#!/bin/false # You must specify a python interpreter.
import sys; assert sys.version_info < (3,), ur"Tahoe-LAFS does not run under Python 3. Please use a version of Python between 2.6 and 2.7.x inclusive."

import os, subprocess

where = os.path.realpath(sys.argv[0])
base = os.path.dirname(os.path.dirname(where))

if sys.platform == "win32":
    perhaps_installed_tahoe = os.path.join(os.path.dirname(sys.executable), 'Scripts', 'tahoe.pyscript')
else:
    perhaps_installed_tahoe = "/usr/bin/tahoe"

whoami = '''\
I am a "bin%stahoe" executable for the convenience of running Tahoe-LAFS
from its source distribution -- I work only when invoked as the "tahoe"
script that lives in the "bin" subdirectory of a Tahoe source code
distribution, and only if you have already run "python setup.py build".
''' % (os.path.sep,)

# look for Tahoe.home .
homemarker = os.path.join(base, "Tahoe.home")
if not os.path.exists(homemarker):
    print(whoami)
    print('''\
I just tried to run and found that I am not living in such a directory, so I
am stopping now. To run Tahoe after it has been is installed, please execute
my brother, who gets installed into the appropriate place for executables
when you run "make install" (perhaps as "%s").
''' % (perhaps_installed_tahoe,))
    sys.exit(1)

# we've found our home. Put the tahoe support/lib etc. in our PYTHONPATH.
if sys.platform == "win32":
    supportdir = os.path.join(base, "support", "Lib", "site-packages")
else:
    supportdir = os.path.join(base, "support",
                              "lib",
                              "python%d.%d" % sys.version_info[:2],
                              "site-packages")

# update PYTHONPATH so that child processes (like twistd) will use this too
pp = os.environ.get("PYTHONPATH")
if pp:
    pp = os.pathsep.join([supportdir] + pp.split(os.pathsep))
else:
    pp = supportdir
os.environ["PYTHONPATH"] = pp

# find commandline args and the location of the tahoe executable.
if sys.platform == "win32":
    import re
    from ctypes import WINFUNCTYPE, POINTER, byref, c_wchar_p, c_int, windll

    GetCommandLineW = WINFUNCTYPE(c_wchar_p)(("GetCommandLineW", windll.kernel32))
    CommandLineToArgvW = WINFUNCTYPE(POINTER(c_wchar_p), c_wchar_p, POINTER(c_int)) \
                            (("CommandLineToArgvW", windll.shell32))

    argc = c_int(0)
    argv_unicode = CommandLineToArgvW(GetCommandLineW(), byref(argc))

    # See src/allmydata/scripts/runner.py for the corresponding unmangler.
    # Note that this doesn't escape \x7F. If it did, test_unicode_arguments_and_output
    # in test_runner.py wouldn't work.
    def mangle(s):
        return str(re.sub(u'[^\\x20-\\x7F]', lambda m: u'\x7F%x;' % (ord(m.group(0)),), s))

    argv = [mangle(argv_unicode[i]) for i in xrange(0, argc.value)]

    # Take only the suffix with the same number of arguments as sys.argv.
    # This accounts for anything that can cause initial arguments to be stripped,
    # for example, the Python interpreter or any options passed to it, or runner
    # scripts such as 'coverage run'. It works even if there are no such arguments,
    # as in the case of a frozen executable created by bb-freeze or similar.

    argv = argv[-len(sys.argv):]

    # On Windows, the script is not directly executable and must be run via python.
    prefix = [sys.executable]
    script = os.path.join(base, "support", "Scripts", "tahoe.pyscript")
    args = argv[1:]
else:
    # On non-Windows, invoke the script directly, so that 'top' for example shows 'tahoe'.
    prefix = []
    script = os.path.join(base, "support", "bin", "tahoe")
    args = sys.argv[1:]

# Support indirection via another "runner" script (e.g. coverage).
# For example: bin/tahoe @RUNNER RUNNER_ARGS @tahoe TAHOE_ARGS

if len(args) >= 1 and args[0].startswith('@'):
    runner = args[0][1:]
    if runner.endswith('.py') or runner.endswith('.pyscript'):
        prefix = [sys.executable]
    else:
        prefix = []

    def _subst(a):
        if a == '@tahoe': return script
        return a
    command = prefix + [runner] + map(_subst, args[1:])
else:
    runner = script
    command = prefix + [script] + args

    if not os.path.exists(script):
        print(whoami)
        print('''\
I could not find the support script
"%s".

To run an installed version of Tahoe-LAFS, please execute the "tahoe"
script that is installed into the appropriate place for executables
when you run "python setup.py install" (perhaps as "%s").
''' % (script, perhaps_installed_tahoe))
        sys.exit(1)

try:
    res = subprocess.call(command, env=os.environ)
except Exception as le:
    print(whoami)
    print('''\
I just tried to invoke "%s"
and got an exception.
''' % (runner,))
    raise
else:
    sys.exit(res)
