First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

server/db.py

@@ -0,0 +1,77 @@
+import json
+import os
+import time
+from datetime import datetime
+from pathlib import Path
+
+DB_PATH = Path(__file__).parent / "database.json"
+
+def load_db():
+    if DB_PATH.exists():
+        try:
+            with open(DB_PATH, "r", encoding="utf-8") as f:
+                return json.load(f)
+        except Exception:
+            return []
+    return []
+
+def save_db(users):
+    with open(DB_PATH, "w", encoding="utf-8") as f:
+        json.dump(users, f, indent=2)
+
+def get_user_by_username(username: str):
+    for u in load_db():
+        if u.get("username") == username:
+            return u
+    return None
+
+def get_user_by_id(user_id: int):
+    for u in load_db():
+        if u.get("id") == user_id:
+            return u
+    return None
+
+def create_user(user_data: dict):
+    users = load_db()
+    new_user = {
+        **user_data,
+        "id": int(time.time() * 1000),
+        "createdAt": datetime.now().isoformat(),
+        "history": []
+    }
+    users.append(new_user)
+    save_db(users)
+    return new_user
+
+def add_history_record(user_id: int, markdown_text: str):
+    users = load_db()
+    for u in users:
+        if u.get("id") == user_id:
+            if "history" not in u:
+                u["history"] = []
+            
+            # 取前50个字符作为摘要
+            summary = markdown_text[:50].replace('\n', ' ') + ('...' if len(markdown_text) > 50 else '')
+            
+            record = {
+                "id": int(time.time() * 1000),
+                "timestamp": datetime.now().isoformat(),
+                "summary": summary if summary.strip() else "空文档",
+                "markdown": markdown_text
+            }
+            # 插入到最前面
+            u["history"].insert(0, record)
+            
+            # 最多保存 100 条
+            if len(u["history"]) > 100:
+                u["history"] = u["history"][:100]
+                
+            save_db(users)
+            return record
+    return None
+
+def get_history_records(user_id: int):
+    user = get_user_by_id(user_id)
+    if user:
+        return user.get("history", [])
+    return []