"""Reperform one fictional bond through HTM, AFS, and trading reporting lanes.

Run with: uv run python linden-peak-debt-security-lanes.py
No third-party packages are required.
"""

from __future__ import annotations


def money(amount: float) -> str:
    """Format a signed dollar amount with commas and parentheses."""
    return f"(${abs(amount):,.2f})" if amount < 0 else f"${amount:,.2f}"


def present_value_of_bond(face: float, coupon: float, periodic_yield: float, periods: int) -> float:
    coupon_value = coupon * (1 - (1 + periodic_yield) ** -periods) / periodic_yield
    principal_value = face * (1 + periodic_yield) ** -periods
    return coupon_value + principal_value


face_amount = 500_000.0
stated_annual_rate = 0.05
effective_annual_rate = 0.06
payments_per_year = 2
remaining_periods = 6

cash_interest = face_amount * stated_annual_rate / payments_per_year
periodic_yield = effective_annual_rate / payments_per_year
opening_amortized_cost = present_value_of_bond(
    face_amount, cash_interest, periodic_yield, remaining_periods
)
interest_revenue = opening_amortized_cost * periodic_yield
discount_amortization = interest_revenue - cash_interest
ending_amortized_cost = opening_amortized_cost + discount_amortization

print("LINDEN PEAK — ONE BOND, THREE SUPPLIED CLASSIFICATIONS")
print("All entities, judgments, and amounts are fictional.\n")
print("1. Shared contractual and effective-interest row")
print(f"   Coupon cash: {money(face_amount)} × 5.00% ÷ 2 = {money(cash_interest)}")
print(f"   Opening amortized cost: {money(opening_amortized_cost)}")
print(f"   Interest revenue: {money(opening_amortized_cost)} × 3.00% = {money(interest_revenue)}")
print(
    f"   Discount amortization: {money(interest_revenue)} − {money(cash_interest)} "
    f"= {money(discount_amortization)}"
)
print(f"   Ending amortized cost: {money(ending_amortized_cost)}\n")

held_to_maturity_allowance = 4_500.0
held_to_maturity_reported = ending_amortized_cost - held_to_maturity_allowance
print("2. Supplied held-to-maturity lane")
print(f"   Gross amortized cost: {money(ending_amortized_cost)}")
print(f"   Less supplied credit allowance: {money(-held_to_maturity_allowance)}")
print(f"   Net reported asset: {money(held_to_maturity_reported)}\n")

available_for_sale_fair_value = 470_000.0
available_for_sale_credit = 3_000.0
total_decline = available_for_sale_fair_value - ending_amortized_cost
noncredit_oci = total_decline + available_for_sale_credit
print("3. Supplied available-for-sale lane")
print(f"   Ending amortized cost: {money(ending_amortized_cost)}")
print(f"   Supplied credit loss in earnings: {money(-available_for_sale_credit)}")
print(f"   Noncredit fair-value loss in OCI: {money(noncredit_oci)}")
print(f"   Reported fair-value asset: {money(available_for_sale_fair_value)}")
afs_check = (
    ending_amortized_cost
    - available_for_sale_credit
    + noncredit_oci
    - available_for_sale_fair_value
)
print(f"   Bridge difference: {money(afs_check)}\n")

trading_fair_value = 490_000.0
trading_gain = trading_fair_value - ending_amortized_cost
print("4. Supplied trading lane")
print(f"   Ending amortized cost: {money(ending_amortized_cost)}")
print(f"   Fair-value gain in earnings: {money(trading_gain)}")
print(f"   Reported fair-value asset: {money(trading_fair_value)}\n")

print("BOUNDARY")
print("This script does not establish classification, intent and ability, credit loss,")
print("fair value, valuation technique, tax, entries, or disclosure compliance.")