from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from dotenv import load_dotenv
import os

load_dotenv()  # 加载 .env

app = FastAPI(title="Hyperliquid DEX Backend")

# 添加 CORS（允许前端访问）
app.add_middleware(
    CORSMiddleware,
    allow_origins=["http://localhost:5173", "http://101.32.51.95:5173"],  # 前端 URL
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

@app.get("/")
def read_root():
    return {"message": "Hyperliquid DEX Backend 就绪！"}

@app.get("/health")
def health_check():
    return {"status": "OK", "builder_address": os.getenv("BUILDER_ADDRESS")}


from hyperliquid.exchange import Exchange
from hyperliquid.utils import constants
from hyperliquid.utils.signing import get_timestamp_ms
from eth_account import Account
import json

TESTNET_API_URL = constants.TESTNET_API_URL
info = None  # 全局 Info
exchange = None  # 全局 Exchange

@app.on_event("startup")
async def startup_event():
    global info, exchange
    info = Info(TESTNET_API_URL, skip_ws=False)
    # 初始化 Exchange，用你的私钥（代理钱包）
    private_key = os.getenv("PRIVATE_KEY")
    account = Account.from_key(private_key)
    wallet_address = account.address
    exchange = Exchange(TESTNET_API_URL, account=account, skip_ws=True)

@app.post("/approve-builder")
async def approve_builder(user_address: str, max_fee_rate: int = 50):
    """
    用户批准 Builder Fee：签名批准你的地址的最大费率。
    前端调用：POST { "user_address": "0xUserAddress" }
    """
    try:
        # 构建批准消息（Hyperliquid Builder Fee 批准格式）
        timestamp = get_timestamp_ms()
        action = {
            "type": "BuilderApprove",
            "builder": os.getenv("BUILDER_ADDRESS"),
            "maxBuilderFeeBps": max_fee_rate * 10,  # 0.05% = 50 * 10 = 500 bps
            "nonce": timestamp,
        }
        # 用户签名消息（前端提供签名，此处模拟代理）
        # 实际：前端用 Wagmi 签名，传签名到后端验证
        signed_action = exchange.sign_action(action, user_address)  # 需调整为用户签名
        # 调用 SDK 提交批准
        result = exchange.builder_approve(signed_action)
        return {"status": "批准成功", "result": result, "fee_rate": max_fee_rate}
    except Exception as e:
        return {"error": str(e)}

# 测试查询价格（从阶段 1 复用）
@app.get("/prices")
def get_prices():
    global info
    mids = info.all_mids()
    return {"prices": mids}


if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)