#!/usr/bin/env python
# -*- 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

import os
import syslog
import pwd
from typing import Optional  # NOQA

from clcommon.clproc import ProcLve
from clcommon import cpapi, ClPwd
from clcommon.cpapi.cpapiexceptions import NotSupported

from clveconfig import ve_config

from lve_utils.pylve_wrapper import PyLveError, PyLve  # noqa: F401 — re-exported for callers

from websiteisolation import config as _ws_config
from websiteisolation import id_registry as _ws_id_registry
from websiteisolation.exceptions import LvdError


LVP_XML_TAG_NAME = "reseller"
LVE_NO_UBC = 1 << 1
LVE_NO_MAXENTER = 1 << 2




class NameMapError(Exception):
    pass


class NameMapConfigError(NameMapError):
    pass


class NameMapNotInitialized(NameMapError):
    pass


class NameMap:
    """
    Container for backend storing resellers_name<=>resellers_id map
    As backend store use ve.cfg

    Usage:
    >>> name_map = NameMap()
    >>> name_map.link_xml_node()

    >>> name_map.id_list()
    [1001]
    """
    def __init__(self, xml_tag_name=LVP_XML_TAG_NAME):
        self._xml_tag_name = xml_tag_name
        self._xml_node = None
        # Reseller name to id map (list of corteges)
        self._reseller_id_name_map = None

    def get_id(self, name):
        for name_, id_ in self.load_from_node():
            if name_ == name:
                return id_

    def get_name(self, id_):
        for name_, _id in self.load_from_node():
            if id_ == _id:
                return name_

    def id_list(self):
        return [id_ for _, id_ in self.load_from_node()]

    def link_xml_node(self, xml_node=None, use_cache=True):
        """
        Initialize NameMap. If xml_node is none,
        config will be loaded automatically
        :param use_cache: Bool whether bypass ve.cfg xml cache
        :param xml_node: !! DEPRECATED PARAM !!
                         this param is left only for
                         compatibility with our old code
        """
        if xml_node is None:
            # New mode, Load reseller_id, reseller_name pairs from ve.cfg to dictionary
            self._xml_node = None
            self._load_resellers_map_from_ve_cfg(use_cache)
        else:
            # For compatibility with our old code
            self._xml_node = xml_node
            self._reseller_id_name_map = None

    def _load_resellers_map_from_ve_cfg(self, use_cache):
        """
        Fills self._reseller_id_name_map from ve.cfg file
        :return:
        """
        self._reseller_id_name_map = []
        ve_cfg, xml_node = self._try_get_xml_node(use_cache=use_cache)
        for el_ in xml_node:
            name = el_.getAttribute('user')
            id_ = int(el_.getAttribute('id'))
            if name and id_ and id_ not in self._reseller_id_name_map:
                self._reseller_id_name_map.append((id_, name))
        # Force delete XML object to avoid high memory load
        del xml_node
        del ve_cfg

    def _try_get_xml_node(self, use_cache=True):
        try:
            ve_cfg, xml_node = ve_config.get_xml_config(use_cache=use_cache)
        except ve_config.BadVeConfigException as e:
            self._reseller_id_name_map = None
            raise NameMapConfigError("Error happened while loading data from ve.cfg") from e
        return ve_cfg, xml_node.getElementsByTagName(self._xml_tag_name)

    def load_from_node(self):
        """
        Obtain data from xml node as (name, id_) list
        """
        if self._xml_node is None and self._reseller_id_name_map is None:
            raise NameMapNotInitialized('Name map is not initialized. '
                                        'Use obj.link_xml_node() to get data from config')
        if self._xml_node:
            # For compatibility with our old code
            for el_ in self._xml_node.getElementsByTagName(self._xml_tag_name):
                name = el_.getAttribute('user')
                id_ = int(el_.getAttribute('id'))
                if name and id_:
                    yield name, id_

        if self._reseller_id_name_map:
            # New mode, use resellers map
            for id_, name in self._reseller_id_name_map:
                yield name, id_


