Add getLastWonBid method in billboard.sol

.gas-snapshot

@@ -10,54 +10,55 @@ ACLManagerTest:testRenounceRole() (gas: 27841)
 ACLManagerTest:testRoles() (gas: 15393)
 ACLManagerTest:testTransferRole() (gas: 21528)
 BillboardTest:testAddToWhitelist() (gas: 35114)
-BillboardTest:testApproveAndTransfer() (gas: 162512)
-BillboardTest:testCalculateTax() (gas: 22822)
-BillboardTest:testCannnotWithdrawTaxIfSmallAmount(uint8) (runs: 256, μ: 410878, ~: 424702)
-BillboardTest:testCannnotWithdrawTaxIfZero() (gas: 377863)
+BillboardTest:testApproveAndTransfer() (gas: 162535)
+BillboardTest:testCalculateTax() (gas: 22778)
+BillboardTest:testCannnotWithdrawTaxIfSmallAmount(uint8) (runs: 256, μ: 411584, ~: 424725)
+BillboardTest:testCannnotWithdrawTaxIfZero() (gas: 377886)
 BillboardTest:testCannotAddToWhitelistByAttacker() (gas: 9037)
-BillboardTest:testCannotApproveByAttacker() (gas: 130271)
-BillboardTest:testCannotClearAuctionIfAuctionNotEnded() (gas: 578827)
-BillboardTest:testCannotClearAuctionOnNewBoard() (gas: 136253)
-BillboardTest:testCannotMintBoardByAttacker() (gas: 13321)
-BillboardTest:testCannotPlaceBidByAttacker() (gas: 139222)
-BillboardTest:testCannotPlaceBidTwice(uint96) (runs: 256, μ: 624744, ~: 630975)
+BillboardTest:testCannotApproveByAttacker() (gas: 130294)
+BillboardTest:testCannotClearAuctionIfAuctionNotEnded() (gas: 578872)
+BillboardTest:testCannotClearAuctionOnNewBoard() (gas: 136276)
+BillboardTest:testCannotMintBoardByAttacker() (gas: 13344)
+BillboardTest:testCannotPlaceBidByAttacker() (gas: 139245)
+BillboardTest:testCannotPlaceBidTwice(uint96) (runs: 256, μ: 624767, ~: 630998)
 BillboardTest:testCannotRemoveToWhitelistByAttacker() (gas: 9104)
-BillboardTest:testCannotSafeTransferByAttacker() (gas: 127438)
-BillboardTest:testCannotSetBoardProprtiesByAttacker() (gas: 157292)
+BillboardTest:testCannotSafeTransferByAttacker() (gas: 127461)
+BillboardTest:testCannotSetBoardProprtiesByAttacker() (gas: 157361)
 BillboardTest:testCannotSetIsOpenedByAttacker() (gas: 8994)
-BillboardTest:testCannotSetTaxRateByAttacker() (gas: 9006)
-BillboardTest:testCannotTransferByOperator() (gas: 132771)
-BillboardTest:testCannotTransferToZeroAddress() (gas: 128258)
-BillboardTest:testCannotUpgradeRegistryByAttacker() (gas: 9128)
-BillboardTest:testCannotWithBidTwice(uint96) (runs: 256, μ: 903306, ~: 903306)
-BillboardTest:testCannotWithdrawBidIfAuctionNotCleared(uint96) (runs: 256, μ: 743847, ~: 743847)
-BillboardTest:testCannotWithdrawBidIfAuctionNotEnded(uint96) (runs: 256, μ: 619025, ~: 619025)
-BillboardTest:testCannotWithdrawBidIfNotFound() (gas: 413160)
-BillboardTest:testCannotWithdrawBidIfWon(uint96) (runs: 256, μ: 710721, ~: 710721)
+BillboardTest:testCannotSetTaxRateByAttacker() (gas: 8962)
+BillboardTest:testCannotTransferByOperator() (gas: 132794)
+BillboardTest:testCannotTransferToZeroAddress() (gas: 128281)
+BillboardTest:testCannotUpgradeRegistryByAttacker() (gas: 9084)
+BillboardTest:testCannotWithBidTwice(uint96) (runs: 256, μ: 903329, ~: 903329)
+BillboardTest:testCannotWithdrawBidIfAuctionNotCleared(uint96) (runs: 256, μ: 743870, ~: 743870)
+BillboardTest:testCannotWithdrawBidIfAuctionNotEnded(uint96) (runs: 256, μ: 619048, ~: 619048)
