app.py

import os
import json
import hashlib
import datetime
import time
import uuid
import pytz  # 处理多伦多时区
from fastapi import FastAPI, Request, Response
from fastapi.responses import PlainTextResponse, JSONResponse
from fastapi.middleware.cors import CORSMiddleware
import gspread
from google.oauth2.service_account import Credentials
import uvicorn
from apscheduler.schedulers.background import BackgroundScheduler
from apscheduler.triggers.cron import CronTrigger

app = FastAPI()

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

# ===================== 配置 =====================
SHEET_ID = os.getenv('SHEET_ID')
TOKEN_EXPIRE_MIN = 15
TORONTO_TZ = pytz.timezone('America/Toronto')
T_WINDOW = 10  # 允许的时间误差：10秒
#Transfer_Cooldown_Card = {}
#Transfer_Cooldown = {}
TRANSFER_LIMIT = 1500      # 普通转账单次限额
CARD_PAY_LIMIT = 200       # 刷卡转账单次限额

# --- 防 DDoS 配置 ---
visit_history = {} 
BLACKLIST = os.getenv("BLACKLIST_IPS", "").split(",") 

def get_gc_client():
    creds_json = os.getenv("G_CREDS")
    info = json.loads(creds_json)
    creds = Credentials.from_service_account_info(info, scopes=[
        "https://www.googleapis.com/auth/spreadsheets",
        "https://www.googleapis.com/auth/drive"
    ])
    return gspread.authorize(creds)

gc = get_gc_client()
spreadsheet = gc.open_by_key(SHEET_ID)

# ===================== 核心防御中间件 =====================

def is_rate_limited(ip: str):
    now = time.time()
    if ip in [x.strip() for x in BLACKLIST if x.strip()]:
        return True
    if ip not in visit_history:
        visit_history[ip] = []
    visit_history[ip] = [t for t in visit_history[ip] if now - t < 10]
    if len(visit_history[ip]) >= 30: 
        return True
    visit_history[ip].append(now)
    return False

@app.middleware("http")
async def ddos_protection_middleware(request: Request, call_next):
    forwarded = request.headers.get("X-Forwarded-For")
    ip = forwarded.split(",")[0].strip() if forwarded else request.client.host
    if is_rate_limited(ip):
        return PlainTextResponse("error: too many requests", status_code=429)
    response = await call_next(request)
    return response


@app.middleware("http")
async def add_security_headers(request, call_next):
    response = await call_next(request)
    
    # 1. 防嗅探：告诉浏览器必须听服务器的 Content-Type
    response.headers["X-Content-Type-Options"] = "nosniff"
    
    # 2. 防点击劫持：禁止或限制网页被嵌入 iFrame
    response.headers["X-Frame-Options"] = "DENY"
    
    # 3. 开启 HSTS：强制走 HTTPS (Hugging Face 默认支持)
    response.headers["Strict-Transport-Security"] = "max-age=31536000; includeSubDomains"
    
    # 4. 内容安全策略 (CSP)：最强防线
    # 这里先设置一个较宽松的，允许加载自家的脚本和样式
    response.headers["Content-Security-Policy"] = "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline';"
    
    # 5. 权限控制：禁用摄像头、麦克风等（如果你用不到）
    response.headers["Permissions-Policy"] = "camera=(), microphone=(), geolocation=()"
    
    return response




# ===================== 工具函数 =====================

def get_now_toronto():
    return datetime.datetime.now(TORONTO_TZ).strftime('%Y-%m-%d %H:%M:%S')

def write_system_log(user: str, action: str, status: str, request: Request):
    try:
        sh = spreadsheet.worksheet('SystemLogs')
        now = get_now_toronto()
        forwarded = request.headers.get("X-Forwarded-For")
        ip = forwarded.split(",")[0].strip() if forwarded else request.client.host
        sh.append_row([now, user, action, status, ip])
    except: pass

