# -*- 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 print_function
from __future__ import absolute_import
from __future__ import division

import os
import pwd
import requests
import requests.packages.urllib3.exceptions as urllib_exceptions                #pylint: disable=E0401
import shutil
from requests.exceptions import ConnectionError
from future.utils import iteritems
from past.builtins import basestring

from . import clpassenger
from . import clselectctl
from . import utils
from clcommon.cpapi import userdomains
from clcommon.utils import mod_makedirs
from .clselectexcept import ClSelectExcept
from .clselectnodejs.apps_manager import ApplicationsManager
from .clselectnodejsuser import environments, interpreters
from .baseclselect import APP_STARTED_CONST, APP_STOPPED_CONST
from .clselectprint import clprint

DEFAULT_STARTUP_FILE = 'app.js'
DEFAULT_APP_STATE = APP_STARTED_CONST


def _create_environment(user, directory, version, env_name=None, destroy_first=False):
    prefix = _get_prefix(user, directory)
    if not env_name:
        env_name = version
    environment = environments.Environment(env_name, user, prefix)
    if not environment.exists() or destroy_first:
        try:
            interpreter = interpreters.interpreters(key='version')[version]
        except KeyError:
            raise ClSelectExcept.NoSuchAlternativeVersion(version)
        environment.create(interpreter, destroy_first=destroy_first)
    return environment


def _get_environment(user, directory, app_summary=None):
    prefix = _get_prefix(user, directory)
    if app_summary is None:
        user_summary = clpassenger.summary(user)
        try:
            app_summary = utils.get_using_realpath_keys(user, directory, user_summary)
        except KeyError:
            raise ClSelectExcept.NoSuchApplication(
                'No such application (or application not configured) "%s"' %
                directory)
    binary = app_summary['binary']
    env_name = os.path.basename(os.path.dirname(os.path.dirname(binary)))
    environment = environments.Environment(env_name, user, prefix)
    return environment


def _get_prefix(user, directory):
    _, rel_dir = utils.get_abs_rel(user, directory)
    return os.path.join(environments.DEFAULT_PREFIX, rel_dir)


def _ensure_version_enabled(version, user):
    """
    Check whether particular interpreter version is enabled and raises
    exception if not
    :param user: user to include in exception
    """
    from .clselectnodejs import node_manager
    if not node_manager.NodeManager().is_version_enabled(version):
        raise ClSelectExcept.UnableToSetAlternative(
            user, version, 'version is not enabled')


def _get_existing_nesting_app_for(new_app_directory, user, apps_manager=None):
    """
    Return None if new_app_directory is not nested inside an existing
    user application, and the name of conflicting application otherwise
    """

    if apps_manager is None:
        apps_manager = ApplicationsManager()

    abs_app_path, _ = utils.get_abs_rel(user, new_app_directory)
    full_config = apps_manager.get_user_config_data(user)
    for existing_app in full_config.keys():
        # In case home directory was symlinked after config was written
        existing_app_abs_path, _ = utils.get_abs_rel(user, existing_app)
        if (abs_app_path + os.sep).startswith(existing_app_abs_path + os.sep):
            return existing_app
    return None


def create(user, directory, alias, version=None, doc_root=None, app_mode=None,
           env_vars=None, startup_file=None, domain_name=None, apps_manager=None, passenger_log_file=None):
    """
    Create application
    :param user: unix user name
    :param directory: application path in user's home (app-root)
    :param alias: alias (app-uri)
    :param version: version of interpreter
    :param doc_root: doc_root
    :param app_mode: application mode for nodejs
    :param env_vars: dict with enviroment variables
    :param startup_file: main application file
    :param domain_name: domain name
    :param apps_manager: Application Manager. Class that responsible
           for gathering and writing information about applications
    :param passenger_log_file: Passenger log filename to write to app's .htaccess
    :return: None
    """

    if apps_manager is None:
        apps_manager = ApplicationsManager()

    if version is None:
        raise ClSelectExcept.WrongData('Not passed version as argument')
    _ensure_version_enabled(version, user)

    if startup_file is None:
        startup_file = DEFAULT_STARTUP_FILE
    if env_vars is None:
        env_vars = {}
    if app_mode is None:
        app_mode = 'production'

    conflicting_app = _get_existing_nesting_app_for(directory, user, apps_manager)
    if conflicting_app is not None:
        raise ClSelectExcept.BusyApplicationRoot(conflicting_app)

    alias = clselectctl.get_alias(alias)
    environment = _create_environment(user, directory, version)
    binary = environment.interpreter().binary

