Add toggle read/unread action with 'u' keybinding in mail app

PROJECT_PLAN.md

@@ -452,7 +452,7 @@ Implement `/` keybinding for search across all apps with similar UX:
 4. Calendar: Sidebar mini-calendar
 5. Calendar: Calendar invites sidebar
 6. ~~Mail: Add refresh keybinding~~ (DONE - `r` key)
-7. Mail: Add mark read/unread action
+7. ~~Mail: Add mark read/unread action~~ (DONE - `u` key)
 8. Mail: Folder message counts
 9. ~~Mail: URL compression in markdown view~~ (DONE)
 10. Mail: Enhance subject styling

src/mail/app.py

@@ -133,6 +133,7 @@ class EmailViewerApp(App):
             Binding("space", "toggle_selection", "Toggle selection"),
             Binding("escape", "clear_selection", "Clear selection"),
             Binding("/", "search", "Search"),
+            Binding("u", "toggle_read", "Toggle read/unread"),
         ]
     )
 
@@ -905,6 +906,86 @@ class EmailViewerApp(App):
             self.refresh_list_view_items()  # Refresh all items to uncheck checkboxes
             self._update_list_view_subtitle()
 
+    async def action_toggle_read(self) -> None:
+        """Toggle read/unread status for the current or selected messages."""
+        folder = self.folder if self.folder else None
+        account = self.current_account if self.current_account else None
+
+        if self.selected_messages:
+            # Toggle multiple selected messages
+            for message_id in self.selected_messages:
+                await self._toggle_message_read_status(message_id, folder, account)
+            self.show_status(
+                f"Toggled read status for {len(self.selected_messages)} messages"
+            )
+            self.selected_messages.clear()
+        else:
+            # Toggle current message
+            if self.current_message_id:
+                await self._toggle_message_read_status(
+                    self.current_message_id, folder, account
+                )
+
+        # Refresh the list to show updated read status
+        await self.fetch_envelopes().wait()
+
+    async def _toggle_message_read_status(
+        self, message_id: int, folder: str | None, account: str | None
+    ) -> None:
+        """Toggle read status for a single message."""
+        # Find the message in the store to check current status
+        metadata = self.message_store.get_metadata(message_id)
+        if not metadata:
+            return
+
+        index = metadata.get("index", -1)
+        if index < 0 or index >= len(self.message_store.envelopes):
+            return
+
+        envelope_data = self.message_store.envelopes[index]
+        if not envelope_data or envelope_data.get("type") == "header":
+            return
+
+        flags = envelope_data.get("flags", [])
+        is_read = "Seen" in flags
+
+        if is_read:
+            # Mark as unread
+            result, success = await himalaya_client.mark_as_unread(
+                message_id, folder=folder, account=account
+            )
+            if success:
+                if "Seen" in envelope_data.get("flags", []):
+                    envelope_data["flags"].remove("Seen")
+                self.show_status(f"Marked message {message_id} as unread")
+                self._update_envelope_read_state(index, is_read=False)
+        else:
+            # Mark as read
+            result, success = await himalaya_client.mark_as_read(
+                message_id, folder=folder, account=account
+            )
+            if success:
+                if "flags" not in envelope_data:
+                    envelope_data["flags"] = []
+                if "Seen" not in envelope_data["flags"]:
+                    envelope_data["flags"].append("Seen")
+                self.show_status(f"Marked message {message_id} as read")
+                self._update_envelope_read_state(index, is_read=True)
+
+    def _update_envelope_read_state(self, index: int, is_read: bool) -> None:
+        """Update the visual state of an envelope in the list."""
+        try:
+            list_view = self.query_one("#envelopes_list", ListView)
+            list_item = list_view.children[index]
+            envelope_widget = list_item.query_one(EnvelopeListItem)
+            envelope_widget.is_read = is_read
+            if is_read:
+                envelope_widget.remove_class("unread")
+            else:
+                envelope_widget.add_class("unread")
+        except Exception:
+            pass  # Widget may not exist
+
     def action_oldest(self) -> None:
         self.fetch_envelopes() if self.reload_needed else None
         self.show_message(self.message_store.get_oldest_id())

src/services/himalaya/client.py

@@ -312,6 +312,49 @@ async def mark_as_read(
         return str(e), False
 
 
+async def mark_as_unread(
+    message_id: int,
+    folder: Optional[str] = None,
+    account: Optional[str] = None,
+) -> Tuple[Optional[str], bool]:
+    """
+    Mark a message as unread by removing the 'seen' flag.
+
+    Args:
+        message_id: The ID of the message to mark as unread
+        folder: The folder containing the message
+        account: The account to use
+
+    Returns:
+        Tuple containing:
+        - Result message or error
+        - Success status (True if operation was successful)
+    """
+    try:
+        cmd = f"himalaya flag remove seen {message_id}"
+        if folder:
+            cmd += f" -f '{folder}'"
+        if account:
+            cmd += f" -a '{account}'"
+
+        process = await asyncio.create_subprocess_shell(
+            cmd,
+            stdout=asyncio.subprocess.PIPE,
+            stderr=asyncio.subprocess.PIPE,
+        )
+        stdout, stderr = await process.communicate()
+
+        if process.returncode == 0:
+            return stdout.decode().strip() or "Marked as unread", True
+        else:
+            error_msg = stderr.decode().strip()
+            logging.error(f"Error marking message as unread: {error_msg}")
+            return error_msg or "Unknown error", False
+    except Exception as e:
+        logging.error(f"Exception during marking message as unread: {e}")
+        return str(e), False
+
+
 async def search_envelopes(
     query: str,
     folder: Optional[str] = None,