feat: add backup system

src/illogical/modules/backup_manager.py

@@ -0,0 +1,286 @@
+from __future__ import annotations
+
+import hashlib
+import json
+import shutil
+from datetime import UTC, datetime, timedelta
+from typing import TYPE_CHECKING
+
+from logic_plugin_manager.defaults import tags_path
+
+from illogical.modules.backup_models import (
+    BackupChanges,
+    BackupInfo,
+    BackupManifest,
+    BackupSettings,
+    BackupTrigger,
+)
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+MANIFEST_VERSION = 1
+MANIFEST_FILENAME = "manifest.json"
+BACKUP_INDEX_FILENAME = ".backup_index.json"
+
+TAGS_PATH = tags_path
+BACKUPS_PATH = tags_path.parent / ".nothing_to_see_here_just_illogical_saving_ur_ass"
+
+
+def _compute_file_checksum(file_path: Path) -> str:
+    sha256 = hashlib.sha256()
+    with file_path.open("rb") as f:
+        for chunk in iter(lambda: f.read(65536), b""):
+            sha256.update(chunk)
+    return f"sha256:{sha256.hexdigest()}"
+
+
+def _get_backup_files() -> list[Path]:
+    if not TAGS_PATH.exists():
+        return []
+    return [f for f in TAGS_PATH.iterdir() if f.is_file()]
+
+
+def _generate_backup_name(trigger: BackupTrigger) -> str:
+    timestamp = datetime.now(UTC).strftime("%Y-%m-%d_%H-%M-%S")
+    return f"{timestamp}_{trigger.value}"
+
+
+def _load_manifest(backup_path: Path) -> BackupManifest | None:
+    manifest_file = backup_path / MANIFEST_FILENAME
+    if not manifest_file.exists():
+        return None
+    try:
+        with manifest_file.open() as f:
+            return BackupManifest.from_dict(json.load(f))
+    except (json.JSONDecodeError, KeyError, ValueError):
+        return None
+
+
+def _save_manifest(backup_path: Path, manifest: BackupManifest) -> None:
+    manifest_file = backup_path / MANIFEST_FILENAME
+    with manifest_file.open("w") as f:
+        json.dump(manifest.to_dict(), f, indent=2)
+
+
+def _get_latest_backup() -> BackupInfo | None:
+    backups = list_backups()
+    return backups[0] if backups else None
+
+
+def _compute_changes_between(
+    current_files: dict[str, str], previous_files: dict[str, str]
+) -> BackupChanges:
+    added = [f for f in current_files if f not in previous_files]
+    deleted = [f for f in previous_files if f not in current_files]
+    modified = [
+        f
+        for f in current_files
+        if f in previous_files and current_files[f] != previous_files[f]
+    ]
+    return BackupChanges(added=added, modified=modified, deleted=deleted)
+
+
+def create_backup(
+    trigger: BackupTrigger = BackupTrigger.MANUAL, description: str = ""
+) -> BackupInfo:
+    BACKUPS_PATH.mkdir(parents=True, exist_ok=True)
+
+    backup_name = _generate_backup_name(trigger)
+    backup_path = BACKUPS_PATH / backup_name
+    backup_path.mkdir()
+
+    source_files = _get_backup_files()
+    checksums: dict[str, str] = {}
+    total_size = 0
+
+    for src_file in source_files:
+        dst_file = backup_path / src_file.name
+        shutil.copy2(src_file, dst_file)
+        checksums[src_file.name] = _compute_file_checksum(src_file)
+        total_size += src_file.stat().st_size
+
+    latest = _get_latest_backup()
+    previous_backup = latest.name if latest else None
+
+    if latest:
+        previous_manifest = _load_manifest(latest.path)
+        if previous_manifest:
+            changes = _compute_changes_between(checksums, previous_manifest.checksums)
+        else:
+            changes = BackupChanges()
+    else:
+        changes = BackupChanges(added=list(checksums.keys()))
+
+    manifest = BackupManifest(
+        version=MANIFEST_VERSION,
+        timestamp=datetime.now(UTC),
+        trigger=trigger,
+        description=description,
+        file_count=len(source_files),
+        total_size_bytes=total_size,
+        previous_backup=previous_backup,
+        changes=changes,
+        checksums=checksums,
+    )
+    _save_manifest(backup_path, manifest)
+
+    return BackupInfo(
+        name=backup_name,
+        path=backup_path,
+        timestamp=manifest.timestamp,
+        trigger=trigger,
+        file_count=manifest.file_count,
+        total_size_bytes=manifest.total_size_bytes,
+        description=description,
+    )
+
+
+def list_backups() -> list[BackupInfo]:
+    if not BACKUPS_PATH.exists():
+        return []
+
+    backups: list[BackupInfo] = []
+    for backup_dir in BACKUPS_PATH.iterdir():
+        if not backup_dir.is_dir() or backup_dir.name.startswith("."):
+            continue
+
