from __future__ import annotations

from typing import Dict
import threading

# Simple in-process cancel flags storage (per pipeline_id)
# Thread-safe for FastAPI workers in same process
_cancel_flags: Dict[str, bool] = {}
# Mode of cancellation per pipeline: "graceful" (default) or "abort"
_cancel_modes: Dict[str, str] = {}
_lock = threading.Lock()


def request_cancel(pipeline_id: str, mode: str = "graceful") -> None:
    """Set cancel flag for given pipeline id with an optional mode.

    mode:
      - "graceful": do not interrupt in-flight operations, stop before next step
      - "abort": attempt to cancel in-flight operations immediately
    """
    pid = str(pipeline_id or "pipeline_editor")
    m = str(mode or "graceful").lower().strip()
    if m not in {"graceful", "abort"}:
        m = "graceful"
    with _lock:
        _cancel_flags[pid] = True
        _cancel_modes[pid] = m


def clear_cancel(pipeline_id: str) -> None:
    """Clear cancel flag for given pipeline id."""
    pid = str(pipeline_id or "pipeline_editor")
    with _lock:
        _cancel_flags.pop(pid, None)
        _cancel_modes.pop(pid, None)


def is_cancelled(pipeline_id: str) -> bool:
    """Check cancel flag for given pipeline id."""
    pid = str(pipeline_id or "pipeline_editor")
    with _lock:
        return bool(_cancel_flags.get(pid, False))


def get_cancel_mode(pipeline_id: str) -> str:
    """Return current cancel mode for given pipeline id: 'graceful' or 'abort' (default graceful)."""
    pid = str(pipeline_id or "pipeline_editor")
    with _lock:
        m = _cancel_modes.get(pid)
    return m if m in {"graceful", "abort"} else "graceful"