refactor: reorganize backend module boundaries

app/application/filter.py

@@ -0,0 +1,66 @@
+from typing import List, Optional
+
+from app.db.systemconfig_oper import SystemConfigOper
+from app.domain.context import MediaInfo
+from app.schemas import CustomRule, FilterRuleGroup
+from app.schemas.types import SystemConfigKey
+
+
+class RuleHelper:
+    """读取用户过滤规则配置，并按媒体上下文选择适用规则组。"""
+
+    @staticmethod
+    def get_rule_groups() -> List[FilterRuleGroup]:
+        """返回用户配置的全部过滤规则组。"""
+        rule_groups: List[dict] = SystemConfigOper().get(
+            SystemConfigKey.UserFilterRuleGroups
+        )
+        if not rule_groups:
+            return []
+        return [FilterRuleGroup(**group) for group in rule_groups]
+
+    def get_rule_group(self, group_name: str) -> Optional[FilterRuleGroup]:
+        """按名称返回过滤规则组。"""
+        return next(
+            (group for group in self.get_rule_groups() if group.name == group_name),
+            None,
+        )
+
+    def get_rule_group_by_media(
+        self,
+        media: Optional[MediaInfo] = None,
+        group_names: Optional[list] = None,
+    ) -> List[FilterRuleGroup]:
+        """按媒体类型、分类和候选名称筛选适用规则组。"""
+        rule_groups = self.get_rule_groups()
+        if group_names:
+            rule_groups = [
+                group for group in rule_groups if group.name in group_names
+            ]
+        return [
+            group
+            for group in rule_groups
+            if not group.media_type
+            or (
+                media
+                and (
+                    (not group.category and group.media_type == media.type.value)
+                    or group.category == media.category
+                )
+            )
+        ]
+
+    @staticmethod
+    def get_custom_rules() -> List[CustomRule]:
+        """返回用户配置的全部自定义过滤规则。"""
+        rules: List[dict] = SystemConfigOper().get(SystemConfigKey.CustomFilterRules)
+        if not rules:
+            return []
+        return [CustomRule(**rule) for rule in rules]
+
+    def get_custom_rule(self, rule_id: str) -> Optional[CustomRule]:
+        """按 ID 返回一条自定义过滤规则。"""
+        return next(
+            (rule for rule in self.get_custom_rules() if rule.id == rule_id),
+            None,
+        )