def create_session_in_sheet(username: str):
    sh = spreadsheet.worksheet('Sessions')
    token = str(uuid.uuid4())
    # 修改这里：使用带时区的当前时间
    now_utc = datetime.datetime.now(datetime.timezone.utc)
    expire_at = (now_utc + datetime.timedelta(minutes=TOKEN_EXPIRE_MIN)).isoformat()
    
    rows = sh.get_all_values()
    updated = False
    for i, row in enumerate(rows[1:], start=2):
        if row[1] == username:
            sh.update(values=[[token, username, expire_at]], range_name=f"A{i}:C{i}")
            updated = True
            break
    if not updated:
        sh.append_row([token, username, expire_at])
    return token


def read_account(username: str):
    try:
        sh = spreadsheet.worksheet('Accounts')
        rows = sh.get_all_values()
        for i, row in enumerate(rows[1:], start=2):
            if row[0].strip() == username.strip():
                # 补全列，防止读取老数据时越界
                row = row + ["0"] * (10 - len(row))
                return {
                    "rowIndex": i, "username": row[0], "passwordHex": row[1],
                    "money": float(row[2] or 0), "logs": json.loads(row[3]) if row[3] else [],
                    "admin": str(row[4]).upper() == "TRUE", "email": row[5] if len(row) > 5 else "",
                    "cardHash": row[6] if len(row) > 6 else "", "payPinHash": row[7] if len(row) > 7 else "",
                    "dailyTransTotal": float(row[8] or 0),  # I列
                    "dailyCardTotal": float(row[9] or 0)    # J列
                }
    except: return None
    return None

def find_account_by_card_hash(card_hash: str):
    try:
        sh = spreadsheet.worksheet('Accounts')
        rows = sh.get_all_values()
        for i, row in enumerate(rows[1:], start=2):
            if len(row) >= 7 and row[6].strip() == card_hash.strip():
                return read_account(row[0])
    except: return None
    return None

# ===================== 路由接口 =====================

@app.get("/")
@app.head("/")
async def heartbeat():
    return PlainTextResponse("API Active: 10s Security Window Enabled")

@app.get("/ping")
async def ping():
    return PlainTextResponse("ping ok") # 返回服务器时间，方便Scratch同步

#@app.get("/register")
async def register(username: str, passwordHex: str, pin: str, request: Request):
    if read_account(username):
        write_system_log(username, "REGISTER", "FAIL: EXISTS", request)
        return PlainTextResponse("username wrong")
    generated_card_hash = str(uuid.uuid4())
    sh = spreadsheet.worksheet('Accounts')
    # 新账号自动补全 I 列和 J 列的初始值 0
    sh.append_row([username, passwordHex, 0, "[]", "FALSE", "", generated_card_hash, pin, 0, 0])
    write_system_log(username, "REGISTER", "SUCCESS", request)
    return PlainTextResponse(f"register ok|{generated_card_hash}")

@app.get("/getinfo_by_card")
async def getinfo_by_card(card_hash: str, request: Request):
    acc = find_account_by_card_hash(card_hash)
    if not acc: return PlainTextResponse("error: invalid card")
    return JSONResponse({"ok": True, "username": acc["username"], "money": acc["money"], "admin": acc["admin"], "logs": acc["logs"]})

@app.get("/transfer_by_card")
async def transfer_by_card(card_hash: str, pin: str, t: str, to: str, money: str, request: Request):
    try:
        if abs(int(time.time()) - int(t)) > T_WINDOW:
            return PlainTextResponse("error: expired")
    except: return PlainTextResponse("error: invalid time")

    acc_f = find_account_by_card_hash(card_hash)
    if not acc_f: return PlainTextResponse("error: invalid card")
    