+        manifest = _load_manifest(backup_dir)
+        if manifest:
+            backups.append(
+                BackupInfo(
+                    name=backup_dir.name,
+                    path=backup_dir,
+                    timestamp=manifest.timestamp,
+                    trigger=manifest.trigger,
+                    file_count=manifest.file_count,
+                    total_size_bytes=manifest.total_size_bytes,
+                    description=manifest.description,
+                )
+            )
+        else:
+            try:
+                parts = backup_dir.name.rsplit("_", 1)
+                timestamp_str = parts[0]
+                trigger_str = parts[1] if len(parts) > 1 else "manual"
+                timestamp = datetime.strptime(
+                    timestamp_str, "%Y-%m-%d_%H-%M-%S"
+                ).replace(tzinfo=UTC)
+                trigger = BackupTrigger(trigger_str)
+            except (ValueError, IndexError):
+                continue
+
+            files = list(backup_dir.glob("*"))
+            total_size = sum(f.stat().st_size for f in files if f.is_file())
+            backups.append(
+                BackupInfo(
+                    name=backup_dir.name,
+                    path=backup_dir,
+                    timestamp=timestamp,
+                    trigger=trigger,
+                    file_count=len(files),
+                    total_size_bytes=total_size,
+                )
+            )
+
+    backups.sort(key=lambda b: b.timestamp, reverse=True)
+    return backups
+
+
+def compute_changes(backup_name: str) -> BackupChanges:
+    backup_path = BACKUPS_PATH / backup_name
+    if not backup_path.exists():
+        return BackupChanges()
+
+    backup_manifest = _load_manifest(backup_path)
+    if not backup_manifest:
+        return BackupChanges()
+
+    current_files = _get_backup_files()
+    current_checksums = {f.name: _compute_file_checksum(f) for f in current_files}
+    backup_checksums = backup_manifest.checksums
+
+    added = [f for f in current_checksums if f not in backup_checksums]
+    deleted = [f for f in backup_checksums if f not in current_checksums]
+    modified = [
+        f
+        for f in current_checksums
+        if f in backup_checksums and current_checksums[f] != backup_checksums[f]
+    ]
+
+    return BackupChanges(added=added, modified=modified, deleted=deleted)
+
+
+def restore_backup(backup_name: str) -> bool:
+    backup_path = BACKUPS_PATH / backup_name
+    if not backup_path.exists():
+        return False
+
+    create_backup(BackupTrigger.AUTO, f"Auto-backup before restoring {backup_name}")
+
+    for existing_file in TAGS_PATH.iterdir():
+        if existing_file.is_file():
+            existing_file.unlink()
+
+    for backup_file in backup_path.iterdir():
+        if backup_file.is_file() and backup_file.name != MANIFEST_FILENAME:
+            shutil.copy2(backup_file, TAGS_PATH / backup_file.name)
+
+    return True
+
+
+def purge_old_backups(settings: BackupSettings) -> int:
+    if not BACKUPS_PATH.exists():
+        return 0
+
+    backups = list_backups()
+    if not backups:
+        return 0
+
+    to_delete: list[BackupInfo] = []
+    cutoff_date = datetime.now(UTC) - timedelta(days=settings.retention_days)
+
+    for i, backup in enumerate(backups):
+        if i >= settings.max_backups or (
+            settings.retention_days > 0 and backup.timestamp < cutoff_date
+        ):
+            to_delete.append(backup)
+
+    for backup in to_delete:
+        shutil.rmtree(backup.path)
+
+    return len(to_delete)
+
+
+def get_storage_usage() -> tuple[int, int]:
+    if not BACKUPS_PATH.exists():
+        return (0, 0)
+
+    total_bytes = 0
+    count = 0
+
+    for backup_dir in BACKUPS_PATH.iterdir():
+        if not backup_dir.is_dir() or backup_dir.name.startswith("."):
+            continue
+        count += 1
+        for file in backup_dir.iterdir():
+            if file.is_file():
+                total_bytes += file.stat().st_size
+
+    return (total_bytes, count)
+
+
+def get_last_auto_backup_time() -> datetime | None:
+    backups = list_backups()
+    for backup in backups:
+        if backup.trigger == BackupTrigger.AUTO:
+            return backup.timestamp
+    return None
+
+
+def should_create_auto_backup(min_interval_seconds: int = 300) -> bool:
+    last_auto = get_last_auto_backup_time()
+    if last_auto is None:
+        return True
+    elapsed = (datetime.now(UTC) - last_auto).total_seconds()
+    return elapsed >= min_interval_seconds

