Add smart tab management and duplicate request handling

Duplicate Name Detection:
- Warn when saving request with existing name in same project
- Show overwrite confirmation dialog with destructive styling
- Update existing request on overwrite (preserves ID, updates timestamp)
- Request names are unique within projects (but can duplicate across projects)

Save Request Improvements:
- Clear modified flag (•) when request is saved or overwritten
- Pre-fill save dialog with original request name and project
- Pre-fill save dialog with tab name for copy tabs
- Auto-select text in name field for easy editing

Smart Tab Loading:
- Switch to existing tab when loading unmodified saved request
- Create new tab only when needed (modified or doesn't exist)
- Avoid duplicate tabs for same request
- Show toast notification when switching to existing tab

Copy Tab Management:
- Create numbered copies when loading modified request again
- Naming: "ReqA (copy)", "ReqA (copy 2)", "ReqA (copy 3)", etc.
- Copy tabs are NOT linked to saved request (no saved_request_id)
- Copy tabs marked as unsaved (•) to encourage saving with new name
- Unique copy names prevent conflicts

Tab Response Persistence:
- Restore response when switching between tabs
- Each tab maintains independent response state
- Clear response area when switching to tab without response

Project Manager:
- Add find_request_by_name() for duplicate detection
- Add update_request() for overwriting existing requests
- Update request modified_at timestamp on save

Files Modified:
- src/project_manager.py: Duplicate detection and update methods
- src/window.py: Smart tab management and copy handling

src/project_manager.py

@@ -20,7 +20,7 @@
 import json
 import uuid
 from pathlib import Path
-from typing import List
+from typing import List, Optional
 from datetime import datetime, timezone
 from .models import Project, SavedRequest, HttpRequest
 
@@ -112,6 +112,35 @@ class ProjectManager:
         self.save_projects(projects)
         return saved_request
 
+    def find_request_by_name(self, project_id: str, name: str) -> Optional[SavedRequest]:
+        """Find a request by name within a project. Returns None if not found."""
+        projects = self.load_projects()
+        for p in projects:
+            if p.id == project_id:
+                for req in p.requests:
+                    if req.name == name:
+                        return req
+                break
+        return None
+
+    def update_request(self, project_id: str, request_id: str, name: str, request: HttpRequest) -> SavedRequest:
+        """Update an existing request."""
+        projects = self.load_projects()
+        updated_request = None
+        for p in projects:
+            if p.id == project_id:
+                for req in p.requests:
+                    if req.id == request_id:
+                        req.name = name
+                        req.request = request
+                        req.modified_at = datetime.now(timezone.utc).isoformat()
+                        updated_request = req
+                        break
+                break
+        if updated_request:
+            self.save_projects(projects)
+        return updated_request
+
     def delete_request(self, project_id: str, request_id: str):
         """Delete a saved request."""
         projects = self.load_projects()

src/window.py

@@ -270,6 +270,57 @@ class RosterWindow(Adw.ApplicationWindow):
 
         return is_empty
 
+    def _find_tab_by_saved_request_id(self, saved_request_id):
+        """Find a tab by its saved_request_id. Returns None if not found."""
+        for tab in self.tab_manager.tabs:
+            if tab.saved_request_id == saved_request_id:
+                return tab
+        return None
+
+    def _generate_copy_name(self, base_name):
+        """Generate a unique copy name like 'ReqA (copy)', 'ReqA (copy 2)', etc."""
+        # Check if "Name (copy)" exists
+        existing_names = {tab.name for tab in self.tab_manager.tabs}
+
+        copy_name = f"{base_name} (copy)"
+        if copy_name not in existing_names:
+            return copy_name
+
+        # Find the highest number used
+        counter = 2
+        while f"{base_name} (copy {counter})" in existing_names:
+            counter += 1
+
+        return f"{base_name} (copy {counter})"
+
+    def _switch_to_tab(self, tab_id):
+        """Switch to a specific tab."""
+        tab = self.tab_manager.get_tab_by_id(tab_id)
+        if not tab:
+            return
+
+        # Update tab manager
+        self.tab_manager.set_active_tab(tab_id)
+        self.current_tab_id = tab_id
+
+        # Load the tab's request into UI
+        self._load_request_to_ui(tab.request)
+
+        # Restore response if available
+        if tab.response:
+            self._display_response(tab.response)
+        else:
+            # Clear response area
+            self.status_label.set_text("Ready")
+            self.time_label.set_text("")
+            buffer = self.response_headers_textview.get_buffer()
+            buffer.set_text("")
+            buffer = self.response_body_sourceview.get_buffer()
+            buffer.set_text("")
+
+        # Update tab bar
+        self._update_tab_bar_visibility()
+
     def _create_new_tab(self, name="New Request", request=None, saved_request_id=None):
         """Create a new tab (simplified version - just clears current request for now)."""
         # Create tab in tab manager
@@ -1072,16 +1123,40 @@ class RosterWindow(Adw.ApplicationWindow):
 
