## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-

from __future__ import print_function

import types

import re

import os

import subprocess

import shutil

import sys

from waflib import Task, Options, Configure, TaskGen, Logs, Build, Utils, Errors

from waflib.Errors import WafError

# feature  = TaskGen.feature

# after = TaskGen.after

# https://github.com/gjcarneiro/pybindgen

REQUIRED_PYBINDGEN_VERSION = '0.17.0.post41+ngd10fa60'

REQUIRED_PYGCCXML_VERSION = (0, 9, 5)

RUN_ME=-3

# return types of some APIs differ in Python 2/3 (type string vs class bytes)

# This method will decode('utf-8') a byte object in Python 3,

# and do nothing in Python 2

def maybe_decode(input):

    if sys.version_info < (3,):

        return input

    else:

        try: 

            return input.decode('utf-8')

        except:

            sys.exc_clear()

            return input

def add_to_python_path(path):

    if os.environ.get('PYTHONPATH', ''):

        os.environ['PYTHONPATH'] = path + os.pathsep + os.environ.get('PYTHONPATH')

    else:

        os.environ['PYTHONPATH'] = path

def set_pybindgen_pythonpath(env):

    if env['WITH_PYBINDGEN']:

        add_to_python_path(env['WITH_PYBINDGEN'])

def options(opt):

    opt.load('python')

    opt.add_option('--disable-python',

                   help=("Don't build Python bindings."),

                   action="store_true", default=False,

                   dest='python_disable')

    opt.add_option('--apiscan',

                   help=("Rescan the API for the indicated module(s), for Python bindings.  "

                         "Needs working GCCXML / pygccxml environment.  "

                         "The metamodule 'all' expands to all available ns-3 modules."),

                   default=None, dest='apiscan', metavar="MODULE[,MODULE...]")

    opt.add_option('--with-pybindgen',

                   help=('Path to an existing pybindgen source tree to use.'),

                   default=None,

                   dest='with_pybindgen', type="string")

    opt.add_option('--with-python',

                   help=('Path to the Python interpreter to use.'),

                   default=None, dest='with_python', type="string")

    opt.add_option('--no32bit-scan',

                   help=("Don't scan for the 32-bit variant of the bindings on 64-bit platforms."),

                   action="store_true", default=False,

                   dest='no32bit_scan')

def configure(conf):

    conf.env['ENABLE_PYTHON_BINDINGS'] = False

    if Options.options.python_disable:

        conf.report_optional_feature("python", "Python Bindings", False,

                                     "disabled by user request")

        return

    # Disable python in static builds (bug #1253)

    if ((conf.env['ENABLE_STATIC_NS3']) or \

      (conf.env['ENABLE_SHARED_AND_STATIC_NS3'])):

        conf.report_optional_feature("python", "Python Bindings", False,

                                     "bindings incompatible with static build")

        return

    enabled_modules = list(conf.env['NS3_ENABLED_MODULES'])

    enabled_modules.sort()

    available_modules = list(conf.env['NS3_MODULES'])

    available_modules.sort()

    all_modules_enabled = (enabled_modules == available_modules)

    conf.load('misc', tooldir=['waf-tools'])

    if sys.platform == 'cygwin':

        conf.report_optional_feature("python", "Python Bindings", False,

                                     "unsupported platform 'cygwin'")

        Logs.warn("Python is not supported in CygWin environment.  Try MingW instead.")

        return

    ## Check for Python

    if Options.options.with_python is not None:

        conf.env.PYTHON = Options.options.with_python

    try:

        conf.load('python')

    except Errors.ConfigurationError as ex:

        conf.report_optional_feature("python", "Python Bindings", False,

                                     "The python interpreter was not found")

        return

    try:

        conf.check_python_version((2,3))

    except Errors.ConfigurationError as ex:

        conf.report_optional_feature("python", "Python Bindings", False,

                                     "The python found version is too low (2.3 required)")

        return

    try:

        conf.check_python_headers()

    except Errors.ConfigurationError as ex:

        conf.report_optional_feature("python", "Python Bindings", False,

                                     "Python library or headers missing")

        return

    # stupid Mac OSX Python wants to build extensions as "universal

    # binaries", i386, x86_64, and ppc, but this way the type

    # __uint128_t is not available.  We need to disable the multiarch

    # crap by removing the -arch parameters.

    for flags_var in ["CFLAGS_PYEXT", "CFLAGS_PYEMBED", "CXXFLAGS_PYEMBED",

                      "CXXFLAGS_PYEXT", "LINKFLAGS_PYEMBED", "LINKFLAGS_PYEXT"]:

        flags = conf.env[flags_var]

        i = 0

        while i < len(flags):

            if flags[i] == '-arch':

                del flags[i]

                del flags[i]

                continue

            i += 1

        conf.env[flags_var] = flags

    # -fvisibility=hidden optimization

    if (conf.env['CXX_NAME'] == 'gcc' and [int(x) for x in conf.env['CC_VERSION']] >= [4,0,0]

        and conf.check_compilation_flag('-fvisibility=hidden')):

        conf.env.append_value('CXXFLAGS_PYEXT', '-fvisibility=hidden')

        conf.env.append_value('CCFLAGS_PYEXT', '-fvisibility=hidden')

    if conf.check_compilation_flag('-Wno-array-bounds'):

        conf.env.append_value('CXXFLAGS_PYEXT', '-Wno-array-bounds')

