"""Volatility 3 framework"""
import inspect

# ##
#
# Libtool version scheme
#
# Current - The number of the current interface exported by the library
# Revision - The implementation number of the most recent interface exported by this library
# Age - The number of previous additional interfaces supported by this library
#
# 1. If the source changes, increment the revision
# 2. If the interface has changed, increment current, set revision to 0
# 3. If only additions to the interface have been made, increment age
# 4. If changes or removals of the interface have been made, set age to 0
import logging
import os
import sys

CURRENT = 4  # Number of releases of the library with any change
REVISION = 0  # Number of changes that don't affect the interface
AGE = 0  # Number of consecutive versions of the interface the current version supports

vollog = logging.getLogger("volatility")


def version():
    """Provides the so version number of the library"""
    return CURRENT - AGE, AGE, REVISION


def require_version(*args):
    """Checks the required version of a plugin"""
    if len(args):
        if args[0] != version()[0]:
            raise RuntimeError("Framework version " + str(version()[0]) +
                               " is incompatible with required version " + str(args[0]))
        if len(args) > 1:
            if args[1] > version()[1]:
                raise RuntimeError("Framework version " + ".".join([str(x) for x in version()[0:1]]) +
                                   " is an older revision than the required version " +
                                   ".".join([str(x) for x in args[0:2]]))


def class_subclasses(cls):
    """Returns all the (recursive) subclasses of a given class"""
    if not inspect.isclass(cls):
        raise TypeError(repr(cls) + " is not a class.")
    for clazz in cls.__subclasses__():
        yield clazz
        for return_value in class_subclasses(clazz):
            yield return_value


def import_files(base_module):
    """Imports all plugins present under plugins path"""
    if not isinstance(base_module.__path__, list):
        raise TypeError("[base_module].__path__ must be a list of paths")
    for path in base_module.__path__:
        for root, _, files in os.walk(path, followlinks = True):
            # TODO: Figure out how to import pycache files
            if root.endswith("__pycache__"):
                continue
            for f in files:
                if (f.endswith(".py") or f.endswith(".pyc") or f.endswith(".pyo")) and not f.startswith("__"):
                    modpath = os.path.join(root[len(path) + len(os.path.sep):], f[:f.rfind(".")])
                    module = modpath.replace(os.path.sep, ".")
                    if module not in sys.modules:
                        try:
                            vollog.debug("Importing " + base_module.__name__ + "." + module)
                            __import__(base_module.__name__ + "." + module)
                        except ImportError:
                            vollog.warning("Failed to import module " + module + " based on file " + modpath)
                            raise
                    else:
                        vollog.info("Skipping existing module " + module)


# Check the python version to ensure it's suitable
if sys.version_info.major != 3 or sys.version_info.minor < 4:
    raise RuntimeError("Volatility framework requires python version 3.4 or greater")

from volatility.framework import interfaces, symbols, layers, contexts, configuration