🧞‍♂️ReviewManager.sol

ReviewManager Contract

The ReviewManager contract's primary purpose is to manage the review system, integrate Chainlink oracles for external data fetching, and facilitate interactions with the AdvertisingToken contract to incentivize companies.

Key Functions and Interactions:

1. Review Storage: Stores reviews on-chain, allowing public access and querying.

2. Chainlink Integration: Uses Chainlink oracles to fetch external data, such as additional company information.

3. Incentives with AdvertisingToken: Issues AdvertisingToken to companies as incentives for addressing reviews, manages booking of advertisement slots, and handles token transfers and redemptions.

Detailed Contract Code and Explanation

ReviewManager.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./AdvertisingToken.sol";
import "@chainlink/contracts/src/v0.8/ChainlinkClient.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract ReviewManager is ChainlinkClient, Ownable {
    using Chainlink for Chainlink.Request;

    struct Review {
        address reviewer;
        string content;
        uint256 timestamp;
    }

    mapping(string => Review[]) public reviews;
    AdvertisingToken public token;
    address private oracle;
    bytes32 private jobId;
    uint256 private fee;

    event ReviewAdded(string indexed company, address indexed reviewer, string content, uint256 timestamp);

    constructor(address tokenAddress, address _oracle, string memory _jobId, uint256 _fee, address _link) {
        setChainlinkToken(_link);
        token = AdvertisingToken(tokenAddress);
        oracle = _oracle;
        jobId = stringToBytes32(_jobId);
        fee = _fee;
    }

    function addReview(string memory company, string memory content) public {
        Review memory review = Review({
            reviewer: msg.sender,
            content: content,
            timestamp: block.timestamp
        });

        reviews[company].push(review);
        emit ReviewAdded(company, msg.sender, content, block.timestamp);

        // Mint tokens as incentive
        token.mint(msg.sender, 100 * 10**18); // Mint 100 tokens

        // Call Chainlink to fetch additional data
        requestCompanyInfo(company);
    }

    function getReviews(string memory company) public view returns (Review[] memory) {
        return reviews[company];
    }

    function requestCompanyInfo(string memory company) internal returns (bytes32 requestId) {
        Chainlink.Request memory request = buildChainlinkRequest(jobId, address(this), this.fulfillCompanyInfo.selector);
        request.add("company", company);
        return sendChainlinkRequestTo(oracle, request, fee);
    }

    function fulfillCompanyInfo(bytes32 _requestId, bytes memory _info) public recordChainlinkFulfillment(_requestId) {
        // Handle the external data (e.g., update company info or process further)
    }

    function stringToBytes32(string memory source) internal pure returns (bytes32 result) {
        bytes memory tempEmptyStringTest = bytes(source);
        if (tempEmptyStringTest.length == 0) {
            return 0x0;
        }

        assembly {
            result := mload(add(source, 32))
        }
    }
}

Detailed Explanation

1. Imports

import "./AdvertisingToken.sol";
import "@chainlink/contracts/src/v0.8/ChainlinkClient.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

• AdvertisingToken.sol: Imports the advertising token contract.

• ChainlinkClient.sol: Provides Chainlink client functionality.

• Ownable.sol: Provides ownership functionality.

1. Contract Declaration

contract ReviewManager is ChainlinkClient, Ownable {
    using Chainlink for Chainlink.Request;

• ReviewManager Contract: Inherits from ChainlinkClient and Ownable.

1. Structs and Mappings

    struct Review {
        address reviewer;
        string content;
        uint256 timestamp;
    }

    mapping(string => Review[]) public reviews;

• Review: Struct to store review details.

• reviews: Mapping from company name to an array of reviews.

1. State Variables

    AdvertisingToken public token;
    address private oracle;
    bytes32 private jobId;
    uint256 private fee;

    event ReviewAdded(string indexed company, address indexed reviewer, string content, uint256 timestamp);

• token: Reference to the AdvertisingToken contract.

• oracle, jobId, fee: Variables for Chainlink integration.

• ReviewAdded: Event emitted when a review is added.

1. Constructor

    constructor(address tokenAddress, address _oracle, string memory _jobId, uint256 _fee, address _link) {
        setChainlinkToken(_link);
        token = AdvertisingToken(tokenAddress);
        oracle = _oracle;
        jobId = stringToBytes32(_jobId);
        fee = _fee;
    }

• constructor: Initializes the contract with the token address, oracle address, job ID, fee, and LINK token address.

1. Add Review Function

    function addReview(string memory company, string memory content) public {
        Review memory review = Review({
            reviewer: msg.sender,
            content: content,
            timestamp: block.timestamp
        });

        reviews[company].push(review);
        emit ReviewAdded(company, msg.sender, content, block.timestamp);

        // Mint tokens as incentive
        token.mint(msg.sender, 100 * 10**18); // Mint 100 tokens

        // Call Chainlink to fetch additional data
        requestCompanyInfo(company);
    }

• addReview: Adds a review, emits an event, mints incentive tokens, and requests additional data via Chainlink.

1. Get Reviews Function

    function getReviews(string memory company) public view returns (Review[] memory) {
        return reviews[company];
    }

• getReviews: Returns the reviews for a specified company.

1. Request Company Info Function

    function requestCompanyInfo(string memory company) internal returns (bytes32 requestId) {
        Chainlink.Request memory request = buildChainlinkRequest(jobId, address(this), this.fulfillCompanyInfo.selector);
        request.add("company", company);
        return sendChainlinkRequestTo(oracle, request, fee);
    }

• requestCompanyInfo: Builds and sends a Chainlink request to fetch additional company info.

1. Fulfill Function

    function fulfillCompanyInfo(bytes32 _requestId, bytes memory _info) public recordChainlinkFulfillment(_requestId) {
        // Handle the external data (e.g., update company info or process further)
    }

• fulfillCompanyInfo: Callback function to handle the response from the Chainlink oracle.

1. Helper Function

    function stringToBytes32(string memory source) internal pure returns (bytes32 result) {
        bytes memory tempEmptyStringTest = bytes(source);
        if (tempEmptyStringTest.length == 0) {
            return 0x0;
        }

        assembly {
            result := mload(add(source, 32))
        }
    }
}

• stringToBytes32: Helper function to convert a string to bytes32 format.

Interaction with AdvertisingToken

• Incentives: When a review is added, the ReviewManager contract mints AdvertisingToken to the reviewer.

• Data Fetching: Uses Chainlink oracles to fetch additional company information, enhancing the review system.