src/illogical/modules/backup_models.py

@@ -0,0 +1,122 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from datetime import UTC, datetime
+from enum import Enum
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+class BackupTrigger(Enum):
+    MANUAL = "manual"
+    AUTO = "auto"
+
+
+@dataclass
+class BackupChanges:
+    added: list[str] = field(default_factory=list)
+    modified: list[str] = field(default_factory=list)
+    deleted: list[str] = field(default_factory=list)
+
+    def to_dict(self) -> dict[str, list[str]]:
+        return {"added": self.added, "modified": self.modified, "deleted": self.deleted}
+
+    @classmethod
+    def from_dict(cls, data: dict[str, list[str]]) -> BackupChanges:
+        return cls(
+            added=data.get("added", []),
+            modified=data.get("modified", []),
+            deleted=data.get("deleted", []),
+        )
+
+    @property
+    def is_empty(self) -> bool:
+        return not self.added and not self.modified and not self.deleted
+
+    @property
+    def total_count(self) -> int:
+        return len(self.added) + len(self.modified) + len(self.deleted)
+
+
+@dataclass
+class BackupManifest:
+    version: int
+    timestamp: datetime
+    trigger: BackupTrigger
+    description: str
+    file_count: int
+    total_size_bytes: int
+    previous_backup: str | None
+    changes: BackupChanges
+    checksums: dict[str, str]
+
+    def to_dict(self) -> dict:
+        return {
+            "version": self.version,
+            "timestamp": self.timestamp.isoformat(),
+            "trigger": self.trigger.value,
+            "description": self.description,
+            "file_count": self.file_count,
+            "total_size_bytes": self.total_size_bytes,
+            "previous_backup": self.previous_backup,
+            "changes": self.changes.to_dict(),
+            "checksums": self.checksums,
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict) -> BackupManifest:
+        ts = datetime.fromisoformat(data["timestamp"])
+        if ts.tzinfo is None:
+            ts = ts.replace(tzinfo=UTC)
+        return cls(
+            version=data["version"],
+            timestamp=ts,
+            trigger=BackupTrigger(data["trigger"]),
+            description=data.get("description", ""),
+            file_count=data["file_count"],
+            total_size_bytes=data["total_size_bytes"],
+            previous_backup=data.get("previous_backup"),
+            changes=BackupChanges.from_dict(data.get("changes", {})),
+            checksums=data.get("checksums", {}),
+        )
+
+
+@dataclass
+class BackupInfo:
+    name: str
+    path: Path
+    timestamp: datetime
+    trigger: BackupTrigger
+    file_count: int
+    total_size_bytes: int
+    description: str = ""
+
+    @property
+    def display_name(self) -> str:
+        trigger_label = "Manual" if self.trigger == BackupTrigger.MANUAL else "Auto"
+        return f"{self.timestamp.strftime('%Y-%m-%d %H:%M:%S')} ({trigger_label})"
+
+    @property
+    def size_display(self) -> str:
+        return _format_size(self.total_size_bytes)
+
+
+_BYTES_PER_KB = 1024
+
+
+def _format_size(size_bytes: int) -> str:
+    size = float(size_bytes)
+    for unit in ("B", "KB", "MB", "GB"):
+        if size < _BYTES_PER_KB:
+            return f"{size:.1f} {unit}" if unit != "B" else f"{int(size)} {unit}"
+        size /= _BYTES_PER_KB
+    return f"{size:.1f} TB"
+
+
+@dataclass
+class BackupSettings:
+    retention_days: int = 30
+    max_backups: int = 100
+    auto_purge: bool = True

src/illogical/modules/backup_service.py

@@ -0,0 +1,134 @@
+from __future__ import annotations
+
+import logging
+
+from PySide6.QtCore import QObject, QThread, Signal
+
+from illogical.modules import backup_manager
+from illogical.modules.backup_models import BackupSettings, BackupTrigger
+
+logger = logging.getLogger(__name__)
+
+
+class BackupWorker(QObject):
+    backup_created = Signal(object)
+    backup_list_ready = Signal(list)
+    restore_completed = Signal(bool, str)
+    changes_computed = Signal(str, object)
+    storage_usage_ready = Signal(int, int)
+    purge_completed = Signal(int)
+    error_occurred = Signal(str)
+
+    def create_backup(
+        self, trigger: BackupTrigger = BackupTrigger.MANUAL, description: str = ""
+    ) -> None:
+        try:
+            backup_info = backup_manager.create_backup(trigger, description)
+            self.backup_created.emit(backup_info)
+        except OSError as e:
+            logger.exception("Backup creation failed")
+            self.error_occurred.emit(str(e))
+
+    def list_backups(self) -> None:
+        try:
+            backups = backup_manager.list_backups()
+            self.backup_list_ready.emit(backups)
+        except OSError as e:
+            logger.exception("Listing backups failed")
+            self.error_occurred.emit(str(e))
+
+    def restore_backup(self, backup_name: str) -> None:
+        try:
+            success = backup_manager.restore_backup(backup_name)
+            self.restore_completed.emit(success, backup_name)
+        except OSError as e:
+            logger.exception("Restore failed")
+            self.error_occurred.emit(str(e))
+
+    def compute_changes(self, backup_name: str) -> None:
+        try:
+            changes = backup_manager.compute_changes(backup_name)
+            self.changes_computed.emit(backup_name, changes)
+        except OSError as e:
+            logger.exception("Computing changes failed")
+            self.error_occurred.emit(str(e))
+
+    def get_storage_usage(self) -> None:
+        try:
+            total_bytes, count = backup_manager.get_storage_usage()
+            self.storage_usage_ready.emit(total_bytes, count)
+        except OSError as e:
+            logger.exception("Getting storage usage failed")
+            self.error_occurred.emit(str(e))
+
+    def purge_old_backups(self, settings: BackupSettings) -> None:
+        try:
+            deleted_count = backup_manager.purge_old_backups(settings)
+            self.purge_completed.emit(deleted_count)
+        except OSError as e:
+            logger.exception("Purging backups failed")
+            self.error_occurred.emit(str(e))
+
+    def ensure_backup_before_change(self) -> None:
+        try:
+            if backup_manager.should_create_auto_backup():
+                backup_info = backup_manager.create_backup(
+                    BackupTrigger.AUTO, "Auto-backup before plugin modification"
+                )
+                self.backup_created.emit(backup_info)
+        except OSError as e:
+            logger.exception("Auto-backup before change failed")
+            self.error_occurred.emit(str(e))
+
+
+class BackupService(QObject):
+    backup_created = Signal(object)
+    backup_list_ready = Signal(list)
+    restore_completed = Signal(bool, str)
+    changes_computed = Signal(str, object)
+    storage_usage_ready = Signal(int, int)
+    purge_completed = Signal(int)
+    error_occurred = Signal(str)
+
+    def __init__(self, parent: QObject | None = None) -> None:
+        super().__init__(parent)
+        self._thread = QThread()
+        self._worker = BackupWorker()
+        self._worker.moveToThread(self._thread)
+
+        self._worker.backup_created.connect(self.backup_created)
+        self._worker.backup_list_ready.connect(self.backup_list_ready)
+        self._worker.restore_completed.connect(self.restore_completed)
+        self._worker.changes_computed.connect(self.changes_computed)
+        self._worker.storage_usage_ready.connect(self.storage_usage_ready)
+        self._worker.purge_completed.connect(self.purge_completed)
+        self._worker.error_occurred.connect(self.error_occurred)
+
+        self._thread.start()
+
+    def create_backup(
+        self, trigger: BackupTrigger = BackupTrigger.MANUAL, description: str = ""
+    ) -> None:
+        self._worker.create_backup(trigger, description)
+
+    def list_backups(self) -> None:
+        self._worker.list_backups()
+
+    def restore_backup(self, backup_name: str) -> None:
+        self._worker.restore_backup(backup_name)
+
+    def compute_changes(self, backup_name: str) -> None:
+        self._worker.compute_changes(backup_name)
+
+    def get_storage_usage(self) -> None:
+        self._worker.get_storage_usage()
+
+    def purge_old_backups(self, settings: BackupSettings) -> None:
+        self._worker.purge_old_backups(settings)
+
+    def ensure_backup_before_change(self) -> None:
+        self._worker.ensure_backup_before_change()
+
+    def shutdown(self) -> None:
+        self._thread.quit()
+        self._thread.wait()

