from __future__ import annotations

import io
import queue
import re

# Strip ANSI escape sequences and normalise carriage returns so tqdm output
# is readable in the log textbox (which has no terminal emulation).
_ANSI_RE = re.compile(
    r"\x1b\[[0-9;]*[A-Za-z]"           # CSI sequences  e.g. \x1b[32m
    r"|\x1b\][^\x07\x1b]*(?:\x07|\x1b\\)"  # OSC sequences, BEL or ST terminator
)


class _QueueWriter(io.TextIOBase):
    """Redirect sys.stdout / sys.stderr into a Queue for the Logs panel."""

    def __init__(self, q: queue.Queue[str]) -> None:
        self._q = q

    def write(self, text: str) -> int:  # type: ignore[override]
        if text:
            cleaned = _ANSI_RE.sub("", text)
            cleaned = cleaned.replace("\r\n", "\n")  # Windows CRLF → LF
            cleaned = cleaned.replace("\r", "\n")    # bare CR → newline
            if cleaned:
                self._q.put(cleaned)
        return len(text)

    def flush(self) -> None:
        pass