#!/usr/bin/env python

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# You can obtain one at http://mozilla.org/MPL/2.0/.

# TODO: it might be a good idea of adding a system name (e.g. 'Ubuntu' for
# linux) to the information; I certainly wouldn't want anyone parsing this
# information and having behaviour depend on it

from __future__ import absolute_import, print_function

import os
import platform
import re
import sys
from .string_version import StringVersion
from ctypes.util import find_library

# keep a copy of the os module since updating globals overrides this
_os = os


class unknown(object):
    """marker class for unknown information"""

    def __nonzero__(self):
        return False

    def __str__(self):
        return 'UNKNOWN'


unknown = unknown()  # singleton


def get_windows_version():
    import ctypes

    class OSVERSIONINFOEXW(ctypes.Structure):
        _fields_ = [('dwOSVersionInfoSize', ctypes.c_ulong),
                    ('dwMajorVersion', ctypes.c_ulong),
                    ('dwMinorVersion', ctypes.c_ulong),
                    ('dwBuildNumber', ctypes.c_ulong),
                    ('dwPlatformId', ctypes.c_ulong),
                    ('szCSDVersion', ctypes.c_wchar * 128),
                    ('wServicePackMajor', ctypes.c_ushort),
                    ('wServicePackMinor', ctypes.c_ushort),
                    ('wSuiteMask', ctypes.c_ushort),
                    ('wProductType', ctypes.c_byte),
                    ('wReserved', ctypes.c_byte)]

    os_version = OSVERSIONINFOEXW()
    os_version.dwOSVersionInfoSize = ctypes.sizeof(os_version)
    retcode = ctypes.windll.Ntdll.RtlGetVersion(ctypes.byref(os_version))
    if retcode != 0:
        raise OSError

    return os_version.dwMajorVersion, os_version.dwMinorVersion, os_version.dwBuildNumber


# get system information
info = {'os': unknown,
        'processor': unknown,
        'version': unknown,
        'os_version': unknown,
        'bits': unknown,
        'has_sandbox': unknown,
        'webrender': bool(os.environ.get("MOZ_WEBRENDER", False)),
        'automation': bool(os.environ.get("MOZ_AUTOMATION", False)),
        }
(system, node, release, version, machine, processor) = platform.uname()
(bits, linkage) = platform.architecture()

# get os information and related data
if system in ["Microsoft", "Windows"]:
    info['os'] = 'win'
    # There is a Python bug on Windows to determine platform values
    # http://bugs.python.org/issue7860
    if "PROCESSOR_ARCHITEW6432" in os.environ:
        processor = os.environ.get("PROCESSOR_ARCHITEW6432", processor)
    else:
        processor = os.environ.get('PROCESSOR_ARCHITECTURE', processor)
    system = os.environ.get("OS", system).replace('_', ' ')
    (major, minor, _, _, service_pack) = os.sys.getwindowsversion()
    info['service_pack'] = service_pack
    if major >= 6 and minor >= 2:
        # On windows >= 8.1 the system call that getwindowsversion uses has
        # been frozen to always return the same values. In this case we call
        # the RtlGetVersion API directly, which still provides meaningful
        # values, at least for now.
        major, minor, build_number = get_windows_version()
        version = "%d.%d.%d" % (major, minor, build_number)

    os_version = "%d.%d" % (major, minor)
elif system.startswith(('MINGW', 'MSYS_NT')):
    # windows/mingw python build (msys)
    info['os'] = 'win'
    os_version = version = unknown
elif system == "Linux":
    if hasattr(platform, "linux_distribution"):
        (distro, os_version, codename) = platform.linux_distribution()
    else:
        (distro, os_version, codename) = platform.dist()
    if not processor:
        processor = machine
    version = "%s %s" % (distro, os_version)

    # Bug in Python 2's `platform` library:
    # It will return a triple of empty strings if the distribution is not supported.
    # It works on Python 3. If we don't have an OS version,
    # the unit tests fail to run.
    if not distro and not os_version and not codename:
        distro = 'lfs'
        version = release
        os_version = release

    info['os'] = 'linux'
    info['linux_distro'] = distro
elif system in ['DragonFly', 'FreeBSD', 'NetBSD', 'OpenBSD']:
    info['os'] = 'bsd'
    version = os_version = sys.platform
elif system == "Darwin":
    (release, versioninfo, machine) = platform.mac_ver()
    version = "OS X %s" % release
    versionNums = release.split('.')[:2]
    os_version = "%s.%s" % (versionNums[0], versionNums[1])
    info['os'] = 'mac'
elif sys.platform in ('solaris', 'sunos5'):
    info['os'] = 'unix'
    os_version = version = sys.platform
else:
    os_version = version = unknown

info['version'] = version
info['os_version'] = StringVersion(os_version)