src/illogical/modules/models.py

@@ -100,9 +100,9 @@ class PluginTableModel(QAbstractTableModel):
             if col == COL_NAME:
                 return plugin.name
             if col == COL_CUSTOM_NAME:
-                return getattr(plugin, "custom_name", "") or ""
+                return plugin.tagset.nickname
             if col == COL_SHORT_NAME:
-                return getattr(plugin, "short_name", "") or ""
+                return plugin.tagset.shortname
             if col == COL_TYPE:
                 return plugin.type_name.display_name
             if col == COL_MANUFACTURER:
@@ -170,8 +170,8 @@ class PluginTableModel(QAbstractTableModel):
                 return getattr(plugin, "version", 0) or 0
             values = {
                 COL_NAME: plugin.name,
-                COL_CUSTOM_NAME: getattr(plugin, "custom_name", "") or "",
-                COL_SHORT_NAME: getattr(plugin, "short_name", "") or "",
+                COL_CUSTOM_NAME: plugin.tagset.nickname or "",
+                COL_SHORT_NAME: plugin.tagset.shortname or "",
                 COL_TYPE: plugin.type_code,
                 COL_MANUFACTURER: plugin.manufacturer,
             }

src/illogical/modules/settings.py

@@ -0,0 +1,54 @@
+from __future__ import annotations
+
+from PySide6.QtCore import QSettings
+
+from illogical.modules.backup_models import BackupSettings
+
+_BACKUP_RETENTION_DAYS = "backup/retention_days"
+_BACKUP_MAX_COUNT = "backup/max_count"
+_BACKUP_AUTO_PURGE = "backup/auto_purge"
+
+
+class Settings:
+    def __init__(self) -> None:
+        self._settings = QSettings("com.kotikot.illogical", "illogical")
+
+    @property
+    def backup_retention_days(self) -> int:
+        value = self._settings.value(_BACKUP_RETENTION_DAYS, 30)
+        return int(str(value)) if value is not None else 30
+
+    @backup_retention_days.setter
+    def backup_retention_days(self, value: int) -> None:
+        self._settings.setValue(_BACKUP_RETENTION_DAYS, value)
+
+    @property
+    def backup_max_count(self) -> int:
+        value = self._settings.value(_BACKUP_MAX_COUNT, 100)
+        return int(str(value)) if value is not None else 100
+
+    @backup_max_count.setter
+    def backup_max_count(self, value: int) -> None:
+        self._settings.setValue(_BACKUP_MAX_COUNT, value)
+
+    @property
+    def backup_auto_purge(self) -> bool:
+        default_value = True
+        value = self._settings.value(_BACKUP_AUTO_PURGE, default_value, type=bool)  # type: ignore[call-overload]
+        return bool(value)
+
+    @backup_auto_purge.setter
+    def backup_auto_purge(self, value: bool) -> None:
+        self._settings.setValue(_BACKUP_AUTO_PURGE, value)
+
+    def get_backup_settings(self) -> BackupSettings:
+        return BackupSettings(
+            retention_days=self.backup_retention_days,
+            max_backups=self.backup_max_count,
+            auto_purge=self.backup_auto_purge,
+        )
+
+    def save_backup_settings(self, settings: BackupSettings) -> None:
+        self.backup_retention_days = settings.retention_days
+        self.backup_max_count = settings.max_backups
+        self.backup_auto_purge = settings.auto_purge

