#!/usr/bin/env python

import math
import random
import sys

class Latitude:
    def __init__(self, lat):
        self.latitude = lat
        self.area = 500
        self.sundigit = 10
        self.randomlist = []
        self.energy = []
        self.cv = []

        self.months = {
                'January':[0,31],
                'February':[31,28],
                }

    def calcv(self, latitude, t):
        return (23.5*math.sin(math.pi*(t-80)/180)+90-latitude)/90

    def decide(self, v):
        """
        Short desription
        """
        if 0 < v < 1:
            return v**2
        if v >= 1:
            return 1
        if v <= 0:
            return 0

    def calcenergy(self, f):
        """
        Short desription
        """
        self.randomlist.append(random.random())
        return self.area * f * self.sundigit * self.randomlist[-1]

    def gen_yearly_data(self):
        """
        Short desription
        """
        for t in xrange(365):
            v = self.calcv(self.latitude, t)
            f = self.decide(v)
            self.cv.append(f)
            self.energy.append(self.calcenergy(f))

    def show_month(self, m):
        """
        Generate a nice printout for specified month
        """

        index, days = self.months[m]

        r, cv, energy = self.randomlist[index:index+days],\
                        self.cv[index:index+days], \
                        self.energy[index:index+days]

        print
        print m
        print len(m)*'='

        print "{:<4} {:<4} {:<4} {:<4} {:<4} {:<4} {:<4}".format(
                "Area", "soltal", "latitud", "dag",
                "solighetsfaktor","f(t,latitud)","W(t)")

        for a, b, c in zip(r, cv, energy):
            print "{:<4} {:<4} {:<4} {:<4} {:.4f} {:.4f} {:.4f}".format(
                    self.area,
                    self.sundigit,
                    self.latitude,
                    index, a, b, c)
            index += 1

def get_input():
    """
    Prompt user for input
    """
    number = int(input("How many latitudes do you want to calculate? "))
    latitudes = []

    x=0
    while x < number:
        lat = int(input("latitude: "))
        if lat > 0 and lat < 90:
            latitudes.append(lat)
            x = x + 1
        else:
            print("Next time say a latitude between 0 and 90")

    return latitudes

def main():
    """
    Main entrypoint for your program
    """

    latitudes = get_input()
    print latitudes

    # L contains a list of classes for the
    # user specified latitudes. The method 'gen_yearly_data()'
    # is called to calculate the data and store the result
    # int member variables
    L = [Latitude(i) for i in latitudes]
    for i in L:
        i.gen_yearly_data()

    # Now print some monthly data for a specific latitude
    L[0].show_month('January')
    L[0].show_month('February')

if __name__ == "__main__":
    main()