From 282d9478dfa37bafbd26128530093bb73969d2b7 Mon Sep 17 00:00:00 2001
From: Ladd Hoffman <laddhoffman@gmail.com>
Date: Fri, 28 Jun 2024 10:46:21 -0500
Subject: [PATCH] add global forum contract

---
 ethereum/contracts/GlobalForum.sol | 90 ++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 ethereum/contracts/GlobalForum.sol

diff --git a/ethereum/contracts/GlobalForum.sol b/ethereum/contracts/GlobalForum.sol
new file mode 100644
index 0000000..dc063f5
--- /dev/null
+++ b/ethereum/contracts/GlobalForum.sol
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: Unlicense
+pragma solidity ^0.8.24;
+
+struct Reference {
+    int weightPPM;
+    string targetPostId;
+}
+
+struct Author {
+    uint weightPPM;
+    address authorAddress;
+}
+
+struct Post {
+    string id;
+    address sender;
+    Author[] authors;
+    Reference[] references;
+    string content;
+}
+
+contract GlobalForum {
+    mapping(string => Post) public posts;
+    string[] public postIds;
+    uint public postCount;
+
+    event PostAdded(string id);
+
+    function addPost(
+        string calldata postId,
+        Author[] calldata authors,
+        Reference[] calldata references,
+        string calldata content
+    ) external {
+        require(authors.length > 0, "Post must include at least one author");
+        postCount++;
+        postIds.push(postId);
+        Post storage post = posts[postId];
+        require(
+            post.authors.length == 0,
+            "A post with this postId already exists"
+        );
+        post.sender = msg.sender;
+        post.id = postId;
+        post.content = content;
+        uint authorTotalWeightPPM;
+        for (uint i = 0; i < authors.length; i++) {
+            authorTotalWeightPPM += authors[i].weightPPM;
+            post.authors.push(authors[i]);
+        }
+        require(
+            authorTotalWeightPPM == 1000000,
+            "Author weights must sum to 1000000"
+        );
+        for (uint i = 0; i < references.length; i++) {
+            post.references.push(references[i]);
+        }
+        int totalReferenceWeightPos;
+        int totalReferenceWeightNeg;
+        for (uint i = 0; i < post.references.length; i++) {
+            int weight = post.references[i].weightPPM;
+            require(
+                weight >= -1000000,
+                "Each reference weight must be >= -1000000"
+            );
+            require(
+                weight <= 1000000,
+                "Each reference weight must be <= 1000000"
+            );
+            if (weight > 0) totalReferenceWeightPos += weight;
+            else totalReferenceWeightNeg += weight;
+        }
+        require(
+            totalReferenceWeightPos <= 1000000,
+            "Sum of positive references must be <= 1000000"
+        );
+        require(
+            totalReferenceWeightNeg >= -1000000,
+            "Sum of negative references must be >= -1000000"
+        );
+        emit PostAdded(postId);
+    }
+
+    function getPostAuthors(
+        string calldata postId
+    ) external view returns (Author[] memory) {
+        Post storage post = posts[postId];
+        return post.authors;
+    }
+}