Enhance entry addition process: implement immediate file save after adding an entry and handle save failure by removing the entry for improved reliability.

src/hosts/core/manager.py

@@ -296,7 +296,18 @@ class HostsManager:
         try:
             # Add the new entry at the end
             hosts_file.entries.append(entry)
-            return True, "Entry added successfully"
+
+            # Save the file immediately
+            save_success, save_message = self.save_hosts_file(hosts_file)
+            if not save_success:
+                # If save fails, remove the entry that was just added
+                hosts_file.entries.pop()
+                return False, f"Failed to save after adding entry: {save_message}"
+
+            canonical_hostname = (
+                entry.hostnames[0] if entry.hostnames else entry.ip_address
+            )
+            return True, f"Entry added: {canonical_hostname}"
 
         except Exception as e:
             return False, f"Error adding entry: {e}"
@@ -331,7 +342,11 @@ class HostsManager:
 
             # Remove the entry
             deleted_entry = hosts_file.entries.pop(index)
-            canonical_hostname = deleted_entry.hostnames[0] if deleted_entry.hostnames else deleted_entry.ip_address
+            canonical_hostname = (
+                deleted_entry.hostnames[0]
+                if deleted_entry.hostnames
+                else deleted_entry.ip_address
+            )
 
             # Save the file immediately
             save_success, save_message = self.save_hosts_file(hosts_file)

src/hosts/tui/app.py

@@ -7,7 +7,7 @@ all the handlers and provides the primary user interface.
 
 from textual.app import App, ComposeResult
 from textual.containers import Horizontal, Vertical
-from textual.widgets import Header, Static, DataTable, Input, Checkbox, Label
+from textual.widgets import Header, Static, DataTable, Input, Checkbox
 from textual.reactive import reactive
 
 from ..core.parser import HostsParser
@@ -91,24 +91,80 @@ class HostsManagerApp(App):
             # Right pane - entry details or edit form
             with Vertical(classes="common-pane right-pane") as right_pane:
                 right_pane.border_title = "Entry Details"
-                yield DataTable(
-                    id="entry-details-table",
-                    show_header=False,
-                    show_cursor=False,
-                    disabled=True,
-                )
+
+                # Details display form (disabled inputs)
+                with Vertical(id="entry-details-display", classes="entry-form"):
+                    with Vertical(
+                        classes="default-section section-no-top-margin"
+                    ) as ip_address:
+                        ip_address.border_title = "IP Address"
+                        yield Input(
+                            placeholder="No entry selected",
+                            id="details-ip-input",
+                            disabled=True,
+                            classes="default-input",
+                        )
+
+                    with Vertical(classes="default-section") as hostnames:
+                        hostnames.border_title = "Hostnames (comma-separated)"
+                        yield Input(
+                            placeholder="No entry selected",
+                            id="details-hostname-input",
+                            disabled=True,
+                            classes="default-input",
+                        )
+
+                    with Vertical(classes="default-section") as comment:
+                        comment.border_title = "Comment:"
+                        yield Input(
+                            placeholder="No entry selected",
+                            id="details-comment-input",
+                            disabled=True,
+                            classes="default-input",
+                        )
+
+                    with Vertical(classes="default-section") as active:
+                        active.border_title = "Active"
+                        yield Checkbox(
+                            "Active",
+                            id="details-active-checkbox",
+                            disabled=True,
+                            classes="default-checkbox",
+                        )
 
                 # Edit form (initially hidden)
-                with Vertical(id="entry-edit-form", classes="hidden"):
-                    yield Label("IP Address:")
-                    yield Input(placeholder="Enter IP address", id="ip-input")
-                    yield Label("Hostnames (comma-separated):")
-                    yield Input(placeholder="Enter hostnames", id="hostname-input")
-                    yield Label("Comment:")
-                    yield Input(
-                        placeholder="Enter comment (optional)", id="comment-input"
-                    )
-                    yield Checkbox("Active", id="active-checkbox")
+                with Vertical(id="entry-edit-form", classes="entry-form hidden"):
+                    with Vertical(
+                        classes="default-section section-no-top-margin"
+                    ) as ip_address:
+                        ip_address.border_title = "IP Address"
+                        yield Input(
+                            placeholder="Enter IP address",
+                            id="ip-input",
+                            classes="default-input",
+                        )
+
+                    with Vertical(classes="default-section") as hostnames:
+                        hostnames.border_title = "Hostnames (comma-separated)"
+                        yield Input(
+                            placeholder="Enter hostnames",
+                            id="hostname-input",
+                            classes="default-input",
+                        )
+
+                    with Vertical(classes="default-section") as comment:
+                        comment.border_title = "Comment:"
+                        yield Input(
+                            placeholder="Enter comment (optional)",
+                            id="comment-input",
+                            classes="default-input",
+                        )
+
+                    with Vertical(classes="default-section") as active:
+                        active.border_title = "Active"
+                        yield Checkbox(
+                            "Active", id="active-checkbox", classes="default-checkbox"
+                        )
 
