#!/usr/bin/env python3
"""Find break-even scenarios for rental property cash flow Day 1"""

# Fixed assumptions
MONTHLY_RENT = 2000
VACANCY = 0.05
EFFECTIVE_MONTHLY = MONTHLY_RENT * (1 - VACANCY)  # $1,900
PROPERTY_TAX_RATE = 0.007  # ~$2400 on $345K
INSURANCE_RATE = 0.004  # ~$1400 on $345K
MAINTENANCE_RATE = 0.006  # ~$2000 on $345K
DOWN_PAYMENT_PCT = 0.20

print("=" * 70)
print("BREAK-EVEN ANALYSIS: What price + rate = Day 1 cash flow positive?")
print("=" * 70)
print(f"\nFixed: Rent $2,000/mo | Vacancy 5% | Effective income: ${EFFECTIVE_MONTHLY:,.0f}/mo")
print(f"Down payment: 20% | 30-year fixed\n")

# Calculate monthly mortgage payment
def monthly_payment(principal, annual_rate, years=30):
    r = annual_rate / 12
    n = years * 12
    if r == 0:
        return principal / n
    return principal * (r * (1 + r)**n) / ((1 + r)**n - 1)

print(f"{'Price':>10} {'Rate':>6} {'Down':>10} {'Loan':>10} {'P&I':>8} {'Tax/Ins':>8} {'Maint':>7} {'Total':>8} {'Cash Flow':>10} {'Rent/Price':>10}")
print("-" * 100)

results = []
for price in range(200000, 360000, 10000):
    for rate_bps in range(300, 700, 25):
        rate = rate_bps / 10000
        
        down = price * DOWN_PAYMENT_PCT
        loan = price * (1 - DOWN_PAYMENT_PCT)
        pi = monthly_payment(loan, rate)
        
        tax_ins = (price * PROPERTY_TAX_RATE + price * INSURANCE_RATE) / 12
        maint = (price * MAINTENANCE_RATE) / 12
        
        total_monthly = pi + tax_ins + maint
        cash_flow = EFFECTIVE_MONTHLY - total_monthly
        rent_to_price = (MONTHLY_RENT / price) * 100
        
        results.append((price, rate, down, loan, pi, tax_ins, maint, total_monthly, cash_flow, rent_to_price))

# Show scenarios that are cash flow positive or near break-even
print("\n📗 CASH FLOW POSITIVE SCENARIOS (Day 1):")
print("-" * 100)
positive = [r for r in results if r[8] >= 0]
for r in sorted(positive, key=lambda x: -x[8])[:20]:
    price, rate, down, loan, pi, tax_ins, maint, total, cf, rtp = r
    print(f"${price:>9,} {rate:>5.2%} ${down:>9,} ${loan:>9,} ${pi:>7,.0f} ${tax_ins:>7,.0f} ${maint:>6,.0f} ${total:>7,.0f}  ${cf:>+8,.0f}    {rtp:.2f}%")

print(f"\n\n📕 YOUR CURRENT DEAL ($345K @ 6.25%):")
price, rate = 345000, 0.0625
down = price * DOWN_PAYMENT_PCT
loan = price * (1 - DOWN_PAYMENT_PCT)
pi = monthly_payment(loan, rate)
tax_ins = (price * PROPERTY_TAX_RATE + price * INSURANCE_RATE) / 12
maint = (price * MAINTENANCE_RATE) / 12
total = pi + tax_ins + maint
cf = EFFECTIVE_MONTHLY - total
print(f"${price:>9,} {rate:>5.2%} ${down:>9,} ${loan:>9,} ${pi:>7,.0f} ${tax_ins:>7,.0f} ${maint:>6,.0f} ${total:>7,.0f}  ${cf:>+8,.0f}    {(MONTHLY_RENT/price)*100:.2f}%")

# Find exact break-even rate at different price points
print(f"\n\n📊 BREAK-EVEN INTEREST RATE BY PRICE POINT:")
print("-" * 50)
for price in [200000, 220000, 240000, 260000, 280000, 300000, 320000, 345000]:
    for rate_bps in range(100, 1000, 1):
        rate = rate_bps / 10000
        loan = price * (1 - DOWN_PAYMENT_PCT)
        pi = monthly_payment(loan, rate)
        tax_ins = (price * PROPERTY_TAX_RATE + price * INSURANCE_RATE) / 12
        maint = (price * MAINTENANCE_RATE) / 12
        total = pi + tax_ins + maint
        cf = EFFECTIVE_MONTHLY - total
        if cf <= 0:
            # Previous rate was break-even
            be_rate = (rate_bps - 1) / 10000
            print(f"  ${price:>9,}  →  break-even at {be_rate:.2%} or lower")
            break
    else:
        print(f"  ${price:>9,}  →  cash flows positive even at 10%+")

# Find exact break-even price at different rates
print(f"\n\n📊 BREAK-EVEN PRICE BY INTEREST RATE:")
print("-" * 50)
for rate_pct in [3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.25]:
    rate = rate_pct / 100
    for price in range(400000, 100000, -1000):
        loan = price * (1 - DOWN_PAYMENT_PCT)
        pi = monthly_payment(loan, rate)
        tax_ins = (price * PROPERTY_TAX_RATE + price * INSURANCE_RATE) / 12
        maint = (price * MAINTENANCE_RATE) / 12
        total = pi + tax_ins + maint
        cf = EFFECTIVE_MONTHLY - total
        if cf >= 0:
            print(f"  {rate_pct:.2f}%  →  max price ${price:>9,}  (rent/price: {(MONTHLY_RENT/price)*100:.2f}%)")
            break
    else:
        print(f"  {rate_pct:.2f}%  →  no viable price found")

# The 1% rule check
print(f"\n\n📊 1% RULE CHECK:")
print(f"  $2,000 rent × 100 = $200,000 max purchase price")
print(f"  Your deal: $345,000 = {(2000/345000)*100:.2f}% (needs to be ≥1.0%)")
print(f"  To hit 1% at $345K, rent needs to be: ${345000*0.01:,.0f}/mo")
print(f"  To hit 0.8% at $345K, rent needs to be: ${345000*0.008:,.0f}/mo")