def _reset_sys_path():
    # Clear generic sys.path[0]
    import sys, os
    resources = os.environ['RESOURCEPATH']
    while sys.path[0] == resources:
        del sys.path[0]
_reset_sys_path()


def _site_packages():
    import site, sys, os
    paths = []
    prefixes = [sys.prefix]
    if sys.exec_prefix != sys.prefix:
        prefixes.append(sys.exec_prefix)
    for prefix in prefixes:
        paths.append(os.path.join(prefix, 'lib', 'python' + sys.version[:3],
            'site-packages'))
    if os.path.join('.framework', '') in os.path.join(sys.prefix, ''):
        home = os.environ.get('HOME')
        if home:
            paths.append(os.path.join(home, 'Library', 'Python',
                sys.version[:3], 'site-packages'))

    # Work around for a misfeature in setuptools: easy_install.pth places
    # site-packages way to early on sys.path and that breaks py2app bundles.
    # NOTE: this is hacks into an undocumented feature of setuptools and
    # might stop to work without warning.
    sys.__egginsert = len(sys.path)

    for path in paths:
        site.addsitedir(path)
_site_packages()


"""
sys.argv emulation

This module starts a basic event loop to collect file- and url-open AppleEvents. Those get
converted to strings and stuffed into sys.argv. When that is done we continue starting
the application.

This is a workaround to convert scripts that expect filenames on the command-line to work
in a GUI environment. GUI applications should not use this feature.

NOTE: This module uses ctypes and not the Carbon modules in the stdlib because the latter
don't work in 64-bit mode and are also not available with python 3.x.
"""

import sys
import os
import time

import ctypes
import struct

class AEDesc (ctypes.Structure):
    _fields_ = [
        ('descKey', ctypes.c_int),
        ('descContent', ctypes.c_void_p),
    ]

class EventTypeSpec (ctypes.Structure):
    _fields_ = [
        ('eventClass',      ctypes.c_int),
        ('eventKind',       ctypes.c_uint),
    ]

def _ctypes_setup():
    carbon = ctypes.CDLL('/System/Library/Carbon.framework/Carbon')

    timer_func = ctypes.CFUNCTYPE(
            None, ctypes.c_void_p, ctypes.c_long)

    ae_callback = ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_void_p,
        ctypes.c_void_p, ctypes.c_void_p)
    carbon.AEInstallEventHandler.argtypes = [
            ctypes.c_int, ctypes.c_int, ae_callback,
            ctypes.c_void_p, ctypes.c_char ]
    carbon.AERemoveEventHandler.argtypes = [
            ctypes.c_int, ctypes.c_int, ae_callback,
            ctypes.c_char ]

    carbon.AEProcessEvent.restype = ctypes.c_int
    carbon.AEProcessEvent.argtypes = [ctypes.c_void_p]


    carbon.ReceiveNextEvent.restype = ctypes.c_int
    carbon.ReceiveNextEvent.argtypes = [
        ctypes.c_long,  ctypes.POINTER(EventTypeSpec),
        ctypes.c_double, ctypes.c_char,
        ctypes.POINTER(ctypes.c_void_p)
    ]


    carbon.AEGetParamDesc.restype = ctypes.c_int
    carbon.AEGetParamDesc.argtypes = [
            ctypes.c_void_p, ctypes.c_int, ctypes.c_int,
            ctypes.POINTER(AEDesc)]

    carbon.AECountItems.restype = ctypes.c_int
    carbon.AECountItems.argtypes = [ ctypes.POINTER(AEDesc),
            ctypes.POINTER(ctypes.c_long) ]

    carbon.AEGetNthDesc.restype = ctypes.c_int
    carbon.AEGetNthDesc.argtypes = [
            ctypes.c_void_p, ctypes.c_long, ctypes.c_int,
            ctypes.c_void_p, ctypes.c_void_p ]

    carbon.AEGetDescDataSize.restype = ctypes.c_int
    carbon.AEGetDescDataSize.argtypes = [ ctypes.POINTER(AEDesc) ]

    carbon.AEGetDescData.restype = ctypes.c_int
    carbon.AEGetDescData.argtypes = [
            ctypes.POINTER(AEDesc),
            ctypes.c_void_p,
            ctypes.c_int,
            ]


    carbon.FSRefMakePath.restype = ctypes.c_int
    carbon.FSRefMakePath.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_uint]

    return carbon

def _run_argvemulator(timeout = 60):

