from input.natural_constants import *
import numpy as np
from datetime import datetime
import time
from astropy.time import Time

from astropy.time import TimeISO
class TimeYearDayTimeCustom(TimeISO):
   """
   day-of-year as "<DOY>".
   The day-of-year (DOY) goes from 001 to 365 (366 in leap years).
   The allowed subformat is:
   - 'doy': day of year
   """
   name = 'doy'  # Unique format name
   subfmts = (('doy',
               '%j',
               '{yday:03d}'),
              ('doy',
               '%j',
               '{yday:03d}'),
              ('doy',
               '%j',
               '{yday:03d}'))

def AirMass(x, p_0, ELV, h):
    p_air = x
    ELV_rad = np.deg2rad(ELV)  # convert ELV from degree to radian
    Dip = np.arccos(R_E / (R_E + h))  # Dip in radian

    if ELV_rad >= -Dip and ELV_rad < 0:
        res = p_air/p_0 * (1 + ELV_rad/Dip) - 70 * ELV_rad/Dip
    else:
        res = (p_air/p_0) * ((1229 + (614 * np.sin(ELV_rad)) ** 2) ** (1/2) - 614 * np.sin(ELV_rad))

    return res

#if ELV >= -(180/np.pi * np.arccos(R_e / (R_e + h))):
#    tau_atm = 0.5 * (np.exp(-0.65 * AirMass(p_air, p_0, ELV, h)) + np.exp(-0.095 * AirMass(p_air, p_0, ELV, h)))
#    tau_atmIR = 1.716 - 0.5 * (np.exp(-0.65 * p_air/p_0) + np.exp(-0.095 * p_air/p_0))
#else:
#    tau_atm = 0
#    tau_atmIR = 0
#
#doy = int(utc.doy)
#
#MA = (357.52911 + 0.98560028 * (utc.jd - 2451545)) % 360  # in degree, reference: see folder "literature"
#TA = MA + 2 * e * np.sin(np.deg2rad(MA)) + 5/4 * e ** 2 * np.sin(np.deg2rad(2 * MA))
#I_Sun = 1367.5 * ((1 + e * np.cos(np.deg2rad(TA)))/(1 - e ** 2)) ** 2
#I_SunZ = I_Sun * tau_atm
#q_sun = I_SunZ
#
#q_IRground = epsilon_ground * sigma * T_ground ** 4
#
#q_IREarth = q_IRground * tau_atmIR
#
#if ELV <= 0:
#    q_Albedo = 0
#else:
#    q_Albedo = Albedo * I_Sun * np.sin(np.deg2rad(ELV))
#
### NEEDED:
# Diameter = ...
# V_relative = ...
# rho_air = ...
# rho_gas = ...
# T_film = ...
# T_air = ...
# T_gas = ...
#
#my_air = (1.458 * 10 ** -6 * T_air ** 1.5) / (T_air + 110.4)
#my_gas = 1.895 * 10 ** -5 * (T_gas/273.15) ** 0.647
#k_air = 0.0241 * (T_air/273.15) ** 0.9
#k_gas = 0.144 * (T_gas/273.15) ** 0.7
#Pr_air = 0.804 - 3.25 * 10 ** (-4) * T_air
#Pr_gas = 0.729 - 1.6 * 10 ** (-4) * T_gas
#
#Gr_air = (rho_air ** 2 * g * np.abs(T_film - T_air) * Diameter ** 3) / (T_air * my_air ** 2)
#Nu_air = 2 + 0.45 * (Gr_air * Pr_air) ** 0.25
#HC_free = Nu_air * k_air / Diameter
#Re = V_relative * Diameter * rho_air / my_air
#HC_forced = k_air / Diameter * (2 + 0.41 * Re ** 0.55)
#HC_internal = 0.13 * k_gas * ((rho_gas ** 2 * g * np.abs(T_film - T_gas) * Pr_gas) / (T_gas * my_air ** 2)) ** (1/3)
#HC_external = np.maximum(HC_free, HC_forced)
#
#Q_Sun = alpha_VIS * A_proj * q_sun * (1 + tau_VIS/(1 - r_VIS))
#Q_Albedo = alpha_VIS * A_surf * q_Albedo * ViewFactor * (1 + tau_VIS/(1 - r_VIS))
#Q_IREarth = alpha_IR * A_surf * q_IREarth * ViewFactor * (1 + tau_IR/(1 - r_IR))
#Q_IRFilm = sigma * epsilon * alpha_IR * A_surf * T_film ** 4 * 1/(1 - r_IR)
#Q_IROut = sigma * epsilon * A_surf * T_film ** 4 * (1 * tau_IR/(1 - r_IR))
#Q_ConvExt = HC_external * A_effective * (T_air - T_film)
#Q_ConvInt = HC_internal * A_effective * (T_film - T_gas)
#
#HalfConeAngle = np.arcsin(R_E/(R_E + h))
#ViewFactor = (1 - np.cos(HalfConeAngle))/2
#
#
#
#RoC = -V_z
#
#dT_gas = (Q_ConvInt/(gamma * c_v * M_gas) - (gamma - 1)/gamma * rho_air * g / (rho_gas * R_gas) * RoC) * dt
#dT_film = ((Q_Sun + Q_Albedo + Q_IREarth + Q_IRfilm + Q_ConvExt - Q_ConvInt - Q_IRout)/(c_f * M_film)) * dt