// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: contracts/ReferralManager.sol



pragma solidity ^0.8.4;

import "@openzeppelin/contracts/access/Ownable.sol";

contract ReferralManager is Ownable {
    mapping(address => address) private _referrers;
    mapping(address => bool) private _validReferrers;
    mapping(string => address) private _linksToAddresses; 
    address private _referralManagerManager;

    address[] private _users; 

    event ReferrerAdded(address referrer, string link);

    // Get referrer for customer
    function getReferrer(address account) public view returns (address) {
        return _referrers[account];
    }

    // Check if a referrer address is valid
    function isValidReferrer(address referrer) public view returns (bool) {
        return _validReferrers[referrer];
    }

    // Map customer to referrer
    function setReferrer(address account, address referrer) public {
        require(msg.sender == _referralManagerManager, "Caller is not the ReferralManagerManager");
        require(_referrers[account] == address(0), "Referrer already set");
        require(_validReferrers[referrer], "Not a valid referrer");
        _referrers[account] = referrer;
        _users.push(account); // add user to the list of users
    }

    // Add referrer
    function addValidReferrer(address referrer, string memory link) public onlyOwner {
        _validReferrers[referrer] = true;
        _linksToAddresses[link] = referrer; 

        emit ReferrerAdded(referrer, link);
    }

    // Remove referrer 
    function removeValidReferrer(address referrer) public onlyOwner {
        _validReferrers[referrer] = false;
    }

    // Set the ReferralManagerManager
    function setReferralManagerManager(address newManager) public onlyOwner {
        _referralManagerManager = newManager;
    }

    // Check if a referral link is valid
    function isValidLink(string memory link) public view returns (bool) {
        address referrerAddress = _linksToAddresses[link];
        return isValidReferrer(referrerAddress);
    }
    
    // Get the address associated with a referral code
    function getReferrerAddress(string memory link) public view returns (address) {
        return _linksToAddresses[link];
    }

    // Get all users
    function getUsers() public view returns (address[] memory) {
        return _users;
    }

    // Get all referrers
    function getReferrers() public view returns (address[] memory) {
        address[] memory referrers = new address[](_users.length);
        for (uint i = 0; i < _users.length; i++) {
            referrers[i] = _referrers[_users[i]];
        }
        return referrers;
    }
}