    clpassenger.configure(user, directory, alias, apps_manager.INTERPRETER, binary,
                          doc_root=doc_root, startup_file=startup_file,
                          passenger_log_file=passenger_log_file)
    #  webapp was started
    clpassenger.restart(user, directory)
    if not domain_name:
        # if domain name not defined - try to detemine it
        summary_data = clpassenger.summary(user)
        app_summary = utils.get_using_realpath_keys(user, directory, summary_data)
        domain_name = app_summary['domain']
    app_data = {
        u'nodejs_version': version,
        u'domain': domain_name,
        u'app_uri': alias,
        u'app_status': DEFAULT_APP_STATE,
        u'startup_file': startup_file,
        u'app_mode': app_mode,
        u'config_files': [],
        u'env_vars': env_vars,
    }
    if passenger_log_file:
        app_data[u'passenger_log_file'] = passenger_log_file
    apps_manager.add_app_to_config(user, directory, app_data)
    try:
        apps_manager.add_env_vars_for_htaccess(user, directory, env_vars, doc_root)
    except Exception as err:
        clprint.print_diag('text', {'status': 'ERROR', 'message': str(err)})


def _create_symlink_to_node_modules(username, environment_path, app_root):
    """
    Creates symlink to app's node_modules in app_root
    :param username: user name
    :param environment_path: Path to app's virtual environment
    :param app_root: Application root
    :return: None
    """
    # This function logic is duplicated in npm wrapper, but we still need it here too. See commit
    # message of LVEMAN-1335
    message = 'Cloudlinux NodeJS Selector demands to store node modules for application '\
              'in separate folder (virtual environment) pointed by symlink '\
              'called "node_modules". That`s why application should not contain folder/file '\
              'with such name in application root'
    link_name = os.path.join(pwd.getpwnam(username).pw_dir, app_root, 'node_modules')
    if os.path.islink(link_name):
        try:
            os.remove(link_name)
        except OSError:
            raise ClSelectExcept.RemoveSymlinkError(
                'Can`t remove symlink %(link_name)s' %
                {'link_name': link_name}
            )
    elif os.path.exists(link_name):  # link_name not a old symlink, but exists
        raise ClSelectExcept.SymlinkError(message)
    link_to = os.path.join(environment_path, 'lib/node_modules')
    if not os.path.exists(link_to):
        mod_makedirs(link_to, 0o775)
    try:
        os.symlink(link_to, link_name)
    except OSError:
        raise ClSelectExcept.CreateSymlinkError('Error creating symlink. ' + message)


def destroy(user, app_directory, doc_root, apps_manager=None):
    """
    Destroy web app with specified directory for specified user
    :param user: username
    :param app_directory: application directory
    :param doc_root: Document root for selected domain
    :param apps_manager: Application Manager. Class that responsible
           for gathering and writing information about applications
    :return: None
    """

    if apps_manager is None:
        apps_manager = ApplicationsManager()

    # get app state
    app_config = apps_manager.get_app_config(user, app_directory)
    # remove env from htaccess
    try:
        # if domain is already removed we shouldn't do anything
        if doc_root is not None:
            apps_manager.add_env_vars_for_htaccess(user, app_directory, None, doc_root)
    except Exception as err:
        clprint.print_diag('text', {'status': 'ERROR', 'message': str(err)})

    if app_config.get('app_status') == APP_STOPPED_CONST:
        # stopped app
        user_home = pwd.getpwnam(user).pw_dir
        # Remove app's nodenv, e.g. /home/cltest1/nodevenv/test_app
        nodevenv_path = '/'.join([user_home, 'nodevenv', app_directory])
        try:
            # Remove app's nodenv, e.g. /home/cltest1/nodevenv/test_app
            shutil.rmtree(nodevenv_path)
        except OSError:
            pass
        # if domain is already removed we shouldn't do anything
        if doc_root is not None:
            # Remove NodeJS lines from .htaccess
            htaccess_filename = apps_manager.get_htaccess_by_appdir(user, app_directory, doc_root)
            clpassenger.remove_passenger_lines_from_htaccess(htaccess_filename)
        # remove app from node-selector.json file
        apps_manager.remove_app_from_config(user, app_directory)
        # Update application status in passenger
        try:
            clpassenger.restart(user, app_directory)
        except ClSelectExcept.MissingApprootDirectory:
            pass
        return
    # Moved before removing an app from node-selector.json because in case if
    # app_root is absent we still want to remove venv dir of an application.
    # The method didn't anyhing if app_root is absent and skip other commands
    # including removal of a venv dir
    prefix = _get_prefix(user, app_directory)
    abs_dir, _ = utils.get_abs_rel(user, prefix)
    try:
        # Remove app's nodenv, e.g. /home/cltest1/nodevenv/test_app
        shutil.rmtree(abs_dir)
    except OSError:
        pass
    user_summary = clpassenger.summary(user)
    # remove app from node-selector.json file
    app_in_config = apps_manager.remove_app_from_config(user, app_directory)
    try:
        utils.get_using_realpath_keys(user, app_directory, user_summary)
    except KeyError:
        # if app was existed and app's dir is not exists, we skip all further actions
        if app_in_config:
            return None
        else:
            raise ClSelectExcept.WrongData("No such application (or application not configured) \"%s\""
                                           % app_directory)

