when the provided secret does not match the hashed value.
• ESecretLengthWrong: Thrown when the length of the provided secret is incorrect.
• ERefund3rdParty: Thrown when a third party tries to refund the lock.
• ERefundEarly: Thrown when a refund is attempted before the deadline.

Functions:

• create_lock_object: Creates a new HTLC with a specified duration.
• create_lock_object_48: Convenience function to create an HTLC with a default duration of 48 hours.
• create_lock_object_24: Convenience function to create an HTLC with a default duration of 24 hours.
• redeem: Redeems the locked coin by providing the correct secret.
• refund: Refunds the locked coin after the deadline, ensuring only authorized addresses can perform the refund.

Summary of Improvements:

Detailed Documentation:

Enhanced comments and documentation for structs, functions, and events.

Convenience Functions:

Added functions for creating locks with default durations.

Error Handling:

Clearer and more descriptive error handling.

Events:

Detailed event structures to capture important actions and state changes.