src/illogical/ui/backup_settings_window.py

@@ -0,0 +1,133 @@
+from __future__ import annotations
+
+from PySide6.QtCore import Qt, Signal
+from PySide6.QtWidgets import (
+    QCheckBox,
+    QComboBox,
+    QDialog,
+    QGroupBox,
+    QHBoxLayout,
+    QLabel,
+    QPushButton,
+    QSpinBox,
+    QVBoxLayout,
+    QWidget,
+)
+
+from illogical.modules.backup_models import BackupSettings, _format_size
+
+RETENTION_OPTIONS = [(7, "7 days"), (30, "30 days"), (90, "90 days"), (0, "Forever")]
+
+
+class BackupSettingsWindow(QDialog):
+    settings_saved = Signal(object)
+    purge_requested = Signal()
+
+    def __init__(self, settings: BackupSettings, parent: QWidget | None = None) -> None:
+        super().__init__(parent)
+        self._settings = settings
+        self._setup_ui()
+        self._load_settings()
+
+    def _setup_ui(self) -> None:
+        self.setWindowTitle("Backup Settings")
+        self.setFixedSize(400, 300)
+        self.setWindowModality(Qt.WindowModality.WindowModal)
+
+        layout = QVBoxLayout(self)
+        layout.setSpacing(16)
+        layout.setContentsMargins(20, 20, 20, 20)
+
+        layout.addWidget(self._create_retention_group())
+        layout.addWidget(self._create_storage_group())
+        layout.addStretch()
+        layout.addWidget(self._create_buttons())
+
+    def _create_retention_group(self) -> QGroupBox:
+        group = QGroupBox("Retention Policy")
+        layout = QVBoxLayout(group)
+        layout.setSpacing(12)
+
+        retention_row = QHBoxLayout()
+        retention_row.addWidget(QLabel("Keep backups for:"))
+        self._retention_combo = QComboBox()
+        for _, label in RETENTION_OPTIONS:
+            self._retention_combo.addItem(label)
+        retention_row.addWidget(self._retention_combo)
+        retention_row.addStretch()
+        layout.addLayout(retention_row)
+
+        max_row = QHBoxLayout()
+        max_row.addWidget(QLabel("Maximum backups:"))
+        self._max_spin = QSpinBox()
+        self._max_spin.setRange(5, 500)
+        self._max_spin.setValue(100)
+        max_row.addWidget(self._max_spin)
+        max_row.addStretch()
+        layout.addLayout(max_row)
+
+        self._auto_purge_check = QCheckBox("Automatically purge old backups")
+        layout.addWidget(self._auto_purge_check)
+
+        return group
+
+    def _create_storage_group(self) -> QGroupBox:
+        group = QGroupBox("Storage")
+        layout = QVBoxLayout(group)
+        layout.setSpacing(12)
+
+        self._storage_label = QLabel("Loading...")
+        layout.addWidget(self._storage_label)
+
+        self._purge_button = QPushButton("Purge Old Backups Now")
+        self._purge_button.clicked.connect(self._on_purge_clicked)
+        layout.addWidget(self._purge_button)
+
+        return group
+
+    def _create_buttons(self) -> QWidget:
+        container = QWidget()
+        layout = QHBoxLayout(container)
+        layout.setContentsMargins(0, 0, 0, 0)
+
+        layout.addStretch()
+
+        cancel_btn = QPushButton("Cancel")
+        cancel_btn.clicked.connect(self.reject)
+        layout.addWidget(cancel_btn)
+
+        save_btn = QPushButton("Save")
+        save_btn.setDefault(True)
+        save_btn.clicked.connect(self._on_save)
+        layout.addWidget(save_btn)
+
+        return container
+
+    def _load_settings(self) -> None:
+        retention_days = self._settings.retention_days
+        for i, (days, _) in enumerate(RETENTION_OPTIONS):
+            if days == retention_days:
+                self._retention_combo.setCurrentIndex(i)
+                break
+
+        self._max_spin.setValue(self._settings.max_backups)
+        self._auto_purge_check.setChecked(self._settings.auto_purge)
+
+    def _on_save(self) -> None:
+        idx = self._retention_combo.currentIndex()
+        retention_days = RETENTION_OPTIONS[idx][0]
+
+        settings = BackupSettings(
+            retention_days=retention_days,
+            max_backups=self._max_spin.value(),
+            auto_purge=self._auto_purge_check.isChecked(),
+        )
+        self.settings_saved.emit(settings)
+        self.accept()
+
+    def _on_purge_clicked(self) -> None:
+        self.purge_requested.emit()
+
+    def update_storage_info(self, total_bytes: int, count: int) -> None:
+        size_display = _format_size(total_bytes)
+        self._storage_label.setText(f"{count} backups using {size_display}")

src/illogical/ui/main_window.py

@@ -4,17 +4,28 @@ from typing import TYPE_CHECKING
 
 import pyqt_liquidglass as glass
 from PySide6.QtCore import Qt, QTimer
-from PySide6.QtWidgets import QHBoxLayout, QMainWindow, QSplitter, QWidget
+from PySide6.QtWidgets import QHBoxLayout, QMainWindow, QMessageBox, QSplitter, QWidget
 
+from illogical.modules.backup_service import BackupService
 from illogical.modules.plugin_service import PluginService
+from illogical.modules.settings import Settings
+from illogical.ui.backup_settings_window import BackupSettingsWindow
 from illogical.ui.loading_overlay import LoadingOverlay
+from illogical.ui.menu_bar import MenuBar
 from illogical.ui.plugin_table import PluginTableView
+from illogical.ui.restore_backup_window import RestoreBackupWindow
 from illogical.ui.sidebar import Sidebar
 
 if TYPE_CHECKING:
     from logic_plugin_manager import Logic, SearchResult
     from PySide6.QtGui import QCloseEvent, QKeyEvent, QShowEvent
 
