# indie:lang_version = 5
from indie import indicator, MainContext, sec_context, format, param, source, param_ref, level, color, plot
from indie.algorithms import Corr


@sec_context
@param_ref('source')
def SecContext(self, source):
    return source[0]


@indicator('CC', format=format.PRICE)  # Correlation Coefficient
@param.str('exchange', default='NASDAQ')
@param.str('ticker', default='GOOG')
@param.source('source', default=source.CLOSE)
@param.int('length', default=20, min=1)
@level(1, line_color=color.GRAY)
@level(0)
@level(-1, line_color=color.GRAY)
@plot.line(color=color.BLUE, title='Correlation')
class Main(MainContext):
    def __init__(self, exchange, ticker):
        self.ctx_other = self.calc_on(SecContext, exchange=exchange, ticker=ticker)

    def calc(self, source, length):
        corr = Corr.new(source, self.ctx_other, length)
        return corr[0]