contracts: create abstract stamp

.vscode/settings.json

@@ -1,5 +1,12 @@
 {
 	"wake.compiler.solc.remappings": [
-		"forge-std/=lib/forge-std/src/"
-	]
-}
+		"@openzeppelin/=lib/openzeppelin-contracts/",
+		"@openzeppelin/contracts/=lib/openzeppelin-contracts/contracts/",
+		"ds-test/=lib/openzeppelin-contracts/lib/forge-std/lib/ds-test/src/",
+		"erc4626-tests/=lib/openzeppelin-contracts/lib/erc4626-tests/",
+		"forge-std/=lib/forge-std/src/",
+		"openzeppelin-contracts/=lib/openzeppelin-contracts/"
+	],
+	"solidity.packageDefaultDependenciesContractsDirectory": "src",
+	"solidity.packageDefaultDependenciesDirectory": "lib"
+}

src/stamps/Stamp.sol

@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
+import "@openzeppelin/contracts/utils/cryptography/EIP712.sol";
+import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
+
+abstract contract Stamp is ERC721Enumerable, EIP712 {
+    using ECDSA for bytes32;
+
+    // Signer address
+    address public immutable signer;
+
+    constructor(
+        string memory stampName,
+        string memory stampSymbol,
+        string memory eip712version,
+        address _signer
+    ) ERC721(stampName, stampSymbol) EIP712("Plasa Stamps", eip712version) {
+        signer = _signer;
+    }
+
+    // Abstract function to be implemented by child contracts
+    function getTypedDataHash(
+        bytes memory data
+    ) public view virtual returns (bytes32);
+
+    // Custom error for when a user has already minted a stamp
+    error AlreadyMintedStamp(address user, uint256 stampId);
+    // New custom error for invalid signature
+    error InvalidSignature();
+
+    // Internal minting function
+    function _mintStamp(
+        address to,
+        bytes calldata data,
+        bytes calldata signature
+    ) internal virtual returns (uint256) {
+        if (!_verify(data, signature)) {
+            revert InvalidSignature();
+        }
+
+        if (balanceOf(to) > 0) {
+            revert AlreadyMintedStamp(to, tokenOfOwnerByIndex(to, 0));
+        }
+
+        uint256 newStampId = totalSupply() + 1;
+        _safeMint(to, newStampId);
+
+        return newStampId;
+    }
+
+    // Signature verification
+    function _verify(
+        bytes calldata data,
+        bytes calldata signature
+    ) internal view returns (bool) {
+        return
+            signer ==
+            _hashTypedDataV4(getTypedDataHash(data)).recover(signature);
+    }
+
+    // Override required by Solidity
+    function supportsInterface(
+        bytes4 interfaceId
+    ) public view virtual override(ERC721Enumerable) returns (bool) {
+        return super.supportsInterface(interfaceId);
+    }
+}