"""
This program is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.


This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
See the GNU General Public License for more details.


You should have received a copy of the GNU General Public License
 along with this program.  If not, see <https://www.gnu.org/licenses/>.

Copyright © 2019 Cloud Linux Software Inc.

This software is also available under ImunifyAV commercial license,
see <https://www.imunify360.com/legal/eula>
"""
import asyncio
import binascii
import functools
import os
import pwd
import shutil
import time
from collections import defaultdict
from logging import getLogger
from pathlib import Path
from typing import (
    Callable,
    Collection,
    Dict,
    Iterable,
    List,
    TYPE_CHECKING,
    Tuple,
    TypeVar,
    Union,
    cast,
)

from peewee import IntegrityError

from defence360agent.contracts.config import (
    Core,
    HackerTrap,
    MyImunifyConfig,
    UserType,
    choose_use_backups_start_from_date,
    choose_value_from_config,
    should_try_autorestore_malicious,
)
from defence360agent.contracts.permissions import (
    MS_CONFIG_DEFAULT_ACTION_EDIT,
    has_permission,
    myimunify_protection_enabled,
)
from defence360agent.internals.global_scope import g
from defence360agent.model.simplification import run_in_executor
from defence360agent.subsys import web_server
from defence360agent.subsys.panels import hosting_panel
from defence360agent.subsys.panels.base import (
    ModsecVendorsError,
    PanelException,
)
from defence360agent.utils import (
    COPY_TO_MODSEC_MAXTRIES,
    LazyLock,
    atomic_rewrite,
    base64_decode_filename,
    base64_encode_filename,
    log_failed_to_copy_to_modsec,
    retry_on,
    safe_sequence,
)
from imav.contracts.messages import (
    MalwareCleanupRevert,
    MalwareCleanupTask,
)
from imav.malwarelib.config import (
    ADDED_TO_IGNORE,
    CLEANUP,
    CLEANUP_DONE,
    CLEANUP_ON_SCHEDULE,
    CLEANUP_REMOVED,
    DELETED_FROM_IGNORE,
    FAILED_TO_CLEANUP,
    FAILED_TO_DELETE_FROM_IGNORE,
    FAILED_TO_IGNORE,
    FAILED_TO_RESTORE_FROM_BACKUP,
    FAILED_TO_RESTORE_ORIGINAL,
    FAILED_TO_STORE_ORIGINAL,
    FOUND,
    MalwareEvent,
    MalwareEventPostponed,
    MalwareHitStatus,
    MalwareScanResourceType,
    MalwareScanType,
    NOTIFY,
    REQUIRES_MYIMUNIFY_PROTECTION,
    RESTORED_FROM_BACKUP,
    RESTORED_ORIGINAL,
    SUBMITTED_FOR_ANALYSIS,
    UNABLE_TO_CLEANUP,
)
from imav.malwarelib.model import (
    MalwareHistory,
    MalwareHit,
    MalwareHitAlternate,
    MalwareIgnorePath,
    MalwareScan,
)
from imav.malwarelib.scan.mds.report import MalwareDatabaseHitInfo
from imav.malwarelib.subsys.restore_from_backup import restore_files
from imav.malwarelib.utils import hash_path
from imav.malwarelib.utils.submit import submit_in_background
from imav.plugins.event_hook_executor import detected_hook

if TYPE_CHECKING:
    from imav.malwarelib.cleanup.storage import RestoreReport

logger = getLogger(__name__)
#: a type for generic path functions
PathLike = Union[str, bytes, os.PathLike]
#: Declare type variable, to be used in generic functions
T = TypeVar("T")
#: Type variable for generic apply_default_action function
HitInfoType = TypeVar(
    "HitInfoType", MalwareHitAlternate, MalwareDatabaseHitInfo
)


def update_malware_history(coro):
    """Decorator responsible for logging malware events into DB"""

