feat: adding delegation wall contract

script/Deploy.s.sol

@@ -1,13 +1,13 @@
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity >=0.8.25 <0.9.0;
 
-import { Foo } from "../src/Foo.sol";
+import { DelegationWall } from "../src/DelegationWall.sol";
 
 import { BaseScript } from "./Base.s.sol";
 
 /// @dev See the Solidity Scripting tutorial: https://book.getfoundry.sh/tutorials/solidity-scripting
 contract Deploy is BaseScript {
-    function run() public broadcast returns (Foo foo) {
-        foo = new Foo();
-    }
+  function run() public broadcast returns (DelegationWall delegationWall) {
+    delegationWall = new DelegationWall();
+  }
 }

src/DelegationWall.sol

@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity ^0.8.25;
+
+/// @title DelegationWall - Release 1, Build 1
+/// @author Aragon Association - 2024
+/// @notice A smart contract where any wallet can announce itself as a delegate by providing an IPFS Id
+contract DelegationWall {
+  struct Candidate {
+    bytes contentUrl;
+  }
+
+  /// @dev Stores the data registered by the delegate candidates
+  mapping(address => Candidate) public candidates;
+
+  /// @dev Keeps track of the addresses that have been already registered, used to enumerate.
+  address[] public candidateAddresses;
+
+  /// @notice Emitted when a wallet registers as a candidate
+  event CandidateRegistered(address indexed candidate, bytes contentUrl);
+
+  /// @notice Raised when a delegate registers with an empty contentUrl
+  error EmptyContent();
+
+  /// @notice Registers the given data as a new delegation candidate
+  function register(bytes memory _contentUrl) public {
+    if (_contentUrl.length == 0) revert EmptyContent();
+
+    if (candidates[msg.sender].contentUrl.length == 0) {
+      candidateAddresses.push(msg.sender);
+    }
+
+    candidates[msg.sender].contentUrl = _contentUrl;
+
+    emit CandidateRegistered(msg.sender, _contentUrl);
+  }
+
+  /// @notice Returns the list of candidate addresses registered
+  /// @dev Use this function to get all addresses in a single call. You can still call candidateAddresses[idx] to resolve them one by one.
+  function getCandidateAddresses() public view returns (address[] memory) {
+    return candidateAddresses;
+  }
+
+  /// @notice Returns the number of candidate entries available
+  function candidateCount() public view returns (uint256) {
+    return candidateAddresses.length;
+  }
+}

test/DelegationWall.t.sol

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.25 <0.9.0;
+
+import { Test } from "forge-std/src/Test.sol";
+import { console2 } from "forge-std/src/console2.sol";
+
+import { DelegationWall } from "../src/DelegationWall.sol";
+
+interface IERC20 {
+  function balanceOf(address account) external view returns (uint256);
+}
+
+/// @dev If this is your first time with Forge, read this tutorial in the Foundry Book:
+/// https://book.getfoundry.sh/forge/writing-tests
+contract DelegationWallTest is Test {
+  DelegationWall internal delegationWall;
+
+  /// @dev A function invoked before each test case is run.
+  function setUp() public virtual {
+    // Instantiate the contract-under-test.
+    delegationWall = new DelegationWall();
+  }
+}