    # Check for the location of pybindgen

    if Options.options.with_pybindgen is not None:

        if os.path.isdir(Options.options.with_pybindgen):

            conf.msg("Checking for pybindgen location", ("%s (given)" % Options.options.with_pybindgen))

            conf.env['WITH_PYBINDGEN'] = os.path.abspath(Options.options.with_pybindgen)

    else:

        # ns-3-dev uses ../pybindgen, while ns-3 releases use ../REQUIRED_PYBINDGEN_VERSION

        pybindgen_dir = os.path.join('..', "pybindgen")

        pybindgen_release_str = "pybindgen-" + '.'.join([str(x) for x in REQUIRED_PYBINDGEN_VERSION])

        pybindgen_release_dir = os.path.join('..', pybindgen_release_str)

        if os.path.isdir(pybindgen_dir):

            conf.msg("Checking for pybindgen location", ("%s (guessed)" % pybindgen_dir))

            conf.env['WITH_PYBINDGEN'] = os.path.abspath(pybindgen_dir)

        elif os.path.isdir(pybindgen_release_dir):

            conf.msg("Checking for pybindgen location", ("%s (guessed)" % pybindgen_release_dir))

            conf.env['WITH_PYBINDGEN'] = os.path.abspath(pybindgen_release_dir)

        del pybindgen_dir

        del pybindgen_release_dir

    if not conf.env['WITH_PYBINDGEN']:

        conf.msg("Checking for pybindgen location", False)

    # Check for pybindgen

    set_pybindgen_pythonpath(conf.env)

    try:

        conf.check_python_module('pybindgen')

    except Errors.ConfigurationError:

        Logs.warn("pybindgen missing => no python bindings")

        conf.report_optional_feature("python", "Python Bindings", False,

                                     "PyBindGen missing")

        return

    else:

        out = subprocess.Popen([conf.env['PYTHON'][0], "-c",

                                "import pybindgen.version; "

                                "print(pybindgen.__version__)"],

                                stdout=subprocess.PIPE).communicate()[0]

        pybindgen_version = maybe_decode(out.strip())

        conf.msg('Checking for pybindgen version', pybindgen_version)

        if not (pybindgen_version == REQUIRED_PYBINDGEN_VERSION):

            Logs.warn("pybindgen (found %r), (need %r)" %

                      (pybindgen_version, REQUIRED_PYBINDGEN_VERSION))

            conf.report_optional_feature("python", "Python Bindings", False,

                                         "PyBindGen version not correct and newer version could not be retrieved")

            return

    def test(t1, t2):

        test_program = '''

#include <stdint.h>

#include <vector>

int main ()

{

   std::vector< %(type1)s > t = std::vector< %(type2)s > ();

   return 0;

}

''' % dict(type1=t1, type2=t2)

        try:

            ret = conf.check(compiler='cxx', fragment=test_program, features='cxx')

        except Errors.ConfigurationError:

            ret = False

        conf.msg('Checking for types %s and %s equivalence' % (t1, t2), (ret and 'no' or 'yes'))

        return ret

    uint64_is_long = test("uint64_t", "unsigned long")

    uint64_is_long_long = test("uint64_t", "unsigned long long")

    if uint64_is_long:

        conf.env['PYTHON_BINDINGS_APIDEFS'] = 'gcc-LP64'

    elif uint64_is_long_long:

        conf.env['PYTHON_BINDINGS_APIDEFS'] = 'gcc-ILP32'

    else:

        conf.env['PYTHON_BINDINGS_APIDEFS'] = None

    if conf.env['PYTHON_BINDINGS_APIDEFS'] is None:

        msg = 'none available'

    else:

        msg = conf.env['PYTHON_BINDINGS_APIDEFS']

    conf.msg('Checking for the apidefs that can be used for Python bindings', msg)

    if conf.env['PYTHON_BINDINGS_APIDEFS'] is None:

        conf.report_optional_feature("python", "Python Bindings", False,

                                     "No apidefs are available that can be used in this system")

        return

    ## If all has gone well, we finally enable the Python bindings

    conf.env['ENABLE_PYTHON_BINDINGS'] = True

    conf.report_optional_feature("python", "Python Bindings", True, None)