         # Status bar for error/temporary messages (overlay, doesn't affect layout)
         yield Static("", id="status-bar", classes="status-bar hidden")

src/hosts/tui/details_handler.py

@@ -5,7 +5,7 @@ This module handles the display and updating of entry details
 and edit forms in the right pane.
 """
 
-from textual.widgets import Input, Checkbox, DataTable
+from textual.widgets import Input, Checkbox
 
 
 class DetailsHandler:
@@ -23,30 +23,41 @@ class DetailsHandler:
             self.update_details_display()
 
     def update_details_display(self) -> None:
-        """Update the details display using a DataTable with labeled rows."""
-        details_table = self.app.query_one("#entry-details-table", DataTable)
+        """Update the details display using disabled Input widgets."""
+        details_display = self.app.query_one("#entry-details-display")
         edit_form = self.app.query_one("#entry-edit-form")
 
-        # Show details table, hide edit form
-        details_table.remove_class("hidden")
+        # Show details display, hide edit form
+        details_display.remove_class("hidden")
         edit_form.add_class("hidden")
 
-        # Clear existing data
-        details_table.clear()
+        # Get the input widgets
+        ip_input = self.app.query_one("#details-ip-input", Input)
+        hostname_input = self.app.query_one("#details-hostname-input", Input)
+        comment_input = self.app.query_one("#details-comment-input", Input)
+        active_checkbox = self.app.query_one("#details-active-checkbox", Checkbox)
 
         if not self.app.hosts_file.entries:
-            # Show empty message in a single row
-            if not details_table.columns:
-                details_table.add_column("Field", key="field")
-            details_table.add_row("No entries loaded")
+            # Show empty message
+            ip_input.value = ""
+            ip_input.placeholder = "No entries loaded"
+            hostname_input.value = ""
+            hostname_input.placeholder = "No entries loaded"
+            comment_input.value = ""
+            comment_input.placeholder = "No entries loaded"
+            active_checkbox.value = False
             return
 
         # Get visible entries to check if we need to adjust selection
         visible_entries = self.app.table_handler.get_visible_entries()
         if not visible_entries:
-            if not details_table.columns:
-                details_table.add_column("Field", key="field")
-            details_table.add_row("No visible entries")
+            ip_input.value = ""
+            ip_input.placeholder = "No visible entries"
+            hostname_input.value = ""
+            hostname_input.placeholder = "No visible entries"
+            comment_input.value = ""
+            comment_input.placeholder = "No visible entries"
+            active_checkbox.value = False
             return
 
         # If default entries are hidden and selected_entry_index points to a hidden entry,
@@ -73,36 +84,28 @@ class DetailsHandler:
 
         entry = self.app.hosts_file.entries[self.app.selected_entry_index]
 
-        # Add columns for labeled rows (Field, Value) - only if not already present
-        if not details_table.columns:
-            details_table.add_column("Field", key="field")
-            details_table.add_column("Value", key="value")
+        # Update the input widgets with entry data
+        ip_input.value = entry.ip_address
+        ip_input.placeholder = ""
+        hostname_input.value = ", ".join(entry.hostnames)
+        hostname_input.placeholder = ""
+        comment_input.value = entry.comment or ""
+        comment_input.placeholder = "No comment"
+        active_checkbox.value = entry.is_active
 
-        # Add rows in the same order as edit form
-        details_table.add_row("IP Address", entry.ip_address, key="ip")
-        details_table.add_row("Hostnames", ", ".join(entry.hostnames), key="hostnames")
-        details_table.add_row("Comment", entry.comment or "", key="comment")
-        details_table.add_row(
-            "Active", "Yes" if entry.is_active else "No", key="active"
-        )
-
-        # Add DNS name if present (not in edit form but good to show)
-        if entry.dns_name:
-            details_table.add_row("DNS Name", entry.dns_name, key="dns")
-
-        # Add notice for default system entries
+        # For default entries, show warning in placeholder text
         if entry.is_default_entry():
-            details_table.add_row("", "", key="spacer")
-            details_table.add_row("⚠️  WARNING", "SYSTEM DEFAULT ENTRY", key="warning")
-            details_table.add_row("Note", "This entry cannot be modified", key="note")
+            ip_input.placeholder = "⚠️  SYSTEM DEFAULT ENTRY - Cannot be modified"
+            hostname_input.placeholder = "⚠️  SYSTEM DEFAULT ENTRY - Cannot be modified"
+            comment_input.placeholder = "⚠️  SYSTEM DEFAULT ENTRY - Cannot be modified"
 