    # Configure ctypes
    carbon = _ctypes_setup()

    # Is the emulator running?
    running = [True]

    timeout = [timeout]

    # Configure AppleEvent handlers
    ae_callback = carbon.AEInstallEventHandler.argtypes[2]

    kAEInternetSuite,   = struct.unpack('>i', b'GURL')
    kAEISGetURL,        = struct.unpack('>i', b'GURL')
    kCoreEventClass,    = struct.unpack('>i', b'aevt')
    kAEOpenApplication, = struct.unpack('>i', b'oapp')
    kAEOpenDocuments,   = struct.unpack('>i', b'odoc')
    keyDirectObject,    = struct.unpack('>i', b'----')
    typeAEList,         = struct.unpack('>i', b'list')
    typeChar,           = struct.unpack('>i', b'TEXT')
    typeFSRef,          = struct.unpack('>i', b'fsrf')
    FALSE               = b'\0'
    TRUE                = b'\1'
    eventLoopTimedOutErr = -9875

    kEventClassAppleEvent, = struct.unpack('>i', b'eppc')
    kEventAppleEvent = 1


    @ae_callback
    def open_app_handler(message, reply, refcon):
        # Got a kAEOpenApplication event, which means we can
        # start up. On some OSX versions this event is even
        # sent when an kAEOpenDocuments or kAEOpenURLs event
        # is sent later on.
        #
        # Therefore don't set running to false, but reduce the
        # timeout to at most two seconds beyond the current time.
        timeout[0] = min(timeout[0], time.time() - start + 2)
        #running[0] = False
        return 0

    carbon.AEInstallEventHandler(kCoreEventClass, kAEOpenApplication,
            open_app_handler, 0, FALSE)

    @ae_callback
    def open_file_handler(message, reply, refcon):
        listdesc = AEDesc()
        sts = carbon.AEGetParamDesc(message, keyDirectObject, typeAEList,
                ctypes.byref(listdesc))
        if sts != 0:
            print("argvemulator warning: cannot unpack open document event")
            running[0] = False
            return

        item_count = ctypes.c_long()
        sts = carbon.AECountItems(ctypes.byref(listdesc), ctypes.byref(item_count))
        if sts != 0:
            print("argvemulator warning: cannot unpack open document event")
            running[0] = False
            return

        desc = AEDesc()
        for i in range(item_count.value):
            sts = carbon.AEGetNthDesc(ctypes.byref(listdesc), i+1, typeFSRef, 0, ctypes.byref(desc))
            if sts != 0:
                print("argvemulator warning: cannot unpack open document event")
                running[0] = False
                return

            sz = carbon.AEGetDescDataSize(ctypes.byref(desc))
            buf = ctypes.create_string_buffer(sz)
            sts = carbon.AEGetDescData(ctypes.byref(desc), buf, sz)
            if sts != 0:
                print("argvemulator warning: cannot extract open document event")
                continue

            fsref = buf

            buf = ctypes.create_string_buffer(1024)
            sts = carbon.FSRefMakePath(ctypes.byref(fsref), buf, 1023)
            if sts != 0:
                print("argvemulator warning: cannot extract open document event")
                continue

            if sys.version_info[0] > 2:
                sys.argv.append(buf.value.decode('utf-8'))
            else:
                sys.argv.append(buf.value)

        running[0] = False
        return 0

    carbon.AEInstallEventHandler(kCoreEventClass, kAEOpenDocuments,
            open_file_handler, 0, FALSE)

    @ae_callback
    def open_url_handler(message, reply, refcon):
        listdesc = AEDesc()
        ok = carbon.AEGetParamDesc(message, keyDirectObject, typeAEList,
                ctypes.byref(listdesc))
        if ok != 0:
            print("argvemulator warning: cannot unpack open document event")
            running[0] = False