Persist chat history locally

server.py

@@ -2,6 +2,8 @@ from __future__ import annotations
 
 import json
 import socket
+import uuid
+from datetime import datetime, timezone
 from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
 from pathlib import Path
 
@@ -9,15 +11,71 @@ import ollama
 
 
 ROOT = Path(__file__).parent
+DATA_DIR = ROOT / "data"
+CHATS_FILE = DATA_DIR / "chats.json"
 MODEL = "qwen2.5:7b"
 HOST = "0.0.0.0"
 PORT = 8787
 
 
+def now_iso() -> str:
+    return datetime.now(timezone.utc).isoformat()
+
+
+def read_store() -> dict:
+    if not CHATS_FILE.exists():
+        return {"chats": []}
+
+    try:
+        return json.loads(CHATS_FILE.read_text(encoding="utf-8"))
+    except json.JSONDecodeError:
+        return {"chats": []}
+
+
+def write_store(store: dict) -> None:
+    DATA_DIR.mkdir(exist_ok=True)
+    CHATS_FILE.write_text(json.dumps(store, ensure_ascii=False, indent=2), encoding="utf-8")
+
+
+def chat_title(messages: list[dict]) -> str:
+    for message in messages:
+        if message.get("role") == "user" and message.get("content"):
+            title = " ".join(str(message["content"]).split())
+            return title[:40] or "새 대화"
+    return "새 대화"
+
+
 class Handler(SimpleHTTPRequestHandler):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, directory=str(ROOT), **kwargs)
 
+    def do_GET(self) -> None:
+        if self.path == "/api/chats":
+            store = read_store()
+            chats = [
+                {
+                    "id": chat["id"],
+                    "title": chat.get("title", "새 대화"),
+                    "updatedAt": chat.get("updatedAt", ""),
+                }
+                for chat in store.get("chats", [])
+            ]
+            self._send_json(200, {"chats": chats})
+            return
+
+        if self.path.startswith("/api/chats/"):
+            chat_id = self.path.rsplit("/", 1)[-1]
+            store = read_store()
+            chat = next((item for item in store.get("chats", []) if item["id"] == chat_id), None)
+            if not chat:
+                self._send_json(404, {"error": "Chat not found"})
+                return
+
+            self._send_json(200, {"chat": chat})
+            return
+
+        super().do_GET()
+
     def do_POST(self) -> None:
         if self.path != "/api/chat":
             self.send_error(404)
@@ -25,6 +83,7 @@ class Handler(SimpleHTTPRequestHandler):
 
         length = int(self.headers.get("content-length", 0))
         data = json.loads(self.rfile.read(length) or b"{}")
+        chat_id = data.get("chatId")
         messages = data.get("messages", [])
 
         try:
@@ -38,11 +97,46 @@ class Handler(SimpleHTTPRequestHandler):
                     *messages,
                 ],
             )
-            payload = {"reply": response["message"]["content"]}
+            reply = response["message"]["content"]
+            saved_messages = [*messages, {"role": "assistant", "content": reply}]
+            chat = self._save_chat(chat_id, saved_messages)
+            payload = {"chatId": chat["id"], "reply": reply, "chat": chat}
             self._send_json(200, payload)
         except Exception as exc:
             self._send_json(500, {"error": str(exc)})
 
+    def do_DELETE(self) -> None:
+        if not self.path.startswith("/api/chats/"):
+            self.send_error(404)
+            return
+
+        chat_id = self.path.rsplit("/", 1)[-1]
+        store = read_store()
+        store["chats"] = [item for item in store.get("chats", []) if item["id"] != chat_id]
+        write_store(store)
+        self._send_json(200, {"ok": True})
+
+    def _save_chat(self, chat_id: str | None, messages: list[dict]) -> dict:
+        store = read_store()
+        chats = store.setdefault("chats", [])
+        chat = next((item for item in chats if item["id"] == chat_id), None)
+
+        if not chat:
+            chat = {
+                "id": str(uuid.uuid4()),
+                "createdAt": now_iso(),
+                "title": chat_title(messages),
+                "messages": [],
+            }
+            chats.insert(0, chat)
+
+        chat["title"] = chat_title(messages)
+        chat["messages"] = messages
+        chat["updatedAt"] = now_iso()
+        chats.sort(key=lambda item: item.get("updatedAt", ""), reverse=True)
+        write_store(store)
+        return chat
+
     def _send_json(self, status: int, payload: dict[str, str]) -> None:
         body = json.dumps(payload, ensure_ascii=False).encode("utf-8")
         self.send_response(status)