    @functools.wraps(coro)
    async def async_wrapper(
        cls,
        path,
        file_owner,
        file_user,
        initiator=None,
        cause=None,
        resource_type=None,
        app_name=None,
        db_host=None,
        db_port=None,
        db_name=None,
        table_name=None,
        table_field=None,
        table_row_inf=None,
        scan_id=None,
        **kwargs,
    ):
        result = await coro(
            cls,
            path=path,
            file_owner=file_owner,
            file_user=file_user,
            initiator=initiator or UserType.ROOT,
            app_name=app_name,
            resource_type=resource_type,
            db_host=db_host,
            db_port=db_port,
            db_name=db_name,
            scan_id=scan_id,
            **kwargs,
        )

        await run_in_executor(
            asyncio.get_event_loop(),
            lambda: MalwareHistory.save_event(
                event=result.title,
                path=path,
                app_name=app_name,
                resource_type=resource_type,
                file_owner=file_owner,
                file_user=file_user,
                initiator=initiator,
                cause=cause,
                db_host=db_host,
                db_port=db_port,
                db_name=db_name,
                table_name=table_name,
                table_field=table_field,
                table_row_inf=table_row_inf,
                scan_id=scan_id,
            ),
        )
        return result

    @functools.wraps(coro)
    def wrapper(
        cls,
        path,
        file_owner,
        file_user,
        initiator=None,
        cause=None,
        resource_type=None,
        app_name=None,
        db_host=None,
        db_port=None,
        db_name=None,
        table_name=None,
        table_field=None,
        table_row_inf=None,
        scan_id=None,
        **kwargs,
    ):
        result = coro(  # coro is a ordinary function here
            cls,
            path=path,
            file_owner=file_owner,
            file_user=file_user,
            initiator=initiator or UserType.ROOT,
            app_name=app_name,
            resource_type=resource_type,
            db_host=db_host,
            db_port=db_port,
            db_name=db_name,
            scan_id=scan_id,
            **kwargs,
        )

        MalwareHistory.save_event(
            event=result.title,
            path=path,
            app_name=app_name,
            resource_type=resource_type,
            file_owner=file_owner,
            file_user=file_user,
            initiator=initiator,
            cause=cause,
            db_host=db_host,
            db_port=db_port,
            db_name=db_name,
            table_name=table_name,
            table_field=table_field,
            table_row_inf=table_row_inf,
            scan_id=scan_id,
        )
        return result

    return async_wrapper if asyncio.iscoroutinefunction(coro) else wrapper


def multiple_update_malware_history(coro):
    """
    Decorator responsible for logging multiple malware events into DB at once.
    Decorated function accepts an iterable of `MalwareHit`s.
    """

    async def wrapper(
        cls, hits: Iterable[MalwareHit], initiator=None, cause=None
    ):
        results = await asyncio.gather(
            *(
                coro(
                    cls,
                    path=hit.orig_file,
                    file_owner=hit.owner,
                    file_user=hit.user,
                )
                for hit in hits
            )
        )
        if not results:
            return results
        MalwareHistory.save_events(
            [
                {
                    "event": result.title,
                    "path": hit.orig_file,
                    "resource_type": hit.resource_type,
                    "app_name": hit.app_name,
                    "file_owner": hit.owner,
                    "file_user": hit.user,
                    "cause": cause or MalwareScanType.MANUAL,
                    "initiator": initiator or UserType.ROOT,
                    "db_host": hit.db_host,
                    "db_port": hit.db_port,
                    "db_name": hit.db_name,
                    "scan_id": hit.scanid,
                }
                for hit, result in zip(hits, results)
            ]
        )
        return results

    return wrapper


def bulk_update_malware_history(coro):
    """
    Decorator responsible for logging multiple malware events into DB at once.
    Decorated function accepts an iterable of `MalwareHit`s.
    """

    async def wrapper(
        cls, hits: Iterable[MalwareHit], cause=None, initiator=None, **kwargs
    ):
        hit_results = await coro(cls, hits, **kwargs)
        if not hit_results:
            return hit_results
        MalwareHistory.save_events(
            [
                {
                    "event": result.title,
                    "path": hit.orig_file,
                    "file_owner": hit.owner,
                    "file_user": hit.user,
                    "cause": cause or MalwareScanType.MANUAL,
                    "initiator": initiator or UserType.ROOT,
                }
                for hit, result in hit_results.items()
            ]
        )
        return hit_results

