音楽で楽しみましょう！-Let's have fun with music!-

Signed-off-by: Shin'ya Minazuki <shinyoukai@laidback.moe>

api/funquail_api/common/preferences.py

@@ -0,0 +1,107 @@
+import json
+
+from django import forms
+from django.conf import settings
+from django.contrib.postgres.forms import JSONField
+from dynamic_preferences import serializers, types
+from dynamic_preferences.registries import global_preferences_registry
+
+
+class DefaultFromSettingMixin:
+    def get_default(self):
+        return getattr(settings, self.setting)
+
+
+def get(pref):
+    manager = global_preferences_registry.manager()
+    return manager[pref]
+
+
+def all():
+    manager = global_preferences_registry.manager()
+    return manager.all()
+
+
+def set(pref, value):
+    manager = global_preferences_registry.manager()
+    manager[pref] = value
+
+
+class StringListSerializer(serializers.BaseSerializer):
+    separator = ","
+    sort = True
+
+    @classmethod
+    def to_db(cls, value, **kwargs):
+        if not value:
+            return
+
+        if type(value) not in [list, tuple]:
+            raise cls.exception(
+                f"Cannot serialize, value {value} is not a list or a tuple"
+            )
+
+        if cls.sort:
+            value = sorted(value)
+        return cls.separator.join(value)
+
+    @classmethod
+    def to_python(cls, value, **kwargs):
+        if not value:
+            return []
+        return value.split(",")
+
+
+class StringListPreference(types.BasePreferenceType):
+    serializer = StringListSerializer
+    field_class = forms.MultipleChoiceField
+
+    def get_api_additional_data(self):
+        d = super().get_api_additional_data()
+        d["choices"] = self.get("choices")
+        return d
+
+
+class JSONSerializer(serializers.BaseSerializer):
+    required = True
+
+    @classmethod
+    def to_db(cls, value, **kwargs):
+        if not cls.required and value is None:
+            return json.dumps(value)
+        data_serializer = cls.data_serializer_class(data=value)
+        if not data_serializer.is_valid():
+            raise cls.exception(
+                f"{value} is not a valid value: {data_serializer.errors}"
+            )
+        value = data_serializer.validated_data
+        try:
+            return json.dumps(value, sort_keys=True)
+        except TypeError:
+            raise cls.exception(
+                f"Cannot serialize, value {value} is not JSON serializable"
+            )
+
+    @classmethod
+    def to_python(cls, value, **kwargs):
+        return json.loads(value)
+
+
+class SerializedPreference(types.BasePreferenceType):
+    """
+    A preference that store arbitrary JSON and validate it using a rest_framework
+    serializer
+    """
+
+    serializer = JSONSerializer
+    data_serializer_class = None
+    field_class = JSONField
+    widget = forms.Textarea
+
+    @property
+    def serializer(self):
+        class _internal(JSONSerializer):
+            data_serializer_class = self.data_serializer_class
+            required = self.get("required")
+
+        return _internal