+    from illogical.modules.backup_models import (
+        BackupChanges,
+        BackupInfo,
+        BackupSettings,
+    )
+
 
 class MainWindow(QMainWindow):
     def __init__(self) -> None:
@@ -25,12 +36,22 @@ class MainWindow(QMainWindow):
 
         self._logic: Logic | None = None
         self._glass_applied = False
+        self._settings = Settings()
 
         self._setup_ui()
         self._setup_service()
+        self._setup_backup_service()
+        self._setup_menu_bar()
 
         glass.prepare_window_for_glass(self)
 
+    def _setup_menu_bar(self) -> None:
+        self._menu_bar = MenuBar(self)
+
+        self._menu_bar.backup_now_triggered.connect(self._on_backup_now)
+        self._menu_bar.restore_backup_triggered.connect(self._on_restore_backup)
+        self._menu_bar.backup_settings_triggered.connect(self._on_backup_settings)
+
     def _setup_ui(self) -> None:
         self._central = QWidget()
         layout = QHBoxLayout(self._central)
@@ -71,6 +92,19 @@ class MainWindow(QMainWindow):
         self._service.search_results.connect(self._on_search_results)
         self._service.error_occurred.connect(self._on_error)
 
+    def _setup_backup_service(self) -> None:
+        self._backup_service = BackupService(self)
+        self._backup_service.backup_created.connect(self._on_backup_created)
+        self._backup_service.backup_list_ready.connect(self._on_backup_list_ready)
+        self._backup_service.restore_completed.connect(self._on_restore_completed)
+        self._backup_service.changes_computed.connect(self._on_changes_computed)
+        self._backup_service.storage_usage_ready.connect(self._on_storage_usage_ready)
+        self._backup_service.purge_completed.connect(self._on_purge_completed)
+        self._backup_service.error_occurred.connect(self._on_backup_error)
+
+        self._restore_window: RestoreBackupWindow | None = None
+        self._settings_window: BackupSettingsWindow | None = None
+
     def showEvent(self, event: QShowEvent) -> None:  # noqa: N802
         super().showEvent(event)
         if not self._glass_applied:
@@ -125,6 +159,83 @@ class MainWindow(QMainWindow):
     def _on_error(self, message: str) -> None:
         self._loading_overlay.set_message(f"Error: {message}")
 
+    def _on_backup_now(self) -> None:
+        self._backup_service.create_backup()
+
+    def _on_restore_backup(self) -> None:
+        self._restore_window = RestoreBackupWindow(self)
+        self._restore_window.backup_selected.connect(self._on_restore_backup_selected)
+        self._restore_window.restore_requested.connect(self._on_restore_requested)
+        self._backup_service.list_backups()
+        self._restore_window.show()
+
+    def _on_backup_settings(self) -> None:
+        settings = self._settings.get_backup_settings()
+        self._settings_window = BackupSettingsWindow(settings, self)
+        self._settings_window.settings_saved.connect(self._on_settings_saved)
+        self._settings_window.purge_requested.connect(self._on_purge_requested)
+        self._backup_service.get_storage_usage()
+        self._settings_window.show()
+
+    def _on_backup_created(self, backup_info: BackupInfo) -> None:
+        QMessageBox.information(
+            self,
+            "Backup Created",
+            f"Backup created successfully.\n\n"
+            f"Files: {backup_info.file_count}\n"
+            f"Size: {backup_info.size_display}",
+        )
+
+    def _on_backup_list_ready(self, backups: list[BackupInfo]) -> None:
+        if self._restore_window:
+            self._restore_window.set_backups(backups)
+
+    def _on_restore_backup_selected(self, backup_name: str) -> None:
+        self._backup_service.compute_changes(backup_name)
+
+    def _on_changes_computed(self, backup_name: str, changes: BackupChanges) -> None:
+        if self._restore_window:
+            self._restore_window.set_changes(backup_name, changes)
+
+    def _on_restore_requested(self, backup_name: str) -> None:
+        self._backup_service.restore_backup(backup_name)
+
+    def _on_restore_completed(self, success: bool, backup_name: str) -> None:  # noqa: FBT001
+        if success:
+            QMessageBox.information(
+                self,
+                "Restore Complete",
+                f"Backup '{backup_name}' has been restored.\n\n"
+                "Please restart the application to see the changes.",
+            )
+        else:
+            QMessageBox.warning(
+                self, "Restore Failed", f"Failed to restore backup '{backup_name}'."
+            )
+
+    def _on_storage_usage_ready(self, total_bytes: int, count: int) -> None:
+        if self._settings_window:
+            self._settings_window.update_storage_info(total_bytes, count)
+
+    def _on_settings_saved(self, settings: BackupSettings) -> None:
+        self._settings.save_backup_settings(settings)
+        if settings.auto_purge:
+            self._backup_service.purge_old_backups(settings)
+
+    def _on_purge_requested(self) -> None:
+        settings = self._settings.get_backup_settings()
+        self._backup_service.purge_old_backups(settings)
+
+    def _on_purge_completed(self, deleted_count: int) -> None:
+        self._backup_service.get_storage_usage()
+        if deleted_count > 0:
+            QMessageBox.information(
+                self, "Purge Complete", f"Deleted {deleted_count} old backup(s)."
+            )
+
+    def _on_backup_error(self, message: str) -> None:
+        QMessageBox.warning(self, "Backup Error", message)
+
     def keyPressEvent(self, event: QKeyEvent) -> None:  # noqa: N802
         mods = event.modifiers()
         key = event.key()
@@ -175,4 +286,5 @@ class MainWindow(QMainWindow):
 
