Feat #2: add Host Entry from selected

README.md

@@ -66,6 +66,7 @@ including persistence behavior and manual recovery.
 | `Ctrl+E` | Enter or leave Privileged Mode |
 | `b` | Review and restore the session Pre-edit Backup |
 | `n` | Add a Host Entry |
+| `Shift+N` | Add a Host Entry based on the selected Host Entry |
 | `e` | Open the selected Host Entry in the Entry Editor |
 | `d` | Delete the selected Host Entry |
 | `Space` | Activate or deactivate the selected Host Entry |

docs/user-guide.md

@@ -63,6 +63,7 @@ separate from the Entry Editor used to change one Host Entry.
 In Privileged Mode:
 
 - Press `n` to add a Host Entry.
+- Press `Shift+N` to add a Host Entry based on the selected Host Entry.
 - Select a non-default Host Entry and press `e` to open the Entry Editor.
 - Press `d` and confirm to delete the selected Host Entry.
 - Press `Space` to activate or deactivate the selected Host Entry.
@@ -253,6 +254,7 @@ continually retrying it.
 | Key | Action |
 | --- | --- |
 | `n` | Add a Host Entry |
+| `Shift+N` | Add a Host Entry based on the selected Host Entry |
 | `e` | Open the selected Host Entry in the Entry Editor |
 | `d` | Delete the selected Host Entry |
 | `Space` | Activate or deactivate the selected Host Entry |

src/hosts/tui/add_entry_modal.py

@@ -28,13 +28,40 @@ class AddEntryModal(ModalScreen[HostEntry | None]):
         Binding("ctrl+s", "save", "Save"),
     ]
 
-    def __init__(self):
+    def __init__(self, source_entry: HostEntry | None = None):
         super().__init__()
+        self._source_hostname = (
+            source_entry.hostnames[0]
+            if source_entry is not None and source_entry.hostnames
+            else None
+        )
+        self._hostnames_draft = (
+            ", ".join(source_entry.hostnames) if source_entry is not None else ""
+        )
+        self._comment_draft = source_entry.comment or "" if source_entry else ""
+        self._is_dns_draft = bool(source_entry and source_entry.has_dns_name())
+        self._ip_draft = (
+            ""
+            if self._is_dns_draft
+            else (source_entry.ip_address if source_entry else "")
+        )
+        self._dns_draft = (
+            source_entry.dns_name or "" if self._is_dns_draft and source_entry else ""
+        )
+        self._active_draft = (
+            source_entry.is_active if source_entry and not self._is_dns_draft else True
+        )
 
     def compose(self) -> ComposeResult:
         """Create the add entry modal layout."""
         with VerticalScroll(classes="add-entry-container"):
-            yield Static("Add New Host Entry", classes="add-entry-title")
+            yield Static("Add Host Entry", classes="add-entry-title")
+            if self._source_hostname:
+                yield Static(
+                    f"Based on: {self._source_hostname}",
+                    id="entry-source",
+                    classes="entry-source",
+                )
 
             # Entry Type Selection
             with Vertical(classes="default-flex-section") as entry_type:
@@ -112,7 +139,21 @@ class AddEntryModal(ModalScreen[HostEntry | None]):
 
     def on_mount(self) -> None:
         """Focus the entry type choice when the modal opens."""
-        self.query_one("#entry-type-radio", RadioSet).focus()
+        if not self._source_hostname:
+            self.query_one("#entry-type-radio", RadioSet).focus()
+            return
+
+        self.query_one("#hostnames-input", Input).value = self._hostnames_draft
+        self.query_one("#ip-address-input", Input).value = self._ip_draft
+        self.query_one("#dns-name-input", Input).value = self._dns_draft
+        self.query_one("#comment-input", Input).value = self._comment_draft
+        self.query_one("#active-checkbox", Checkbox).value = self._active_draft
+        if self._is_dns_draft:
+            self.query_one("#dns-entry-radio", RadioButton).value = True
+
+        hostnames_input = self.query_one("#hostnames-input", Input)
+        hostnames_input.focus()
+        hostnames_input.cursor_position = len(hostnames_input.value)
 
     def on_radio_set_changed(self, event: RadioSet.Changed) -> None:
         """Handle entry type radio button changes."""
@@ -128,8 +169,11 @@ class AddEntryModal(ModalScreen[HostEntry | None]):
                 ip_section.remove_class("hidden")
                 dns_section.add_class("hidden")
 
-                # Reset checkbox to default (active) for IP entries
-                active_checkbox.value = True
+                self._dns_draft = self.query_one("#dns-name-input", Input).value
+                ip_input = self.query_one("#ip-address-input", Input)
+                ip_input.value = self._ip_draft
+                active_checkbox.value = self._active_draft
+                active_checkbox.disabled = False
                 if isinstance(active_section, Vertical):
                     active_section.border_title = "Activate Entry"
 
@@ -144,8 +188,13 @@ class AddEntryModal(ModalScreen[HostEntry | None]):
                 ip_section.add_class("hidden")
                 dns_section.remove_class("hidden")
 
