scripts/demo_ledger.py

"""End-to-end: book a freelancer's month into the ledger, then let the engine read
the real aggregates and compute what's owed. No model — just storage + math.

Run from the project root:  python -m scripts.demo_ledger
"""

import sys

try:
    sys.stdout.reconfigure(encoding="utf-8")
except (AttributeError, ValueError):
    pass

from src.engine import (
    isr_provisional_monthly,
    iva_monthly,
    profit_margin,
    resico_isr_monthly,
    taxable_base,
)
from src.ledger import Ledger


def rule(title):
    print("\n" + "═" * 64 + f"\n{title}\n" + "═" * 64)


def main():
    lg = Ledger(":memory:")  # in real use: data/user/ledger.db

    # --- A month of activity for a freelance designer (May 2024) ----------
    lg.record_income("2024-05-03", "Branding — Café Luna", 18000, iva_rate="0.16")
    lg.record_income("2024-05-17", "Sitio web — Dental MX", 27000, iva_rate="0.16",
                     isr_retenido="2700", iva_retenido="2880")  # invoiced a persona moral
    lg.record_expense("2024-05-05", "Adobe Creative Cloud", 1300, iva_rate="0.16")
    lg.record_expense("2024-05-12", "Renta de oficina (parte)", 4000, iva_rate="0.16")
    lg.record_expense("2024-05-22", "Comida no deducible", 600, iva_rate="0.16",
                      deductible=False)

    rule("LEDGER · May 2024 — what got booked")
    m = lg.month_totals(2024, 5)
    print(f"Income (CFDI-backed):     {m.income}")
    print(f"Deductible expenses:      {m.deductible_expenses}")
    print(f"Non-deductible expenses:  {m.nondeductible_expenses}")
    print(f"IVA trasladado (cobrado): {m.iva_trasladado}")
    print(f"IVA acreditable (pagado): {m.iva_acreditable}")
    print(f"IVA retenido by clients:  {m.iva_retenido}")
    print(f"ISR retenido by clients:  {m.isr_retenido}")

    rule("TAXES · computed from the real ledger (RESICO vs general)")
    print(resico_isr_monthly(m.income).explain())
    print()
    base = taxable_base(m.income, m.deductible_expenses)
    print(f"General-regime taxable base = {m.income} − {m.deductible_expenses} = {base}")
    print(isr_provisional_monthly(base).explain())
    print()
    print(iva_monthly(m.iva_trasladado, m.iva_acreditable, m.iva_retenido).explain())

    rule("STATEMENTS")
    s = lg.income_statement(2024, 5)
    print(f"Income statement {s.period}: revenue {s.revenue} − expenses {s.expenses} "
          f"= net {s.net_profit}")
    print(profit_margin(s.net_profit, s.revenue).explain())
    bs = lg.balance_sheet("2024-05-31")
    print(f"Balance sheet @ {bs.as_of}: assets {bs.assets} = liabilities "
          f"{bs.liabilities} + equity {bs.equity}")

    lg.close()
    print("\nThe books balance, and every tax figure was derived from booked "
          "transactions — not typed in by hand.")


if __name__ == "__main__":
    main()