monthly_rent = 3000
monthly_downpayment_saved = 2000
monthly_mortgage = 4000
monthly_prop_tax_plus_insurance = 477
closing_costs = 10000
interest = 0.04
pmi_table = [572, 566, 560, 555, 549, \
421, 417, 412, 408, 403, \
310, 306, 303, 299, 296, \
218, 216, 213, 210, 208]

done = False
for transition_month in range(0, 50 * 12):
    total_paid = 0
    downpayment_saved = 0
    loan_remaining = 700000
    print "Transitioning at month " + str(transition_month)
    for month_num in range(50 * 12):
        if month_num < transition_month:
            total_paid += monthly_rent
            downpayment_saved += monthly_downpayment_saved
            total_paid += monthly_downpayment_saved
        if month_num == transition_month:
            if downpayment_saved > loan_remaining:
                total_paid += loan_remaining
                total_paid -= downpayment_saved - loan_remaining
                loan_remaining = 0
                done = True
            else:
                total_paid += closing_costs
                downpayment_percent = int(downpayment_saved * 100.0 / loan_remaining + 0.5)
                print "Downpayment: $" + str(downpayment_saved) + " (" + str(downpayment_percent) + "%)"
                if downpayment_percent >= 20:
                    pmi = 0
                else:
                    pmi = pmi_table[downpayment_percent]
        if month_num >= transition_month:
            if loan_remaining == 0:
                total_paid += monthly_prop_tax_plus_insurance
            else:
                loan_remaining = loan_remaining * (1 + interest/12)
                loan_payment = monthly_mortgage - monthly_prop_tax_plus_insurance - pmi
                if loan_payment > loan_remaining: loan_payment = loan_remaining
                loan_remaining -= loan_payment
                total_paid += loan_payment + monthly_prop_tax_plus_insurance + pmi
        # print "Month " + str(month_num) + ": total_paid: " + str(total_paid) + ", loan_remaining: " + str(loan_remaining)
    print "Total Cost of Housing: $" + str(total_paid)
    if done: break