Create Soroban coupon_nft.rs contract for NFT coupon emission and redemption

[Josue19-08]

➡️ Title

Create Soroban coupon_nft.rs contract for NFT coupon emission and redemption

📘 Description

Develop a smart contract in Soroban that allows minting unique NFTs as utility coupons when a user purchases project tokens. The contract must guarantee immutable conditions for expiration, uniqueness, and secure redemption.

Context: Every time a user purchases a participation token, an NFT coupon is automatically generated that can be redeemed at allied tourism companies. This contract ensures that usage rules cannot be manipulated.

✅ Acceptance Criteria

Contract structure

• Create file contracts/contracts/coupon-nft/src/lib.rs
• Create file contracts/contracts/coupon-nft/src/contract.rs
• Create file contracts/contracts/coupon-nft/src/storage.rs
• Create file contracts/contracts/coupon-nft/src/events.rs
• Create file contracts/contracts/coupon-nft/src/types.rs
• Create file contracts/contracts/coupon-nft/Cargo.toml

Main contract functions

• mint_coupon(env, owner, metadata_uri, expiration_date): Mints unique NFT with initial owner
• redeem_coupon(env, token_id, redeemer): Marks coupon as redeemed or burns it
• is_valid_coupon(env, token_id): Returns coupon status (valid/redeemed/expired)
• get_coupon_metadata(env, token_id): Gets metadata URI of the coupon
• get_coupon_owner(env, token_id): Returns current NFT owner

Validation logic

• Verify that only the owner can redeem their coupon
• Prevent double redemption of the same token_id
• Validate expiration date before allowing redemption
• Emit events for mint and redemption

Data structure

• DataKey::TokenCounter: Incremental counter for unique IDs
• DataKey::TokenOwner(token_id): Mapping token_id → owner
• DataKey::TokenMetadata(token_id): IPFS metadata URI
• DataKey::TokenExpiration(token_id): Expiration date
• DataKey::TokenRedeemed(token_id): Redemption status

Testing

• Create tests in contracts/contracts/coupon-nft/src/test.rs
• Test successful coupon minting
• Test valid redemption
• Test expired redemption should fail
• Test double redemption should fail
• Test redemption by unauthorized user should fail

Documentation

• Create contracts/contracts/coupon-nft/src/coupon-nft.md explaining:
  • Contract purpose
  • Minting and redemption flow
  • Expiration handling
  • Events emitted

⚠ Use kebab-case for all file and folder names.
⚠ Do not use default alias imports or relative paths like ../../components/foo.
⚠ Use alias paths with @, e.g. @/components/foo.
⚠ Structure the code with reusable components and reuse existing ones.

[JosueBrenes]

Hi, can i work in this issue? please