         box = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, spacing=12)
 
+        # Check if current tab has a saved request (for pre-filling)
+        current_tab = None
+        preselect_project_index = 0
+        prefill_name = ""
+        if self.current_tab_id:
+            current_tab = self.tab_manager.get_tab_by_id(self.current_tab_id)
+            if current_tab:
+                if current_tab.saved_request_id:
+                    # Find which project this request belongs to
+                    for i, p in enumerate(projects):
+                        for req in p.requests:
+                            if req.id == current_tab.saved_request_id:
+                                preselect_project_index = i
+                                prefill_name = current_tab.name
+                                break
+                elif current_tab.name and current_tab.name != "New Request":
+                    # Copy tab or named unsaved tab - prefill with tab name
+                    prefill_name = current_tab.name
+
         # Project dropdown
         project_list = Gtk.StringList()
         for p in projects:
             project_list.append(p.name)
         dropdown = Gtk.DropDown(model=project_list)
+        dropdown.set_selected(preselect_project_index)  # Pre-select project
         box.append(dropdown)
 
         # Name entry
         entry = Gtk.Entry()
         entry.set_placeholder_text("Request name")
+        if prefill_name:
+            entry.set_text(prefill_name)  # Pre-fill name
+            # Select all text for easy editing
+            entry.select_region(0, -1)
         box.append(entry)
 
         dialog.set_extra_child(box)
@@ -1096,12 +1171,70 @@ class RosterWindow(Adw.ApplicationWindow):
                 if name:
                     selected = dropdown.get_selected()
                     project = projects[selected]
-                    self.project_manager.add_request(project.id, name, request)
+                    # Check for duplicate name
+                    existing = self.project_manager.find_request_by_name(project.id, name)
+                    if existing:
+                        # Show overwrite confirmation
+                        self._show_overwrite_dialog(project, name, existing.id, request)
+                    else:
+                        # No duplicate, save normally
+                        saved_request = self.project_manager.add_request(project.id, name, request)
                         self._load_projects()
+                        self._show_toast(f"Saved as '{name}'")
+
+                        # Clear modified flag on current tab
+                        self._mark_tab_as_saved(saved_request.id, name, request)
 
         dialog.connect("response", on_response)
         dialog.present(self)
 