    # 动态加盐校验：sha256(t + 数据库存的PIN_HEX)
    expected_sign = hashlib.sha256(f"{t}{acc_f['payPinHash']}".encode()).hexdigest()
    if pin.strip() != expected_sign:
        write_system_log(acc_f["username"], "CARD_PAY", "FAIL: WRONG DYNAMIC PIN", request)
        return PlainTextResponse("error: wrong pin")
    
    acc_t = read_account(to)
    if not acc_t: return PlainTextResponse("error: to user wrong")

    if acc_f["username"] == acc_t["username"]:
        return PlainTextResponse("error: to user wrong")
    
    amount = float(money)
    if not acc_f["admin"]:
        if amount <= 0 or acc_f["money"] < amount:
            return PlainTextResponse("error: money wrong")
        # 每日刷卡限额校验 (J列)
        if acc_f["dailyCardTotal"] + amount > CARD_PAY_LIMIT:
            return PlainTextResponse("error: money wrong")
    
    acc_f["money"] = round(acc_f["money"] - amount, 2)
    acc_t["money"] = round(acc_t["money"] + amount, 2)
    # 累加每日卡交易金额
    acc_f["dailyCardTotal"] = round(acc_f["dailyCardTotal"] + amount, 2)
    
    local_time = get_now_toronto()
    acc_f["logs"].append(f"{local_time} Card Paid Đ{money} to {to}.")
    acc_t["logs"].append(f"{local_time} Received Đ{money} from Card({acc_f['username']}).")

    sh_acc = spreadsheet.worksheet('Accounts')
    for acc in [acc_f, acc_t]:
        row_data = [
            acc['username'], acc['passwordHex'], acc['money'], json.dumps(acc['logs']), 
            str(acc['admin']).upper(), acc['email'], acc['cardHash'], acc['payPinHash'],
            acc['dailyTransTotal'], acc['dailyCardTotal']
        ]
        # 更新范围扩大到 J 列
        sh_acc.update(values=[row_data], range_name=f"A{acc['rowIndex']}:J{acc['rowIndex']}")
    
    write_system_log(acc_f["username"], "CARD_PAY", f"SUCCESS: {money} TO {to}", request)
    return PlainTextResponse("pay ok")

@app.get("/login")
async def login(username: str, t: str, sign: str, request: Request):
    acc = read_account(username)
    if not acc: return PlainTextResponse("wrong")
    expected = hashlib.sha256(f"{username}{t}{acc['passwordHex']}".encode()).hexdigest()
    if sign == expected and abs(int(time.time()) - int(t)) < T_WINDOW:
        token = create_session_in_sheet(username)
        write_system_log(username, "LOGIN", "SUCCESS", request)
        return PlainTextResponse(token)
    write_system_log(username, "LOGIN", "Failed", request)
    return PlainTextResponse("error: bad sign")

@app.get("/getinfo")
async def get_info(t: str, sign: str, request: Request):
    sh_s = spreadsheet.worksheet('Sessions')
    s_rows = sh_s.get_all_values()
    # 修改这里：使用带时区的当前时间
    now = datetime.datetime.now(datetime.timezone.utc)
    
    for row in s_rows[1:]:
        token, user, expire_str = row[0], row[1], row[2]
        # 修改这里：解析时确保包含时区信息
        expire_dt = datetime.datetime.fromisoformat(expire_str)
        if expire_dt.tzinfo is None:
            expire_dt = expire_dt.replace(tzinfo=datetime.timezone.utc)
            
        if now > expire_dt: continue
        
        if hashlib.sha256(f"{token}{t}".encode()).hexdigest() == sign:
            acc = read_account(user)
            return JSONResponse({"ok": True, "money": acc["money"], "admin": acc["admin"], "logs": acc["logs"]})
    return PlainTextResponse("error: invalid session")


@app.get("/transfer")
async def transfer(t: str, sign: str, to: str, money: str, request: Request):
    sh_s = spreadsheet.worksheet('Sessions')
    s_rows = sh_s.get_all_values()
    # 强制获取带 UTC 标记的当前时间
    now = datetime.datetime.now(datetime.timezone.utc)
    
    for row in s_rows[1:]:
        token, user, expire_str = row[0], row[1], row[2]
        
