integration: add chat/api/routes.py

chat/api/routes.py

@@ -0,0 +1,113 @@
+# chat/api/routes.py
+"""
+DeepSeek V4 chat API — endpoints under /api/v1/chat/*.
+
+Sessions are held in memory (bounded history). Model calls go through
+DeepSeekV4Client — API mode with DEEPSEEK_API_KEY, local echo otherwise.
+"""
+
+from __future__ import annotations
+
+import time
+from typing import Any, Dict, List
+
+from fastapi import APIRouter, HTTPException
+from pydantic import BaseModel, Field
+
+from chat.core import SOVEREIGN_SYSTEM_PROMPT, ChatSession, get_client
+
+router = APIRouter(prefix="/api/v1/chat", tags=["chat"])
+
+sessions: Dict[str, ChatSession] = {}
+
+
+class SendIn(BaseModel):
+    message: str = Field(min_length=1)
+    session_id: str = ""
+    temperature: float = 0.7
+    max_tokens: int = 1024
+
+
+class SessionOut(BaseModel):
+    session_id: str
+    model: str
+    messages: List[Dict[str, Any]]
+    created_at: float
+
+
+def _get_or_create(session_id: str) -> ChatSession:
+    if session_id and session_id in sessions:
+        return sessions[session_id]
+    session = ChatSession()
+    session.add("system", SOVEREIGN_SYSTEM_PROMPT)
+    sessions[session.session_id] = session
+    return session
+
+
+@router.post("/sessions")
+async def create_session() -> Dict[str, Any]:
+    """Create a new chat session."""
+    session = _get_or_create("")
+    return {
+        "session_id": session.session_id,
+        "model": session.model,
+        "mode": "api" if not get_client().local_mode else "local",
+        "created_at": session.created_at,
+    }
+
+
+@router.get("/sessions/{session_id}")
+async def get_session(session_id: str) -> Dict[str, Any]:
+    """Session + message history."""
+    session = sessions.get(session_id)
+    if session is None:
+        raise HTTPException(status_code=404, detail="session not found")
+    return {
+        "session_id": session.session_id,
+        "model": session.model,
+        "messages": [{"role": m.role, "content": m.content, "ts": m.timestamp}
+                     for m in session.messages],
+        "created_at": session.created_at,
+    }
+
+
+@router.post("/send")
+async def send_message(body: SendIn) -> Dict[str, Any]:
+    """Send a message and get an assistant reply."""
+    client = get_client()
+    session = _get_or_create(body.session_id)
+    session.add("user", body.message)
+    try:
+        result = client.complete(session, temperature=body.temperature,
+                                 max_tokens=body.max_tokens)
+    except RuntimeError as exc:
+        raise HTTPException(status_code=502, detail=str(exc)) from exc
+    session.add("assistant", result["content"])
+    return {
+        "session_id": session.session_id,
+        "reply": result["content"],
+        "model": result["model"],
+        "mode": result["mode"],
+        "usage": result.get("usage", {}),
+        "timestamp": time.time(),
+    }
+
+
+@router.get("/models")
+async def list_models() -> Dict[str, Any]:
+    """Available models."""
+    return {"models": get_client().list_models(),
+            "active": get_client().model,
+            "mode": "api" if not get_client().local_mode else "local"}
+
+
+@router.get("/status")
+async def chat_status() -> Dict[str, Any]:
+    """Chat module status."""
+    client = get_client()
+    return {
+        "mode": "api" if not client.local_mode else "local",
+        "model": client.model,
+        "base_url": client.base_url,
+        "sessions": len(sessions),
+    }