"""Utility functions for unit testing."""

import functools
import os
import sys
import tempfile
import types

from contextlib import contextmanager
from textwrap import dedent

__all__ = ["skip", "skipIf", "temporary_file"]

def _id(obj):
    return obj

try:
    from unittest import skip
except ImportError:
    # Provide basic replacement for unittest.skip
    def skip(reason):
        """Unconditionally skip a test."""
        def decorator(test_item):
            if not isinstance(test_item, (type, types.ClassType)):
                @functools.wraps(test_item)
                def skip_wrapper(*args, **kwds):
                    if reason:
                        sys.stderr.write("skipped, %s ... " % reason)
                    else:
                        sys.stderr.write("skipped, ")
                    return
                test_item = skip_wrapper
            return test_item
        return decorator

try:
    from unittest import skipIf
except ImportError:
    # Provide basic replacement for unittest.skipIf
    def skipIf(condition, reason):
        """Skip a test if the condition is true."""
        if condition:
            return skip(reason)
        return _id


@contextmanager
def temporary_file(content=None, mode=None):
    tmpf, tmpfname = tempfile.mkstemp()
    os.close(tmpf)

    if mode is None:
        if content is None:
            mode = "rb"
        else:
            mode = "wb"

    tmpf = open(tmpfname, mode)
    if content is not None:
        if isinstance(content, unicode):
            tmpf.write(dedent(content).encode("utf8"))
        else:
            tmpf.write(content)

    tmpf.close()
    yield tmpfname
    os.unlink(tmpfname)
