#     Copyright 2014, 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.
#
""" Recursion into other modules.

"""

from logging import debug, warning

from nuitka import Importing, ModuleRegistry, Options, Utils
from nuitka.freezer.BytecodeModuleFreezer import isFrozenModule

from . import Building, ImportCache


def recurseTo(module_package, module_filename, module_relpath, module_kind,
             reason):
    if not ImportCache.isImportedModuleByPath(module_relpath):
        module, source_ref, source_filename = Building.decideModuleTree(
            filename = module_filename,
            package  = module_package,
            is_top   = False,
            is_main  = False,
            is_shlib = module_kind == "shlib"
        )

        # Check if the module name is known. In order to avoid duplicates,
        # learn the new filename, and continue build if its not.
        if not ImportCache.isImportedModuleByName(module.getFullName()):
            debug(
                "Recurse to import '%s' from %s. (%s)",
                module.getFullName(),
                module_relpath,
                reason
            )

            if module_kind == "py" and source_filename is not None:
                try:
                    Building.createModuleTree(
                        module          = module,
                        source_ref      = source_ref,
                        source_filename = source_filename,
                        is_main         = False
                    )
                except ( SyntaxError, IndentationError ) as e:
                    if module_filename not in Importing.warned_about:
                        Importing.warned_about.add( module_filename )

                        warning(
                            """\
Cannot recurse to import module '%s' (%s) because of '%s'""",
                            module_relpath,
                            module_filename,
                            e.__class__.__name__
                        )

                    return None, False

            ImportCache.addImportedModule(
                module_relpath,
                module
            )

            is_added = True
        else:
            ImportCache.addImportedModule(
                module_relpath,
                ImportCache.getImportedModuleByName( module.getFullName() )
            )

            module = ImportCache.getImportedModuleByName(
                module.getFullName()
            )

            is_added = False

        assert not module_relpath.endswith( "/__init__.py" ), module

        return module, is_added
    else:
        return ImportCache.getImportedModuleByPath( module_relpath ), False


def decideRecursion(module_filename, module_name, module_package,
                    module_kind ):
    # Many branches, which make decisions immediately, pylint: disable=R0911

    if module_kind == "shlib":
        if Options.isStandaloneMode():
            return True, "Shared library for inclusion."
        else:
            return False, "Shared library cannot be inspected."

    if module_package is None:
        full_name = module_name
    else:
        full_name = module_package + "." + module_name

    if isFrozenModule(full_name):
        return False, "Module is frozen."

    no_case_modules = Options.getShallFollowInNoCase()

    for no_case_module in no_case_modules:
        if full_name == no_case_module:
            return (
                False,
                "Module listed explicitely to not recurse to."
            )

        if full_name.startswith(no_case_module + "."):
            return (
                False,
                "Module in package listed explicitely to not recurse to."
            )

    any_case_modules = Options.getShallFollowModules()

    for any_case_module in any_case_modules:
        if full_name == any_case_module:
            return (
                True,
                "Module listed explicitely to recurse to."
            )

        if full_name.startswith( any_case_module + "." ):
            return (
                True,
                "Module in package listed explicitely to recurse to."
            )

    if Options.shallFollowNoImports():
        return (
            False,
            "Requested to not recurse at all."
        )

    if Importing.isStandardLibraryPath(module_filename):
        return (
            Options.shallFollowStandardLibrary(),
            "Requested to %srecurse to standard library." % (
                "" if Options.shallFollowStandardLibrary() else "not "
            )
        )

    if Options.shallFollowAllImports():
        return (
            True,
            "Requested to recurse to all non-standard library modules."
        )

    # Means, we were not given instructions how to handle things.
    return (
        None,
        "Default behaviour, not recursing without request."
    )


def considerFilename(module_filename, module_package):
    assert module_package is None or \
           ( type( module_package ) is str and module_package != "" )

    module_filename = Utils.normpath( module_filename )

    if Utils.isDir( module_filename ):
        module_filename = Utils.abspath( module_filename )

        module_name = Utils.basename( module_filename )
        module_relpath = Utils.relpath( module_filename )

        return module_filename, module_relpath, module_name
    elif module_filename.endswith( ".py" ):
        module_name = Utils.basename( module_filename )[:-3]
        module_relpath = Utils.relpath( module_filename )

        return module_filename, module_relpath, module_name
    else:
        return None

def isSameModulePath(path1, path2):
    if Utils.basename(path1) == "__init__.py":
        path1 = Utils.dirname(path1)
    if Utils.basename(path2) == "__init__.py":
        path2 = Utils.dirname(path2)

    return Utils.abspath(path1) == Utils.abspath(path2)

def _checkPluginPath(plugin_filename, module_package):
    debug(
        "Checking detail plugin path %s %s",
        plugin_filename,
        module_package
    )

    plugin_info = considerFilename(
        module_package  = module_package,
        module_filename = plugin_filename
    )

    if plugin_info is not None:
        module, is_added = recurseTo(
            module_filename = plugin_info[0],
            module_relpath  = plugin_info[1],
            module_package  = module_package,
            module_kind     = "py",
            reason          = "Lives in plugin directory."
        )

        if module:
            if not is_added:
                warning(
                    "Recursed to %s '%s' at '%s' twice.",
                    "package" if module.isPythonPackage() else "module",
                    module.getName(),
                    plugin_info[0]
                )

                if not isSameModulePath(module.getFilename(), plugin_info[0]):
                    warning(
                        "Duplicate ignored '%s'.",
                        plugin_info[1]
                    )

                    return

            debug(
                "Recursed to %s %s %s",
                module.getName(),
                module.getPackage(),
                module
            )

            if module.isPythonPackage():
                package_filename = module.getFilename()

                if Utils.isDir(package_filename):
                    # Must be a namespace package.
                    assert Utils.python_version >= 330

                    package_dir = package_filename

                    # Only include it, if it contains actual modules, which will
                    # recurse to this one and find it again.
                    useful = False
                else:
                    package_dir = Utils.dirname(package_filename)

                    # Real packages will always be included.
                    useful = True

                debug(
                    "Package directory %s",
                    package_dir
                )


                for sub_path, sub_filename in Utils.listDir(package_dir):
                    if sub_filename in ("__init__.py", "__pycache__"):
                        continue

                    assert sub_path != plugin_filename

                    if Importing.isPackageDir(sub_path) or \
                       sub_path.endswith(".py"):
                        _checkPluginPath(sub_path, module.getFullName())
            else:
                # Modules should always be included.
                useful = True

            if useful:
                ModuleRegistry.addRootModule(module)

        else:
            warning( "Failed to include module from '%s'.", plugin_info[0] )

def checkPluginPath(plugin_filename, module_package):
    debug(
        "Checking top level plugin path %s %s",
        plugin_filename,
        module_package
    )

    plugin_info = considerFilename(
        module_package  = module_package,
        module_filename = plugin_filename
    )

    if plugin_info is not None:
        # File or package makes a difference, handle that
        if Utils.isFile(plugin_info[0]) or \
           Importing.isPackageDir(plugin_info[0]):
            _checkPluginPath(plugin_filename, module_package)
        elif Utils.isDir(plugin_info[0]):
            for sub_path, sub_filename in Utils.listDir(plugin_info[0]):
                assert sub_filename != "__init__.py"

                if Importing.isPackageDir(sub_path) or \
                   sub_path.endswith(".py"):
                    _checkPluginPath(sub_path, None)
        else:
            warning("Failed to include module from '%s'.", plugin_info[0])
    else:
        warning("Failed to recurse to directory '%s'.", plugin_filename)
