From 372df8b80e720556295c93cfa761fa8c7f053424 Mon Sep 17 00:00:00 2001
From: Alex Connolly <alexconnolly@Alexs-MacBook-Air.local>
Date: Fri, 12 Jan 2024 15:34:09 +1100
Subject: [PATCH] Basic Crafting Factory pattern.

---
 contracts/crafting/Factory.sol               | 51 ++++++++++++++++++++
 contracts/crafting/IRecipe.sol               | 45 +++++++++++++++++
 contracts/crafting/examples/SimpleRecipe.sol | 51 ++++++++++++++++++++
 3 files changed, 147 insertions(+)
 create mode 100644 contracts/crafting/Factory.sol
 create mode 100644 contracts/crafting/IRecipe.sol
 create mode 100644 contracts/crafting/examples/SimpleRecipe.sol

diff --git a/contracts/crafting/Factory.sol b/contracts/crafting/Factory.sol
new file mode 100644
index 00000000..4e9693ed
--- /dev/null
+++ b/contracts/crafting/Factory.sol
@@ -0,0 +1,51 @@
+// Copyright Immutable Pty Ltd 2018 - 2023
+// SPDX-License-Identifier: Apache 2.0
+pragma solidity 0.8.19;
+
+import { IRecipe, ERC1155Input, ERC721Input, ERC20Input, ERC1155Asset } from "./IRecipe.sol";
+
+contract Factory {
+
+    uint256 public craftCounter;
+
+    event CraftComplete(uint256 indexed craftID, IRecipe indexed recipe);
+
+    function craft(
+        IRecipe recipe,
+        ERC20Input[] calldata erc20Inputs,
+        ERC721Input[] calldata erc721Inputs,
+        ERC1155Input[] calldata erc1155Inputs,
+        bytes calldata data
+    ) external {
+
+        uint craftID = craftCounter++;
+
+        recipe.beforeTransfers(craftID, erc20Inputs, erc721Inputs, erc1155Inputs, data);
+
+        for (uint i = 0; i < erc20Inputs.length; i++) {
+            ERC20Input memory input = erc20Inputs[i];
+            input.erc20.transferFrom(msg.sender, input.destination, input.amount);
+        }
+
+
+        for (uint i = 0; i < erc721Inputs.length; i++) {
+            ERC721Input memory input = erc721Inputs[i];
+            for (uint j = 0; j < input.tokenIDs.length; j++) {
+                input.erc721.safeTransferFrom(msg.sender, input.destination, input.tokenIDs[j]);
+            }
+        }
+
+        for (uint i = 0; i < erc1155Inputs.length; i++) {
+            ERC1155Input memory input = erc1155Inputs[i];
+            for (uint j = 0; j < input.assets.length; j++) {
+                ERC1155Asset memory asset = input.assets[j];
+                input.erc1155.safeTransferFrom(msg.sender, input.destination, asset.tokenID, asset.amount, "0x0");
+            }
+        }
+
+        recipe.afterTransfers(craftID, data);
+        
+        emit CraftComplete(craftID, recipe);
+    }
+
+}
\ No newline at end of file
diff --git a/contracts/crafting/IRecipe.sol b/contracts/crafting/IRecipe.sol
new file mode 100644
index 00000000..b5ec8816
--- /dev/null
+++ b/contracts/crafting/IRecipe.sol
@@ -0,0 +1,45 @@
+// Copyright Immutable Pty Ltd 2018 - 2023
+// SPDX-License-Identifier: Apache 2.0
+pragma solidity 0.8.19;
+
+import { IERC1155 } from "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
+import { IERC721 } from "@openzeppelin/contracts/token/ERC721/IERC721.sol";
+import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+
+struct ERC1155Asset {
+    uint256 tokenID;
+    uint256 amount;
+}
+
+struct ERC1155Input {
+    IERC1155 erc1155;
+    ERC1155Asset[] assets;
+    address destination;
+}
+
+struct ERC721Input {
+    IERC721 erc721;
+    uint256[] tokenIDs;
+    address destination;
+}
+
+struct ERC20Input {
+    IERC20 erc20;
+    uint256 amount;
+    address destination;
+}
+
+interface IRecipe {
+
+    function beforeTransfers(
+        uint256 craftID,
+        ERC20Input[] calldata erc20s,
+        ERC721Input[] calldata erc721s,
+        ERC1155Input[] calldata erc1155s,
+        bytes calldata data
+    ) external;
+
+    function afterTransfers(uint256 craftID, bytes calldata data) external;
+
+}
\ No newline at end of file
diff --git a/contracts/crafting/examples/SimpleRecipe.sol b/contracts/crafting/examples/SimpleRecipe.sol
new file mode 100644
index 00000000..60146f86
--- /dev/null
+++ b/contracts/crafting/examples/SimpleRecipe.sol
@@ -0,0 +1,51 @@
+// Copyright Immutable Pty Ltd 2018 - 2023
+// SPDX-License-Identifier: Apache 2.0
+pragma solidity 0.8.19;
+
+import { IRecipe, ERC20Input, ERC721Input, ERC1155Input } from "../IRecipe.sol";
+import { IERC721 } from "@openzeppelin/contracts/token/ERC721/IERC721.sol";
+
+contract SimpleRecipe is IRecipe {
+
+    IERC721 public token;
+    address private factory;
+
+    constructor(IERC721 _token, address _factory) {
+        token = _token;
+        factory = _factory;
+    }
+
+    modifier onlyFactory {
+        require(msg.sender == factory, "Caller must be Factory");
+        _;
+    }
+
+    function beforeTransfers(
+        uint256,
+        ERC20Input[] calldata erc20s,
+        ERC721Input[] calldata erc721s,
+        ERC1155Input[] calldata erc1155s,
+        bytes calldata
+    ) external view onlyFactory {
+
+        require(erc20s.length == 0, "No ERC20s allowed.");
+        require(erc1155s.length == 0, "No ERC1155s allowed.");
+        require(erc721s.length == 1, "Must be only one ERC721 input.");
+
+        ERC721Input memory input = erc721s[0];
+        require(input.erc721 == token, "Must be crafting game assets."); 
+        require(input.destination == address(0), "Only allowed destination is 0x0.");
+        
+        // No need to check that the 5 assets are unique as transferring them will fail in the Factory. 
+
+        // Can log any events you want
+    }
+
+    function afterTransfers(uint256 craftID, bytes calldata data) external onlyFactory {
+        // mint a new NFT to the user
+        // token.mint() etc. 
+
+        // Can log any events you want
+    }
+
+}
\ No newline at end of file