from pathlib import Path
from .number import StreamNumber, LOG_DIR

def clear_logs():
    if LOG_DIR.exists():
        for p in LOG_DIR.glob("*"):
            p.unlink()
    LOG_DIR.mkdir(parents=True, exist_ok=True)

def add(num_a: StreamNumber, num_b: StreamNumber) -> StreamNumber:
    """Digit-by-digit streamed addition."""
    out_file = LOG_DIR / f"{num_a.hash}_add_{num_b.hash}.bin"

    carry = 0
    a_buf = list(num_a.stream(1))
    b_buf = list(num_b.stream(1))

    # align lengths
    max_len = max(len(a_buf), len(b_buf))
    a_buf = ["0"] * (max_len - len(a_buf)) + a_buf
    b_buf = ["0"] * (max_len - len(b_buf)) + b_buf

    with open(out_file, "wb") as out:
        for i in range(max_len - 1, -1, -1):
            s = int(a_buf[i]) + int(b_buf[i]) + carry
            carry, digit = divmod(s, 10)
            out.write(str(digit).encode())
        if carry:
            out.write(str(carry).encode())
    return StreamNumber(out_file)

def sub(num_a, num_b):
    """Basic streamed subtraction (assumes a >= b)."""
    # similar pattern with borrow propagation...
    pass

def mul(num_a, num_b):
    """Chunked multiplication using repeated addition."""
    # create temporary stage files for partial sums
    pass

def div(num_a, num_b):
    """Long division, streamed stage by stage."""
    # create multiple intermediate files: div_stage_1, div_stage_2, etc.
    pass