     def closeEvent(self, event: QCloseEvent) -> None:  # noqa: N802
         self._service.shutdown()
+        self._backup_service.shutdown()
         super().closeEvent(event)

src/illogical/ui/menu_bar.py

@@ -0,0 +1,93 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from PySide6.QtCore import Signal
+from PySide6.QtGui import QAction, QKeySequence
+from PySide6.QtWidgets import QMenuBar
+
+if TYPE_CHECKING:
+    from PySide6.QtWidgets import QMainWindow
+
+
+class MenuBar(QMenuBar):
+    backup_now_triggered = Signal()
+    restore_backup_triggered = Signal()
+    backup_settings_triggered = Signal()
+
+    def __init__(self, main_window: QMainWindow | None = None) -> None:
+        super().__init__()
+        self._main_window = main_window
+        self.setNativeMenuBar(True)
+        self._setup_menus()
+
+    def _setup_menus(self) -> None:
+        self._setup_file_menu()
+        self._setup_edit_menu()
+        self._setup_backup_menu()
+        self._setup_help_menu()
+
+    def _setup_file_menu(self) -> None:
+        file_menu = self.addMenu("File")
+
+        close_action = QAction("Close Window", self)
+        close_action.setShortcut(QKeySequence.StandardKey.Close)
+        if self._main_window is not None:
+            close_action.triggered.connect(self._main_window.close)
+        file_menu.addAction(close_action)
+
+    def _setup_edit_menu(self) -> None:
+        edit_menu = self.addMenu("Edit")
+
+        undo_action = QAction("Undo", self)
+        undo_action.setShortcut(QKeySequence.StandardKey.Undo)
+        undo_action.setEnabled(False)
+        edit_menu.addAction(undo_action)
+
+        redo_action = QAction("Redo", self)
+        redo_action.setShortcut(QKeySequence.StandardKey.Redo)
+        redo_action.setEnabled(False)
+        edit_menu.addAction(redo_action)
+
+        edit_menu.addSeparator()
+
+        cut_action = QAction("Cut", self)
+        cut_action.setShortcut(QKeySequence.StandardKey.Cut)
+        edit_menu.addAction(cut_action)
+
+        copy_action = QAction("Copy", self)
+        copy_action.setShortcut(QKeySequence.StandardKey.Copy)
+        edit_menu.addAction(copy_action)
+
+        paste_action = QAction("Paste", self)
+        paste_action.setShortcut(QKeySequence.StandardKey.Paste)
+        edit_menu.addAction(paste_action)
+
+        select_all_action = QAction("Select All", self)
+        select_all_action.setShortcut(QKeySequence.StandardKey.SelectAll)
+        edit_menu.addAction(select_all_action)
+
+    def _setup_backup_menu(self) -> None:
+        backup_menu = self.addMenu("Backup")
+
+        backup_now_action = QAction("Backup Now", self)
+        backup_now_action.setShortcut(QKeySequence("Ctrl+B"))
+        backup_now_action.triggered.connect(self.backup_now_triggered)
+        backup_menu.addAction(backup_now_action)
+
+        backup_menu.addSeparator()
+
+        restore_action = QAction("Restore Backup...", self)
+        restore_action.setShortcut(QKeySequence("Ctrl+Shift+R"))
+        restore_action.triggered.connect(self.restore_backup_triggered)
+        backup_menu.addAction(restore_action)
+
+        backup_menu.addSeparator()
+
+        settings_action = QAction("Backup Settings...", self)
+        settings_action.setShortcut(QKeySequence.StandardKey.Preferences)
+        settings_action.triggered.connect(self.backup_settings_triggered)
+        backup_menu.addAction(settings_action)
+
+    def _setup_help_menu(self) -> None:
+        self.addMenu("Help")

