#! /usr/bin/env python

import sys
import os.path

import pybindgen.settings
from pybindgen.gccxmlparser import ModuleParser, PygenClassifier, PygenSection, WrapperWarning
from pybindgen.typehandlers.codesink import FileCodeSink
from pygccxml.declarations import templates
from pygccxml.declarations.class_declaration import class_t
from pygccxml.declarations.calldef import free_function_t, member_function_t, constructor_t


## we need the smart pointer type transformation to be active even
## during gccxml scanning.
import ns3modulegen_core_customizations


## silence gccxmlparser errors; we only want error handling in the
## generated python script, not while scanning.
class ErrorHandler(pybindgen.settings.ErrorHandler):
    def handle_error(self, dummy_wrapper, dummy_exception, dummy_traceback_):
        return True
pybindgen.settings.error_handler = ErrorHandler()
import warnings
warnings.filterwarnings(category=WrapperWarning, action='ignore')

type_annotations = {
    '::ns3::RefCountBase': {
        'incref_method': 'Ref',
        'decref_method': 'Unref',
        'peekref_method': 'GetReferenceCount',
        'automatic_type_narrowing': 'true',
        },
    '::ns3::Object': {
        'incref_method': 'Ref',
        'decref_method': 'Unref',
        'peekref_method': 'GetReferenceCount',
        'automatic_type_narrowing': 'true',
        },
    '::ns3::Packet': {
        'incref_method': 'Ref',
        'decref_method': 'Unref',
        'peekref_method': 'GetReferenceCount',
        },
    '::ns3::CallbackImplBase': {
        'incref_method': 'Ref',
        'decref_method': 'Unref',
        'peekref_method': 'GetReferenceCount',
        },
    '::ns3::PacketMetadata': {
        'ignore': None,
        },
    '::ns3::AttributeChecker': {
        'automatic_type_narrowing': 'true',
        'allow_subclassing': 'false',
        },
    '::ns3::AttributeValue': {
        'automatic_type_narrowing': 'true',
        'allow_subclassing': 'false',
        },
    'ns3::RandomVariable::RandomVariable(ns3::RandomVariableBase const & variable) [constructor]': {
        'ignore': None,
        },
    'ns3::RandomVariableBase * ns3::RandomVariable::Peek() const [member function]': {
        'ignore': None,
        },
    'void ns3::RandomVariable::GetSeed(uint32_t * seed) const [member function]': {
        'params': {'seed':{'direction':'out',
                           'array_length':'6'}}
        },
    'bool ns3::TypeId::LookupAttributeByName(std::string name, ns3::TypeId::AttributeInfo * info) const [member function]': {
        'params': {'info':{'transfer_ownership': 'false'}}
        },
    'static bool ns3::TypeId::LookupByNameFailSafe(std::string name, ns3::TypeId * tid) [member function]': {
        'params': {'tid': {'transfer_ownership': 'false'}}
        },
    'bool ns3::TraceSourceAccessor::ConnectWithoutContext(ns3::ObjectBase * obj, ns3::CallbackBase const & cb) const [member function]': {
        'params': {'obj': {'transfer_ownership':'false'}}
        },
    'bool ns3::TraceSourceAccessor::Connect(ns3::ObjectBase * obj, std::string context, ns3::CallbackBase const & cb) const [member function]': {
        'params': {'obj': {'transfer_ownership':'false'}}
        },
    'bool ns3::TraceSourceAccessor::DisconnectWithoutContext(ns3::ObjectBase * obj, ns3::CallbackBase const & cb) const [member function]': {
        'params': {'obj': {'transfer_ownership':'false'}}
        },
    'bool ns3::TraceSourceAccessor::Disconnect(ns3::ObjectBase * obj, std::string context, ns3::CallbackBase const & cb) const [member function]': {
        'params': {'obj': {'transfer_ownership':'false'}}
        },
    'bool ns3::AttributeAccessor::Set(ns3::ObjectBase * object, ns3::AttributeValue const & value) const [member function]': {
        'params': {'object': {'transfer_ownership':'false'}}
        },
    'ns3::EmpiricalVariable::EmpiricalVariable(ns3::RandomVariableBase const & variable) [constructor]': {
        'ignore': None
        },
    'static ns3::AttributeList * ns3::AttributeList::GetGlobal() [member function]': {
        'caller_owns_return': 'false'
        },
    'void ns3::CommandLine::Parse(int argc, char * * argv) const [member function]': {
        'ignore': None # manually wrapped
        },
    'extern void ns3::PythonCompleteConstruct(ns3::Ptr<ns3::Object> object, ns3::TypeId typeId, ns3::AttributeList const & attributes) [free function]': {
        'ignore': None # used transparently by, should not be wrapped
        },
    }

