Fix undo and redo by using initial commit hash for chat (#94)

src/ipc/handlers/chat_handlers.ts

@@ -1,19 +1,59 @@
 import { ipcMain } from "electron";
 import { db } from "../../db";
-import { chats } from "../../db/schema";
+import { apps, chats, messages } from "../../db/schema";
 import { desc, eq } from "drizzle-orm";
 import type { ChatSummary } from "../../lib/schemas";
+import * as git from "isomorphic-git";
+import * as fs from "fs";
+import * as path from "path";
+import log from "electron-log";
+import { getDyadAppPath } from "../../paths/paths";
+
+const logger = log.scope("chat_handlers");
 
 export function registerChatHandlers() {
   ipcMain.handle("create-chat", async (_, appId: number) => {
+    // Get the app's path first
+    const app = await db.query.apps.findFirst({
+      where: eq(apps.id, appId),
+      columns: {
+        path: true,
+      },
+    });
+
+    if (!app) {
+      throw new Error("App not found");
+    }
+
+    let initialCommitHash = null;
+    try {
+      // Get the current git revision of main branch
+      initialCommitHash = await git.resolveRef({
+        fs,
+        dir: getDyadAppPath(app.path),
+        ref: "main",
+      });
+    } catch (error) {
+      logger.error("Error getting git revision:", error);
+      // Continue without the git revision
+    }
+
     // Create a new chat
     const [chat] = await db
       .insert(chats)
       .values({
         appId,
+        initialCommitHash,
       })
       .returning();
-
+    logger.info(
+      "Created chat:",
+      chat.id,
+      "for app:",
+      appId,
+      "with initial commit hash:",
+      initialCommitHash
+    );
     return chat.id;
   });
 
@@ -70,7 +110,17 @@ export function registerChatHandlers() {
       await db.delete(chats).where(eq(chats.id, chatId));
       return { success: true };
     } catch (error) {
-      console.error("Error deleting chat:", error);
+      logger.error("Error deleting chat:", error);
+      return { success: false, error: (error as Error).message };
+    }
+  });
+
+  ipcMain.handle("delete-messages", async (_, chatId: number) => {
+    try {
+      await db.delete(messages).where(eq(messages.chatId, chatId));
+      return { success: true };
+    } catch (error) {
+      logger.error("Error deleting messages:", error);
       return { success: false, error: (error as Error).message };
     }
   });