# processor type and bits
if processor in ["i386", "i686"]:
    if bits == "32bit":
        processor = "x86"
    elif bits == "64bit":
        processor = "x86_64"
elif processor.upper() == "AMD64":
    bits = "64bit"
    processor = "x86_64"
elif processor.upper() == "ARM64":
    bits = "64bit"
    processor = "aarch64"
elif processor == "Power Macintosh":
    processor = "ppc"
bits = re.search('(\d+)bit', bits).group(1)
info.update({'processor': processor,
             'bits': int(bits),
             })

if info['os'] == 'linux':
    import ctypes
    import errno
    PR_SET_SECCOMP = 22
    SECCOMP_MODE_FILTER = 2
    ctypes.CDLL(find_library("c"), use_errno=True).prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, 0)
    info['has_sandbox'] = ctypes.get_errno() == errno.EFAULT
else:
    info['has_sandbox'] = True

# standard value of choices, for easy inspection
choices = {'os': ['linux', 'bsd', 'win', 'mac', 'unix'],
           'bits': [32, 64],
           'processor': ['x86', 'x86_64', 'ppc']}


def sanitize(info):
    """Do some sanitization of input values, primarily
    to handle universal Mac builds."""
    if "processor" in info and info["processor"] == "universal-x86-x86_64":
        # If we're running on OS X 10.6 or newer, assume 64-bit
        if release[:4] >= "10.6":  # Note this is a string comparison
            info["processor"] = "x86_64"
            info["bits"] = 64
        else:
            info["processor"] = "x86"
            info["bits"] = 32

# method for updating information


def update(new_info):
    """
    Update the info.

    :param new_info: Either a dict containing the new info or a path/url
                     to a json file containing the new info.
    """

    PY3 = sys.version_info[0] == 3
    if PY3:
        string_types = str,
    else:
        string_types = basestring,
    if isinstance(new_info, string_types):
        # lazy import
        import mozfile
        import json
        f = mozfile.load(new_info)
        new_info = json.loads(f.read())
        f.close()

    info.update(new_info)
    sanitize(info)
    globals().update(info)

    # convenience data for os access
    for os_name in choices['os']:
        globals()['is' + os_name.title()] = info['os'] == os_name
    # unix is special
    if isLinux or isBsd:  # noqa
        globals()['isUnix'] = True


def find_and_update_from_json(*dirs, **kwargs):
    """Find a mozinfo.json file, load it, and update global symbol table.

    This method will first check the relevant objdir directory for the
    necessary mozinfo.json file, if the current script is being run from a
    Mozilla objdir.

    If the objdir directory did not supply the necessary data, this method
    will then look for the required mozinfo.json file from the provided
    tuple of directories.

    If file is found, the global symbols table is updated via a helper method.

    If no valid files are found, this method no-ops unless the raise_exception
    kwargs is provided with explicit boolean value of True.

    :param tuple dirs: Directories in which to look for the file.
    :param dict kwargs: optional values:
                        raise_exception: if True, exceptions are raised.
                                         False by default.
    :returns: None: default behavior if mozinfo.json cannot be found.
              json_path: string representation of mozinfo.json path.
    :raises: IOError: if raise_exception is True and file is not found.
    """
    # First, see if we're in an objdir
    try:
        from mozbuild.base import MozbuildObject, BuildEnvironmentNotFoundException
        from mozbuild.mozconfig import MozconfigFindException
        build = MozbuildObject.from_environment()
        json_path = _os.path.join(build.topobjdir, "mozinfo.json")
        if _os.path.isfile(json_path):
            update(json_path)
            return json_path
    except ImportError:
        pass
    except (BuildEnvironmentNotFoundException, MozconfigFindException):
        pass

    for d in dirs:
        d = _os.path.abspath(d)
        json_path = _os.path.join(d, "mozinfo.json")
        if _os.path.isfile(json_path):
            update(json_path)
            return json_path

    # by default, exceptions are suppressed. Set this to True if otherwise
    # desired.
    if kwargs.get('raise_exception', False):
        raise IOError('mozinfo.json could not be found.')
    return None


def output_to_file(path):
    import json
    with open(path, 'w') as f:
        f.write(json.dumps(info))


update({})

# exports
__all__ = list(info.keys())
__all__ += ['is' + os_name.title() for os_name in choices['os']]
__all__ += [
    'info',
    'unknown',
    'main',
    'choices',
    'update',
    'find_and_update_from_json',
    'output_to_file',
    'StringVersion',
]


def main(args=None):

    # parse the command line
    from optparse import OptionParser
    parser = OptionParser(description=__doc__)
    for key in choices:
        parser.add_option('--%s' % key, dest=key,
                          action='store_true', default=False,
                          help="display choices for %s" % key)
    options, args = parser.parse_args()

    # args are JSON blobs to override info
    if args:
        # lazy import
        import json
        for arg in args:
            if _os.path.exists(arg):
                string = open(arg).read()
            else:
                string = arg
            update(json.loads(string))

    # print out choices if requested
    flag = False
    for key, value in options.__dict__.items():
        if value is True:
            print('%s choices: %s' % (key, ' '.join([str(choice)
                                                     for choice in choices[key]])))
            flag = True
    if flag:
        return

    # otherwise, print out all info
    for key, value in info.items():
        print('%s: %s' % (key, value))


if __name__ == '__main__':
    main()
