# Copyright 2014-2017 Insight Software Consortium.
# Copyright 2004-2009 Roman Yakovenko.
# Distributed under the Boost Software License, Version 1.0.
# See http://www.boost.org/LICENSE_1_0.txt

"""Logger classes and a few convenience methods."""

import os
import sys
import platform
import logging
import tempfile
import shutil
import subprocess
import warnings


def is_str(string):
    """
    Python 2 and 3 compatible string checker.

    Args:
        string (str | basestring): the string to check

    Returns:
        bool: True or False

    """
    if sys.version_info[:2] >= (3, 0):
        return isinstance(string, str)

    return isinstance(string, basestring)


def find_xml_generator(name="castxml"):
    """
    Try to find a c++ parser (xml generator)

    Args:
        name (str): name of the c++ parser (e.g. castxml)

    Returns:
        path (str), name (str): path to the xml generator and it's name


    If no c++ parser is found the function raises an exception.
    pygccxml does currently only support castxml as c++ parser.

    """

    if sys.version_info[:2] >= (3, 3):
        path = _find_xml_generator_for_python_greater_equals_33(name)
    else:
        path = _find_xml_generator_for_legacy_python(name)

    if path == "" or path is None:
        raise Exception("No c++ parser found. Please install castxml.")
    return path.rstrip(), name


def _find_xml_generator_for_python_greater_equals_33(name):
    return shutil.which(name)


def _find_xml_generator_for_legacy_python(name):
    if platform.system() == "Windows":
        command = "where"
    else:
        command = "which"
    p = subprocess.Popen([command, name], stdout=subprocess.PIPE,
                         stderr=subprocess.PIPE)
    path = p.stdout.read().decode("utf-8")
    p.wait()
    p.stdout.close()
    p.stderr.close()
    return path.rstrip()


def _create_logger_(name):
    """Implementation detail, creates a logger."""
    logger = logging.getLogger(name)
    handler = logging.StreamHandler()
    handler.setFormatter(logging.Formatter('%(levelname)s %(message)s'))
    logger.addHandler(handler)
    logger.setLevel(logging.INFO)
    return logger


class loggers(object):
    """Class-namespace, defines a few loggers classes, used in the project."""

    cxx_parser = _create_logger_('pygccxml.cxx_parser')
    """
    Logger for C++ parser functionality

    If you set this logger level to DEBUG, you will be able to see the exact
    command line, used to invoke GCC-XML  and errors that occures during XML
    parsing

    """

    pdb_reader = _create_logger_('pygccxml.pdb_reader')
    """
    Logger for MS .pdb file reader functionality

    """

    queries_engine = _create_logger_('pygccxml.queries_engine')
    """
    Logger for query engine functionality.

    If you set this logger level to DEBUG, you will be able to see what queries
    you do against declarations tree, measure performance and may be even to
    improve it.
    Query engine reports queries and whether they are optimized or not.

    """

    declarations_cache = _create_logger_('pygccxml.declarations_cache')
    """
    Logger for declarations tree cache functionality

    If you set this logger level to DEBUG, you will be able to see what is
    exactly happens, when you read the declarations from cache file. You will
    be able to decide, whether it worse for you to use this or that cache
    strategy.

    """

    root = logging.getLogger('pygccxml')
    """
    Root logger exists for your convenience only.

    """

    all_loggers = [
        root, cxx_parser, queries_engine, declarations_cache, pdb_reader]
    """
    Contains all logger classes, defined by the class.

    """

    @staticmethod
    def set_level(level):
        """Set the same logging level for all the loggers at once."""
        for logger in loggers.all_loggers:
            logger.setLevel(level)


def remove_file_no_raise(file_name, config):
    """Removes file from disk if exception is raised."""
    # The removal can be disabled by the config for debugging purposes.
    if config.keep_xml:
        return True

    try:
        if os.path.exists(file_name):
            os.remove(file_name)
    except IOError as error:
        loggers.root.error(
            "Error occurred while removing temporary created file('%s'): %s",
            file_name, str(error))


def create_temp_file_name(suffix, prefix=None, directory=None):
    """
    Small convenience function that creates temporary files.

    This function is a wrapper around the Python built-in
    function tempfile.mkstemp.

    """

    if not prefix:
        prefix = tempfile.gettempprefix()
    fd, name = tempfile.mkstemp(suffix=suffix, prefix=prefix, dir=directory)
    file_obj = os.fdopen(fd)
    file_obj.close()
    return name


def normalize_path(some_path):
    """Return os.path.normpath(os.path.normcase(some_path))."""
    return os.path.normpath(os.path.normcase(some_path))


def contains_parent_dir(fpath, dirs):
    """
    Returns true if paths in dirs start with fpath.

    Precondition: dirs and fpath should be normalized before calling
    this function.

    """
    # Note: this function is used nowhere in pygccxml but is used
    # at least by pypluplus; so it should stay here.

    return bool([x for x in dirs if _f(fpath, x)])


def _f(fpath, dir_):
    """Helper function for contains_parent_dir function."""
    return fpath.startswith(dir_)


def get_architecture():
    """
    Returns computer architecture: 32 or 64.

