import numpy as np

def cc_required_time(
    cc_prev: float,
    CCo: float,
    CCx: float,
    CGC: float,
    CDC: float,
    Mode: str,
    ) -> float:
    """
    Function to find time required to reach canopy_cover at end of previous day, given current CGC or CDC

    <a href="https://www.fao.org/3/BR248E/br248e.pdf#page=30" target="_blank">Reference Manual: canopy_cover devlopment</a> (pg. 21-24)


    Arguments:

        cc_prev (float): Canopy Cover at previous timestep.

        CCo (float): Fractional canopy cover size at emergence

        CCx (float): Maximum canopy cover (fraction of soil cover)

        CGC (float): Canopy growth coefficient (fraction per gdd)

        CDC (float): Canopy decline coefficient (fraction per gdd/calendar day)

        Mode (str): Canopy growth/decline coefficient (fraction per gdd/calendar day)


    Returns:

        tReq (float): time required to reach canopy_cover at end of previous day





    """

    ## Get CGC and/or time (gdd or CD) required to reach canopy_cover on previous day ##
    if Mode == "CGC":
        if cc_prev <= (CCx / 2):

            # print(cc_prev,CCo,(tSum-dt),tSum,dt)
            CGCx = np.log(cc_prev / CCo)
            # print(np.log(cc_prev/CCo),(tSum-dt),CGCx)
        else:
            # print(CCx,CCo,cc_prev)
            CGCx = np.log((0.25 * CCx * CCx / CCo) / (CCx - cc_prev))

        tReq = CGCx / CGC

    elif Mode == "CDC":
        tReq = (np.log(1 + (1 - cc_prev / CCx) / 0.05)) / (CDC / CCx)

    return tReq