#!/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

import os
import platform
import re
import sys
from .string_version import StringVersion


# 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 }
(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'):
    # 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 == "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("libc.so.6", 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.
    """

    if isinstance(new_info, basestring):
        # 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:
        globals()['isUnix'] = True

def find_and_update_from_json(*dirs):
    """
    Find a mozinfo.json file, load it, and update the info with the
    contents.

    :param dirs: Directories in which to look for the file. They will be
                 searched after first looking in the root of the objdir
                 if the current script is being run from a Mozilla objdir.

    Returns the full path to mozinfo.json if it was found, or None otherwise.
    """
    # First, see if we're in an objdir
    try:
        from mozbuild.base import MozbuildObject, BuildEnvironmentNotFoundException
        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:
        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

    return None

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

update({})

# exports
__all__ = 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 = file(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()
