---

from decimal import Decimal, InvalidOperation
from pathlib import Path


def parse_price(raw: str) -> Decimal:
    """'45.50', '45,50', '450' -> Decimal"""
    return Decimal(raw.strip().replace(",", "."))


def load_purchases(path: Path):
    items = []
    with path.open(encoding="utf-8") as f:
        for line_no, line in enumerate(f, 1):
            line = line.strip()
            if not line:
                continue
            # режем по ПОСЛЕДНЕМУ пробелу
            parts = line.rsplit(" ", 1)
            if len(parts) != 2:
                print(f"[строка {line_no}] пропущено: {line!r}")
                continue
            name, price_raw = parts[0].strip(), parts[1]
            try:
                price = parse_price(price_raw)
            except InvalidOperation:
                print(f"[строка {line_no}] неверная цена: {price_raw!r}")
                continue
            items.append((name, price))
    return items


def make_report(items, vat_rate=Decimal("0.20")) -> str:
    if not items:
        return "Список покупок пуст."

    total = sum((p for _, p in items), Decimal("0"))
    avg = total / len(items)
    vat = total * vat_rate / (Decimal("1") + vat_rate)  # НДС "внутри" цены
    net = total - vat

    lines = ["=" * 55,
             f"{'Товар':<35}{'Цена, руб':>20}",
             "-" * 55]
    for name, price in items:
        lines.append(f"{name:<35}{price:>20.2f}")
    lines += ["-" * 55,
              f"{'ИТОГО':<35}{total:>20.2f}",
              f"{'Средняя цена товара':<35}{avg:>20.2f}",
              f"{'В т.ч. НДС 20%':<35}{vat:>20.2f}",
              f"{'Без НДС':<35}{net:>20.2f}",
              "=" * 55]

    cheapest = min(items, key=lambda x: x[1])
    priciest = max(items, key=lambda x: x[1])
    lines.append(f"Самый дешёвый : {cheapest[0]} — {cheapest[1]:.2f}")
    lines.append(f"Самый дорогой : {priciest[0]} — {priciest[1]:.2f}")
    lines.append(f"Позиций в чеке: {len(items)}")
    return "\n".join(lines)


def main():
    path = Path("purchases.txt")
    if not path.exists():
        path.write_text(
            "Хлеб белый 45.50\n"
            "Молоко 3.2% 89,90\n"
            "Сыр Российский 450\n"
            "Яблоки 120.75\n"
            "Кофе растворимый 350,00\n",
            encoding="utf-8",
        )
        print(f"Создан пример {path}")

    items = load_purchases(path)
    report = make_report(items)
    print(report)

    out = Path("report.txt")
    out.write_text(report, encoding="utf-8")
    print(f"\nОтчёт сохранён в {out}")


if __name__ == "__main__":
    main()