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 []