    # remove app from passenger
    clpassenger.unconfigure(user, app_directory)        # Clear .htaccess
    try:
        clpassenger.restart(user, app_directory)
    except ClSelectExcept.MissingApprootDirectory:
        pass


def start(user, app_directory, doc_root, apps_manager=None):
    """
    Starts web app with specified directory for specified user
    :param user: username
    :param app_directory: application directory
    :param doc_root: Document root for selected domain
    :param apps_manager: Application Manager. Class that responsible
           for gathering and writing information about applications
    :return: None
    """

    if apps_manager is None:
        apps_manager = ApplicationsManager()

    app_config = apps_manager.get_app_config(user, app_directory)
    if app_config is None:
        raise ClSelectExcept.WrongData("No such application (or application not configured) \"%s\""
                                       % app_directory)
    # Do nothing if application already started
    if app_config.get('app_status') == APP_STARTED_CONST:
        return
    # Create .htaccess file for the application
    apps_manager.update_htaccess_file(user, app_directory, doc_root)
    # Save new application status in user's config
    apps_manager.set_app_status(user, app_directory, APP_STARTED_CONST)
    # Update application status in passenger
    clpassenger.restart(user, app_directory)


def restart(user, app_directory, doc_root, apps_manager=None):
    """
    Restarts web app with specified directory for specified user
    :param user: username
    :param app_directory: application directory
    :param doc_root: Document root for selected domain
    :param apps_manager: Application Manager. Class that responsible
           for gathering and writing information about applications
    :return: None
    """

    if apps_manager is None:
        apps_manager = ApplicationsManager()

    app_config = apps_manager.get_app_config(user, app_directory)
    if app_config is None:
        raise ClSelectExcept.WrongData("No such application (or application not configured) \"%s\""
                                       % app_directory)
    # If application was stopped - start it
    if app_config.get('app_status') == APP_STOPPED_CONST:
        start(user, app_directory, doc_root)
    else:
        clpassenger.restart(user, app_directory)


def stop(user, app_directory, doc_root, apps_manager=None):
    """
    Stops web app with specified directory for specified user
    :param user: username
    :param app_directory: application directory
    :param doc_root: Document root for selected domain
    :param apps_manager: Application Manager. Class that responsible
           for gathering and writing information about applications
    :return: None
    """

    if apps_manager is None:
        apps_manager = ApplicationsManager()

    app_config = apps_manager.get_app_config(user, app_directory)
    if app_config is None:
        raise ClSelectExcept.WrongData("No such application (or application not configured) \"%s\""
                                       % app_directory)
    # Do nothing if application is not started
    if app_config.get('app_status') == APP_STOPPED_CONST:
        return
    htaccess_filename = apps_manager.get_htaccess_by_appdir(user, app_directory, doc_root, app_config)
    # Remove NodeJS lines from .htaccess
    clpassenger.remove_passenger_lines_from_htaccess(htaccess_filename)
    # Save new application status in user's config
    apps_manager.set_app_status(user, app_directory, APP_STOPPED_CONST)
    # Update application status in passenger
    clpassenger.restart(user, app_directory)


def check_response_from_webapp(domain, alias, action=None):
    """
    Check response from user's webapp before and after calling action.
    Also compare both responses
    :param domain: domain associated with webapp
    :param alias: URI associated with webapp
    :param action: called action, that make something with webapp: install modules, transit it, etc
    :return: None
    """

    app_is_inaccessible_before = 'Web application is inaccessible by its address "%s". The operation wasn\'t performed.'
    app_is_inaccessible_after = 'The operation was performed, but check availability of application has failed. ' \
                                'Web application is inaccessible by its address "%s" after the operation.'
    app_is_broken = 'The operation was performed, but check availability of application has failed. ' \
                    'Web application responds, but its return code "%s" or ' \
                    'content type before operation "%s" doesn\'t equal to contet type after operation "%s".'

