#     Copyright 2019, Kay Hayen, mailto:kay.hayen@gmail.com
#
#     Part of "Nuitka", an optimizing Python compiler that is compatible and
#     integrates with CPython, but also works on its own.
#
#     Licensed under the Apache License, Version 2.0 (the "License");
#     you may not use this file except in compliance with the License.
#     You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
#     Unless required by applicable law or agreed to in writing, software
#     distributed under the License is distributed on an "AS IS" BASIS,
#     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#     See the License for the specific language governing permissions and
#     limitations under the License.
#
""" Demotion of compiled modules to bytecode modules.

"""

import marshal
from logging import debug

from nuitka.importing.ImportCache import replaceImportedModule
from nuitka.ModuleRegistry import replaceRootModule
from nuitka.nodes.ModuleNodes import makeUncompiledPythonModule
from nuitka.plugins.Plugins import Plugins
from nuitka.tree.SourceReading import readSourceCodeFromFilename


def demoteCompiledModuleToBytecode(module):
    """ Demote a compiled module to uncompiled (bytecode).

    """

    full_name = module.getFullName()
    filename = module.getCompileTimeFilename()

    debug("Demoting module '%s' to bytecode from '%s'.", full_name, filename)

    source_code = readSourceCodeFromFilename(full_name, filename)

    source_code = Plugins.onFrozenModuleSourceCode(
        module_name=full_name, is_package=False, source_code=source_code
    )

    bytecode = compile(source_code, filename, "exec", dont_inherit=True)

    bytecode = Plugins.onFrozenModuleBytecode(
        module_name=full_name, is_package=False, bytecode=bytecode
    )

    uncompiled_module = makeUncompiledPythonModule(
        module_name=full_name,
        filename=filename,
        bytecode=marshal.dumps(bytecode),
        is_package=module.isCompiledPythonPackage(),
        user_provided=True,
        technical=False,
    )

    replaceImportedModule(old=module, new=uncompiled_module)

    replaceRootModule(old=module, new=uncompiled_module)

    assert module.trace_collection is not None
    uncompiled_module.setUsedModules(module.trace_collection.getUsedModules())