+    def _mark_tab_as_saved(self, saved_request_id, name, request):
+        """Mark the current tab as saved (clear modified flag)."""
+        if self.current_tab_id:
+            current_tab = self.tab_manager.get_tab_by_id(self.current_tab_id)
+            if current_tab:
+                # Update tab metadata
+                current_tab.saved_request_id = saved_request_id
+                current_tab.name = name
+                current_tab.modified = False
+
+                # Update original_request to match saved state
+                current_tab.original_request = HttpRequest(
+                    method=request.method,
+                    url=request.url,
+                    headers=request.headers.copy(),
+                    body=request.body,
+                    syntax=request.syntax
+                )
+
+                # Update tab bar to remove modified indicator
+                self._update_tab_bar_visibility()
+
+    def _show_overwrite_dialog(self, project, name, existing_request_id, request):
+        """Show dialog asking if user wants to overwrite existing request."""
+        dialog = Adw.AlertDialog()
+        dialog.set_heading("Request Already Exists")
+        dialog.set_body(f"A request named '{name}' already exists in '{project.name}'.\n\nDo you want to overwrite it?")
+
+        dialog.add_response("cancel", "Cancel")
+        dialog.add_response("overwrite", "Overwrite")
+        dialog.set_response_appearance("overwrite", Adw.ResponseAppearance.DESTRUCTIVE)
+        dialog.set_default_response("cancel")
+        dialog.set_close_response("cancel")
+
+        def on_overwrite_response(dlg, response):
+            if response == "overwrite":
+                # Update the existing request
+                self.project_manager.update_request(project.id, existing_request_id, name, request)
+                self._load_projects()
+                self._show_toast(f"Updated '{name}'")
+
+                # Clear modified flag on current tab
+                self._mark_tab_as_saved(existing_request_id, name, request)
+
+        dialog.connect("response", on_overwrite_response)
+        dialog.present(self)
+
     def _on_add_to_project(self, widget, project):
         """Save current request to specific project."""
         request = self._build_request_from_ui()
@@ -1126,8 +1259,19 @@ class RosterWindow(Adw.ApplicationWindow):
             if response == "save":
                 name = entry.get_text().strip()
                 if name:
-                    self.project_manager.add_request(project.id, name, request)
+                    # Check for duplicate name
+                    existing = self.project_manager.find_request_by_name(project.id, name)
+                    if existing:
+                        # Show overwrite confirmation
+                        self._show_overwrite_dialog(project, name, existing.id, request)
+                    else:
+                        # No duplicate, save normally
+                        saved_request = self.project_manager.add_request(project.id, name, request)
                         self._load_projects()
+                        self._show_toast(f"Saved as '{name}'")
+
+                        # Clear modified flag on current tab
+                        self._mark_tab_as_saved(saved_request.id, name, request)
 
         dialog.connect("response", on_response)
         dialog.present(self)
@@ -1136,6 +1280,26 @@ class RosterWindow(Adw.ApplicationWindow):
         """Load saved request - smart loading based on current tab state."""
         req = saved_request.request
 
+        # First, check if this request is already open in an unmodified tab
+        existing_tab = self._find_tab_by_saved_request_id(saved_request.id)
+        if existing_tab and not existing_tab.is_modified():
+            # Switch to the existing unmodified tab
+            self._switch_to_tab(existing_tab.id)
+            self._show_toast(f"Switched to '{saved_request.name}'")
+            return
+
+        # Check if there's a modified tab with this saved_request_id
+        # If so, this is a copy and should not be linked
+        is_copy = existing_tab and existing_tab.is_modified()
+
+        if is_copy:
+            # Generate numbered copy name
+            tab_name = self._generate_copy_name(saved_request.name)
+            link_to_saved = None
+        else:
+            tab_name = saved_request.name
+            link_to_saved = saved_request.id
+
         # Check if current tab is an empty "New Request"
         if self._is_empty_new_request_tab():
             # Replace the empty tab with this request
@@ -1143,9 +1307,16 @@ class RosterWindow(Adw.ApplicationWindow):
                 current_tab = self.tab_manager.get_tab_by_id(self.current_tab_id)
                 if current_tab:
                     # Update the tab
-                    current_tab.name = saved_request.name
+                    current_tab.name = tab_name
                     current_tab.request = req
-                    current_tab.saved_request_id = saved_request.id
+                    current_tab.saved_request_id = link_to_saved
+
+                    if is_copy:
+                        # This is a copy - mark as unsaved
+                        current_tab.original_request = None
+                        current_tab.modified = True
+                    else:
+                        # This is linked to saved request
                         current_tab.original_request = HttpRequest(
                             method=req.method,
                             url=req.url,
@@ -1161,12 +1332,20 @@ class RosterWindow(Adw.ApplicationWindow):
         else:
             # Current tab has changes or is not a "New Request"
             # Create a new tab
-            self._create_new_tab(
+            tab_id = self._create_new_tab(
-                name=saved_request.name,
+                name=tab_name,
                 request=req,
-                saved_request_id=saved_request.id
+                saved_request_id=link_to_saved
             )
 
+            # If it's a copy, clear the original_request to mark as unsaved
+            if is_copy:
+                new_tab = self.tab_manager.get_tab_by_id(tab_id)
+                if new_tab:
+                    new_tab.original_request = None
+                    new_tab.modified = True
+                    self._update_tab_bar_visibility()
+
         # Switch to headers tab
         self.request_stack.set_visible_child_name("headers")