    requests.packages.urllib3.disable_warnings(urllib_exceptions.InsecureRequestWarning)        #pylint: disable=E1101

    if not callable(action):
        raise ClSelectExcept.WrongData('Wrong action for calling in checking webapp')
    webapp_url = 'https://{domain}/{alias}'.format(
        domain=domain,
        alias=alias,
    )
    # for hiding from the module of Apache `mod_security`
    headers = {
        'User-Agent': 'Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.13) '
                      'Gecko/20101209 CentOS/3.6-2.el5.centos Firefox/3.6.13'
    }
    try:
        request = requests.get(webapp_url, verify=False, headers=headers)
    except ConnectionError:
        # site is not available by https protocol
        webapp_url = webapp_url.replace('https://', 'http://')
        try:
            request = requests.get(webapp_url, verify=False, headers=headers)
        except ConnectionError:
            raise ClSelectExcept.WebAppError(app_is_inaccessible_before % webapp_url)
    before_mime_type = request.headers.get('Content-Type')
    before_status = request.headers.get('Status')
    action()
    try:
        request = requests.get(webapp_url, verify=False, headers=headers)
    except ConnectionError:
        raise ClSelectExcept.WebAppError(app_is_inaccessible_after % webapp_url)
    after_mime_type = request.headers.get('Content-Type')
    after_status = request.headers.get('Status')
    # assume that app is broken if:
    # it's response Content-Type or Status code (if first code wasn't 500) changed
    # if last Status code was 500 (internal error)
    if before_mime_type.lower() != after_mime_type.lower() or \
        (before_status != after_status and before_status is not None and before_status[:3] != '500') \
            or (after_status is not None and after_status[:3] == '500'):
        raise ClSelectExcept.WebAppError(app_is_broken % (after_status, before_mime_type, after_mime_type))


def _get_info_about_webapp(app_summary=None, user=None):
    """
    Get info (alias and domain) about user's web application
    :param app_summary: dict -> summary info about user's web application
    :param user: str -> name of unix user
    :return: tuple -> (alias, domain)
    """

    if app_summary is None:
        raise ClSelectExcept.WrongData('Was passed incorrect summary info about application')
    if user is None:
        raise ClSelectExcept.WrongData('Was passed incorrect name of user')
    alias = app_summary['alias']
    user_domains = userdomains(user)
    found_domains = [
            domain for domain, doc_root in user_domains
            if utils.realpaths_are_equal(user, doc_root, app_summary['docroot'])]
    if len(found_domains) == 0:
        raise ClSelectExcept.WrongData('Can not found suitable domain for application')
    app_domain = found_domains[0]

    return alias, app_domain


def install(user, directory, extension='-', skip_web_check=False, apps_manager=None):
    """
    Install nodejs extension to user's webapp
    :param user: name os unix user
    :param directory: directory with webapp (app-root)
    :param extension: name and version of extension
    :param skip_web_check: skip check web application after change it's properties
    :param apps_manager: Application Manager. Class that responsible
           for gathering and writing information about applications
    :return: None
    """

    if apps_manager is None:
        apps_manager = ApplicationsManager()

    user_config = apps_manager.get_user_config_data(user)
    try:
        app_data = utils.get_using_realpath_keys(user, directory, user_config)
    except KeyError:
        raise ClSelectExcept.WrongData('Record about application {} is absent'.format(directory))
    if app_data['app_status'] != APP_STARTED_CONST:
        skip_web_check = True
    else:
        alias = app_data['app_uri']
        app_domain = app_data['domain']
    nodejs_version = app_data['nodejs_version']
    cwd, _ = utils.get_abs_rel(user, directory)
    environment = _create_environment(user, directory, nodejs_version)

    def action():
        # npm install
        environment.extension_install(extension=extension, cwd=cwd)
        clpassenger.restart(user, directory)

    if not skip_web_check:
        try:
            check_response_from_webapp(
                domain=app_domain,
                alias=alias,
                action=action,
            )
        except ClSelectExcept.WebAppError as err:
            raise ClSelectExcept.WebAppError('An error occured during installation of modules. %s' % err)
    else:
        action()


def summary(user):
    summ = {}
    for directory, data in iteritems(clpassenger.summary(user)):
        if data['interpreter'] != ApplicationsManager.INTERPRETER:
            continue

        environment = _get_environment(user, directory, data).as_deepdict()
        summ[directory] = {
            'domain': data['domain'],
            'alias': data['alias'],
            'environment': environment['name'],
            'interpreter': environment['interpreter'],
        }
        # add only list with additions domains
        if "domains" in data and len(data["domains"]) > 1:
            summ[directory]["domains"] = data["domains"]

    return summ


def validate_env_vars(env_vars):
    if type(env_vars) is not dict:
        raise TypeError
    for item in env_vars:
        if not isinstance(env_vars[item], basestring):
            raise TypeError
    return env_vars