    return wrapper


def choose_action_for_malicious(username: str) -> Tuple[str, str]:
    if MyImunifyConfig.ENABLED:
        if not myimunify_protection_enabled(username):
            return NOTIFY, username

    if has_permission(MS_CONFIG_DEFAULT_ACTION_EDIT, username):
        return choose_value_from_config(
            "MALWARE_SCANNING", "default_action", username
        )

    return choose_value_from_config("MALWARE_SCANNING", "default_action")


class MalwareAction:
    """
    Responsible for manipulations with malware files.
    As long as each handler function is wrapped in `update_malware_history`,
    arguments should be passed in kwargs form.
    """

    _CALLBACK = defaultdict(set)

    @classmethod
    async def run_callbacks_for(cls, method_name, path, title):
        """Execute callback for specific action"""

        for callback in cls._CALLBACK[method_name]:
            try:
                await callback(path, MalwareEvent(title))
            except asyncio.CancelledError:
                raise
            except Exception as e:
                logger.exception(
                    "Error '{!r}' happened when run callback {} for"
                    "MalwareAction {} method".format(e, callback, method_name)
                )

    @classmethod
    def add_callback(cls, method_name, coro):
        cls._CALLBACK[method_name].add(coro)

    @classmethod
    @update_malware_history
    async def submit_for_analysis(
        cls, path, type, reason=None, **_
    ) -> MalwareEvent:
        submit_in_background(path, type, reason)
        return MalwareEvent(SUBMITTED_FOR_ANALYSIS)

    @classmethod
    @update_malware_history
    async def ignore(cls, path, resource_type, **_) -> MalwareEvent:
        try:
            await run_in_executor(
                asyncio.get_event_loop(),
                lambda: MalwareIgnorePath.create(
                    path=path, resource_type=resource_type
                ),
            )
        except IntegrityError:
            title = FAILED_TO_IGNORE
        else:
            title = ADDED_TO_IGNORE
        return MalwareEvent(title)

    @classmethod
    @update_malware_history
    def delete_from_ignore_sync(cls, path, **_) -> MalwareEvent:
        deleted = (
            MalwareIgnorePath.delete()
            .where(MalwareIgnorePath.path == path)
            .execute()
        )
        return MalwareEvent(
            DELETED_FROM_IGNORE if deleted else FAILED_TO_DELETE_FROM_IGNORE
        )

    @classmethod
    @update_malware_history
    async def notify(cls, *_, **__):
        # TODO: should be sending email here, but not implemented yet
        return MalwareEvent(FOUND)

    @classmethod
    @update_malware_history
    async def cleanup_failed_restore(cls, *_, **__):
        return MalwareEvent(FAILED_TO_RESTORE_ORIGINAL)

    @classmethod
    @update_malware_history
    async def cleanup_failed_store(cls, *_, **__):
        return MalwareEvent(FAILED_TO_STORE_ORIGINAL)

    @classmethod
    @update_malware_history
    async def cleanup_restored_original(
        cls, *_, initiator: str, report: "RestoreReport" = None, **__
    ):
        if report and (sink := g.get("sink")):
            report.initiator = initiator
            await sink.process_message(MalwareCleanupRevert(report.to_dict()))
        return MalwareEvent(RESTORED_ORIGINAL)

    @classmethod
    @multiple_update_malware_history
    async def cleanup_unable(cls, *_, **__):
        return MalwareEvent(UNABLE_TO_CLEANUP)

    @classmethod
    @multiple_update_malware_history
    async def cleanup_done(cls, path, *_, **__):
        await cls.run_callbacks_for("cleanup", path, CLEANUP_DONE)
        return MalwareEvent(CLEANUP_DONE)

    @classmethod
    @multiple_update_malware_history
    async def cleanup_removed(cls, *_, **__):
        return MalwareEvent(CLEANUP_REMOVED)

    @classmethod
    @multiple_update_malware_history
    async def cleanup_failed(cls, *_, **__):
        return MalwareEvent(FAILED_TO_CLEANUP)