class LvpMap:
    """
    Container for storing information about lve:lvp mapping
    In which reseller container stored lve
    """
    def __init__(self):
        self.name_map = NameMap()
        self._id_name_map = {}
        self._name_id_map = {}
        self._reseller_id_map_panel = None
        self._pwd = ClPwd()

    def _add_map(self, name, id_):
        self._id_name_map[id_] = name
        self._name_id_map[name] = id_

    def pw_uid(self, name, default=None):
        try:
            return self._pwd.get_pw_by_name(name).pw_uid
        except ClPwd.NoSuchUserException:
            return default

    def _get_panel_reseller_id(self, reseller):
        # type: (str) -> Optional[int]
        uid = self.pw_uid(reseller)
        if uid is not None:
            return uid
        # in case when we cannot find reseller in passwd file
        # let's ask control panel for reseller's id
        if self._reseller_id_map_panel is None:
            self._reseller_id_map_panel = cpapi.get_reseller_id_pairs()
        return self._reseller_id_map_panel.get(reseller)

    def get_reseller_id(self, name):
        # type: (str) -> Optional[int]
        """
        Convert reseller name to an LVE id.
        It supports resellers without a system account (for Plesk compatibility).
        """
        uid = self.name_map.get_id(name) or self._name_id_map.get(name)
        if uid is not None:
            return uid
        try:
            uid = self._get_panel_reseller_id(name)
        except NotSupported:
            uid = None
        if uid is not None:
            self._add_map(name, uid)
        return uid

    def get_reseller_name(self, id_):
        """
        Convert reseller id to reseller name
        It support resellers without system account (for Plesk compatibilyty)
        """
        # add attribute fo in memory cache support
        name = self.name_map.get_name(id_) or self._id_name_map.get(id_)
        if name is not None:
            return name
        try:
            name = pwd.getpwuid(id_).pw_name
            if cpapi.is_reseller(name):
                self._add_map(name, id_)
            else:
                name = None
        except KeyError:
            name = None
        return name

    def lve_lvp_pairs(self):
        """
        This method loops over all user:reseller pairs in control panel
        and returns appropriate lve_id:lvp_id pairs.
        THIS METHOD WON'T CHECK IF 'RESELLER LIMITS' IS ENABLED IN ve.cfg
        """
        resellers = set(cpapi.resellers())
        reseller_uids = {}
        for reseller in resellers:
            try:
                reseller_uids[reseller] = self.get_reseller_id(reseller)
            except NotSupported:
                syslog.syslog(
                    syslog.LOG_WARNING, f"Reseller {reseller} still exists in control panel, "
                                        "but absent in /etc/passwd file")
        for cplogin, reseller in cpapi.cpinfo(keyls=('cplogin', 'reseller')):
            lve_id = self.pw_uid(cplogin)
            # for some reasons (process of destroying user died
            # or admin called 'pure' userdel), user may still exist in control panel
            # but absent in /etc/passwd file; we can do nothing with that,
            # so just skip and write a warning to syslog
            if lve_id is None:
                syslog.syslog(
                    syslog.LOG_WARNING, f"user {cplogin} still exists in control panel, "
                                        "but absent in /etc/passwd file")
                continue
            lvp_id = reseller_uids.get(reseller, 0)
            yield lve_id, lvp_id

    @staticmethod
    def resellers():
        for reseller_name in cpapi.resellers():
            yield reseller_name

    @staticmethod
    def reseller_uids(name):
        """
        Obtain from control panel resellers uids
        """
        uids = []
        reseller_users = cpapi.reseller_users(name)
        for user in reseller_users:
            try:
                id_ = pwd.getpwnam(user).pw_uid
                uids.append(id_)
            except KeyError:
                syslog.syslog(
                    syslog.LOG_WARNING, f"user {user} still exists in control panel, "
                                        "but absent in /etc/passwd file")
        return uids

    def lvp_lve_id_list(self, lvp_id):
        reseller_name = self.get_reseller_name(lvp_id)
        return self.reseller_uids(reseller_name)




class Lve:
    def __init__(self, proc=None, py=None, map=None):
        self.proc = proc or ProcLve()
        self.py = py or PyLve()
        self.map = map or LvpMap()

    def lve_id_lvp_id_pairs(self):
        """
        Obtain {lve id}:{lvp id} pairs iterator based on ve.cfg config
        (detect enabled resellers containers)

