# -*- coding: utf-8 -*-

# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT

from __future__ import absolute_import
from __future__ import print_function
from __future__ import division
import os
import pwd
import re
from collections import namedtuple
import logging
import traceback

import cldetectlib as detect
from typing import List  # NOQA
from future.utils import iteritems

from . import clpassenger

from clcommon.cpapi import cpusers, getCPName
from clcommon.clpwd import drop_privileges, ClPwd
from clcommon.cpapi.plugins.cpanel import is_no_php_binaries_on_cpanel
from .clselectexcept import ClSelectExcept
from .clselectnodejs.node_manager import NodeManager
from .clselectpython.python_manager import PythonManager
from .utils import get_abs_rel
from typing import Optional, List  # NOQA

DISABLED_DIRECTORY_NAMES = ['public_html', 'rubyvenv', 'virtualenv', '.cl.selector', '.cagefs', 'www', 'nodevenv']
ApplicationSummary = namedtuple('ApplicationSummary', ('user', 'version', 'doc_root', 'interpreter', 'app_status'))
InterpreterSummary = namedtuple('InterpreterSummary', ('version', 'version_full', 'enabled', 'installed'))


def check_directory(directory):
    if ' ' in directory:
        raise ValueError('Directory should not contain spaces')
    if os.path.isabs(directory):
        raise ValueError('Directory should be relative to user\'s home')
    if directory[-1] == '/':
        raise ValueError('Directory should not contain a trailing slash')
    if directory in DISABLED_DIRECTORY_NAMES:
        raise ValueError('Directory "%s" not allowed' % directory)
    all_valid = re.match(r'[-\.\w\/]+$', directory)
    if all_valid is None:
        raise ValueError('Directory name contains invalid characters')


def get_alias(alias):
    for c in ('#', '?', './'):
        if c in alias:
            raise ValueError('Alias is not valid')

    # root aliases
    if alias in ('.', ''):
        alias = '/'
    return alias.strip('/')


def get_directory(prefix):
    return prefix.replace('_', '/').replace('//', '_')


def get_prefix(directory):
    return directory.replace('_', '__').replace('/', '_')


def get_user(user):
    if not user:
        current_euid = os.geteuid()
        user = pwd.getpwuid(current_euid).pw_name
    if user == 'root':
        raise ValueError('User parameter must be specified if current user is root')
    return user


def _verify_application(interpreter, app_root, binary_path=None):
    """
    Application is valid only if binary and app_root exists
    :param binary_path: path to binary in virtual environment
    :param app_root: path to root directory of application
    :return: result of checking
    :rtype: bool
    """
    if interpreter in ('nodejs', 'python'):
        return os.path.isdir(app_root)
    return os.path.isfile(binary_path) and os.path.isdir(app_root)


def server_applications_summary(interpreter):
    # type: (str) -> List[ApplicationSummary]
    """Find and return all apps for given interpreter on server"""

    domains_data = None

    applications = []
    # LVEMAN-1408
    euid = os.geteuid()
    for user in cpusers():
        try:
            if detect.is_da():
                # NB: python will import this only 1 time
                from clcommon.cpapi.plugins.directadmin import userdomains
                domains_list = userdomains(user, as_root=True),  # called as root to save time on right's escalated call
                domains_data = list(
                    filter(
                        None,
                        map(
                            lambda x: x[0] if x else None,     # take only domain from (domain, docroot) tuples
                            domains_list,
                        )
                    )
                )
            # drop permissions in order not to
            with drop_privileges(user):
                # LVEMAN-1408: Force check user existence after drop user rights
                pwd.getpwnam(user)
                applications.extend(
                    _user_applications_short_summary(user, interpreter, domains_data))
        except ClPwd.NoSuchUserException:
            continue
        except KeyError:
            # LVEMAN-1408: this may be thrown by pwd.getpwnam in clpassenger.py module.
            # It uses python pwd library instead ClPwd
            # Send debug message to sentry
            logger = logging.getLogger(__name__)
            logger.error("DEBUG: user %s present in panel but doesn't exist in system. Process euid=%d. Trace: %s at %s" %
                         (user, euid, traceback.format_exc(), str(traceback.extract_stack())))
    return applications


