Contract 6: ChainLink Functions to fetch RW Data

function requestFitnessData(uint256 tokenId) external {
    require(block.timestamp >= lastUpdateTime[tokenId] + 1 hours, "Update too frequent");
    
    // In production, this would make a Chainlink Functions request
    // to fetch data from fitness APIs like Fitbit, Apple Health, etc.
    
    bytes32 requestId = keccak256(abi.encodePacked(tokenId, block.timestamp));
    requestToTokenId[requestId] = tokenId;
    
    emit OracleRequest(requestId, tokenId, "fitness");
}

What's happening here?

• Prevents spam by limiting updates to once per hour

• In real implementation, would call external APIs (Fitbit, Apple Health)

• Creates unique request ID and emits event for off-chain oracle to process

function fulfillFitnessData(bytes32 requestId, uint256 steps) external onlyRole(ORACLE_ROLE) {
    uint256 tokenId = requestToTokenId[requestId];
    gameEngine.updateSteps(tokenId, steps);
    lastUpdateTime[tokenId] = block.timestamp;
    
    emit OracleResponse(requestId, tokenId, abi.encode(steps));
}

What's happening here?

• Oracle calls this function with real-world data

• Updates the game with actual step count

• Records timestamp to enforce rate limiting