From 0ff42d90836744b32130e5cf004041c1f790e41f Mon Sep 17 00:00:00 2001
From: Abi Raja <abimanyuraja@gmail.com>
Date: Thu, 29 Aug 2024 17:57:52 +0200
Subject: [PATCH] make commits immutable after a new commit is added

---
 frontend/src/components/commits/types.ts      |  1 +
 frontend/src/components/commits/utils.ts      | 23 ++++-
 frontend/src/components/variants/Variants.tsx |  8 +-
 frontend/src/store/project-store.ts           | 94 +++++++++++++------
 4 files changed, 88 insertions(+), 38 deletions(-)

diff --git a/frontend/src/components/commits/types.ts b/frontend/src/components/commits/types.ts
index 173663a..eb9ea12 100644
--- a/frontend/src/components/commits/types.ts
+++ b/frontend/src/components/commits/types.ts
@@ -8,6 +8,7 @@ export type BaseCommit = {
   hash: CommitHash;
   parentHash: CommitHash | null;
   dateCreated: Date;
+  isCommitted: boolean;
   variants: Variant[];
   selectedVariantIndex: number;
 };
diff --git a/frontend/src/components/commits/utils.ts b/frontend/src/components/commits/utils.ts
index 874f67e..640f83e 100644
--- a/frontend/src/components/commits/utils.ts
+++ b/frontend/src/components/commits/utils.ts
@@ -8,10 +8,25 @@ import {
 
 export function createCommit(
   commit:
-    | Omit<AiCreateCommit, "hash" | "dateCreated" | "selectedVariantIndex">
-    | Omit<AiEditCommit, "hash" | "dateCreated" | "selectedVariantIndex">
-    | Omit<CodeCreateCommit, "hash" | "dateCreated" | "selectedVariantIndex">
+    | Omit<
+        AiCreateCommit,
+        "hash" | "dateCreated" | "selectedVariantIndex" | "isCommitted"
+      >
+    | Omit<
+        AiEditCommit,
+        "hash" | "dateCreated" | "selectedVariantIndex" | "isCommitted"
+      >
+    | Omit<
+        CodeCreateCommit,
+        "hash" | "dateCreated" | "selectedVariantIndex" | "isCommitted"
+      >
 ): Commit {
   const hash = nanoid();
-  return { ...commit, hash, dateCreated: new Date(), selectedVariantIndex: 0 };
+  return {
+    ...commit,
+    hash,
+    isCommitted: false,
+    dateCreated: new Date(),
+    selectedVariantIndex: 0,
+  };
 }
diff --git a/frontend/src/components/variants/Variants.tsx b/frontend/src/components/variants/Variants.tsx
index 9a9fc45..1a1eb43 100644
--- a/frontend/src/components/variants/Variants.tsx
+++ b/frontend/src/components/variants/Variants.tsx
@@ -8,10 +8,12 @@ function Variants() {
     return null;
   }
 
-  const variants = commits[head].variants;
-  const selectedVariantIndex = commits[head].selectedVariantIndex;
+  const commit = commits[head];
+  const variants = commit.variants;
+  const selectedVariantIndex = commit.selectedVariantIndex;
 
-  if (variants.length <= 1) {
+  // If there is only one variant or the commit is already committed, don't show the variants
+  if (variants.length <= 1 || commit.isCommitted) {
     return <div className="mt-2"></div>;
   }
 
diff --git a/frontend/src/store/project-store.ts b/frontend/src/store/project-store.ts
index 3830232..b9e26a9 100644
--- a/frontend/src/store/project-store.ts
+++ b/frontend/src/store/project-store.ts
@@ -49,8 +49,17 @@ export const useProjectStore = create<ProjectStore>((set) => ({
   head: null,
 
   addCommit: (commit: Commit) => {
+    // When adding a new commit, make sure all existing commits are marked as committed
     set((state) => ({
-      commits: { ...state.commits, [commit.hash]: commit },
+      commits: {
+        ...Object.fromEntries(
+          Object.entries(state.commits).map(([hash, existingCommit]) => [
+            hash,
+            { ...existingCommit, isCommitted: true },
+          ])
+        ),
+        [commit.hash]: commit,
+      },
     }));
   },
   removeCommit: (hash: CommitHash) => {
@@ -63,41 +72,64 @@ export const useProjectStore = create<ProjectStore>((set) => ({
   resetCommits: () => set({ commits: {} }),
 
   appendCommitCode: (hash: CommitHash, numVariant: number, code: string) =>
-    set((state) => ({
-      commits: {
-        ...state.commits,
-        [hash]: {
-          ...state.commits[hash],
-          variants: state.commits[hash].variants.map((variant, index) =>
-            index === numVariant
-              ? { ...variant, code: variant.code + code }
-              : variant
-          ),
+    set((state) => {
+      const commit = state.commits[hash];
+      // Don't update if the commit is already committed
+      if (commit.isCommitted) {
+        throw new Error("Attempted to append code to a committed commit");
+      }
+      return {
+        commits: {
+          ...state.commits,
+          [hash]: {
+            ...commit,
+            variants: commit.variants.map((variant, index) =>
+              index === numVariant
+                ? { ...variant, code: variant.code + code }
+                : variant
+            ),
+          },
         },
-      },
-    })),
+      };
+    }),
   setCommitCode: (hash: CommitHash, numVariant: number, code: string) =>
-    set((state) => ({
-      commits: {
-        ...state.commits,
-        [hash]: {
-          ...state.commits[hash],
-          variants: state.commits[hash].variants.map((variant, index) =>
-            index === numVariant ? { ...variant, code } : variant
-          ),
+    set((state) => {
+      const commit = state.commits[hash];
+      // Don't update if the commit is already committed
+      if (commit.isCommitted) {
+        throw new Error("Attempted to set code of a committed commit");
+      }
+      return {
+        commits: {
+          ...state.commits,
+          [hash]: {
+            ...commit,
+            variants: commit.variants.map((variant, index) =>
+              index === numVariant ? { ...variant, code } : variant
+            ),
+          },
         },
-      },
-    })),
+      };
+    }),
   updateSelectedVariantIndex: (hash: CommitHash, index: number) =>
-    set((state) => ({
-      commits: {
-        ...state.commits,
-        [hash]: {
-          ...state.commits[hash],
-          selectedVariantIndex: index,
+    set((state) => {
+      const commit = state.commits[hash];
+      // Don't update if the commit is already committed
+      if (commit.isCommitted) {
+        throw new Error(
+          "Attempted to update selected variant index of a committed commit"
+        );
+      }
+      return {
+        commits: {
+          ...state.commits,
+          [hash]: {
+            ...commit,
+            selectedVariantIndex: index,
+          },
         },
-      },
-    })),
+      };
+    }),
 
   setHead: (hash: CommitHash) => set({ head: hash }),
   resetHead: () => set({ head: null }),