#!/usr/bin/env python3
"""Recompute Cedar Trail's fictional note and early-retirement schedules.

Run with ``uv run python`` and this file's path. This dependency-free script
uses supplied scope conclusions; it does not decide whether changed terms are a
modification or extinguishment, establish fair value, or approve disclosures.
"""


def money(amount: float) -> str:
    """Format a number as accounting-style US dollars."""
    return f"${amount:,.2f}" if amount >= 0 else f"(${abs(amount):,.2f})"


def heading(title: str) -> None:
    print(f"\n{title}\n{'-' * len(title)}")


heading("1. Zero-coupon note")
zero_face = 500_000.00
zero_rate = 0.08
zero_periods = 3
zero_issue_price = zero_face / (1 + zero_rate) ** zero_periods
print(f"{'Maturity amount':<34} {money(zero_face):>18}")
print(f"{'Issue price':<34} {money(zero_issue_price):>18}")
print(f"{'Original discount':<34} {money(zero_face - zero_issue_price):>18}")
print(f"\n{'Year':>4} {'Opening':>18} {'Cash':>14} {'Expense':>16} {'Ending':>18}")
zero_carrying = zero_issue_price
zero_total_interest = 0.0
for year in range(1, zero_periods + 1):
    opening = zero_carrying
    interest_expense = opening * zero_rate
    zero_carrying = opening + interest_expense
    zero_total_interest += interest_expense
    print(
        f"{year:>4} {money(opening):>18} {money(0):>14} "
        f"{money(interest_expense):>16} {money(zero_carrying):>18}"
    )

heading("2. Level-payment equipment note")
note_principal = 300_000.00
note_rate = 0.07
note_periods = 3
note_payment = note_principal * note_rate / (1 - (1 + note_rate) ** -note_periods)
print(f"{'Opening principal':<34} {money(note_principal):>18}")
print(f"{'Equal annual payment':<34} {money(note_payment):>18}")
print(
    f"\n{'Year':>4} {'Opening':>18} {'Payment':>14} {'Interest':>14} "
    f"{'Principal':>16} {'Ending':>18}"
)
note_carrying = note_principal
total_principal_reduction = 0.0
for year in range(1, note_periods + 1):
    opening = note_carrying
    interest_expense = opening * note_rate
    principal_reduction = note_payment - interest_expense
    note_carrying = opening - principal_reduction
    total_principal_reduction += principal_reduction
    print(
        f"{year:>4} {money(opening):>18} {money(note_payment):>14} "
        f"{money(interest_expense):>14} {money(principal_reduction):>16} "
        f"{money(note_carrying):>18}"
    )

heading("3. Supplied extinguishment")
net_carrying_amount = 612_400.00
reacquisition_price = 625_000.00
extinguishment_loss = reacquisition_price - net_carrying_amount
print(f"{'Reacquisition consideration':<34} {money(reacquisition_price):>18}")
print(f"{'Net carrying amount removed':<34} {money(-net_carrying_amount):>18}")
print(f"{'Loss on extinguishment':<34} {money(extinguishment_loss):>18}")

heading("4. Reconciliations")
print(f"{'Zero-coupon ending amount':<34} {money(zero_carrying):>18}")
print(f"{'Zero-coupon total interest':<34} {money(zero_total_interest):>18}")
print(f"{'Installment principal repaid':<34} {money(total_principal_reduction):>18}")
print(f"{'Installment ending principal':<34} {money(note_carrying):>18}")

if abs(zero_carrying - zero_face) > 0.000001:
    raise SystemExit("FAIL: zero-coupon note does not accrete to maturity")
if abs(note_carrying) > 0.000001:
    raise SystemExit("FAIL: installment note does not amortize to zero")
if abs(extinguishment_loss - 12_600.00) > 0.005:
    raise SystemExit("FAIL: extinguishment consequence does not reconcile")

print("\nPASS: both note schedules and the supplied $12,600.00 loss reconcile.")
print("Boundary: PASS verifies arithmetic only; every scope and reporting judgment remains open.")