Stub for validation pool

ethereum/contracts/DAO.sol

@@ -4,22 +4,41 @@ pragma solidity ^0.8.24;
 import {ERC721} from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
 import "./ReputationHolder.sol";
 
+struct Stake {
+    bool inFavor;
+    uint256 amount;
+    address worker;
+}
+
+enum ValidationPoolStatus {
+    Open,
+    Closed
+}
+
+struct ValidationPool {
+    mapping(uint => Stake) stakes;
+    uint stakeCount;
+    ValidationPoolStatus status;
+}
+
 /// This contract must manage validation pools and reputation,
 /// because otherwise there's no way to enforce appropriate permissions on
 /// transfer of value between reputation NFTs.
 contract DAO is ERC721("Reputation", "REP"), ReputationHolder {
-    mapping(uint256 tokenId => uint256) _tokenValues;
-    uint256 _nextTokenId;
+    mapping(uint256 tokenId => uint256) tokenValues;
+    uint256 nextTokenId;
+    mapping(uint => ValidationPool) validationPools;
+    uint validationPoolCount;
 
     /// Inspect the value of a given reputation NFT
     function valueOf(uint256 tokenId) public view returns (uint256 value) {
-        value = _tokenValues[tokenId];
+        value = tokenValues[tokenId];
     }
 
     /// Internal function to mint a new reputation NFT
     function mint() internal returns (uint256 tokenId) {
         // Generate a new (sequential) ID for the token
-        tokenId = _nextTokenId++;
+        tokenId = nextTokenId++;
         // Mint the token, initially to be owned by the current contract.
         _mint(address(this), tokenId);
     }
@@ -32,7 +51,20 @@ contract DAO is ERC721("Reputation", "REP"), ReputationHolder {
     ) internal {
         require(amount >= 0);
         require(valueOf(fromTokenId) >= amount);
-        _tokenValues[fromTokenId] -= amount;
-        _tokenValues[toTokenId] += amount;
+        tokenValues[fromTokenId] -= amount;
+        tokenValues[toTokenId] += amount;
+    }
+
+    /// Accept fee to initiate a validation pool
+    function initiateValidationPool() public {}
+
+    /// Accept reputation stakes toward a validation pool
+    function onERC721Received(
+        address,
+        address from,
+        uint256 tokenId,
+        bytes calldata
+    ) public override returns (bytes4) {
+        return super.onERC721Received.selector;
     }
 }

ethereum/contracts/ReputationHolder.sol

@@ -1,6 +1,15 @@
 // SPDX-License-Identifier: Unlicense
 pragma solidity ^0.8.24;
 
-import {ERC721Holder} from "@openzeppelin/contracts/token/ERC721/utils/ERC721Holder.sol";
+import {IERC721Receiver} from "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
 
-abstract contract ReputationHolder is ERC721Holder {}
+abstract contract ReputationHolder is IERC721Receiver {
+    function onERC721Received(
+        address,
+        address,
+        uint256,
+        bytes calldata
+    ) public virtual returns (bytes4) {
+        return IERC721Receiver.onERC721Received.selector;
+    }
+}

ethereum/contracts/Work1.sol

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense
 pragma solidity ^0.8.24;
 
-import {IERC721Receiver} from "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
 import "./DAO.sol";
 import "./ReputationHolder.sol";
 
@@ -27,7 +26,7 @@ struct WorkRequest {
     bool approval;
 }
 
-contract Work1 is IERC721Receiver {
+contract Work1 is ReputationHolder {
     DAO dao;
     uint public immutable price;
     mapping(uint => AvailabilityStake) stakes;
@@ -48,12 +47,12 @@ contract Work1 is IERC721Receiver {
         address from,
         uint256 tokenId,
         bytes calldata
-    ) external override returns (bytes4) {
+    ) public override returns (bytes4) {
         AvailabilityStake storage stake = stakes[stakeCount++];
         stake.worker = from;
         stake.tokenId = tokenId;
         stake.amount = dao.valueOf(tokenId);
-        return IERC721Receiver.onERC721Received.selector;
+        return super.onERC721Received.selector;
     }
 
     /// Select a worker randomly from among the available workers, weighted by amount staked