from fastapi import APIRouter, Query, HTTPException
from typing import Optional
from app.services.bybit_service import get_bybit_client
from app.schemas.candle import CandleResponseSchema
import json
import os
import pandas as pd
import numpy as np

router = APIRouter()

ACCOUNTS_FILE = os.path.join(os.path.dirname(__file__), '../../accounts.json')

def get_user_api(user_id: str):
    try:
        with open(ACCOUNTS_FILE, 'r', encoding='utf-8') as f:
            accounts = json.load(f)
        for acc in accounts:
            if acc['id'] == user_id:
                return acc['bybit_api_key'], acc['bybit_api_secret']
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Lỗi đọc file accounts: {e}")
    raise HTTPException(status_code=404, detail="Không tìm thấy userId")

def ema(series, period):
    return series.ewm(span=period, adjust=False).mean()

def macd(series, fast=45, slow=90, signal=9):
    ema_fast = ema(series, fast)
    ema_slow = ema(series, slow)
    macd_line = ema_fast - ema_slow
    signal_line = macd_line.ewm(span=signal, adjust=False).mean()
    macd_hist = macd_line - signal_line
    return macd_line, signal_line, macd_hist

def rsi(series, period=14):
    delta = series.diff()
    gain = (delta.where(delta > 0, 0)).rolling(window=period, min_periods=1).mean()
    loss = (-delta.where(delta < 0, 0)).rolling(window=period, min_periods=1).mean()
    loss = loss.replace(0, np.nan)  # tránh chia cho 0
    rs = gain / loss
    rsi = 100 - (100 / (1 + rs))
    rsi = rsi.replace([np.inf, -np.inf], np.nan)
    return rsi

@router.get("/candles", response_model=CandleResponseSchema, response_model_exclude_none=True, tags=["Candle"])
def get_candles(
    userId: str = Query(..., description="ID của user để lấy API key/secret"),
    symbol: str = Query(..., description="Mã giao dịch, ví dụ: BTCUSDT"),
    interval: str = Query("1", description="Khung thời gian nến, ví dụ: 1, 3, 5, 15, 30, 60, 240, D, W, M"),
    limit: Optional[int] = Query(200, description="Số lượng nến trả về (tối đa 1000)"),
    start: Optional[int] = Query(None, description="Timestamp bắt đầu (miliseconds)"),
    end: Optional[int] = Query(None, description="Timestamp kết thúc (miliseconds)")
):
    api_key, api_secret = get_user_api(userId)
    client = get_bybit_client(api_key, api_secret)
    params = {
        "category": "linear",  # hoặc "spot" nếu lấy spot
        "symbol": symbol,
        "interval": interval,
        "limit": limit
    }
    if start:
        params["start"] = start
    if end:
        params["end"] = end
    res = client.get_kline(**params)
    if 'retCode' in res and res['retCode'] != 0:
        raise HTTPException(status_code=400, detail=f"Bybit API error: {res.get('retMsg', 'Unknown error')}")
    candles = res.get('result', {}).get('list', [])
    if not candles:
        return {"data": [], "indicators": {}}
    # Chuyển đổi sang DataFrame
    df = pd.DataFrame(candles, columns=[
        "timestamp", "open", "high", "low", "close", "volume", "turnover"
    ])
    df = df.astype({
        "timestamp": np.int64,
        "open": np.float64,
        "high": np.float64,
        "low": np.float64,
        "close": np.float64,
        "volume": np.float64,
        "turnover": np.float64
    })
    df = df.sort_values("timestamp", ascending=False)
    # Tính chỉ báo
    close = df["close"]
    macd_line, macd_signal, macd_hist = macd(close, fast=45, slow=90, signal=9)
    df["macd"] = macd_line
    df["macdsignal"] = macd_signal
    df["macdhist"] = macd_hist
    df["ema34"] = ema(close, 34)
    df["ema50"] = ema(close, 50)
    df["ema100"] = ema(close, 100)
    df["ema200"] = ema(close, 200)
    df["rsi"] = rsi(close)
    # Trả về kết quả
    data = df.replace({np.nan: None}).to_dict(orient="records")
    return {
        "data": data,
        "indicators": {
            "macd": {"fast": 45, "slow": 90, "signal": 9},
            "ema": [34, 50, 100, 200],
            "rsi": True
        }
    }