from importlib import import_module
from os import environ
import sys

from packaging.version import Version

from pythonforandroid.prerequisites import (
 check_and_install_default_prerequisites,
)


def check_python_dependencies():
 """
 Check if the Python requirements are installed. This must appears
 before other imports because otherwise they're imported elsewhere.

 Using the ok check instead of failing immediately so that all
 errors are printed at once.
 """

 ok = True

 modules = [("colorama", "0.3.3"), "appdirs", ("sh", "1.10"), "jinja2"]

 for module in modules:
 if isinstance(module, tuple):
 module, version = module
 else:
 version = None

 try:
 import_module(module)
 except ImportError:
 if version is None:
 print(
 "ERROR: The {} Python module could not be found, please "
 "install it.".format(module)
 )
 ok = False
 else:
 print(
 "ERROR: The {} Python module could not be found, "
 "please install version {} or higher".format(
 module, version
 )
 )
 ok = False
 else:
 if version is None:
 continue
 try:
 cur_ver = sys.modules[module].__version__
 except AttributeError: # this is sometimes not available
 continue
 if Version(cur_ver) < Version(version):
 print(
 "ERROR: {} version is {}, but python-for-android needs "
 "at least {}.".format(module, cur_ver, version)
 )
 ok = False

 if not ok:
 print("python-for-android is exiting due to the errors logged above")
 exit(1)


def check():
 if not environ.get("SKIP_PREREQUISITES_CHECK", "0") == "1":
 check_and_install_default_prerequisites()
 check_python_dependencies()