add hasoshi contract

contracts/hasoshi.sol

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: MIT
+
+// Warning: For educational purposes only. Do not use with real funds.
+
+pragma solidity ^0.8.9;
+
+import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.7.2/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
+
+contract Hasoshi is ERC721Enumerable {
+    using Strings for uint256;
+
+    uint internal tokenCount;
+    string internal baseURI;
+    mapping(uint => uint) public tokenVariant; // Map tokenId to the tokenVariant
+
+    constructor() ERC721("Hasoshi", "HAS") {
+        baseURI = "https://raw.githubusercontent.com/cifunibas/Smart-Contracts-DeFi/main/assets/hasoshi/json/";
+    }
+
+    function mint() public {
+        // Determine which of the 10 variants is minted
+        // 1% chance for variant 10, equal chance for variants 1-9
+        uint d100 = block.timestamp % 100; // "random" number from 0-99
+        uint variant = d100 % 10 + 1;
+        if (variant == 10) {
+            variant = d100 / 10 + 1;
+        }
+        uint tokenId = ++tokenCount;
+        tokenVariant[tokenId] = variant;
+        _safeMint(msg.sender, tokenId);
+    }
+
+    function tokenURI(uint tokenId) public view override returns (string memory) {
+        _requireMinted(tokenId);
+        uint variant = tokenVariant[tokenId];
+        return string(
+            abi.encodePacked(
+                baseURI,
+                variant.toString(),
+                ".json"
+            )
+        );
+    }
+
+}