Initial commit: Naddie Jump — Monad Edition

contracts/NaddieJump.sol

@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+/**
+ * @title NaddieJump
+ * @notice On-chain leaderboard and reward contract for Naddie Jump game.
+ * @dev Designed for Monad EVM compatibility.
+ */
+contract NaddieJump {
+    struct Score {
+        address player;
+        uint256 score;
+        uint256 blockHeight;
+        uint256 timestamp;
+    }
+
+    mapping(address => Score) public bestScores;
+    Score[] public leaderboard;
+    uint256 public constant LEADERBOARD_SIZE = 50;
+    uint256 public constant REWARD_THRESHOLD = 50000;
+
+    event ScoreSubmitted(address indexed player, uint256 score, uint256 blockHeight);
+    event RewardClaimed(address indexed player, uint256 amount);
+
+    function submitScore(uint256 score, uint256 blockHeight) external {
+        require(score > 0, "Invalid score");
+
+        Score storage current = bestScores[msg.sender];
+        if (score > current.score) {
+            current.player = msg.sender;
+            current.score = score;
+            current.blockHeight = blockHeight;
+            current.timestamp = block.timestamp;
+            _updateLeaderboard(current);
+        }
+
+        emit ScoreSubmitted(msg.sender, score, blockHeight);
+    }
+
+    function _updateLeaderboard(Score memory newScore) internal {
+        // Simple insertion sort approach for leaderboard
+        bool exists = false;
+        for (uint256 i = 0; i < leaderboard.length; i++) {
+            if (leaderboard[i].player == newScore.player) {
+                leaderboard[i] = newScore;
+                exists = true;
+                break;
+            }
+        }
+        if (!exists && leaderboard.length < LEADERBOARD_SIZE) {
+            leaderboard.push(newScore);
+        }
+        // Sort descending by score (bubble sort for simplicity in prototype)
+        for (uint256 i = 0; i < leaderboard.length; i++) {
+            for (uint256 j = i + 1; j < leaderboard.length; j++) {
+                if (leaderboard[j].score > leaderboard[i].score) {
+                    Score memory tmp = leaderboard[i];
+                    leaderboard[i] = leaderboard[j];
+                    leaderboard[j] = tmp;
+                }
+            }
+        }
+    }
+
+    function getLeaderboard(uint256 count) external view returns (Score[] memory) {
+        uint256 len = count > leaderboard.length ? leaderboard.length : count;
+        Score[] memory result = new Score[](len);
+        for (uint256 i = 0; i < len; i++) {
+            result[i] = leaderboard[i];
+        }
+        return result;
+    }
+
+    function getPlayerBest(address player) external view returns (Score memory) {
+        return bestScores[player];
+    }
+
+    // Placeholder for future ERC-20 reward integration
+    function claimReward() external view returns (bool eligible) {
+        Score storage s = bestScores[msg.sender];
+        eligible = s.score >= REWARD_THRESHOLD;
+        // TODO: mint/transfer ERC-20 $GWEI tokens
+    }
+}