import re
from collections.abc import AsyncIterator, Awaitable, Callable

from mirage.accessor.base import Accessor
from mirage.commands.builtin.utils.stream import _read_stdin_async
from mirage.io.types import ByteSource, IOResult
from mirage.types import PathSpec


async def strings(
    paths: list[PathSpec],
    *,
    read_bytes: Callable[..., Awaitable[bytes]],
    accessor: Accessor | None = None,
    stdin: AsyncIterator[bytes] | bytes | None = None,
    min_len: int = 4,
) -> tuple[ByteSource | None, IOResult]:
    pattern = rb"[\x20-\x7e]{" + str(min_len).encode() + rb",}"
    # Each operand is scanned independently and the matches concatenate in
    # operand order, like GNU strings.
    if paths:
        parts: list[bytes] = []
        for p in paths:
            matches = re.findall(pattern, await read_bytes(accessor, p))
            if matches:
                parts.append(b"\n".join(matches) + b"\n")
        return b"".join(parts), IOResult()
    raw = await _read_stdin_async(stdin)
    if raw is None:
        raw = b""
    matches = re.findall(pattern, raw)
    output = b"\n".join(matches) + b"\n" if matches else b""
    return output, IOResult()


__all__ = ["strings"]