#coding=utf-8

class Volume:
	__instance = None
	def __init__(self):
		pass

	@classmethod
	def getInstance(cls):
		if(cls.__instance == None):
			cls.__instance = Volume()
		return cls.__instance

	#计算平均成交量
	def set_volume_data(self, df, type=1):
		if df is not None and df.shape[0] > 0:
			# 分别计算5日、10日平均成交量
			vol_list = [5, 10]
			for vol in vol_list:
				df['MAVOL' + str(vol)] = df['volume'].rolling(window=vol, center=False).mean()

			df['vol_cross'] = ''
			vol_position = df['MAVOL5'] > df['MAVOL10']
			df.loc[vol_position[(vol_position == True) & (vol_position.shift() == False)].index, 'vol_cross'] = 'gc'
			df.loc[vol_position[(vol_position == False) & (vol_position.shift() == True)].index, 'vol_cross'] = 'dc'
			#df.dropna(how='any', inplace=True)#删除所有空行值的数据
		return df

	#金叉或死叉 gc金叉，dc死叉
	def is_cross(self, df, index, crosstype='gc'):
		if index < 0 or index > df.shape[0]-1:
			return False
		cross_ret = {'gc':df.iloc[index]['vol_cross']=='gc', 'dc':df.iloc[index]['vol_cross']=='dc'}
		return cross_ret[crosstype]

	#是否放量
	def is_fangliang(self, df, index):
		if index < 0 or index > df.shape[0]-1:
			return False
		return df.iloc[index]['volume'] >= df.iloc[index+1]['volume']*2.0

	#是否缩量
	def is_suoliang(self, df, index):
		if index < 0 or index > df.shape[0]-1:
			return False
		return df.iloc[index]['volume']*2.0 <= df.iloc[index+1]['volume']