# coding=utf-8
#
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2020 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENCE.TXT
#

# pylint: disable=no-absolute-import
import os
import sys

import subprocess
from enum import Enum
from functools import wraps
from jwt import exceptions
from typing import AnyStr

from clcommon.lib.consts import CLN_JWT_TOKEN_PATH, CL_EDITION_FILE_FOR_USERS
from clcommon.lib.jwt_token import read_jwt, decode_jwt, jwt_token_check
from clcommon.clexception import FormattedException

CL_EDITION_FILE_MARKER = '/etc/cloudlinux-edition-solo'

SHARED_PRO_EDITION_HUMAN_READABLE = 'CloudLinux OS Shared Pro'
SHARED_EDITION_HUMAN_READABLE = 'CloudLinux OS Shared'
SOLO_EDITION_HUMAN_READABLE = 'CloudLinux OS Solo'
from clcommon.clcagefs import in_cagefs


class SupportedEditions(Enum):
    """
    Keeps supported CloudLinux editions
    """

    SOLO = 'solo'
    SHARED = 'shared'
    SHARED_PRO = 'shared_pro'


class CLEditionDetectionError(FormattedException):
    def __init__(self, message, **context):
        FormattedException.__init__(self, {
            'message': message,
            'context': context
        })


HUMAN_READABLE_TOKEN_EDITION_PAIRS = {
        SOLO_EDITION_HUMAN_READABLE: SupportedEditions.SOLO.value,
        SHARED_PRO_EDITION_HUMAN_READABLE: SupportedEditions.SHARED_PRO.value,
        SHARED_EDITION_HUMAN_READABLE: SupportedEditions.SHARED.value
    }


class CLEditions:

    @staticmethod
    def get_from_jwt(token=None, verify_exp=True):
        """
        Note: be careful when modifying this method.
        Passing token in is used in X-Ray,
        ask @dkavchuk or someone else from C-Projects team for details
        :param token:
        :param verify_exp:
        :return:
        """
        if token is None:
            token = read_jwt(CLN_JWT_TOKEN_PATH)
        try:
            jwt = decode_jwt(token, verify_exp=verify_exp)
        except exceptions.PyJWTError as e:
            raise CLEditionDetectionError(f'Unable to detect edition from jwt token: {CLN_JWT_TOKEN_PATH}. '
                                          f'Please, make sure it is not broken, error: {e}')
        try:
            return jwt['edition']
        except KeyError:
            # fallback for old format of tokens
            cl_plus = jwt.get('cl_plus')
            if cl_plus is None:
                raise CLEditionDetectionError(
                    f'Unable to detect edition from jwt token: {CLN_JWT_TOKEN_PATH}. '
                    f'Please, make sure it is not broken, error: not enough fields for detection')
            return SupportedEditions.SHARED_PRO.value if cl_plus else SupportedEditions.SHARED.value

    @staticmethod
    def is_package_installed(package_name):
        process = subprocess.Popen(['rpm', '-q', package_name],
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE,
                                   text=True)
        out, err = process.communicate()
        if process.returncode != 0 and 'is not installed' in out:
            return False
        elif process.returncode != 0:
            raise CLEditionDetectionError(f'Unable to check is package {package_name} is installed, '
                                          f'reason: {out}, {err}')
        return True

    @classmethod
    def get_cl_edition(cls, skip_jwt_check=False, skip_marker_check=False,
                       raw_jwt=None, verify_exp=True):
        """
        1. Try to detect edition from jwt token
           if edition field is in token -> return edition
           if edition field is not present -> recheck via cl_plus flag
           if token is broken -> raise error about it
        2. Try to detect from file
           if edition is in file -> return edition
           if file is broken -> raise about it
           if file is missed -> check if meta package is present
           Detection from file may be switched off using skip_marker_check
        In case there is no token with correct edition,
        no file we consider edition as regular CL.
        Note: be careful when modifying this method.
        It is used in X-Ray, ask @dkavchuk or someone else from C-Projects team
        for details
        """
        # skipping both jwt and file checks is not allowed
        if skip_jwt_check and skip_marker_check:
            raise CLEditionDetectionError(
                'Unable to detect edition: neither jwt token check, no file marker check enabled')

        if not skip_jwt_check and os.path.isfile(CLN_JWT_TOKEN_PATH):
            try:
                edition = cls.get_from_jwt(token=raw_jwt, verify_exp=verify_exp)
            except PermissionError:
                edition = user_cl_edition()