        This method (unlike LvpMap.lve_lvp_pairs) will check
        if reseller is enabled in ve.cfg and return lvp_id=0
        for users of reseller with disabled reseller limits
        """
        enabled_lvp_id = set(self.map.name_map.id_list())
        for lve_id, lvp_id in self.map.lve_lvp_pairs():
            if lvp_id in enabled_lvp_id:  # load map for enabled resellers only
                yield lve_id, lvp_id
            else:
                yield lve_id, 0

    def lve2lvp(self, lve_id):
        """
        Obtain lvp id based on ve.cfg config (detect enabled resellers containers)
        """
        for lve_id_, lvp_id_ in self.lve_id_lvp_id_pairs():
            if lve_id == lve_id_:
                return lvp_id_
        return 0

    def lve_destroy(self, lve_id, *args, **kwargs):
        """
        safe destroy lve container with preserving lvp mapping
        """
        if os.path.exists(self.proc.proc_lve_map()):
            lvp_id = self.proc.map().get(lve_id, 0)
        else:
            lvp_id = 0
        self.py.lve_destroy(lve_id, *args, **kwargs)
        if lvp_id != 0:
            try:
                pwd.getpwuid(lve_id)
                self.py.lve_lvp_map(lvp_id, lve_id)
            except KeyError:
                pass

    def _map_domain_lves(self, lve_id, proc_map):
        """Place every domain LVE that belongs to *lve_id* under its user LVP.

        Uses lve_lvp_move for domain LVEs that already exist in the kernel,
        and falls back to lve_lvp_map for those that do not yet exist (so
        the kernel will place them under the correct LVP when lve_setup
        creates them later).

        *proc_map* is an lve_id→lvp_id dict (from /proc/lve/map) used to
        skip mappings that are already correct.  Updated in-place so callers
        see the new state.
        """
        config = _ws_config.load_config(lve_id)
        for d in config.domains:
            if not d.name:
                continue

            try:
                docroot = _ws_config.resolve_docroot(d.name)
            except LvdError as e:
                syslog.syslog(syslog.LOG_WARNING,
                              f"failed to resolve docroot for domain '{d.name}': {e}")
                continue

            domain_id = _ws_id_registry.assign_domain_id(lve_id, docroot)
            if proc_map.get(domain_id) == lve_id:
                continue

            if domain_id in proc_map:
                # Domain LVE exists in the kernel — move it.
                self.py.lve_lvp_move(lve_id, domain_id)
            else:
                # Domain LVE does not exist yet — pre-register mapping.
                self.py.lve_lvp_map(lve_id, domain_id)
            proc_map[domain_id] = lve_id

    def apply_domain_lve_limits(self, lve_id):
        """Apply per-domain limits from domains.json to each domain LVE.

        Must be called after lve_set_default() resets all LVEs inside the
        user LVP to the user's defaults.  Each domain LVE is set to its
        stored limits, or all-zeros (unlimited) when unconfigured.
        """
        config = _ws_config.load_config(lve_id)
        for d in config.domains:
            if not d.name:
                continue

            try:
                docroot = _ws_config.resolve_docroot(d.name)
            except LvdError as e:
                syslog.syslog(syslog.LOG_WARNING,
                              f"failed to resolve docroot for domain '{d.name}': {e}")
                continue

            domain_id = _ws_id_registry.assign_domain_id(lve_id, docroot)

            settings = self.py.liblve_settings()
            limits = d.limits.to_dict()
            if 'cpu' in limits:
                settings.ls_cpu = int(limits['cpu'])
            if 'pmem' in limits:
                pmem_bytes = int(limits['pmem'])
                settings.ls_memory_phy = pmem_bytes // 4096 if pmem_bytes else 0
            if 'io' in limits:
                settings.ls_io = int(limits['io'])
            if 'nproc' in limits:
                settings.ls_nproc = int(limits['nproc'])
            if 'iops' in limits:
                settings.ls_iops = int(limits['iops'])
            self.py.lve_setup(
                domain_id, settings,
                err_msg=f'Can`t setup domain LVE {domain_id}; error code {{code}}',
            )

    def _sync_map(self):
        """
        Load lve_id:lvp_id map to kmod-lve.