+BillboardTest:testCannotWithdrawBidIfNotFound() (gas: 413183)
+BillboardTest:testCannotWithdrawBidIfWon(uint96) (runs: 256, μ: 710744, ~: 710744)
 BillboardTest:testCannotWithdrawTaxByAttacker() (gas: 16677)
-BillboardTest:testClearAuctionIfAuctionEnded() (gas: 622677)
-BillboardTest:testClearAuctionsIfAuctionEnded() (gas: 1156582)
-BillboardTest:testGetBids(uint8,uint8,uint8) (runs: 256, μ: 2773780, ~: 1419565)
-BillboardTest:testGetTokenURI() (gas: 154980)
-BillboardTest:testMintBoard() (gas: 225541)
-BillboardTest:testMintBoardByWhitelist() (gas: 154942)
-BillboardTest:testMintBoardIfOpened() (gas: 145715)
-BillboardTest:testPlaceBidByWhitelist() (gas: 461423)
-BillboardTest:testPlaceBidIfAuctionEnded() (gas: 906529)
-BillboardTest:testPlaceBidOnNewBoard(uint96) (runs: 256, μ: 510724, ~: 520900)
-BillboardTest:testPlaceBidWithHigherPrice(uint96) (runs: 256, μ: 739847, ~: 747077)
-BillboardTest:testPlaceBidWithSamePrices(uint96) (runs: 256, μ: 738385, ~: 750061)
-BillboardTest:testPlaceBidZeroPrice() (gas: 354275)
+BillboardTest:testClearAuctionIfAuctionEnded() (gas: 622700)
+BillboardTest:testClearAuctionsIfAuctionEnded() (gas: 1156628)
+BillboardTest:testGetBids(uint8,uint8,uint8) (runs: 256, μ: 2715677, ~: 1414075)
+BillboardTest:testGetLastWonBid() (gas: 1179284)
+BillboardTest:testGetTokenURI() (gas: 155026)
+BillboardTest:testMintBoard() (gas: 225587)
+BillboardTest:testMintBoardByWhitelist() (gas: 154988)
+BillboardTest:testMintBoardIfOpened() (gas: 145738)
+BillboardTest:testPlaceBidByWhitelist() (gas: 461446)
+BillboardTest:testPlaceBidIfAuctionEnded() (gas: 906552)
+BillboardTest:testPlaceBidOnNewBoard(uint96) (runs: 256, μ: 510747, ~: 520923)
+BillboardTest:testPlaceBidWithHigherPrice(uint96) (runs: 256, μ: 739892, ~: 747122)
+BillboardTest:testPlaceBidWithSamePrices(uint96) (runs: 256, μ: 738408, ~: 750084)
+BillboardTest:testPlaceBidZeroPrice() (gas: 354298)
 BillboardTest:testRemoveToWhitelist() (gas: 23207)
-BillboardTest:testSafeTransferByOperator() (gas: 141237)
-BillboardTest:testSetBoardProperties() (gas: 305883)
-BillboardTest:testSetBoardPropertiesAfterTransfer() (gas: 335509)
+BillboardTest:testSafeTransferByOperator() (gas: 141260)
+BillboardTest:testSetBoardProperties() (gas: 305952)
+BillboardTest:testSetBoardPropertiesAfterTransfer() (gas: 335624)
 BillboardTest:testSetIsOpened() (gas: 22661)
-BillboardTest:testSetTaxRate() (gas: 22909)
-BillboardTest:testSomethin() (gas: 1626769)
-BillboardTest:testUpgradeRegistry() (gas: 2968149)
-BillboardTest:testWithdrawBid(uint96) (runs: 256, μ: 904808, ~: 904808)
-BillboardTest:testWithdrawTax(uint96) (runs: 256, μ: 500265, ~: 500265)
+BillboardTest:testSetTaxRate() (gas: 22821)
+BillboardTest:testSomethin() (gas: 1626838)
+BillboardTest:testUpgradeRegistry() (gas: 3153089)
+BillboardTest:testWithdrawBid(uint96) (runs: 256, μ: 904853, ~: 904853)
+BillboardTest:testWithdrawTax(uint96) (runs: 256, μ: 500288, ~: 500288)
 CurationTest:testCannotCurateERC20CurateZeroAmount() (gas: 12194)
 CurationTest:testCannotCurateERC20EmptyURI() (gas: 15797)
 CurationTest:testCannotCurateERC20IfNotApproval() (gas: 21624)

