chore: update gitignore; feat: 新增customer_agent业务模块与api路由

agent/customer_agent/context.py

@@ -0,0 +1,51 @@
+"""Redis short-term conversation context for the customer-service Agent."""
+from __future__ import annotations
+
+import json
+from inspect import isawaitable
+
+
+async def _config(config_getter, key: str, default):
+    value = config_getter(key, str(default))
+    if isawaitable(value):
+        value = await value
+    return type(default)(value)
+
+
+class RedisConversationContext:
+    def __init__(self, redis, *, config_getter, token_counter=None):
+        self.redis = redis
+        self.config_getter = config_getter
+        self.token_counter = token_counter or (lambda text: max(1, len(text) // 4))
+
+    async def append(self, session_id: str, role: str, content: str) -> None:
+        key = f"session:{session_id}:messages"
+        payload = json.dumps(
+            {"role": role, "content": content}, ensure_ascii=False
+        )
+        await self.redis.rpush(key, payload)
+        ttl = await _config(self.config_getter, "agent.customer.session.ttl", 1800)
+        await self.redis.expire(key, ttl)
+        await self._trim(key)
+
+    async def get(self, session_id: str) -> list[dict]:
+        raw_messages = await self.redis.lrange(
+            f"session:{session_id}:messages", 0, -1
+        )
+        return [json.loads(raw) for raw in raw_messages if raw]
+
+    async def _trim(self, key: str) -> None:
+        limit = await _config(
+            self.config_getter, "agent.customer.session_max_token", 4096
+        )
+        raw_messages = [raw for raw in await self.redis.lrange(key, 0, -1) if raw]
+        total = 0
+        keep_from = len(raw_messages)
+        for index in range(len(raw_messages) - 1, -1, -1):
+            message = json.loads(raw_messages[index])
+            total += self.token_counter(message["content"])
+            if total > limit:
+                keep_from = index + 1
+                break
+            keep_from = index
+        await self.redis.ltrim(key, keep_from, -1)