config, defaults: add configuration for backups

Add configuration options for creating backups during the
synchronisation.

src/unisync/config.py

@@ -49,6 +49,18 @@ class UnisonConfig:
     bools: list
     values: dict
 
+@dataclass
+class BackupConfig:
+    """
+    Configuration options relative to backing up the files.
+    """
+    enabled: bool
+    selection: str
+    location: str
+    max_backups: int
+    backupsuffix: str
+    backupprefix: str
+
 @dataclass
 class OtherConfig:
     """
@@ -64,6 +76,7 @@ class Config:
     server: ServerConfig
     roots: RootsConfig
     unison: UnisonConfig
+    backup: BackupConfig
     other: OtherConfig
 
 
@@ -81,6 +94,7 @@ def load_config(config_path:str) -> Config:
     # Check if sections are provided
     server_section = "Server" if "Server" in config.sections() else UNNAMED_SECTION
     roots_section = "Roots" if "Roots" in config.sections() else UNNAMED_SECTION
+    backup_section = "Backup"
     other_section = "Other" if "Other" in config.sections() else UNNAMED_SECTION
 
     server_config = ServerConfig(
@@ -94,6 +108,14 @@ def load_config(config_path:str) -> Config:
             config.get(roots_section, "local", fallback=DEFAULT_ROOTS_LOCAL),
             config.get(roots_section, "remote")
         )
+    backup_config = BackupConfig(
+            config.getboolean(backup_section, "enabled", fallback=DEFAULT_BACKUP_ENABLED),
+            config.get(backup_section, "selection", fallback=DEFAULT_BACKUP_SELECTION),
+            config.get(backup_section, "loction", fallback=DEFAULT_BACKUP_LOC),
+            config.getint(backup_section, "max_backups", fallback=DEFAULT_BACKUP_MAX_BACKUPS),
+            config.get(backup_section, "backupsuffix", fallback=DEFAULT_BACKUP_BACKUPSUFFIX),
+            config.get(backup_section, "backupprefix", fallback=DEFAULT_BACKUP_BACKUPPREFIX)
+        )
     other_config = OtherConfig(
             Path(config.get(other_section, "cache_dir_path", fallback=DEFAULT_MISC_CACHE_DIR_PATH)).expanduser()
         )
@@ -110,4 +132,4 @@ def load_config(config_path:str) -> Config:
                 args_val[key] = val
     unison_config = UnisonConfig(args_bool, args_val)
 
-    return Config(server_config, roots_config, unison_config, other_config)
+    return Config(server_config, roots_config, unison_config, backup_config, other_config)

src/unisync/defaults.py

@@ -16,3 +16,10 @@ DEFAULT_ROOTS_LOCAL: str = str(Path("~/files").expanduser())
 # DEFAULT_ROOTS_REMOTE: str = ""
 
 DEFAULT_MISC_CACHE_DIR_PATH: str = "~/.unisync"
+
+DEFAULT_BACKUP_ENABLED: bool = False
+DEFAULT_BACKUP_SELECTION: str = ""
+DEFAULT_BACKUP_LOC: str = "local"
+DEFAULT_BACKUP_MAX_BACKUPS: int = 2
+DEFAULT_BACKUP_BACKUPSUFFIX: str = ".unison_backups/"
+DEFAULT_BACKUP_BACKUPPREFIX: str = ".$VERSION.bak"