"""
fetcher.py - 从 data_provider HTTP API 拉取 K 线数据。
"""

import requests
import pandas as pd
import logging

logger = logging.getLogger(__name__)

SYMBOL = "BTC/USDT:USDT"
TIMEFRAME = "1m"
PROVIDER_URL = "http://103.179.242.166"
FETCH_LIMIT = 1000


def fetch_ohlcv() -> pd.DataFrame:
    """从 data_provider API 拉取最近 FETCH_LIMIT 根 1m K 线。"""
    url = f"{PROVIDER_URL}/api/candles"
    params = {
        "symbol": SYMBOL,
        "tf": TIMEFRAME,
        "limit": FETCH_LIMIT,
    }
    resp = requests.get(url, params=params, timeout=30)
    resp.raise_for_status()
    data = resp.json()

    if not data:
        logger.warning("API 返回空数据")
        return pd.DataFrame()

    df = pd.DataFrame(data)
    df["timestamp"] = pd.to_datetime(df["timestamp"], unit="ms", utc=True)
    df["date"] = df["timestamp"]

    df = df.drop_duplicates(subset="timestamp").sort_values("timestamp").reset_index(drop=True)
    logger.info(f"拉取 {len(df)} 根 {TIMEFRAME} K 线 from {PROVIDER_URL}")
    return df