            if edition:
                return edition

        # In case if user in cagefs.
        if in_cagefs():
            return user_cl_edition()

        # if fallback to file is applicable
        if not skip_marker_check:
            # jwt has no 'edition' field -> ensure it is really solo via file
            if os.path.isfile(CL_EDITION_FILE_MARKER):
                return SupportedEditions.SOLO.value
            return SupportedEditions.SHARED.value


def is_cl_solo_edition(skip_jwt_check=True, skip_marker_check=False, verify_exp=True):
    """
    Allow skip_jwt_check ONLY if it not critical when license is not valid
    Use skip_marker_check=True when validity of license is critical
     and fallback to file is not applicable
    Note: be careful when modifying this method.
    It is used in X-Ray and SSA,
    ask @dkavchuk or someone else from C-Projects team for details
    """

    edition = CLEditions.get_cl_edition(
        skip_jwt_check=skip_jwt_check,
        skip_marker_check=skip_marker_check,
        verify_exp=verify_exp
    )
    return edition is not None and edition == SupportedEditions.SOLO.value


def is_cl_shared_edition(skip_jwt_check=False, skip_marker_check=False, verify_exp=True):
    """
    Allow skip_jwt_check ONLY if it not critical when license is not valid
    Use skip_marker_check=True when validity of license is critical
     and fallback to file is not applicable
    """

    edition = CLEditions.get_cl_edition(
        skip_jwt_check=skip_jwt_check,
        skip_marker_check=skip_marker_check,
        verify_exp=verify_exp
    )
    return edition is not None and edition == SupportedEditions.SHARED.value


def is_cl_shared_pro_edition(skip_jwt_check=False,
                             skip_marker_check=False,
                             verify_exp=True):
    """
    Allow skip_jwt_check ONLY if it not critical when license is not valid
    Use skip_marker_check=True when validity of license is critical
     and fallback to file is not applicable
    """

    edition = CLEditions.get_cl_edition(
        skip_jwt_check=skip_jwt_check,
        skip_marker_check=skip_marker_check,
        verify_exp=verify_exp
    )
    return edition is not None and edition == SupportedEditions.SHARED_PRO.value


def get_cl_edition_readable() -> AnyStr:
    """
    Function returns current edition of CL:
    - CloudLinux OS Shared
    - CloudLinux OS Shared Pro
    - CloudLinux OS Solo
    - Error string
    """

    try:
        if is_cl_solo_edition(skip_jwt_check=True):
            return SOLO_EDITION_HUMAN_READABLE
    except CLEditionDetectionError:
        return SHARED_EDITION_HUMAN_READABLE

    success_flag, error_message, _ = jwt_token_check()

    # This error message indicates that user could not read jwt.token because not enough privileges
    # We have to check existence of token file, to be sure that privilege error acquired
    if 'read error' in error_message and (os.path.isfile(CLN_JWT_TOKEN_PATH) or in_cagefs()):
        with open(CL_EDITION_FILE_FOR_USERS, 'r') as f:
            return f.read().strip()

    if success_flag:
        return SHARED_PRO_EDITION_HUMAN_READABLE
    else:
        return SHARED_EDITION_HUMAN_READABLE


def skip_on_cl_solo():
    try:
        # we still have some utils that could be run under user (e.g cloudlinux-selector)
        if is_cl_solo_edition(skip_jwt_check=True):
            print('CloudLinux Solo edition detected! \n'
                  'Command is skipped, because it is unsupported and unneeded on current edition')
            sys.exit(0)
    except CLEditionDetectionError as e:
        print(f'Error: {e}')
        sys.exit(1)


def lve_supported_or_exit(f):
    @wraps(f)
    def inner(*args, **kwargs):
        skip_on_cl_solo()
        return f(*args, **kwargs)
    return inner


def user_cl_edition():
    """This function is used as workaround for users to be able to get CL Edition.
    Crontab will write to CL_EDITION_FILE_FOR_USERS, output of cldetect --detect-edition command with 0644 permission.
    """
    if os.path.exists(CL_EDITION_FILE_FOR_USERS):
        with open(CL_EDITION_FILE_FOR_USERS, 'r') as f:
            edition = f.read().strip()

        return HUMAN_READABLE_TOKEN_EDITION_PAIRS.get(edition)
    return None