     def update_edit_form(self) -> None:
         """Update the edit form with current entry values."""
-        details_table = self.app.query_one("#entry-details-table", DataTable)
+        details_display = self.app.query_one("#entry-details-display")
         edit_form = self.app.query_one("#entry-edit-form")
 
-        # Hide details table, show edit form
-        details_table.add_class("hidden")
+        # Hide details display, show edit form
+        details_display.add_class("hidden")
         edit_form.remove_class("hidden")
 
         if not self.app.hosts_file.entries or self.app.selected_entry_index >= len(

src/hosts/tui/keybindings.py

@@ -9,7 +9,7 @@ from textual.binding import Binding
 
 # Key bindings for the hosts manager application
 HOSTS_MANAGER_BINDINGS = [
-    Binding("a", "add_entry", "Add new entry", show=True, id="left:add_entry"),
+    Binding("n", "add_entry", "New entry", show=True, id="left:new_entry"),
     Binding("d", "delete_entry", "Delete entry", show=True, id="left:delete_entry"),
     Binding("e", "edit_entry", "Edit entry", show=True, id="left:edit_entry"),
     Binding(

src/hosts/tui/styles.py

@@ -41,6 +41,10 @@ COMMON_CSS = """
 .hidden {
     display: none;
 }
+
+.section-no-top-margin {
+    margin-top: 0 !important;
+}
 """
 
 # CSS styles for the hosts manager application
@@ -126,39 +130,11 @@ HOSTS_MANAGER_CSS = (
     display: none;
 }
 
-#entry-edit-form {
+.entry-form {
     height: auto;
     padding: 1;
 }
 
-#entry-edit-form Label {
-    margin-bottom: 1;
-    color: $accent;
-    text-style: bold;
-}
-
-#entry-edit-form Input {
-    margin-bottom: 1;
-}
-
-#entry-edit-form Checkbox {
-    margin-bottom: 1;
-}
-
-/* Entry details table styling */
-#entry-details-table {
-    background: $background;
-    height: auto;
-}
-
-#entry-details-table .datatable--even-row {
-    background: $background;
-}
-
-#entry-details-table .datatable--odd-row {
-    background: $surface;
-}
-
 Header {
     height: 1;
 }

tests/test_main.py

@@ -156,16 +156,27 @@ class TestHostsManagerApp:
         ):
             app = HostsManagerApp()
 
-            # Mock the query_one method to return DataTable mock
-            mock_details_table = Mock()
-            mock_details_table.columns = []  # Mock empty columns list
+            # Mock the query_one method to return disabled input widgets
+            mock_details_display = Mock()
             mock_edit_form = Mock()
+            mock_ip_input = Mock()
+            mock_hostname_input = Mock()
+            mock_comment_input = Mock()
+            mock_active_checkbox = Mock()
 
             def mock_query_one(selector, widget_type=None):
-                if selector == "#entry-details-table":
-                    return mock_details_table
+                if selector == "#entry-details-display":
+                    return mock_details_display
                 elif selector == "#entry-edit-form":
                     return mock_edit_form
+                elif selector == "#details-ip-input":
+                    return mock_ip_input
+                elif selector == "#details-hostname-input":
+                    return mock_hostname_input
+                elif selector == "#details-comment-input":
+                    return mock_comment_input
+                elif selector == "#details-active-checkbox":
+                    return mock_active_checkbox
                 return Mock()
 
             app.query_one = mock_query_one
@@ -182,12 +193,13 @@ class TestHostsManagerApp:
 
             app.update_entry_details()
 
-            # Verify DataTable operations were called
-            mock_details_table.remove_class.assert_called_with("hidden")
+            # Verify input widgets were updated with entry data
+            mock_details_display.remove_class.assert_called_with("hidden")
             mock_edit_form.add_class.assert_called_with("hidden")
-            mock_details_table.clear.assert_called_once()
-            mock_details_table.add_column.assert_called()
-            mock_details_table.add_row.assert_called()
+            assert mock_ip_input.value == "127.0.0.1"
+            assert mock_hostname_input.value == "localhost, local"
+            assert mock_comment_input.value == "Test comment"
+            assert mock_active_checkbox.value
 
     def test_update_entry_details_no_entries(self):
         """Test updating entry details with no entries."""
@@ -200,16 +212,27 @@ class TestHostsManagerApp:
         ):
             app = HostsManagerApp()
 