-                # Set checkbox to inactive for DNS entries (will be activated after resolution)
+                self._ip_draft = self.query_one("#ip-address-input", Input).value
+                self._active_draft = active_checkbox.value
+                self.query_one("#dns-name-input", Input).value = self._dns_draft
+
+                # DNS entries stay inactive until resolution.
                 active_checkbox.value = False
+                active_checkbox.disabled = True
                 if isinstance(active_section, Vertical):
                     active_section.border_title = (
                         "Activate Entry (DNS entries activate after resolution)"

src/hosts/tui/app.py

@@ -905,13 +905,39 @@ class HostsManagerApp(App):
 
     def action_add_entry(self) -> None:
         """Show the add entry modal."""
-        if not self._allow_mutation_action():
+        if not self._allow_add_entry_action():
             return
+
+        self._open_add_entry_modal()
+
+    def action_new_from_selected(self) -> None:
+        """Show the add form prefilled from the highlighted visible Host Entry."""
+        if not self._allow_add_entry_action():
+            return
+
+        table = self.query_one("#entries-table", DataTable)
+        visible_entries = self.get_visible_entries()
+        if not visible_entries or not 0 <= table.cursor_row < len(visible_entries):
+            self.update_status(
+                "No Host Entry selected; use n to add a blank Host Entry."
+            )
+            return
+
+        self._open_add_entry_modal(visible_entries[table.cursor_row])
+
+    def _allow_add_entry_action(self) -> bool:
+        """Apply the shared mutation gates for both Add Host Entry actions."""
+        if not self._allow_mutation_action():
+            return False
         if not self.edit_mode:
             self.update_status(
                 "❌ Cannot add entry: Application is in read-only mode. Press 'Ctrl+E' to enable edit mode."
             )
-            return
+            return False
+        return True
+
+    def _open_add_entry_modal(self, source_entry: HostEntry | None = None) -> None:
+        """Open the ordinary Add pipeline, optionally seeded from a Host Entry."""
 
         def handle_add_entry_result(new_entry) -> None:
             if new_entry is None:
@@ -946,7 +972,7 @@ class HostsManagerApp(App):
             else:
                 self.update_status(f"❌ {result.message}")
 
-        self.push_screen(AddEntryModal(), handle_add_entry_result)
+        self.push_screen(AddEntryModal(source_entry), handle_add_entry_result)
 
     def action_delete_entry(self) -> None:
         """Show the delete confirmation modal for the selected entry."""

src/hosts/tui/help_modal.py

@@ -50,7 +50,8 @@ class HelpModal(ModalScreen[None]):
             )
             yield Static("Privileged Mode", classes="help-section")
             yield Static(
-                "Ctrl+E Enter or leave Privileged Mode    b Review Pre-edit Backup",
+                "Ctrl+E Enter or leave Privileged Mode    n Add Host Entry\n"
+                "Shift+N New from selected    b Review Pre-edit Backup",
                 classes="help-copy",
             )
             yield Button("Close", id="help-close", variant="primary")

src/hosts/tui/keybindings.py

@@ -10,6 +10,7 @@ from textual.binding import Binding
 # Key bindings for the hosts manager application
 HOSTS_MANAGER_BINDINGS = [
     Binding("n", "add_entry", "New entry", show=True, id="left:new_entry"),
+    Binding("shift+n", "new_from_selected", "New from selected", show=False),
     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

@@ -313,6 +313,11 @@ AddEntryModal {
     margin-bottom: 1;
 }
 
+.entry-source {
+    color: $text-muted;
+    margin-bottom: 1;
+}
+
 .validation-error {
     color: $error;
     margin: 0 2;

tests/test_add_entry_modal.py

@@ -8,7 +8,7 @@ DNS name entries, validation, and mutual exclusion logic.
 import pytest
 from typing import cast
 from unittest.mock import Mock
-from textual.widgets import Input, Checkbox, RadioSet, Static
+from textual.widgets import Input, Checkbox, RadioSet, RadioButton, Static
 
 from src.hosts.tui.add_entry_modal import AddEntryModal
 from src.hosts.core.models import HostEntry
@@ -267,6 +267,50 @@ class TestAddEntryModalRadioButtonLogic:
         mock_hostname_input.focus.assert_called_once()
 