    # check cxxabi stuff (which Mac OS X Lion breaks)

    fragment = r"""

# include <cxxabi.h>

int main ()

{

   const abi::__si_class_type_info *_typeinfo  __attribute__((unused)) = NULL;

   return 0;

}

"""

    gcc_rtti_abi = conf.check_nonfatal(fragment=fragment, msg="Checking for internal GCC cxxabi",

                                       okmsg="complete", errmsg='incomplete',

                                       mandatory=False)

    conf.env["GCC_RTTI_ABI_COMPLETE"] = str(bool(gcc_rtti_abi))

    ## Check for pygccxml

    try:

        conf.check_python_module('pygccxml')

    except Errors.ConfigurationError:

        conf.report_optional_feature("pygccxml", "Python API Scanning Support", False,

                                     "Missing 'pygccxml' Python module")

        return

    out = subprocess.Popen([conf.env['PYTHON'][0], "-c",

                            "import pygccxml; print pygccxml.__version__"],

                            stdout=subprocess.PIPE).communicate()[0]

    pygccxml_version_str = out.strip()

    # Bug 2013:  pygccxml versions > 1.0.0 prepend a 'v' to version number

    pygccxml_version_str = pygccxml_version_str.lstrip('v')

    pygccxml_version = tuple([int(x) for x in pygccxml_version_str.split('.')])

    conf.msg('Checking for pygccxml version', pygccxml_version_str)

    if not (pygccxml_version >= REQUIRED_PYGCCXML_VERSION):

        Logs.warn("pygccxml (found %s) is too old (need %s) => "

                "automatic scanning of API definitions will not be possible" %

                (pygccxml_version_str,

                 '.'.join([str(x) for x in REQUIRED_PYGCCXML_VERSION])))

        conf.report_optional_feature("pygccxml", "Python API Scanning Support", False,

                                     "pygccxml too old")

        return

    ## Check gccxml version

    try:

        gccxml = conf.find_program('gccxml', var='GCCXML')

    except WafError:

        gccxml = None

    if not gccxml:

        Logs.warn("gccxml missing; automatic scanning of API definitions will not be possible")

        conf.report_optional_feature("pygccxml", "Python API Scanning Support", False,

                                     "gccxml missing")

        return

    gccxml_version_line = os.popen(gccxml[0] + " --version").readline().strip()

    m = re.match( "^GCC-XML version (\d\.\d(\.\d)?)$", gccxml_version_line)

    try:

        gccxml_version = m.group(1)

        gccxml_version_ok = ([int(s) for s in gccxml_version.split('.')] >= [0, 9])

    except AttributeError:

        gccxml_version = gccxml_version_line

        gccxml_version_ok = False

    conf.msg('Checking for gccxml version', gccxml_version)

    if not gccxml_version_ok:

        Logs.warn("gccxml version unknown or too old, need version >= 0.9; automatic scanning of API definitions will not be possible")

        conf.report_optional_feature("pygccxml", "Python API Scanning Support", False,

                                     "gccxml too old")

        return

    ## If we reached

    conf.env['ENABLE_PYTHON_SCANNING'] = True

    conf.report_optional_feature("pygccxml", "Python API Scanning Support", True, None)

# ---------------------

def get_headers_map(bld):

    headers_map = {} # header => module

    for ns3headers in bld.all_task_gen:

        if 'ns3header' in getattr(ns3headers, "features", []):

            if ns3headers.module.endswith('-test'):

                continue

            for h in ns3headers.to_list(ns3headers.headers):

                headers_map[os.path.basename(h)] = ns3headers.module

    return headers_map

def get_module_path(bld, module):

    for ns3headers in bld.all_task_gen:

        if 'ns3header' in getattr(ns3headers, "features", []):

            if ns3headers.module == module:

                break

    else:

        raise ValueError("Module %r not found" % module)

    return ns3headers.path.abspath()

class apiscan_task(Task.Task):

    """Uses gccxml to scan the file 'everything.h' and extract API definitions.

    """

    after = 'gen_ns3_module_header ns3header'

    before = 'cxx command'

    color = "BLUE"

    def __init__(self, curdirnode, env, bld, target, cflags, module):

        self.bld = bld

        super(apiscan_task, self).__init__(generator=self, env=env)

        self.curdirnode = curdirnode

        self.env = env

        self.target = target

        self.cflags = cflags

        self.module = module

    def display(self):

        return 'api-scan-%s\n' % (self.target,)

    def uid(self):

        try:

            return self.uid_

        except AttributeError:

            m = Utils.md5()

            up = m.update

            up(self.__class__.__name__.encode())

            up(self.curdirnode.abspath().encode())

            up(self.target)

            self.uid_ = m.digest()

            return self.uid_

    def run(self):

        self.inputs = [self.bld.bldnode.find_resource("ns3/{0}-module.h".format(self.module))]

        self.outputs = [self.bld.srcnode.find_resource("src/{}/bindings/modulegen__{}.py".format(self.module, self.target))]

        top_builddir = self.bld.bldnode.abspath()

        module_path = get_module_path(self.bld, self.module)

        headers_map = get_headers_map(self.bld)

        scan_header = os.path.join(top_builddir, "ns3", "%s-module.h" % self.module)

        if not os.path.exists(scan_header):

