import asyncio
import os
import logging

logger = logging.getLogger(__name__)

# Allow overriding the zpool binary path via env (for bind-mounted host tools)
ZPOOL_BIN = os.environ.get("ZPOOL_BIN", "zpool")


async def get_zfs_pool_map() -> dict[str, str]:
    """Return a dict mapping device names to ZFS pool names.

    e.g. {"sda": "tank", "sdb": "tank", "sdc": "fast"}
    """
    pool_map = {}
    try:
        # When running in a container with pid:host, use nsenter to run
        # zpool in the host mount namespace so it finds its own libs.
        use_nsenter = os.environ.get("ZFS_USE_NSENTER", "").lower() in ("1", "true")
        if use_nsenter:
            cmd = ["nsenter", "-t", "1", "-m", "--", "zpool", "status", "-P"]
        else:
            cmd = [ZPOOL_BIN, "status", "-P"]

        proc = await asyncio.create_subprocess_exec(
            *cmd,
            stdout=asyncio.subprocess.PIPE,
            stderr=asyncio.subprocess.PIPE,
        )
        stdout, _ = await proc.communicate()
        if proc.returncode != 0:
            return pool_map

        current_pool = None
        for line in stdout.decode().splitlines():
            stripped = line.strip()
            if stripped.startswith("pool:"):
                current_pool = stripped.split(":", 1)[1].strip()
            elif current_pool and "/dev/" in stripped:
                parts = stripped.split()
                dev_path = parts[0]
                try:
                    real = os.path.realpath(dev_path)
                    dev_name = os.path.basename(real)
                    # Strip partition numbers (sda1 -> sda)
                    dev_name = dev_name.rstrip("0123456789")
                    pool_map[dev_name] = current_pool
                except Exception:
                    pass
    except FileNotFoundError:
        logger.debug("zpool not available")
    return pool_map