src/illogical/ui/restore_backup_window.py

@@ -0,0 +1,204 @@
+from __future__ import annotations
+
+from PySide6.QtCore import Qt, Signal
+from PySide6.QtWidgets import (
+    QDialog,
+    QHBoxLayout,
+    QLabel,
+    QListWidget,
+    QListWidgetItem,
+    QMessageBox,
+    QPushButton,
+    QSplitter,
+    QTreeWidget,
+    QTreeWidgetItem,
+    QVBoxLayout,
+    QWidget,
+)
+
+from illogical.modules.backup_models import BackupChanges, BackupInfo, BackupTrigger
+from illogical.modules.sf_symbols import sf_symbol
+
+
+class RestoreBackupWindow(QDialog):
+    restore_requested = Signal(str)
+    backup_selected = Signal(str)
+
+    def __init__(self, parent: QWidget | None = None) -> None:
+        super().__init__(parent)
+        self._backups: list[BackupInfo] = []
+        self._changes_cache: dict[str, BackupChanges] = {}
+        self._setup_ui()
+
+    def _setup_ui(self) -> None:
+        self.setWindowTitle("Restore Backup")
+        self.resize(700, 500)
+        self.setWindowModality(Qt.WindowModality.WindowModal)
+
+        layout = QVBoxLayout(self)
+        layout.setSpacing(12)
+        layout.setContentsMargins(16, 16, 16, 16)
+
+        splitter = QSplitter(Qt.Orientation.Horizontal)
+        splitter.addWidget(self._create_backup_list())
+        splitter.addWidget(self._create_details_panel())
+        splitter.setStretchFactor(0, 1)
+        splitter.setStretchFactor(1, 2)
+        layout.addWidget(splitter, 1)
+
+        layout.addWidget(self._create_buttons())
+
+    def _create_backup_list(self) -> QWidget:
+        container = QWidget()
+        layout = QVBoxLayout(container)
+        layout.setContentsMargins(0, 0, 0, 0)
+        layout.setSpacing(8)
+
+        layout.addWidget(QLabel("Available Backups"))
+
+        self._backup_list = QListWidget()
+        self._backup_list.currentItemChanged.connect(self._on_backup_selected)
+        layout.addWidget(self._backup_list)
+
+        return container
+
+    def _create_details_panel(self) -> QWidget:
+        container = QWidget()
+        layout = QVBoxLayout(container)
+        layout.setContentsMargins(0, 0, 0, 0)
+        layout.setSpacing(8)
+
+        layout.addWidget(QLabel("Details"))
+
+        self._details_label = QLabel("Select a backup to view details")
+        self._details_label.setWordWrap(True)
+        layout.addWidget(self._details_label)
+
+        layout.addWidget(QLabel("Changes if restored:"))
+
+        self._changes_tree = QTreeWidget()
+        self._changes_tree.setHeaderHidden(True)
+        self._changes_tree.setIndentation(16)
+        layout.addWidget(self._changes_tree, 1)
+
+        return container
+
+    def _create_buttons(self) -> QWidget:
+        container = QWidget()
+        layout = QHBoxLayout(container)
+        layout.setContentsMargins(0, 0, 0, 0)
+
+        layout.addStretch()
+
+        cancel_btn = QPushButton("Cancel")
+        cancel_btn.clicked.connect(self.reject)
+        layout.addWidget(cancel_btn)
+
+        self._restore_btn = QPushButton("Restore")
+        self._restore_btn.setEnabled(False)
+        self._restore_btn.clicked.connect(self._on_restore_clicked)
+        layout.addWidget(self._restore_btn)
+
+        return container
+
+    def set_backups(self, backups: list[BackupInfo]) -> None:
+        self._backups = backups
+        self._backup_list.clear()
+
+        for backup in backups:
+            item = QListWidgetItem()
+            item.setText(backup.display_name)
+            item.setData(Qt.ItemDataRole.UserRole, backup.name)
+
+            if backup.trigger == BackupTrigger.MANUAL:
+                icon_name = "hand.tap"
+            else:
+                icon_name = "clock.arrow.circlepath"
+            icon = sf_symbol(icon_name, 16)
+            if not icon.isNull():
+                item.setIcon(icon)
+
+            self._backup_list.addItem(item)
+
+    def _on_backup_selected(self, current: QListWidgetItem | None) -> None:
+        if current is None:
+            self._restore_btn.setEnabled(False)
+            self._details_label.setText("Select a backup to view details")
+            self._changes_tree.clear()
+            return
+
+        backup_name = current.data(Qt.ItemDataRole.UserRole)
+        self._restore_btn.setEnabled(True)
+
+        backup = next((b for b in self._backups if b.name == backup_name), None)
+        if backup:
+            details = (
+                f"Created: {backup.timestamp.strftime('%Y-%m-%d %H:%M:%S')}\n"
+                f"Files: {backup.file_count}\n"
+                f"Size: {backup.size_display}"
+            )
+            if backup.description:
+                details += f"\nNote: {backup.description}"
+            self._details_label.setText(details)
+
+        self.backup_selected.emit(backup_name)
+
+    def set_changes(self, backup_name: str, changes: BackupChanges) -> None:
+        self._changes_cache[backup_name] = changes
+
+        current = self._backup_list.currentItem()
+        if current and current.data(Qt.ItemDataRole.UserRole) == backup_name:
+            self._display_changes(changes)
+
+    def _display_changes(self, changes: BackupChanges) -> None:
+        self._changes_tree.clear()
+
+        if changes.is_empty:
+            item = QTreeWidgetItem(["No changes (identical to current)"])
+            self._changes_tree.addTopLevelItem(item)
+            return
+
+        self._add_change_group(changes.added, "Files to remove", "minus.circle")
+        self._add_change_group(
+            changes.modified, "Files to revert", "arrow.uturn.backward.circle"
+        )
+        self._add_change_group(changes.deleted, "Files to restore", "plus.circle")
+
+    def _add_change_group(self, files: list[str], label: str, icon_name: str) -> None:
+        if not files:
+            return
+        group_item = QTreeWidgetItem([f"{label} ({len(files)})"])
+        icon = sf_symbol(icon_name, 14)
+        if not icon.isNull():
+            group_item.setIcon(0, icon)
+        for filename in sorted(files):
+            QTreeWidgetItem(group_item, [filename])
+        self._changes_tree.addTopLevelItem(group_item)
+        group_item.setExpanded(True)
+
+    def _on_restore_clicked(self) -> None:
+        current = self._backup_list.currentItem()
+        if not current:
+            return
+
+        backup_name = current.data(Qt.ItemDataRole.UserRole)
+        backup = next((b for b in self._backups if b.name == backup_name), None)
+        if not backup:
+            return
+
+        ts = backup.timestamp.strftime("%Y-%m-%d %H:%M:%S")
+        msg = (
+            f"Are you sure you want to restore the backup from {ts}?\n\n"
+            "An automatic backup will be created before restoring."
+        )
+        result = QMessageBox.question(
+            self,
+            "Restore Backup",
+            msg,
+            QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
+            QMessageBox.StandardButton.No,
+        )
+
+        if result == QMessageBox.StandardButton.Yes:
+            self.restore_requested.emit(backup_name)
+            self.accept()