        For users with per-domain isolation configured, builds a nested LVP
        hierarchy instead of a flat reseller mapping:

          lvp<0>
            [lvp<reseller_id>]        ← reseller LVP (if enabled)
              lvp<user_id>            ← user-level LVP with isolation
                lve<user_id>          ← user LVE
                lve<domain_id> ...    ← domain LVEs

          lvp<0>
            [lvp<reseller_id>]        ← reseller LVP (without isolation)
              lve<user_id>            ← user LVE (flat, existing behaviour)
        """
        # load mapping information from kernel (/proc/lve/map)
        proc_map_dict = self.proc.map()

        # loop over user_id:reseller_id pairs
        # lve_id_lvp_id_pairs includes all control panel users
        # and checks for enabled resellers in ve.cfg
        # so user of reseller without reseller limits
        # will be listed in response like 'tuple(user_id, 0)'
        if self.py.domains_supported():
            isolated_users = set(_ws_config.find_all_lve_ids_with_config())
        else:
            isolated_users = set()

        for lve_id, lvp_id in self.lve_id_lvp_id_pairs():
            if lve_id in isolated_users:
                # User has per-domain isolation: build nested LVP hierarchy.
                # Ensure the parent (reseller) LVP exists first.
                if lvp_id != 0 and not self.proc.exist_lvp(lvp_id=lvp_id):
                    self.py.lve_lvp_create(lvp_id)

                # Create user LVP nested under the reseller (or at root
                # when there is no reseller).  lve_apply_all() already
                # creates the nested LVP for reseller users; this handles
                # the non-reseller case and the standalone sync-map call.
                if not self.proc.exist_lvp(lvp_id=lve_id):
                    if lvp_id:
                        self.py.lve_lvp_create2(lve_id, lvp_id)
                    else:
                        self.py.lve_lvp_create(lve_id)

                # Move the user LVE under the user LVP (both share lve_id).
                if proc_map_dict.get(lve_id, 0) != lve_id:
                    self.py.lve_lvp_move(lve_id, lve_id)
                    proc_map_dict[lve_id] = lve_id

                self._map_domain_lves(lve_id, proc_map=proc_map_dict)
            else:
                # Standard behaviour: move user LVE under reseller/root LVP.
                if proc_map_dict.get(lve_id, 0) != lvp_id:  # change map if needed only
                    if not self.proc.exist_lvp(lvp_id=lvp_id):
                        self.py.lve_lvp_create(lvp_id)
                    self.py.lve_lvp_move(lvp_id, lve_id)
                    proc_map_dict[lve_id] = lvp_id

    def sync_map(self):
        """
        wrapped _sync_map function for prevent error if some cpapi not supported
        """
        try:
            self._sync_map()
        except NotSupported:
            pass

    def is_panel_supported(self):
        """
        Check if current panel supported for reseller's limits;
        :rtype: bool
        """
        try:
            return cpapi.is_reseller_limits_supported()
        except NotSupported:
            return False

    def reseller_limit_supported(self):
        """
        Check present all needed (kmod-lve, liblve, /proc/lve, panel) for manipulate resellers limits
        """
        return all((self.py.resellers_supported(),
                    self.proc.resellers_supported(),
                    self.is_panel_supported()))

    def is_lve10(self):
        """
        Check present all needed (kmod-lve, liblve, /proc/lve) for manipulate resellers limits
        """
        return all((self.py.resellers_supported(), self.proc.resellers_supported()))