feat(compare): add accessible directory comparison preview

src/portkeydrop/app.py

@@ -15,6 +15,8 @@
 
 from portkeydrop import __version__
 from portkeydrop.accessible_list import AccessibleReportList, create_report_list, file_row_text
+from portkeydrop.directory_compare import compare_directories
+from portkeydrop.dialogs.directory_compare import create_directory_compare_dialog
 from portkeydrop.dialogs.properties import PropertiesDialog
 from portkeydrop.dialogs.quick_connect import QuickConnectDialog
 from portkeydrop.dialogs.settings import SettingsDialog
@@ -102,6 +104,7 @@
 ID_FOCUS_LOCAL_PANE = wx.NewIdRef()
 ID_FOCUS_REMOTE_PANE = wx.NewIdRef()
 ID_FOCUS_ACTIVITY_LOG_PANE = wx.NewIdRef()
+ID_COMPARE_DIRECTORIES = wx.NewIdRef()
 
 
 class MainFrame(wx.Frame):
@@ -194,6 +197,12 @@ def _build_menu(self) -> None:
             "Hide &Activity Log",
             "Toggle activity log panel visibility",
         )
+        view_menu.AppendSeparator()
+        view_menu.Append(
+            ID_COMPARE_DIRECTORIES,
+            "Compare &Directories\tCtrl+Shift+C",
+            "Compare the current local and remote directories",
+        )
         menubar.Append(view_menu, "&View")
 
         # Transfer menu
@@ -484,6 +493,7 @@ def _bind_events(self) -> None:
             self._on_focus_activity_log_pane,
             id=ID_FOCUS_ACTIVITY_LOG_PANE,
         )
+        self.Bind(wx.EVT_MENU, self._on_compare_directories, id=ID_COMPARE_DIRECTORIES)
         self.Bind(wx.EVT_MENU, self._on_about, id=wx.ID_ABOUT)
         self.Bind(wx.EVT_CLOSE, self._on_close)
         self.Bind(get_transfer_event_binder(), self._on_transfer_update)
@@ -511,6 +521,7 @@ def _bind_events(self) -> None:
         entries = [
             wx.AcceleratorEntry(wx.ACCEL_NORMAL, wx.WXK_F6, ID_SWITCH_PANE_FOCUS),
             wx.AcceleratorEntry(wx.ACCEL_CTRL, ord("L"), ID_FOCUS_ADDRESS_BAR),
+            wx.AcceleratorEntry(wx.ACCEL_CTRL | wx.ACCEL_SHIFT, ord("C"), ID_COMPARE_DIRECTORIES),
             wx.AcceleratorEntry(wx.ACCEL_CTRL, ord("1"), ID_FOCUS_LOCAL_PANE),
             wx.AcceleratorEntry(wx.ACCEL_CTRL, ord("2"), ID_FOCUS_REMOTE_PANE),
             wx.AcceleratorEntry(wx.ACCEL_CTRL, ord("3"), ID_FOCUS_ACTIVITY_LOG_PANE),
@@ -1544,6 +1555,22 @@ def _show_transfer_queue(self) -> None:
         )
         self._transfer_dlg.Show()
 
+    def _on_compare_directories(self, event) -> None:
+        """Show a read-only accessible comparison of current local and remote panes."""
+        if not self._client or not self._client.connected:
+            self._announce("Connect to a remote server before comparing directories.")
+            return
+        local_files = self._get_visible_files(self._local_files, self._local_filter_text)
+        remote_files = self._get_visible_files(self._remote_files, self._remote_filter_text)
+        result = compare_directories(local_files, remote_files)
+        message = f"Directory comparison: {result.summary}"
+        self._announce(message)
+        dialog = create_directory_compare_dialog(self, result)
+        try:
+            dialog.ShowModal()
+        finally:
+            dialog.Destroy()
+
     # --- File operations (context-aware) ---
 
     def _on_delete(self, event) -> None:

src/portkeydrop/dialogs/directory_compare.py

@@ -0,0 +1,57 @@
+"""Accessible directory comparison preview dialog."""
+
+from __future__ import annotations
+
+from portkeydrop.directory_compare import CompareResult
+
+
+def create_directory_compare_dialog(parent, result: CompareResult):
+    """Create a modal read-only directory comparison dialog. Requires wx."""
+    import wx
+
+    class DirectoryCompareDialog(wx.Dialog):
+        def __init__(self, parent_window, compare_result: CompareResult):
+            super().__init__(
+                parent_window,
+                title="Directory Comparison",
+                style=wx.DEFAULT_DIALOG_STYLE | wx.RESIZE_BORDER,
+                size=(720, 420),
+            )
+            self._result = compare_result
+            self._build_ui()
+            self._populate()
+            self.compare_list.SetFocus()
+
+        def _build_ui(self):
+            root = wx.BoxSizer(wx.VERTICAL)
+
+            summary = wx.StaticText(self, label=f"Summary: {self._result.summary}")
+            root.Add(summary, 0, wx.EXPAND | wx.ALL, 8)
+
+            wx.StaticText(self, label="Comparison results:")
+            self.compare_list = wx.ListCtrl(self, style=wx.LC_REPORT | wx.LC_SINGLE_SEL)
+            self.compare_list.SetName("Directory comparison results")
+            self.compare_list.InsertColumn(0, "Name", width=220)
+            self.compare_list.InsertColumn(1, "Action", width=150)
+            self.compare_list.InsertColumn(2, "Local", width=110)
+            self.compare_list.InsertColumn(3, "Remote", width=110)
+            self.compare_list.InsertColumn(4, "Detail", width=260)
+            root.Add(self.compare_list, 1, wx.EXPAND | wx.LEFT | wx.RIGHT, 8)
+
+            buttons = self.CreateStdDialogButtonSizer(wx.OK)
+            root.Add(buttons, 0, wx.EXPAND | wx.ALL, 8)
+            self.SetSizer(root)
+
+        def _populate(self):
+            for row in self._result.rows:
+                idx = self.compare_list.InsertItem(self.compare_list.GetItemCount(), row.name)
+                self.compare_list.SetItem(idx, 1, row.action_label)
+                self.compare_list.SetItem(idx, 2, row.local.display_size if row.local else "")
+                self.compare_list.SetItem(idx, 3, row.remote.display_size if row.remote else "")
+                self.compare_list.SetItem(idx, 4, row.detail)
+                self.compare_list.SetItemData(idx, idx)
+            if self.compare_list.GetItemCount() > 0:
+                self.compare_list.Select(0)
+                self.compare_list.Focus(0)
+
+    return DirectoryCompareDialog(parent, result)

