# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial

"""
Supporting isolation of warnings

Warnings in unittests are not isolated.
We sometimes use warnings to conveniently accumulate error messages
and eventually report them afterwards as error.
"""

import sys
import os
import warnings
import re
from contextlib import contextmanager

warn_name = "__warningregistry__"
ignore_re = 'Not importing directory .*'


@contextmanager
def isolate_warnings():
    save_warnings = {}
    for name, mod in sys.modules.items():
        if mod and hasattr(mod, warn_name):
            save_warnings[name] = mod.__dict__[warn_name]
            delattr(mod, warn_name)
        else:
            save_warnings[name] = None
    yield
    for name, warn in save_warnings.items():
        mod = sys.modules[name]
        if mod:
            setattr(mod, warn_name, warn)
            if warn is None:
                delattr(mod, warn_name)


@contextmanager
def suppress_warnings():
    with warnings.catch_warnings():
        warnings.simplefilter("ignore")
        yield


def check_warnings():
    for name, mod in sys.modules.items():
        if mod:
            reg = getattr(mod, warn_name, None)
            if reg:
                # XXX We need to filter warnings for Python 2.
                # This should be avoided by renaming the duplicate folders.
                for k in reg:
                    if type(k) is tuple and re.match(ignore_re, k[0]):
                        continue
                    return True
    return False


def warn(message, category=None, stacklevel=2):
    """Issue a warning with the default 'RuntimeWarning'"""
    if category is None:
        category = UserWarning
    warnings.warn(message, category, stacklevel)


def linux_distribution():
    """Returns the Linux distribution"""
    # We have to be more specific because we had differences between
    # RHEL 6.6 and RHEL 7.4 .
    # Note: The platform module is deprecated. We need to switch to the
    # distro package, ASAP! The distro has been extracted from Python,
    # because it changes more often than the Python version.
    distribution = []
    try:
        import distro
        distribution = distro.linux_distribution()
    except ImportError:
        # platform.linux_distribution() was removed in 3.8
        if sys.version_info[:2] < (3, 8):
            import platform
            distribution = platform.linux_distribution()
    if distribution:
        return "".join(distribution[:2]).lower()
    warnings.warn('Cannot determine Linux distribution, please install distro',
                  UserWarning)
    return ""


# Python2 legacy: Correct 'linux2' to 'linux', recommended way.
if sys.platform.startswith('linux'):
    platform_name = linux_distribution()
    # this currently happens on opensuse in 5.14:
    if not platform_name:
        # We intentionally crash when that last resort is also absent:
        platform_name = os.environ["MACHTYPE"]
    platform_name = re.sub('[^0-9a-z]', '_', platform_name)
else:
    platform_name = sys.platform
# In the linux case, we need more information.

is_py3 = sys.version_info[0] == 3
is_ci = os.environ.get("QTEST_ENVIRONMENT", "") == "ci"


def get_script_dir():
    script_dir = os.path.normpath(os.path.dirname(__file__))
    while "sources" not in os.listdir(script_dir):
        script_dir = os.path.dirname(script_dir)
    return script_dir


def qt_version():
    from PySide6.QtCore import __version__
    return tuple(map(int, __version__.split(".")))

# Format a registry file name for version.


def _registry_filename(version, use_ci_module):
    ext_ci = "_ci" if use_ci_module else ""
    name = f"exists_{platform_name}_{version[0]}_{version[1]}_{version[2]}{ext_ci}.py"
    return os.path.join(os.path.dirname(__file__), name)

# Return the expected registry file name.


def get_refpath(use_ci_module=is_ci):
    return _registry_filename(qt_version(), use_ci_module)

# Return the registry file name, either that of the current
# version or fall back to a previous patch release.


def get_effective_refpath(use_ci_module=is_ci):
    refpath = get_refpath(use_ci_module)
    if os.path.exists(refpath):
        return refpath
    version = qt_version()
    major, minor, patch = version[:3]
    while patch >= 0:
        file = _registry_filename((major, minor, patch), use_ci_module)
        if os.path.exists(file):
            return file
        patch -= 1
    return refpath

# Import the CI version of the platform module


def import_refmodule(use_ci_module=is_ci):
    refpath = get_effective_refpath(use_ci_module)
    modname = os.path.basename(os.path.splitext(refpath)[0])
    return __import__(modname)

# eof
