"""趋势相关 API。"""
from flask import Blueprint, jsonify, request
from services.runtime import *  # noqa: F403
from services import runtime as R

bp = Blueprint("trend", __name__)

@bp.route('/api/trend_filter', methods=['GET'])
def trend_filter():
	"""趋势筛选接口（币对）
	参数:
	  timeframe: K线周期
	  start_time, end_time: 毫秒时间戳，可选
	  direction: bull/bear/sideways 可选
	  stage: early/mid/late 可选
	  min_strength: 0-100 可选
	  symbols: 逗号分隔列表，可选；不传则自动加载部分USDT币对
	返回符合条件的币对与简要统计
	"""
	timeframe = request.args.get('timeframe', '1h')
	start_time = request.args.get('start_time')
	end_time = request.args.get('end_time')
	want_direction = request.args.get('direction')  # 可为 None
	want_stage = request.args.get('stage')  # 可为 None
	try:
		min_strength = float(request.args.get('min_strength', '0'))
	except ValueError:
		min_strength = 0.0

	symbols_param = request.args.get('symbols')
	if symbols_param:
		symbols_list = [s.strip() for s in symbols_param.split(',') if s.strip()]
	else:
		symbols_list = load_crypto_symbols(limit=150)

	results = []
	for sym in symbols_list:
		try:
			df = get_crypto_kl_data(sym, timeframe, start_time=start_time, end_time=end_time)
			if df is None or len(df) < 60:
				continue
			df = add_indicators(df)
			direction, stage, strength = classify_trend_stage(df)

			if want_direction and direction != want_direction:
				continue
			if want_stage and stage != want_stage:
				continue
			if strength < min_strength:
				continue

			last_row = df.iloc[-1]
			results.append({
				'symbol': sym,
				'time': int(last_row['timestamp']),
				'close': float(last_row['close']),
				'direction': direction,
				'stage': stage,
				'strength': float(round(strength, 2)),
				'ema5': float(last_row['ema5']),
				'ema10': float(last_row['ema10']),
				'ema24': float(last_row['ema24']),
				'ema52': float(last_row['ema52'])
			})
		except Exception:
			continue

	# 按强度降序
	results.sort(key=lambda x: x['strength'], reverse=True)
	return jsonify({
		'count': len(results),
		'results': results
	})


@bp.route('/api/trend_detail', methods=['GET'])
def trend_detail():
	"""返回单个币对的K线与EMA、用于前端绘制趋势线
	参数: symbol, timeframe, start_time, end_time
	"""
	symbol = request.args.get('symbol')
	timeframe = request.args.get('timeframe', '1h')
	start_time = request.args.get('start_time')
	end_time = request.args.get('end_time')
	timezone_name = request.args.get('timezone', 'Asia/Shanghai')

	if not symbol:
		return jsonify({'error': 'symbol不能为空'})

	df = get_crypto_kl_data(symbol, timeframe, start_time=start_time, end_time=end_time)
	if df is None or len(df) == 0:
		return jsonify({'error': '获取数据失败'})

	df = add_indicators(df)
	direction, stage, strength = classify_trend_stage(df)

	# 简单趋势线: 用最近N根收盘价做线性拟合
	N = min(80, len(df))
	sub = df.tail(N)
	y = sub['close'].values
	x = np.arange(len(y))
	denom = np.dot(x - x.mean(), x - x.mean())
	if denom != 0:
		m = float(np.dot(y - y.mean(), x - x.mean()) / denom)
		b = float(y.mean() - m * x.mean())
	else:
		m, b = 0.0, float(y[-1])

	client_tz = timezone(timezone_name)

	return jsonify({
		'symbol': symbol,
		'timeframe': timeframe,
		'timezone': timezone_name,
		'direction': direction,
		'stage': stage,
		'strength': float(round(strength, 2)),
		'kline_data': clean_dataframe_for_json(df)[['timestamp','open','high','low','close','volume','ema5','ema10','ema24','ema52']].to_dict('records'),
		'trend_line': {
			'offset': int(df.index[-N]),
			'slope': m,
			'intercept': b,
			'length': int(N)
		}
	})