        # 修复：解析过期时间并强制对齐时区
        expire_dt = datetime.datetime.fromisoformat(expire_str)
        if expire_dt.tzinfo is None:
            expire_dt = expire_dt.replace(tzinfo=datetime.timezone.utc)
            
        if now > expire_dt: continue
        
        acc_f = read_account(user)
        if not acc_f: continue
        
        if hashlib.sha256(f"{token}{t}{acc_f['passwordHex']}".encode()).hexdigest() == sign:
            acc_t = read_account(to)
            if not acc_t or (acc_t == acc_f and not acc_f["admin"]): return PlainTextResponse("error: to user wrong")
            
            amount = float(money)
            if not acc_f["admin"]:
                if amount <= 0 or acc_f["money"] < amount: 
                    return PlainTextResponse("error: money wrong")
                # 每日普通转账限额校验 (I列)
                if acc_f["dailyTransTotal"] + amount > TRANSFER_LIMIT:
                    return PlainTextResponse("error: money wrong")
            
            # 执行转账并保留两位小数
            acc_f["money"] = round(acc_f["money"] - amount, 2)
            acc_t["money"] = round(acc_t["money"] + amount, 2)
            # 累加每日转账金额
            acc_f["dailyTransTotal"] = round(acc_f["dailyTransTotal"] + amount, 2)
            
            local_time = get_now_toronto()
            acc_f["logs"].append(f"{local_time} Sent Đ{money} to {to}.")
            acc_t["logs"].append(f"{local_time} Received Đ{money} from {user}.")
            
            sh_acc = spreadsheet.worksheet('Accounts')
            for acc in [acc_f, acc_t]:
                row_data = [
                    acc['username'], acc['passwordHex'], acc['money'], json.dumps(acc['logs']), 
                    str(acc['admin']).upper(), acc['email'], acc['cardHash'], acc['payPinHash'],
                    acc['dailyTransTotal'], acc['dailyCardTotal']
                ]
                # 更新范围扩大到 J 列
                sh_acc.update(values=[row_data], range_name=f"A{acc['rowIndex']}:J{acc['rowIndex']}")
                
            write_system_log(acc_f["username"], "Transfer", f"SUCCESS: {money} TO {to}", request)
            return PlainTextResponse("transfer ok")
            
    return PlainTextResponse("error: security check failed")


@app.get("/logintoken")
async def login_token(t: str, sign: str, request: Request):
    sh_s = spreadsheet.worksheet('Sessions')
    s_rows = sh_s.get_all_values()
    
    # 1. 强制获取带 UTC 时区的当前时间
    now = datetime.datetime.now(datetime.timezone.utc)
    
    # 2. 校验请求时间窗口（防止重放攻击）
    try:
        if abs(int(time.time()) - int(t)) > T_WINDOW: 
            return PlainTextResponse("error: expired")
    except: 
        return PlainTextResponse("error: invalid time")

    for row in s_rows[1:]:
        # 补齐列数，防止索引错误
        row = row + [""] * (3 - len(row))
        token, user, expire_str = row[0], row[1], row[2]
        
        # 3. 修复核心报错：解析过期时间并强制对齐 UTC 时区
        try:
            expire_dt = datetime.datetime.fromisoformat(expire_str)
            if expire_dt.tzinfo is None:
                expire_dt = expire_dt.replace(tzinfo=datetime.timezone.utc)
        except:
            continue # 如果时间格式损坏，跳过此行
            
        # 4. 执行比较
        if now > expire_dt: 
            continue
            
        # 5. 校验签名：sha256(token + t)
        if hashlib.sha256(f"{token}{t}".encode()).hexdigest() == sign: 
            return PlainTextResponse(user)
            
    return PlainTextResponse("error: valid")


