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

agent/customer_agent/__init__.py

@@ -0,0 +1,5 @@
+"""客服 Agent 领域层：会话编排、意图处理和响应策略。"""
+
+package_name = "customer_agent"
+
+__all__ = ["package_name"]

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)

agent/customer_agent/session.py

@@ -0,0 +1,67 @@
+"""Redis-backed anonymous customer-service session primitives."""
+from __future__ import annotations
+
+import time
+import uuid
+from inspect import isawaitable
+
+
+class SessionOwnershipError(Exception):
+    def __init__(self, code: int, message: str):
+        self.code = code
+        self.message = message
+        super().__init__(message)
+
+
+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 AnonymousSessionService:
+    def __init__(self, redis, *, config_getter, clock=time.time):
+        self.redis = redis
+        self.config_getter = config_getter
+        self.clock = clock
+
+    async def create_session(self) -> str:
+        session_id = uuid.uuid4().hex
+        ttl = await _config(self.config_getter, "agent.customer.session.ttl", 1800)
+        await self.redis.set(f"session:{session_id}", "anonymous", ex=ttl)
+        # Redis lists cannot be created empty; the marker is ignored by readers.
+        await self.redis.rpush(f"session:{session_id}:messages", "")
+        await self.redis.expire(f"session:{session_id}:messages", ttl)
+        return session_id
+
+    async def verify_session_ownership(
+        self,
+        session_id: str,
+        *,
+        customer_id: str | None = None,
+        session_customer_id: str | None = None,
+    ) -> None:
+        if not await self.redis.exists(f"session:{session_id}"):
+            raise SessionOwnershipError(404, "会话不存在或已过期")
+        if customer_id is not None and customer_id != session_customer_id:
+            raise SessionOwnershipError(403, "无权访问该会话")
+
+    async def consume_chat_quota(self, session_id: str) -> int | None:
+        window = await _config(
+            self.config_getter, "agent.customer.rate_limit.window_sec", 60
+        )
+        maximum = await _config(
+            self.config_getter, "agent.customer.rate_limit.max_requests", 20
+        )
+        key = f"rate:limit:anon:{session_id}:chat"
+        now = self.clock()
+        await self.redis.zremrangebyscore(key, 0, (now - window) * 1000)
+        count = await self.redis.zcard(key)
+        if count >= maximum:
+            entries = self.redis.sorted_sets.get(key, [])
+            oldest = min((score for score, _ in entries), default=now * 1000)
+            return max(1, int((oldest / 1000 + window) - now))
+        await self.redis.zadd(key, {uuid.uuid4().hex: now * 1000})
+        await self.redis.expire(key, window)
+        return None