    The guess is based on maxint.

    """
    if sys.maxsize == 2147483647:
        return 32
    elif sys.maxsize == 9223372036854775807:
        return 64
    else:
        raise RuntimeError("Unknown architecture")


class cached(property):
    """Convert a method into a cached attribute."""

    # The following code is cut-and-paste from this post:
    # http://groups.google.com/group/comp.lang.python/browse_thread/
    # thread/5b71896c06bd0f76/
    # Thanks to Michele Simionato

    def __init__(self, method):
        private = '_' + method.__name__

        def fget(s):
            try:
                return getattr(s, private)
            except AttributeError:
                value = method(s)
                setattr(s, private, value)
                return value

        def fdel(s):
            del s.__dict__[private]
        super(cached, self).__init__(fget, fdel=fdel)

    def reset(self):
        cls = self.__class__
        for name in dir(cls):
            attr = getattr(cls, name)
            if isinstance(attr, cached):
                delattr(self, name)


def get_tr1(name):
    """In libstd++ the tr1 namespace needs special care.

    Return either an empty string or tr1::, useful for
    appending to search patterns.

    Args:
        name (str): the name of the declaration

    Returns:
        str: an empty string or "tr1::"
    """
    tr1 = ""
    if "tr1" in name:
        tr1 = "tr1::"
    return tr1


class cxx_standard(object):
    """Helper class for parsing the C++ standard version.

    This class holds the C++ standard version the XML generator has been
    configured with, and provides helpers functions for querying C++ standard
    version related information.
    """

    __STD_CXX = {
        '-std=c++98': 199711,
        '-std=gnu++98': 199711,
        '-std=c++03': 199711,
        '-std=gnu++03': 199711,
        '-std=c++0x': 201103,
        '-std=gnu++0x': 201103,
        '-std=c++11': 201103,
        '-std=gnu++11': 201103,
        '-std=c++1y': 201402,
        '-std=gnu++1y': 201402,
        '-std=c++14': 201402,
        '-std=gnu++14': 201402,
        '-std=c++1z': 201703,
        '-std=c++17': 201703,
        '-std=gnu++1z': 201703,
        '-std=gnu++17': 201703,
        '-std=c++2a': float('inf'),
        '-std=gnu++2a': float('inf'),
    }

    def __init__(self, cflags):
        """Class constructor that parses the XML generator's command line

        Args:
            cflags (str): cflags command line arguments passed to the XML
                generator
        """
        super(cxx_standard, self).__init__()

        self._stdcxx = None
        self._is_implicit = False
        for key in cxx_standard.__STD_CXX:
            if key in cflags:
                self._stdcxx = key
                self._cplusplus = cxx_standard.__STD_CXX[key]

        if not self._stdcxx:
            if '-std=' in cflags:
                raise RuntimeError('Unknown -std=c++xx flag used')

            # Assume c++03 by default
            self._stdcxx = '-std=c++03'
            self._cplusplus = cxx_standard.__STD_CXX['-std=c++03']
            self._is_implicit = True

    @property
    def stdcxx(self):
        """Returns the -std=c++xx option passed to the constructor"""
        return self._stdcxx

    @property
    def is_implicit(self):
        """Indicates whether a -std=c++xx was specified"""
        return self._is_implicit

    @property
    def is_cxx03(self):
        """Returns true if -std=c++03 is being used"""
        return self._cplusplus == cxx_standard.__STD_CXX['-std=c++03']

    @property
    def is_cxx11(self):
        """Returns true if -std=c++11 is being used"""
        return self._cplusplus == cxx_standard.__STD_CXX['-std=c++11']

    @property
    def is_cxx11_or_greater(self):
        """Returns true if -std=c++11 or a newer standard is being used"""
        return self._cplusplus >= cxx_standard.__STD_CXX['-std=c++11']

    @property
    def is_cxx14(self):
        """Returns true if -std=c++14 is being used"""
        return self._cplusplus == cxx_standard.__STD_CXX['-std=c++14']

    @property
    def is_cxx14_or_greater(self):
        """Returns true if -std=c++14 or a newer standard is being used"""
        return self._cplusplus >= cxx_standard.__STD_CXX['-std=c++14']

    @property
    def is_cxx1z(self):
        """Returns true if -std=c++1z is being used"""
        return self._cplusplus == cxx_standard.__STD_CXX['-std=c++1z']


class DeprecationWrapper(object):
    """
    A small wrapper class useful when deprecation classes.

    This class is not part of the public API.

    """
    def __init__(self, new_target, old_name, new_name, version):
        self.new_target = new_target
        self.old_name = old_name
        self.new_name = new_name
        self.version = version

    def _warn(self):
        warnings.warn(
            self.old_name + " is deprecated. Please use " + self.new_name +
            " instead. This will be removed in version " + self.version,
            DeprecationWarning)

    def __call__(self, *args, **kwargs):
        self._warn()
        return self.new_target(*args, **kwargs)

    def __getattr__(self, attr):
        self._warn()
        return getattr(self.new_target, attr)
