Add apply to project feature for worktree sessions (#22)

* Add apply to project feature for worktree sessions

* Fix patch application using 3-way merge and include unstaged changes

* Remove 3-way merge from patch application

Author: built-by-as

index.html

@@ -259,6 +259,29 @@ <h2 class="modal-title">Terminal Settings</h2>
       </div>
     </div>
 
+    <!-- Apply to Project Modal -->
+    <div id="apply-to-project-modal" class="modal-overlay hidden">
+      <div class="modal">
+        <h2 class="modal-title">Apply Changes to Project</h2>
+
+        <div class="space-y-3 text-sm text-gray-300">
+          <p>This will apply all changes from this session to the original project directory:</p>
+          <ul class="list-disc list-inside space-y-1 text-gray-400">
+            <li>Branch: <span id="apply-branch-name" class="text-white"></span></li>
+            <li>Parent: <span id="apply-parent-branch" class="text-white"></span></li>
+          </ul>
+          <div class="bg-yellow-900 bg-opacity-30 border border-yellow-700 rounded p-3 mt-3">
+            <p class="text-yellow-300 text-xs">⚠️ This will include all commits and unstaged changes from this branch.</p>
+          </div>
+        </div>
+
+        <div class="btn-group">
+          <button id="cancel-apply-to-project" class="btn-secondary">Cancel</button>
+          <button id="confirm-apply-to-project" class="btn-primary">Apply Changes</button>
+        </div>
+      </div>
+    </div>
+
     <script>
       require('./dist/renderer.js');
     </script>

main.ts

@@ -611,6 +611,72 @@ ipcMain.handle("get-app-version", () => {
   return app.getVersion();
 });
 
+// Apply session changes to project
+ipcMain.handle("apply-session-to-project", async (_event, sessionId: string) => {
+  try {
+    const sessions = getPersistedSessions();
+    const session = sessions.find(s => s.id === sessionId);
+
+    if (!session) {
+      return { success: false, error: "Session not found" };
+    }
+
+    if (session.config.sessionType !== SessionType.WORKTREE) {
+      return { success: false, error: "Only worktree sessions can be applied to project" };
+    }
+
+    if (!session.worktreePath || !session.config.parentBranch) {
+      return { success: false, error: "Session missing worktree path or parent branch" };
+    }
+
+    const projectDir = session.config.projectDir;
+    const worktreePath = session.worktreePath;
+    const parentBranch = session.config.parentBranch;
+    const patchFilename = `fleetcode-patch-${Date.now()}.patch`;
+    const patchPath = path.join("/tmp", patchFilename);
+
+    // Generate patch file from parent branch to current state (includes commits + unstaged changes)
+    // Using diff against parent branch to capture all changes
+    const { stdout: patchContent } = await execAsync(
+      `git diff ${parentBranch}`,
+      { cwd: worktreePath }
+    );
+
+    // If patch is empty, there are no changes to apply
+    if (!patchContent.trim()) {
+      return { success: false, error: "No changes to apply" };
+    }
+
+    // Write patch to temp file
+    fs.writeFileSync(patchPath, patchContent);
+
+    // Apply patch to original project directory
+    try {
+      await execAsync(`git apply "${patchPath}"`, { cwd: projectDir });
+
+      // Clean up patch file on success
+      fs.unlinkSync(patchPath);
+
+      return { success: true };
+    } catch (applyError: any) {
+      // Clean up patch file on error
+      if (fs.existsSync(patchPath)) {
+        fs.unlinkSync(patchPath);
+      }
+
+      return {
+        success: false,
+        error: `Failed to apply patch: ${applyError.message || applyError}`
+      };
+    }
+  } catch (error: any) {
+    return {
+      success: false,
+      error: error.message || String(error)
+    };
+  }
+});
+
 // MCP Server management functions
 async function listMcpServers() {
   try {

renderer.ts

@@ -304,7 +304,7 @@ function addSession(persistedSession: PersistedSession, hasActivePty: boolean) {
   sessions.set(persistedSession.id, session);
 
   // Add to sidebar
-  addToSidebar(persistedSession.id, persistedSession.name, hasActivePty);
+  addToSidebar(persistedSession.id, persistedSession.name, hasActivePty, persistedSession.config);
 
   // Only add tab if terminal is active
   if (hasActivePty) {
@@ -351,10 +351,13 @@ function updateSessionState(sessionId: string, isActive: boolean) {
   }
 }
 