-            # Mock the query_one method to return DataTable mock
-            mock_details_table = Mock()
-            mock_details_table.columns = []  # Mock empty columns list
+            # Mock the query_one method to return disabled input widgets
+            mock_details_display = Mock()
             mock_edit_form = Mock()
+            mock_ip_input = Mock()
+            mock_hostname_input = Mock()
+            mock_comment_input = Mock()
+            mock_active_checkbox = Mock()
 
             def mock_query_one(selector, widget_type=None):
-                if selector == "#entry-details-table":
-                    return mock_details_table
+                if selector == "#entry-details-display":
+                    return mock_details_display
                 elif selector == "#entry-edit-form":
                     return mock_edit_form
+                elif selector == "#details-ip-input":
+                    return mock_ip_input
+                elif selector == "#details-hostname-input":
+                    return mock_hostname_input
+                elif selector == "#details-comment-input":
+                    return mock_comment_input
+                elif selector == "#details-active-checkbox":
+                    return mock_active_checkbox
                 return Mock()
 
             app.query_one = mock_query_one
@@ -217,12 +240,16 @@ class TestHostsManagerApp:
 
             app.update_entry_details()
 
-            # Verify DataTable operations were called for empty state
-            mock_details_table.remove_class.assert_called_with("hidden")
+            # Verify widgets show empty state placeholders
+            mock_details_display.remove_class.assert_called_with("hidden")
             mock_edit_form.add_class.assert_called_with("hidden")
-            mock_details_table.clear.assert_called_once()
-            mock_details_table.add_column.assert_called_with("Field", key="field")
-            mock_details_table.add_row.assert_called_with("No entries loaded")
+            assert mock_ip_input.value == ""
+            assert mock_ip_input.placeholder == "No entries loaded"
+            assert mock_hostname_input.value == ""
+            assert mock_hostname_input.placeholder == "No entries loaded"
+            assert mock_comment_input.value == ""
+            assert mock_comment_input.placeholder == "No entries loaded"
+            assert not mock_active_checkbox.value
 
     def test_update_status_default(self):
         """Test status bar update with default information."""

tests/test_manager.py

@@ -634,3 +634,58 @@ class TestHostsManager:
         finally:
             # Clean up
             Path(temp_path).unlink()
+
+    def test_add_entry_success(self):
+        """Test successfully adding an entry with immediate save."""
+        manager = HostsManager()
+        manager.edit_mode = True
+
+        # Mock the save operation to succeed
+        with patch.object(manager, "save_hosts_file") as mock_save:
+            mock_save.return_value = (True, "File saved successfully")
+
+            hosts_file = HostsFile()
+            test_entry = HostEntry(ip_address="192.168.1.100", hostnames=["testhost"])
+
+            success, message = manager.add_entry(hosts_file, test_entry)
+
+            assert success
+            assert "Entry added: testhost" in message
+            assert len(hosts_file.entries) == 1
+            assert hosts_file.entries[0] == test_entry
+            mock_save.assert_called_once_with(hosts_file)
+
+    def test_add_entry_save_failure(self):
+        """Test adding an entry when save fails."""
+        manager = HostsManager()
+        manager.edit_mode = True
+
+        # Mock the save operation to fail
+        with patch.object(manager, "save_hosts_file") as mock_save:
+            mock_save.return_value = (False, "Permission denied")
+
+            hosts_file = HostsFile()
+            test_entry = HostEntry(ip_address="192.168.1.100", hostnames=["testhost"])
+
+            success, message = manager.add_entry(hosts_file, test_entry)
+
+            assert not success
+            assert "Failed to save after adding entry" in message
+            assert (
+                len(hosts_file.entries) == 0
+            )  # Entry should be removed on save failure
+            mock_save.assert_called_once_with(hosts_file)
+
+    def test_add_entry_not_in_edit_mode(self):
+        """Test adding an entry when not in edit mode."""
+        manager = HostsManager()
+        # edit_mode defaults to False
+
+        hosts_file = HostsFile()
+        test_entry = HostEntry(ip_address="192.168.1.100", hostnames=["testhost"])
+
+        success, message = manager.add_entry(hosts_file, test_entry)
+
+        assert not success
+        assert "Not in edit mode" in message
+        assert len(hosts_file.entries) == 0