def get_ns3_relative_path(path):
    l = []
    head = path
    while head:
        head, tail = os.path.split(head)
        if tail == 'ns3':
            return os.path.join(*l)
        l.insert(0, tail)
    raise AssertionError("is the path %r inside ns3?!" % path)


def pre_scan_hook(dummy_module_parser,
                  pygccxml_definition,
                  global_annotations,
                  parameter_annotations):
    ns3_header = get_ns3_relative_path(pygccxml_definition.location.file_name)

    ## Note: we don't include line numbers in the comments because
    ## those numbers are very likely to change frequently, which would
    ## cause needless changes, since the generated python files are
    ## kept under version control.

    #global_annotations['pygen_comment'] = "%s:%i: %s" % \
    #    (ns3_header, pygccxml_definition.location.line, pygccxml_definition)
    global_annotations['pygen_comment'] = "%s: %s" % \
        (ns3_header, pygccxml_definition)


    ## handle ns3::Object::GetObject (left to its own devices,
    ## pybindgen will generate a mangled name containing the template
    ## argument type name).
    if isinstance(pygccxml_definition, member_function_t) \
            and pygccxml_definition.parent.name == 'Object' \
            and pygccxml_definition.name == 'GetObject':
        template_args = templates.args(pygccxml_definition.demangled_name)
        if template_args == ['ns3::Object']:
            global_annotations['template_instance_names'] = 'ns3::Object=>GetObject'

    ## Don't wrap Simulator::Schedule* (manually wrapped)
    if isinstance(pygccxml_definition, member_function_t) \
            and pygccxml_definition.parent.name == 'Simulator' \
            and pygccxml_definition.name.startswith('Schedule'):
        global_annotations['ignore'] = None

    # unblock python threads for Simulator::Run
    if isinstance(pygccxml_definition, member_function_t) \
            and pygccxml_definition.parent.name == 'Simulator' \
            and pygccxml_definition.name == 'Run':
        global_annotations['unblock_threads'] = True


    ## classes
    if isinstance(pygccxml_definition, class_t):
        # no need for helper classes to allow subclassing in Python, I think...
        if pygccxml_definition.name.endswith('Helper'):
            global_annotations['allow_subclassing'] = 'false'

        if pygccxml_definition.decl_string.startswith('::ns3::Callback<'):
            # manually handled in ns3modulegen_core_customizations.py
            global_annotations['ignore'] = None
            return

        if pygccxml_definition.decl_string.startswith('::ns3::TracedCallback<'):
            global_annotations['ignore'] = None
            return

        if pygccxml_definition.decl_string.startswith('::ns3::Ptr<'):
            # handled by pybindgen "type transformation"
            global_annotations['ignore'] = None
            return

        # table driven class customization
        try:
            annotations = type_annotations[pygccxml_definition.decl_string]
        except KeyError:
            pass
        else:
            global_annotations.update(annotations)

    ## free functions
    if isinstance(pygccxml_definition, free_function_t):
        if pygccxml_definition.name == 'PeekPointer':
            global_annotations['ignore'] = None
            return