src/portkeydrop/directory_compare.py

@@ -0,0 +1,163 @@
+"""Directory comparison helpers for local/remote file panes."""
+
+from __future__ import annotations
+
+from collections import Counter
+from dataclasses import dataclass
+from datetime import datetime
+from enum import Enum
+
+from portkeydrop.protocols import RemoteFile
+
+
+class CompareAction(Enum):
+    """Preview action for a local/remote directory comparison row."""
+
+    SAME = "same"
+    UPLOAD = "upload"
+    DOWNLOAD = "download"
+    LOCAL_NEWER = "local_newer"
+    REMOTE_NEWER = "remote_newer"
+    CONFLICT = "conflict"
+
+
+@dataclass(frozen=True)
+class CompareRow:
+    """One named item in a directory comparison."""
+
+    name: str
+    action: CompareAction
+    local: RemoteFile | None = None
+    remote: RemoteFile | None = None
+    detail: str = ""
+
+    @property
+    def action_label(self) -> str:
+        labels = {
+            CompareAction.SAME: "No action",
+            CompareAction.UPLOAD: "Upload",
+            CompareAction.DOWNLOAD: "Download",
+            CompareAction.LOCAL_NEWER: "Upload newer local",
+            CompareAction.REMOTE_NEWER: "Download newer remote",
+            CompareAction.CONFLICT: "Review conflict",
+        }
+        return labels[self.action]
+
+    @property
+    def speech(self) -> str:
+        detail = f", {self.detail}" if self.detail else ""
+        return f"{self.name}: {self.action_label}{detail}"
+
+
+@dataclass(frozen=True)
+class CompareResult:
+    """Complete directory comparison result."""
+
+    rows: tuple[CompareRow, ...]
+
+    @property
+    def summary_counts(self) -> Counter[CompareAction]:
+        return Counter(row.action for row in self.rows)
+
+    @property
+    def summary(self) -> str:
+        counts = self.summary_counts
+        parts = [
+            f"{len(self.rows)} item{'s' if len(self.rows) != 1 else ''}",
+            f"{counts[CompareAction.UPLOAD] + counts[CompareAction.LOCAL_NEWER]} upload",
+            f"{counts[CompareAction.DOWNLOAD] + counts[CompareAction.REMOTE_NEWER]} download",
+            f"{counts[CompareAction.CONFLICT]} conflict",
+            f"{counts[CompareAction.SAME]} unchanged",
+        ]
+        return ", ".join(parts)
+
+
+def compare_directories(
+    local_files: list[RemoteFile], remote_files: list[RemoteFile]
+) -> CompareResult:
+    """Compare two current-directory file lists by name.
+
+    Parent-directory entries are ignored. The result is read-only: actions describe
+    what a future sync preview would do, but no transfer jobs are created here.
+    """
+
+    local_by_name = _index_by_name(local_files)
+    remote_by_name = _index_by_name(remote_files)
+    names = sorted(set(local_by_name) | set(remote_by_name), key=str.casefold)
+    rows = tuple(
+        _compare_name(name, local_by_name.get(name), remote_by_name.get(name)) for name in names
+    )
+    return CompareResult(rows=rows)
+
+
+def _index_by_name(files: list[RemoteFile]) -> dict[str, RemoteFile]:
+    return {file.name: file for file in files if file.name != ".."}
+
+
+def _compare_name(name: str, local: RemoteFile | None, remote: RemoteFile | None) -> CompareRow:
+    if local is None and remote is not None:
+        return CompareRow(
+            name=name, action=CompareAction.DOWNLOAD, remote=remote, detail="remote only"
+        )
+    if remote is None and local is not None:
+        return CompareRow(name=name, action=CompareAction.UPLOAD, local=local, detail="local only")
+    if local is None or remote is None:  # pragma: no cover - guarded above
+        raise AssertionError("comparison row needs at least one side")
+
+    if local.is_dir != remote.is_dir:
+        return CompareRow(
+            name=name,
+            action=CompareAction.CONFLICT,
+            local=local,
+            remote=remote,
+            detail="file type differs",
+        )
+    if local.is_dir and remote.is_dir:
+        return CompareRow(
+            name=name, action=CompareAction.SAME, local=local, remote=remote, detail="directory"
+        )
+    if local.size != remote.size:
+        return _newer_row(
+            name,
+            local,
+            remote,
+            f"size differs: {local.display_size} local, {remote.display_size} remote",
+        )
+    if _same_modified(local.modified, remote.modified):
+        return CompareRow(
+            name=name,
+            action=CompareAction.SAME,
+            local=local,
+            remote=remote,
+            detail="same size and date",
+        )
+    return _newer_row(name, local, remote, "same size, modified date differs")
+
+
+def _newer_row(name: str, local: RemoteFile, remote: RemoteFile, detail: str) -> CompareRow:
+    if local.modified and remote.modified:
+        if local.modified > remote.modified:
+            return CompareRow(
+                name=name,
+                action=CompareAction.LOCAL_NEWER,
+                local=local,
+                remote=remote,
+                detail=detail,
+            )
+        if remote.modified > local.modified:
+            return CompareRow(
+                name=name,
+                action=CompareAction.REMOTE_NEWER,
+                local=local,
+                remote=remote,
+                detail=detail,
+            )
+    return CompareRow(
+        name=name, action=CompareAction.CONFLICT, local=local, remote=remote, detail=detail
+    )
+
+
+def _same_modified(left: datetime | None, right: datetime | None) -> bool:
+    if left is None or right is None:
+        return left is right
+    return int(left.timestamp()) == int(right.timestamp())

