from decorator import decorator
from syslog import syslog, LOG_ERR, LOG_INFO

LOG_AUTHPRIV = 10 << 3
import subprocess
import getpass, os

tag = "Unknown" + getpass.getuser()


def set_tag(ctag, locker):
    """Sets the tag and usual locker this app is assoiciated with.

    This is used to label log entries, including whether this instance
    is running in an unusual locker."""

    global tag, unusual, user
    l = getpass.getuser()
    user = None
    if l == locker:
        tag = ctag
        unusual = False
    else:
        tag = "%s.%s" % (ctag, l)
        unusual = True
        if os.getuid() != os.getgid():
            # We're running out of a user locker
            user = l


def get_tag():
    return tag


def unusual_locker():
    return unusual


def err(mess, level=LOG_ERR):
    if user:
        zwrite(mess, recip=user, zsig=str(level))
    else:
        syslog(level | LOG_AUTHPRIV, ("%s: %s" % (tag, mess)).encode("utf-8"))


def info(mess):
    err(mess, level=LOG_INFO)


from webob.exc import HTTPException


class ExpectedException(Exception):
    pass


@decorator
def exceptions(func, *args, **kw):
    """Wrap a function such that it logs all exceptions (and reraises them)."""
    try:
        return func(*args, **kw)
    except HTTPException:
        raise
    except ExpectedException:
        raise
    except Exception as e:
        if not getattr(e, "already_syslogged", False):
            from .auth import current_user

            argness = ", ".join(repr(a) for a in args)
            if len(args) > 0 and len(kw) > 0:
                argness += ", "
            argness += ", ".join("%s=%s" % (k, repr(kw[k])) for k in kw)
            err(
                "%s called %s(%s) but got: %s"
                % (current_user(), func.__name__, argness, e)
            )
            e.already_syslogged = True
        raise


def zwrite(message, zclass="scripts", instance="", zsig="", recip=None):
    """Zephyr with the given message, class, instance suffix, and zsig."""
    if instance:
        instance = "%s:%s" % (tag.lower(), instance)
    else:
        instance = tag.lower()
    procness = ["/usr/bin/zwrite", "-d"]
    if recip:
        procness += [recip]
    else:
        procness += ["-c", zclass.encode("utf-8"), "-i", instance.encode("utf-8")]
    procness += ["-q", "-s", zsig.encode("utf-8"), "-m", message.encode("utf-8")]
    zwrite = subprocess.Popen(procness)