    ## table driven methods/constructors/functions customization
    if isinstance(pygccxml_definition, (free_function_t, member_function_t, constructor_t)):
        try:
            annotations = type_annotations[str(pygccxml_definition)]
        except KeyError:
            pass
        else:
            for key,value in annotations.items():
                if key == 'params':
                    parameter_annotations.update (value)
                    del annotations['params']
            global_annotations.update(annotations)


# def post_scan_hook(dummy_module_parser, dummy_pygccxml_definition, pybindgen_wrapper):
#     ## classes
#     if isinstance(pybindgen_wrapper, CppClass):
#         if pybindgen_wrapper.name.endswith('Checker'):
#             print >> sys.stderr, "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!", pybindgen_wrapper
#             #pybindgen_wrapper.set_instance_creation_function(AttributeChecker_instance_creation_function)


def scan_callback_classes(module_parser, callback_classes_file):
    callback_classes_file.write("callback_classes = [\n")
    for cls in module_parser.module_namespace.classes(function=module_parser.location_filter,
                                                      recursive=False):
        if not cls.name.startswith("Callback<"):
            continue
        assert templates.is_instantiation(cls.decl_string), "%s is not a template instantiation" % cls
        dummy_cls_name, template_parameters = templates.split(cls.decl_string)
        callback_classes_file.write("    %r,\n" % template_parameters)
    callback_classes_file.write("]\n")


class MyPygenClassifier(PygenClassifier):
    def __init__(self, headers_map):
        self.headers_map = headers_map

    def classify(self, pygccxml_definition):
        name = os.path.basename(pygccxml_definition.location.file_name)
        try:
            return self.headers_map[name]
        except KeyError:
            return '__main__'


def ns3_module_scan(top_builddir, pygen_file_name, everything_h):

    ns3_modules = eval(sys.stdin.read())

    ## do a topological sort on the modules graph
    from topsort import topsort
    graph = []
    for ns3_module_name, (ns3_module_deps, dummy) in ns3_modules.iteritems():
        for dep in ns3_module_deps:
            graph.append((dep, ns3_module_name))
    sorted_ns3_modules = topsort(graph)
    #print >> sys.stderr, "******* topological sort: ", sorted_ns3_modules

    sections = [PygenSection('__main__', FileCodeSink(open(pygen_file_name, "wt")))]
    headers_map = {} # header_name -> section_name
    for ns3_module in sorted_ns3_modules:
        section_name = "ns3_module_%s" % ns3_module.replace('-', '_')
        file_name = os.path.join(os.path.dirname(pygen_file_name), "%s.py" % section_name)
        sections.append(PygenSection(section_name, FileCodeSink(open(file_name, "wt")),
                                     section_name + "__local"))
        for header in ns3_modules[ns3_module][1]:
            headers_map[header] = section_name

    module_parser = ModuleParser('ns3', 'ns3')

    module_parser.add_pre_scan_hook(pre_scan_hook)
    #module_parser.add_post_scan_hook(post_scan_hook)

    gccxml_options = dict(
        include_paths=[top_builddir],
         define_symbols={
            #'NS3_ASSERT_ENABLE': None,
            #'NS3_LOG_ENABLE': None,
            }
        )

    module_parser.parse_init([everything_h],
                             None, whitelist_paths=[top_builddir, os.path.dirname(everything_h)],
                             #includes=['"ns3/everything.h"'],
                             pygen_sink=sections,
                             pygen_classifier=MyPygenClassifier(headers_map),
                             gccxml_options=gccxml_options)
    module_parser.scan_types()

    callback_classes_file = open(os.path.join(os.path.dirname(pygen_file_name), "callbacks_list.py"), "wt")
    scan_callback_classes(module_parser, callback_classes_file)
    callback_classes_file.close()


    module_parser.scan_methods()
    module_parser.scan_functions()
    module_parser.parse_finalize()

    for section in sections:
        section.code_sink.file.close()



if __name__ == '__main__':
    ns3_module_scan(sys.argv[1], sys.argv[3], sys.argv[2])