feat(saves): save sync v2 service refactoring (#184)

Refactor SaveService to use new adapter and domain capabilities:

- Wire domain save path resolution (resolve_save_dir with roms_base)
  and per-platform save extensions into _find_save_files
- Use build_emulator_tag(active_core) via CoreResolverFn protocol
  instead of hardcoded "retroarch"
- Extend state format: server_device_id, active_core, active_slot,
  tracked_save_id (all backward-compat via .get() defaults)
- Server device registration on v4.7 (register_device API), local
  UUID fallback on v4.6
- Pass device_id and slot to list_saves/upload_save on v4.7
- Use determine_sync_action with device_syncs is_current for v4.7
  conflict detection, avoiding expensive server hash downloads
- Read plugin version from package.json at bootstrap

20 new tests, 1531 total passing.

Author: danielcopper

main.py

@@ -148,6 +148,7 @@ async def _main(self):  # Decky lifecycle — must be async
                 runtime_dir=decky.DECKY_PLUGIN_RUNTIME_DIR,
                 emit=decky.emit,
                 get_saves_path=retrodeck_config.get_saves_path,
+                get_roms_path=retrodeck_config.get_roms_path,
                 save_state=self._save_state,
                 save_settings_to_disk=self._save_settings_to_disk,
                 save_metadata_cache=self._save_metadata_cache,

py_modules/bootstrap.py

@@ -34,6 +34,7 @@
     DebugLogger,
     EventEmitter,
     RommApiProtocol,
+    RomsPathProvider,
     SavesPathProvider,
     SettingsPersister,
     StatePersister,
@@ -71,6 +72,7 @@ class WiringConfig:
 
     # Callbacks
     get_saves_path: SavesPathProvider
+    get_roms_path: RomsPathProvider
     save_state: StatePersister
     save_settings_to_disk: SettingsPersister
     save_metadata_cache: StatePersister
@@ -127,6 +129,18 @@ def bootstrap(
     }
 
 
+def _read_plugin_version(plugin_dir: str) -> str:
+    """Read plugin version from package.json."""
+    import json
+    import os
+
+    try:
+        with open(os.path.join(plugin_dir, "package.json")) as f:
+            return json.load(f).get("version", "0.0.0")
+    except (OSError, json.JSONDecodeError):
+        return "0.0.0"
+
+
 def wire_services(cfg: WiringConfig) -> dict:
     """Create service instances after plugin state is initialised.
 
@@ -148,6 +162,9 @@ def wire_services(cfg: WiringConfig) -> dict:
         logger=cfg.logger,
         runtime_dir=cfg.runtime_dir,
         get_saves_path=cfg.get_saves_path,
+        get_roms_path=cfg.get_roms_path,
+        get_active_core=_es_de_config.get_active_core,
+        plugin_version=_read_plugin_version(cfg.plugin_dir),
     )
 
     playtime_service = PlaytimeService(

py_modules/domain/save_path.py

@@ -16,6 +16,7 @@ def resolve_save_dir(
     saves_base: str,
     system: str,
     *,
+    roms_base: str | None = None,
     sort_by_content: bool = True,
     sort_by_core: bool = False,
     core_name: str | None = None,
@@ -25,12 +26,17 @@ def resolve_save_dir(
     Parameters
     ----------
     rom_path:
-        Relative ROM file path as stored in RomM (e.g. "gba/Game.gba" or
+        ROM file path — absolute or relative (e.g. "gba/Game.gba",
+        "/home/deck/retrodeck/roms/gba/Game.gba", or
         "psx/Game (USA)/Game.m3u").
     saves_base:
         Absolute path to the RetroArch saves root directory.
     system:
         Platform/system slug (e.g. "gba", "psx"). Used as fallback subdir.
+    roms_base:
+        If provided, strip this absolute prefix from rom_path before
+        computing the content directory. Allows callers to pass absolute
+        ROM paths directly without pre-stripping.
     sort_by_content:
         If True, save subdir = last folder component of rom_path.
         RetroDECK default: True.
@@ -45,11 +51,21 @@ def resolve_save_dir(
     str
         Absolute path to the directory where save files should be found/placed.
     """
+    # Strip roms_base prefix if provided to get a relative path
+    effective_path = rom_path
+    if roms_base is not None:
+        norm_rom = os.path.normpath(rom_path)
+        norm_base = os.path.normpath(roms_base)
+        if norm_rom.startswith(norm_base + os.sep):
+            effective_path = norm_rom[len(norm_base) + 1 :]
+        elif norm_rom.startswith(norm_base):
+            effective_path = norm_rom[len(norm_base) :]
+
     parts: list[str] = [saves_base]
 
     if sort_by_content:
-        # Last folder component of the rom_path (i.e. the directory containing the ROM file)
-        rom_dir = os.path.dirname(rom_path)
+        # Last folder component of the effective_path (i.e. the directory containing the ROM file)
+        rom_dir = os.path.dirname(effective_path)
         content_dir = os.path.basename(rom_dir) if rom_dir else system
         parts.append(content_dir)
 

py_modules/services/protocols.py

@@ -318,6 +318,18 @@ class SavesPathProvider(Protocol):
     def __call__(self) -> str: ...
 
 
+class RomsPathProvider(Protocol):
+    """Return the current RetroDECK roms directory path."""
+
+    def __call__(self) -> str: ...
+
+
+class CoreResolverFn(Protocol):
+    """Resolve the active RetroArch core for a system/game."""
+
+    def __call__(self, system_name: str, rom_filename: str | None = None) -> tuple[str | None, str | None]: ...
+
+
 class SyncStateRef(Protocol):
     """Return the current sync state value (used by ArtworkService)."""