            Logs.error("Cannot apiscan module %r: %s does not exist" % (self.module, scan_header))

            return 0

        argv = [

            self.env['PYTHON'][0],

            os.path.join(self.curdirnode.abspath(), 'ns3modulescan-modular.py'), # scanning script

            top_builddir,

            self.module,

            repr(get_headers_map(self.bld)),

            os.path.join(module_path, "bindings", 'modulegen__%s.py' % (self.target)), # output file

            self.cflags,

            ]

        scan = subprocess.Popen(argv, stdin=subprocess.PIPE)

        retval = scan.wait()

        return retval

    def runnable_status(self):

        # By default, Waf Task will skip running a task if the signature of

        # the build has not changed.  We want this task to always run if

        # invoked by the user, particularly since --apiscan=all will require

        # invoking this task many times, once per module.

        return RUN_ME

def get_modules_and_headers(bld):

    """

    Gets a dict of

       module_name => ([module_dep1, module_dep2, ...], [module_header1, module_header2, ...])

    tuples, one for each module.

    """

    retval = {}

    for module in bld.all_task_gen:

        if not module.name.startswith('ns3-'):

            continue

        if module.name.endswith('-test'):

            continue

        module_name = module.name[4:] # strip the ns3- prefix

        ## find the headers object for this module

        headers = []

        for ns3headers in bld.all_task_gen:

            if 'ns3header' not in getattr(ns3headers, "features", []):

                continue

            if ns3headers.module != module_name:

                continue

            for source in ns3headers.to_list(ns3headers.headers):

                headers.append(os.path.basename(source))

        retval[module_name] = (list(module.module_deps), headers)

    return retval

class gen_ns3_compat_pymod_task(Task.Task):

    """Generates a 'ns3.py' compatibility module."""

    before = 'cxx'

    color = 'BLUE'

    def run(self):

        assert len(self.outputs) == 1

        outfile = open(self.outputs[0].abspath(), "w")

        print("import warnings", file=outfile)

        print('warnings.warn("the ns3 module is a compatibility layer '\

            'and should not be used in newly written code", DeprecationWarning, stacklevel=2)', file=outfile)

        print(file=outfile)

        for module in self.bld.env['PYTHON_MODULES_BUILT']:

            print("from ns.%s import *" % (module.replace('-', '_')), file=outfile)

        outfile.close()

        return 0

def build(bld):

    if Options.options.python_disable:

        return

    env = bld.env

    set_pybindgen_pythonpath(env)

    if Options.options.apiscan:

        if not env['ENABLE_PYTHON_SCANNING']:

            raise WafError("Cannot re-scan python bindings: (py)gccxml not available")

        scan_targets = []

        if sys.platform == 'cygwin':

            scan_targets.append(('gcc_cygwin', ''))

        else:

            import struct

            if struct.calcsize('I') == 4 and struct.calcsize('L') == 8 and struct.calcsize('P') == 8:

                if not Options.options.no32bit_scan:

                    scan_targets.append(('gcc_ILP32', '-m32'))

                scan_targets.append(('gcc_LP64', '-m64'))

            elif struct.calcsize('I') == 4 and struct.calcsize('L') == 4 and struct.calcsize('P') == 4:

                scan_targets.append(('gcc_ILP32', ''))

            else:

                raise WafError("Cannot scan python bindings for unsupported data model")

        test_module_path = bld.path.find_dir("../../src/test")

        if Options.options.apiscan == 'all':

            scan_modules = []

            for mod in bld.all_task_gen:

                if not mod.name.startswith('ns3-'):

                    continue

                if mod.path.is_child_of(test_module_path):

                    continue

                if mod.name.endswith('-test'):

                    continue

                bindings_enabled = (mod.name in env.MODULAR_BINDINGS_MODULES)

                #print mod.name, bindings_enabled

                if bindings_enabled:

                    scan_modules.append(mod.name.split('ns3-')[1])

        else:

            scan_modules = Options.options.apiscan.split(',')

        print("Modules to scan: ", scan_modules)

        for target, cflags in scan_targets:

            group = bld.get_group(bld.current_group)

            for module in scan_modules:

                group.append(apiscan_task(bld.path, env, bld, target, cflags, module))