fix(api): follow the cdm config key order for the server CDM

docs/reference/configuration/drm.md

@@ -48,7 +48,7 @@ height is known. If the value is still a dict after that, unshackle uses
 When an entry holds `widevine` and `playready`, their order sets which device unshackle loads
 first. A track that offers the two DRM systems licenses with that system. A track that offers
 only the other system uses the other device. A `widevine` / `playready` dict in a quality key
-does not set the order.
+does not set the order. The server CDM of a remote session follows the same order.
 
 A quality key can also hold a dict of `widevine` / `playready` devices, and so can the
 top-level `default` entry:

tests/core/test_all_drm.py

@@ -17,7 +17,7 @@ from pywidevine.pssh import PSSH
 from rich.table import Table
 
 from unshackle.commands.dl import dl
-from unshackle.core.api.handlers import load_full_cdm, validate_download_parameters
+from unshackle.core.api.handlers import load_full_cdm, resolve_server_cdm, validate_download_parameters
 from unshackle.core.cdm.detect import cdm_type_stub, is_widevine_cdm
 from unshackle.core.drm import PlayReady, Widevine
 from unshackle.core.manifests import HLS
@@ -306,3 +306,22 @@ def test_the_first_drm_system_of_the_config_entry_loads_first(
     assert cmd.get_cdm("EXAMPLE") == expected
     assert load_full_cdm("EXAMPLE", None) == expected
     assert cmd.get_cdm("EXAMPLE", drm="widevine") == "wv_device"
+
+
+@pytest.mark.parametrize(
+    ("entry", "expected"),
+    [
+        ({"playready": "pr_device", "widevine": "wv_device"}, "playready"),
+        ({"widevine": "wv_device", "playready": "pr_device"}, "widevine"),
+    ],
+)
+def test_the_server_cdm_stub_is_the_first_drm_system_of_the_config_entry(
+    monkeypatch: pytest.MonkeyPatch, entry: dict, expected: str
+) -> None:
+    monkeypatch.setattr("unshackle.core.config.config.cdm", {"EXAMPLE": entry})
+    monkeypatch.setattr(
+        "unshackle.core.api.handlers.detect_cdm_type",
+        lambda name, _: "playready" if name == "pr_device" else "widevine",
+    )
+
+    assert is_widevine_cdm(resolve_server_cdm("EXAMPLE", None, None)) is (expected == "widevine")

unshackle/core/api/handlers.py

@@ -3914,7 +3914,8 @@ def resolve_server_cdm(service: str, profile: Optional[str], cdm_type: Optional[
     Checks the server's own CDM config (``config.cdm[service]``) to
     determine the CDM type without loading the full CDM object. This
     makes sure that when you use ``server_cdm: true``, the server's CDM
-    determines device selection (e.g. PlayReady vs Widevine).
+    determines device selection (e.g. PlayReady vs Widevine). An entry with
+    ``widevine`` and ``playready`` gives the DRM system that it lists first.
 
     Falls back to a lightweight stub from *cdm_type* only if the configuration
     has no server CDM for the service.
@@ -3926,7 +3927,8 @@ def resolve_server_cdm(service: str, profile: Optional[str], cdm_type: Optional[
         if isinstance(cdm_name, dict):
             lower_keys = {k.lower(): v for k, v in cdm_name.items()}
             if {"widevine", "playready"} & lower_keys.keys():
-                cdm_name = lower_keys.get("playready") or lower_keys.get("widevine")
+                systems = [lower_keys[key] for key in lower_keys if key in ("widevine", "playready")]
+                cdm_name = next(filter(None, systems), None)
             else:
                 cdm_name = cdm_name.get("default") or next(iter(cdm_name.values()), None)