-function addToSidebar(sessionId: string, name: string, hasActivePty: boolean) {
+function addToSidebar(sessionId: string, name: string, hasActivePty: boolean, config: SessionConfig) {
   const list = document.getElementById("session-list");
   if (!list) return;
 
+  const isWorktree = config.sessionType === SessionType.WORKTREE;
+  const applyMenuItem = isWorktree ? `<button class="session-menu-item apply-to-project-btn" data-id="${sessionId}">Apply to project</button>` : '';
+
   const item = document.createElement("div");
   item.id = `sidebar-${sessionId}`;
   item.className = "session-list-item";
@@ -368,6 +371,7 @@ function addToSidebar(sessionId: string, name: string, hasActivePty: boolean) {
       <button class="session-menu-btn" data-id="${sessionId}" title="Session options">⋯</button>
       <div class="session-menu hidden" data-id="${sessionId}">
         <button class="session-menu-item rename-session-btn" data-id="${sessionId}">Rename</button>
+        ${applyMenuItem}
         <button class="session-menu-item delete-session-btn" data-id="${sessionId}">Delete</button>
       </div>
     </div>
@@ -430,6 +434,14 @@ function addToSidebar(sessionId: string, name: string, hasActivePty: boolean) {
     deleteSession(sessionId);
   });
 
+  // Apply to project button (only for worktree sessions)
+  const applyBtn = item.querySelector(".apply-to-project-btn");
+  applyBtn?.addEventListener("click", (e) => {
+    e.stopPropagation();
+    menu?.classList.add("hidden");
+    showApplyToProjectDialog(sessionId);
+  });
+
   list.appendChild(item);
 }
 
@@ -721,6 +733,27 @@ function deleteSession(sessionId: string) {
   }
 }
 
+function showApplyToProjectDialog(sessionId: string) {
+  const session = sessions.get(sessionId);
+  if (!session) return;
+
+  const modal = document.getElementById("apply-to-project-modal");
+  const branchName = document.getElementById("apply-branch-name");
+  const parentBranch = document.getElementById("apply-parent-branch");
+
+  if (branchName && session.config.branchName) {
+    branchName.textContent = session.config.branchName;
+  }
+  if (parentBranch && session.config.parentBranch) {
+    parentBranch.textContent = session.config.parentBranch;
+  }
+
+  // Store session ID for later use in confirm handler
+  modal?.setAttribute("data-session-id", sessionId);
+
+  modal?.classList.remove("hidden");
+}
+
 // Handle session output
 ipcRenderer.on("session-output", (_event, sessionId: string, data: string) => {
   const session = sessions.get(sessionId);
@@ -1504,6 +1537,45 @@ saveSettingsBtn?.addEventListener("click", async () => {
 // Load settings on startup
 loadSettings();
 
+// Apply to Project Modal
+const applyToProjectModal = document.getElementById("apply-to-project-modal");
+const cancelApplyToProjectBtn = document.getElementById("cancel-apply-to-project");
+const confirmApplyToProjectBtn = document.getElementById("confirm-apply-to-project");
+
+cancelApplyToProjectBtn?.addEventListener("click", () => {
+  applyToProjectModal?.classList.add("hidden");
+});
+
+confirmApplyToProjectBtn?.addEventListener("click", async () => {
+  const sessionId = applyToProjectModal?.getAttribute("data-session-id");
+  if (!sessionId) return;
+
+  // Disable button during operation
+  if (confirmApplyToProjectBtn) {
+    confirmApplyToProjectBtn.textContent = "Applying...";
+    confirmApplyToProjectBtn.setAttribute("disabled", "true");
+  }
+
+  try {
+    const result = await ipcRenderer.invoke("apply-session-to-project", sessionId);
+
+    if (result.success) {
+      alert(`Changes applied successfully to project directory.`);
+      applyToProjectModal?.classList.add("hidden");
+    } else {
+      alert(`Failed to apply changes: ${result.error}`);
+    }
+  } catch (error) {
+    alert(`Error applying changes: ${error}`);
+  } finally {
+    // Re-enable button
+    if (confirmApplyToProjectBtn) {
+      confirmApplyToProjectBtn.textContent = "Apply Changes";
+      confirmApplyToProjectBtn.removeAttribute("disabled");
+    }
+  }
+});
+
 // Close session menus when clicking outside
 document.addEventListener("click", (e) => {
   const target = e.target as HTMLElement;