src/Billboard/Billboard.sol

@@ -304,6 +304,25 @@ contract Billboard is IBillboard {
         return (_total, limit_, offset_, _bids);
     }
 
+    /// @inheritdoc IBillboard
+    function getLastWonBid(uint256 tokenId_) external view returns (IBillboardRegistry.Bid memory bid) {
+        uint256 _auctionId = registry.nextBoardAuctionId(tokenId_);
+        require(_auctionId > 0, "Last cleared auction not found");
+
+        IBillboardRegistry.Auction memory auction = registry.getAuction(tokenId_, _auctionId);
+        bid = registry.getBid(tokenId_, _auctionId, auction.highestBidder);
+
+        // check if the auction is ended
+        if (bid.isWon == true) {
+            return bid;
+        }
+
+        // get previous auction
+        uint256 _lastAuctionId = _auctionId - 1;
+        auction = registry.getAuction(tokenId_, _lastAuctionId);
+        bid = registry.getBid(tokenId_, _lastAuctionId, auction.highestBidder);
+    }
+
     //////////////////////////////
     /// Tax & Withdraw
     //////////////////////////////

src/Billboard/IBillboard.sol

@@ -172,6 +172,13 @@ interface IBillboard {
         uint256 offset_
     ) external view returns (uint256 total, uint256 limit, uint256 offset, IBillboardRegistry.Bid[] memory bids);
 
+    /**
+     * @notice Get the last won bid of a board.
+     *
+     * @param tokenId_ Token ID of a board.
+     */
+    function getLastWonBid(uint256 tokenId_) external view returns (IBillboardRegistry.Bid memory bid);
+
     //////////////////////////////
     /// Tax & Withdraw
     //////////////////////////////

src/Billboard/IBillboardRegistry.sol

@@ -256,7 +256,7 @@ interface IBillboardRegistry is IERC721 {
      * @notice Get an auction
      *
      * @param tokenId_ Token ID of a board.
-     * @param auctionId_ Token ID of a board.
+     * @param auctionId_ Auction ID of a auction.
      */
     function getAuction(uint256 tokenId_, uint256 auctionId_) external view returns (Auction memory auction);
 

src/test/Billboard/BillboardTest.t.sol

@@ -1,6 +1,7 @@
 //SPDX-License-Identifier: Apache-2.0
 pragma solidity ^0.8.20;
 
+import "forge-std/console.sol";
 import "./BillboardTestBase.t.sol";
 import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
 
@@ -791,6 +792,62 @@ contract BillboardTest is BillboardTestBase {
         }
     }
 
+    function testGetLastWonBid() public {
+        (uint256 _tokenId, ) = _mintBoardAndPlaceBid();
+
+        // check the first won bid by ADMIN
+        IBillboardRegistry.Bid memory _bid = operator.getLastWonBid(_tokenId);
+        assertEq(_bid.price, 0);
+
+        // place a bid by USER_A during the second auction
+        uint256 _amount_a = 3 ether;
+        uint256 _tax_a = operator.calculateTax(_amount_a);
+        uint256 _total_a = _amount_a + _tax_a;
+        vm.startPrank(USER_A);
+        vm.deal(USER_A, _total_a);
+        operator.placeBid{value: _total_a}(_tokenId, _amount_a);
+
+        // place a bid by USER_B during the second auction
+        uint256 _amount_b = 1 ether;
+        uint256 _tax_b = operator.calculateTax(_amount_b);
+        uint256 _total_b = _amount_b + _tax_b;
+        vm.startPrank(USER_B);
+        vm.deal(USER_B, _total_b);
+        operator.placeBid{value: _total_b}(_tokenId, _amount_b);
+
+        // check the last won bid is still the first bid before clearing
+        _bid = operator.getLastWonBid(_tokenId);
+        assertEq(_bid.price, 0);
+
+        // clear auction
+        vm.warp(block.timestamp + registry.leaseTerm() + 1 minutes);
+        operator.clearAuction(_tokenId);
+
+        // check the second won bid
+        _bid = operator.getLastWonBid(_tokenId);
+        assertEq(_bid.price, 3 ether);
+
+        // place a bid by USER_A during the thrid auction
+        _amount_a = 5 ether;
+        _tax_a = operator.calculateTax(_amount_a);
+        _total_a = _amount_a + _tax_a;
+        vm.startPrank(USER_A);
+        vm.deal(USER_A, _total_a);
+        operator.placeBid{value: _total_a}(_tokenId, _amount_a);
+
+        // check last won bid is still the second bid before clearing
+        _bid = operator.getLastWonBid(_tokenId);
+        assertEq(_bid.price, 3 ether);
+
+        // clear auction
+        vm.warp(block.timestamp + registry.leaseTerm() + 1 minutes);
+        operator.clearAuction(_tokenId);
+
+        // check the third won bid
+        _bid = operator.getLastWonBid(_tokenId);
+        assertEq(_bid.price, 5 ether);
+    }
+
     //////////////////////////////
     /// Tax & Withdraw
     //////////////////////////////