tests/_wx_stub.py

@@ -136,6 +136,7 @@ def Close() -> None:
     fake_wx.WXK_TAB = 9
     fake_wx.ACCEL_NORMAL = 1
     fake_wx.ACCEL_CTRL = 2
+    fake_wx.ACCEL_SHIFT = 4
     fake_wx.ID_OK = 100
     fake_wx.OK = 100
     fake_wx.YES = 101
@@ -145,6 +146,8 @@ def Close() -> None:
     fake_wx.ICON_INFORMATION = 105
     fake_wx.ID_EXIT = 200
     fake_wx.ID_ABOUT = 201
+    fake_wx.DEFAULT_DIALOG_STYLE = 301
+    fake_wx.RESIZE_BORDER = 302
 
     fake_wx.StaticBox = lambda *args, **kwargs: _SimpleWidget()
     fake_wx.StaticBoxSizer = lambda *args, **kwargs: _SimpleWidget()

tests/test_app.py

@@ -174,6 +174,11 @@ def test_bind_events_sets_f6_and_ctrl_l_accelerators(app_module):
         app.ID_SWITCH_PANE_FOCUS,
     ) in table_entries
     assert (fake_wx.ACCEL_CTRL, ord("L"), app.ID_FOCUS_ADDRESS_BAR) in table_entries
+    assert (
+        fake_wx.ACCEL_CTRL | fake_wx.ACCEL_SHIFT,
+        ord("C"),
+        app.ID_COMPARE_DIRECTORIES,
+    ) in table_entries
 
 
 def test_macos_menu_uses_command_q_for_exit_not_disconnect(app_module):
@@ -262,6 +267,42 @@ def test_focus_address_bar_sets_toolbar_host_focus_and_announces(app_module):
     frame._announce.assert_called_once_with("Address bar")
 
 
+def test_compare_directories_requires_remote_connection(app_module):
+    app, _ = app_module
+    frame = _hydrate_frame(app_module)
+    frame._client = None
+
+    frame._on_compare_directories(None)
+
+    frame._announce.assert_called_once_with(
+        "Connect to a remote server before comparing directories."
+    )
+
+
+def test_compare_directories_announces_summary_and_opens_dialog(app_module):
+    app, _ = app_module
+    frame = _hydrate_frame(app_module)
+    frame._client = MagicMock(connected=True)
+    frame._local_filter_text = ""
+    frame._remote_filter_text = ""
+    frame._settings.display.show_hidden_files = True
+    frame._local_files = [app.RemoteFile(name="local.txt", path="/local.txt")]
+    frame._remote_files = [app.RemoteFile(name="remote.txt", path="/remote.txt")]
+    dialog = MagicMock()
+
+    with patch.object(
+        app, "create_directory_compare_dialog", return_value=dialog
+    ) as dialog_factory:
+        frame._on_compare_directories(None)
+
+    frame._announce.assert_called_once_with(
+        "Directory comparison: 2 items, 1 upload, 1 download, 0 conflict, 0 unchanged"
+    )
+    dialog_factory.assert_called_once()
+    dialog.ShowModal.assert_called_once()
+    dialog.Destroy.assert_called_once()
+
+
 def test_on_upload_directory_updates_status(app_module):
     app, _ = app_module
     frame = _hydrate_frame(app_module)