def _user_applications_short_summary(user, interpreter, domains_docroots_data=None):
    """
    Return generator with all applications for given user and interpreter.
    To increase performance, only a small part of the
    information about the applications is given.
    :param user: name of panel user
    :param interpreter: name of interpreter (python, ruby, etc)
    :param domains_docroots_data: total data about users domains
    :return: Generator[ApplicationSummary]
    """

    userdomains_data = domains_docroots_data

    if interpreter in ('nodejs', 'python'):
        try:
            if interpreter == 'nodejs':
                from .clselectnodejs.apps_manager import ApplicationsManager
            else:
                from .clselectpython.apps_manager import ApplicationsManager

            config_data = ApplicationsManager().get_user_config_data(user)
        except ClSelectExcept.WrongData:
            return
        for app, data in iteritems(config_data):
            try:
                app_root, _ = get_abs_rel(user, app)
            except ClSelectExcept.WrongData:
                continue
            if _verify_application(interpreter, app_root):
                yield ApplicationSummary(
                    user=user,
                    version=data['%s_version' % interpreter],
                    doc_root=data['domain'],
                    interpreter=interpreter,
                    app_status=data['app_status']
                )
    else:
        for dummy, data in iteritems(clpassenger.summary(user, userdomains_data=userdomains_data)):
            if data['interpreter'] != interpreter:
                continue

            # return only really existing applications
            binary, app_root = data['binary'], data['directory']
            if _verify_application(interpreter, app_root, binary):
                it_version = os.path.basename(os.path.dirname(os.path.dirname(binary)))
                yield ApplicationSummary(user=user, version=it_version, doc_root=data['docroot'],
                                         interpreter=data['interpreter'], app_status='started')


def get_default_version(interpreter):
    """Return default version for given interpreter """
    if interpreter == 'nodejs':
        return NodeManager().default_version
    if interpreter == 'python':
        return PythonManager().default_version
    return None


def _iter_interpreters(interpreter):
    """Return generator for interpreters all versions"""
    if interpreter == 'nodejs':
        interpreters = NodeManager().get_summary(installed_interpreters_only=True)
    elif interpreter == 'python':
        interpreters = PythonManager().get_summary(installed_interpreters_only=True)
    else:
        raise NotImplementedError()
    for version, version_info in iteritems(interpreters['available_versions']):
        enabled = version_info['status'] == 'enabled'
        if interpreter == 'nodejs':
            # for nodejs 6.16.0 -> 6
            major_version = str(int(version.split('.')[0]))
        else:
            # for python 2.7.16 -> 2.7
            major_version = '.'.join(version.split('.')[:2])
        yield InterpreterSummary(version=major_version, version_full=version, enabled=enabled, installed=True)


def _iter_php_interpreters():
    """
    Return generator with all PHP versions on server.
    :return: Generator[InterpreterSummary]
    """
    from .clselect import ClSelect
    php = ClSelect()
    versions = php.list_alternatives()
    for version, full_version, _ in versions:
        yield InterpreterSummary(
            version, full_version, installed=True,
            enabled=php.is_version_enabled(version))


def interpreter_versions_short_summary(interpreter):
    # type: (str) -> List[InterpreterSummary]
    """Find and return all versions for given interpreter on server"""
    if interpreter == 'php':
        # if there is no installed php - no sense to collect statistics
        if getCPName() == 'cPanel' and is_no_php_binaries_on_cpanel():
            return []
        return list(_iter_php_interpreters())
    elif interpreter == 'ruby':
        from .clselectruby.interpreters import interpreters
    elif interpreter in ('python', 'nodejs'):
        return list(_iter_interpreters(interpreter))
    else:
        raise NotImplementedError

    it_list = []
    for it in interpreters():
        # for now, both python and ruby interpreters cannot be disabled
        it_list.append(InterpreterSummary(it.version, it.version_full, installed=True, enabled=True))
    return it_list