 
+@pytest.mark.asyncio
+async def test_prefilled_dns_modal_keeps_separate_address_drafts_when_switching_type():
+    """A copied DNS Entry retains both address drafts while its type is changed."""
+    from src.hosts.tui.app import HostsManagerApp
+
+    source = HostEntry(
+        ip_address="192.0.2.45",
+        hostnames=["source.test", "alias.test"],
+        comment="Copied",
+        is_active=True,
+        dns_name="origin.example",
+        resolved_ip="192.0.2.45",
+        dns_resolution_status="resolved",
+    )
+    app = HostsManagerApp()
+    app.hosts_file.entries = [source]
+    app.load_hosts_file = Mock()
+
+    async with app.run_test() as pilot:
+        app.push_screen(AddEntryModal(source))
+        await pilot.pause()
+        modal = app.screen
+        assert modal.query_one("#dns-entry-radio", RadioButton).value
+        assert modal.query_one("#dns-name-input", Input).value == "origin.example"
+        assert modal.query_one("#ip-address-input", Input).value == ""
+        assert not modal.query_one("#active-checkbox", Checkbox).value
+        assert modal.query_one("#active-checkbox", Checkbox).disabled
+
+        await pilot.click("#ip-entry-radio")
+        await pilot.pause()
+        assert modal.query_one("#ip-address-input", Input).value == ""
+        assert modal.query_one("#active-checkbox", Checkbox).value
+        assert not modal.query_one("#active-checkbox", Checkbox).disabled
+
+        modal.query_one("#ip-address-input", Input).value = "198.51.100.8"
+        await pilot.click("#dns-entry-radio")
+        await pilot.pause()
+        assert modal.query_one("#dns-name-input", Input).value == "origin.example"
+
+        await pilot.click("#ip-entry-radio")
+        await pilot.pause()
+        assert modal.query_one("#ip-address-input", Input).value == "198.51.100.8"
+
+
 class TestAddEntryModalSaveLogic:
     """Test cases for save logic in AddEntryModal."""
 

tests/test_app.py

@@ -19,6 +19,7 @@ from src.hosts.tui.custom_footer import CustomFooter
 from src.hosts.tui.backup_restore_modal import BackupRestoreModal
 from src.hosts.tui.filter_modal import FilterModal
 from src.hosts.tui.help_modal import HelpModal
+from src.hosts.tui.add_entry_modal import AddEntryModal
 from src.hosts.tui.privilege_prompt import (
     render_sudo_authentication_notice,
     sudo_authentication_screen,
@@ -97,6 +98,78 @@ async def test_filter_shortcut_does_not_stack_filter_modals():
         assert sum(isinstance(screen, FilterModal) for screen in app.screen_stack) == 1
 
 
+@pytest.mark.asyncio
+async def test_new_from_selected_prefills_the_highlighted_visible_entry():
+    """Shift+N snapshots the highlighted visible Host Entry into the Add form."""
+    app = app_with_filterable_entries()
+    source = app.hosts_file.entries[1]
+    source.hostnames = ["inactive.test", "alias.test"]
+    source.comment = "Copied comment"
+    source.is_active = False
+    app.edit_mode = True
+    app.sort_column = "hostname"
+
+    async with app.run_test(size=(120, 40)) as pilot:
+        app.table_handler.populate_entries_table()
+        app.table_handler.move_cursor_to_entry_index(1)
+        await pilot.pause()
+
+        await pilot.press("shift+n")
+        await pilot.pause()
+
+        assert isinstance(app.screen, AddEntryModal)
+        assert app.screen.query_one("#hostnames-input", Input).value == (
+            "inactive.test, alias.test"
+        )
+        assert app.screen.query_one("#ip-address-input", Input).value == "192.0.2.2"
+        assert app.screen.query_one("#comment-input", Input).value == "Copied comment"
+        assert not app.screen.query_one("#active-checkbox").value
+        assert "Based on: inactive.test" in str(
+            app.screen.query_one("#entry-source", Static).render()
+        )
+        assert app.focused is app.screen.query_one("#hostnames-input", Input)
+
+    assert source.hostnames == ["inactive.test", "alias.test"]
+    assert source.comment == "Copied comment"
+    assert not source.is_active
+
+
+@pytest.mark.asyncio
+async def test_new_from_selected_requires_a_visible_host_entry():
+    """Shift+N does not reuse a stale selection when filters hide every entry."""
+    app = app_with_filterable_entries()
+    app.edit_mode = True
+    app.current_filter_options.search_term = "not-a-match"
+
+    async with app.run_test(size=(120, 40)) as pilot:
+        app.table_handler.populate_entries_table()
+        await pilot.press("shift+n")
+        await pilot.pause()
+
+        assert not isinstance(app.screen, AddEntryModal)
+        assert "No Host Entry selected; use n to add a blank Host Entry." in str(
+            app.query_one("#message-rail", Static).render()
+        )
+
+
+@pytest.mark.asyncio
+async def test_new_from_selected_is_available_at_the_minimum_viewport():
+    """Shift+N keeps the selected-entry add workflow reachable at 100×30."""
+    app = app_with_filterable_entries()
+    app.edit_mode = True
+
+    async with app.run_test(size=(100, 30)) as pilot:
+        app.table_handler.populate_entries_table()
+        await pilot.press("shift+n")
+        await pilot.pause()
+
+        assert isinstance(app.screen, AddEntryModal)
+        assert app.focused is app.screen.query_one("#hostnames-input", Input)
+        await pilot.press("escape")
+        await pilot.pause()
+        assert not isinstance(app.screen, AddEntryModal)
+
+
 @pytest.mark.asyncio
 async def test_help_overlay_closes_to_the_control_that_opened_it():
     """Help is an overlay and returns keyboard focus to its opener."""