@app.get("/logout")
async def logout(t: str, sign: str, request: Request):
    sh_s = spreadsheet.worksheet('Sessions')
    s_rows = sh_s.get_all_values()
    for i, row in enumerate(s_rows[1:], start=2):
        token, user = row[0], row[1]
        if hashlib.sha256(f"{token}{t}".encode()).hexdigest() == sign:
            sh_s.delete_rows(i)
            return PlainTextResponse("logout ok")
    return PlainTextResponse("error: invalid session")


# ===================== 利息与限额调度核心逻辑 =====================

def apply_weekly_interest():
    try:
        print(f"[{get_now_toronto()}] >>> STARTING INTEREST JOB (Positive & Negative) <<<")
        sh = spreadsheet.worksheet('Accounts')
        all_data = sh.get_all_values()
        if len(all_data) <= 1: return 
        
        rows = all_data[1:]
        updated_data = []
        interest_rate = 1.0375
        now_time = get_now_toronto()

        for row in rows:
            # 补齐到 10 列，防止越界
            row = row + ["0"] * (10 - len(row))
            try:
                current_money = float(row[2] or 0)
                # 只要余额不为 0（包括负数），就计算利息
                if current_money != 0:
                    new_money = round(current_money * interest_rate, 2)
                    interest_diff = round(new_money - current_money, 2)
                    
                    # 鲁棒解析日志 JSON
                    try:
                        logs = json.loads(row[3]) if (row[3] and row[3].startswith('[')) else []
                    except:
                        logs = []
                    
                    # 符号处理：正数显示 +，负数本身自带 -
                    prefix = "+" if interest_diff > 0 else ""
                    logs.append(f"{now_time} Weekly Interest: {prefix}Đ{interest_diff}")
                    
                    row[2] = str(new_money) # 转回字符串存入表格
                    row[3] = json.dumps(logs)
                
                updated_data.append(row)
            except Exception as e:
                print(f"Row skip error: {e}")
                updated_data.append(row)

        if updated_data:
            # 扩展到 J 列更新
            sh.update(values=updated_data, range_name=f'A2:J{len(updated_data) + 1}')
        
        print(f"[{get_now_toronto()}] >>> INTEREST JOB SUCCESSFUL <<<")
    except Exception as e:
        print(f"CRITICAL ERROR in interest job: {e}")


def reset_daily_limits():
    """每天 00:00 重置所有用户的 I 和 J 列"""
    try:
        print(f"[{get_now_toronto()}] >>> STARTING DAILY LIMIT RESET <<<")
        sh = spreadsheet.worksheet('Accounts')
        all_data = sh.get_all_values()
        if len(all_data) <= 1: return
        
        row_count = len(all_data)
        # 准备两列全为 0 的数据用于覆盖 (从第2行开始)
        zero_data = [["0", "0"]] * (row_count - 1)
        
        # 批量更新 I2:J{最后一行}
        sh.update(values=zero_data, range_name=f"I2:J{row_count}")
        print(f"[{get_now_toronto()}] >>> DAILY LIMIT RESET SUCCESSFUL <<<")
    except Exception as e:
        print(f"CRITICAL ERROR in reset limits job: {e}")


# ===================== 自动化调度器配置 =====================

scheduler = BackgroundScheduler(timezone=TORONTO_TZ)

# 每周五利息结算
trigger = CronTrigger(day_of_week='fri', hour=17, minute=30)
scheduler.add_job(apply_weekly_interest, trigger)

# 每天凌晨 00:00 执行每日限额清零
reset_trigger = CronTrigger(hour=4, minute=0)
scheduler.add_job(reset_daily_limits, reset_trigger)

scheduler.start()

print("Scheduler started: Weekly interest will be applied every Friday at 17:30 EST.")
print("Scheduler started: Daily limits will be reset every day at 00:00 EST.")

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=7860)