加密猫的demo

src/Online/Access.sol

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+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Pausable.sol";
+import "@openzeppelin/contracts/access/Ownable.sol";
+
+abstract contract Access is ERC721Pausable, Ownable {
+    function pause() public virtual onlyOwner {
+        super._pause();
+    }
+
+    function unpause() public virtual onlyOwner {
+        super._unpause();
+    }
+
+    /**
+     * @dev 这个是为了接收ETH转账用的
+     */
+    receive() external payable virtual {}
+
+    function withdrawBalance() external onlyOwner {
+        // uint256 balance = this.balance;
+        // // Subtract all the currently pregnant kittens we have, plus 1 of margin.
+        // uint256 subtractFees = (pregnantKitties + 1) * autoBirthFee;
+        // if (balance > subtractFees) {
+        //     cfoAddress.transfer(balance - subtractFees);
+        // }
+    }
+}

src/Online/Kitty.sol

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+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "./KittyController.sol";
+
+contract HelloKitty is KittyController {
+    /// 初始化猫
+    constructor() ERC721("CryptoKitties", "CK") {
+        _createKitty(0, 0, 0, (2**256) - 1, _msgSender());
+    }
+
+    function _createKitty(
+        uint256 _matronId,
+        uint256 _sireId,
+        uint256 _generation,
+        uint256 _genes,
+        address _owner
+    ) internal returns (uint256) {
+        require(_matronId == uint256(uint32(_matronId)));
+        require(_sireId == uint256(uint32(_sireId)));
+        require(_generation == uint256(uint16(_generation)));
+
+        // New kitty starts with the same cooldown as parent gen/2
+        uint16 cooldownIndex = uint16(_generation / 2);
+        if (cooldownIndex > 13) {
+            cooldownIndex = 13;
+        }
+
+        Kitty memory _kitty = Kitty({
+            genes: _genes,
+            birthTime: uint64(block.timestamp),
+            cooldownEndBlock: 0,
+            matronId: uint32(_matronId),
+            sireId: uint32(_sireId),
+            siringWithId: 0,
+            cooldownIndex: cooldownIndex,
+            generation: uint16(_generation)
+        });
+        kitties.push(_kitty);
+        uint256 newKittenId = 1;
+        // uint256 newKittenId = kitties.push(_kitty) - 1;
+        // require(newKittenId == uint256(uint32(newKittenId)));
+
+        emit Birth(
+            _owner,
+            newKittenId,
+            uint256(_kitty.matronId),
+            uint256(_kitty.sireId),
+            _kitty.genes
+        );
+
+        super._mint(_owner, newKittenId);
+
+        return newKittenId;
+    }
+}

src/Online/KittyController.sol

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+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts/access/Ownable.sol";
+import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
+import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Pausable.sol";
+import "./Access.sol";
+
+abstract contract KittyController is ERC721, Access {
+    struct Kitty {
+        // 猫的基因
+        uint256 genes;
+        // 出块时间戳
+        uint64 birthTime;
+        // 再次繁育冷却时间
+        uint64 cooldownEndBlock;
+        // 猫的母系ID
+        uint32 matronId;
+        // 父系ID
+        uint32 sireId;
+        // 对于怀孕的母猫，设置为公猫的ID，否则为零。这里的一个非零值是我们如何知道猫怀孕了。用于在出生时检索新小猫的遗传物质。
+        uint32 siringWithId;
+        // 每繁殖一次，递增一次，无论公母
+        uint16 cooldownIndex;
+        // 世代号(i.e. max(matron.generation, sire.generation) + 1)
+        uint16 generation;
+    }
+
+    Kitty[] kitties;
+
+    event Birth(
+        address owner,
+        uint256 kittyId,
+        uint256 matronId,
+        uint256 sireId,
+        uint256 genes
+    );
+
+    function getKitty(uint256 _id) public view returns (Kitty memory) {
+        return kitties[_id];
+    }
+
+    function _beforeTokenTransfer(
+        address from,
+        address to,
+        uint256 firstTokenId,
+        uint256 batchSize
+    ) internal virtual override(ERC721, ERC721Pausable) {
+        super._beforeTokenTransfer(from, to, firstTokenId, batchSize);
+    }
+}