    @classmethod
    @multiple_update_malware_history
    async def cleanup_requires_myimunify_protection(cls, *_, **__):
        return MalwareEvent(REQUIRES_MYIMUNIFY_PROTECTION)

    @classmethod
    async def apply_default_action(
        cls,
        hits: List[MalwareHitAlternate],
        initiator=None,
        cause=None,
        sink=None,
        **kwargs,
    ) -> List[Tuple[MalwareHitAlternate, MalwareEvent, str, bool]]:
        """Perform action with malware which user set in the config"""

        results = []
        for h in hits:
            _, config_owner = choose_action_for_malicious(username=h.user)
            event = await cls.notify(
                file_owner=h.owner,
                file_user=h.user,
                path=h.orig_file,
                initiator=initiator or config_owner,
                cause=cause,
                **kwargs,
            )
            results.append((h, event, NOTIFY, False))

        return results

    @classmethod
    async def multiple(cls, action, hits):
        """
        Apply the action to multiple hits
        :param action: thr action to apply
        :param hits: list of hits
        """
        for hit in hits:
            await action(hit.orig_file, hit.user)

    @classmethod
    def _get_tmp_dir(cls, file_owner):
        hp = hosting_panel.HostingPanel()
        try:
            user = pwd.getpwnam(file_owner)
        except (KeyError, TypeError):
            return Core.TMPDIR
        try:
            tmp_dir = str(hp.base_home_dir(user.pw_dir))
        except (RuntimeError, FileNotFoundError):
            return Core.TMPDIR

        return tmp_dir

    @classmethod
    def _split_hits_on_restore(cls, hits):
        to_restore = []
        not_restore = []
        for hit in hits:
            path = hit.orig_file
            file_ctime = None
            try:
                file_ctime = int(os.path.getctime(path))
            except FileNotFoundError:
                logger.warning(
                    "File %s not found during restore from backup process",
                    safe_sequence.path(path),
                )

            if (
                file_ctime is None
                or MalwareHistory.select()
                .where(
                    MalwareHistory.path == path,
                    MalwareHistory.event == FAILED_TO_RESTORE_FROM_BACKUP,
                    MalwareHistory.ctime >= file_ctime,
                )
                .first()
                is None
            ):
                to_restore.append(hit)
            else:
                not_restore.append(hit)

        return to_restore, not_restore

    @classmethod
    @bulk_update_malware_history
    async def restore_from_backup(
        cls, hits, **kwargs
    ) -> Dict[MalwareHit, MalwareEvent]:
        to_restore, not_restore = cls._split_hits_on_restore(hits)

        for f in not_restore:
            logger.warning(
                "File %s wasn't restored from backup"
                ", because last restore attempt failed",
                safe_sequence.path(f.orig_file),
            )

        user_hits = {}  # Dict[str, List[MalwareHit]]
        for hit in to_restore:
            user_hits.setdefault(hit.user, []).append(hit)

        res = {}  # type: Dict[MalwareHit, MalwareEvent]
        for user, _hits in user_hits.items():
            res.update(
                await cls._restore_from_backup(
                    _hits, file_owner=user, **kwargs
                )
            )
        res.update(
            (hit, MalwareEvent(FAILED_TO_RESTORE_FROM_BACKUP))
            for hit in not_restore
        )
        return res

    @classmethod
    async def _restore_from_backup(
        cls, hits, file_owner, sink=None, **_
    ) -> List[Tuple[MalwareHit, MalwareEvent]]:
        paths = [h.orig_file for h in hits]

        tmp_dir = cls._get_tmp_dir(file_owner)

        restored, failed = await restore_files(
            files=paths,
            until=choose_use_backups_start_from_date(file_owner),
            sink=sink,
            tmp_dir=tmp_dir,
        )
        res = []

        restored_hits = [h for h in hits if h.orig_file in restored]
        failed_hits = [h for h in hits if h.orig_file in failed]

        for p in restored:
            safe_path = safe_sequence.path(p)
            logger.info("File %s was restored from backup", safe_path)

        title = RESTORED_FROM_BACKUP
        res.extend([(rh, MalwareEvent(title)) for rh in restored_hits])

        for p in failed:
            safe_path = safe_sequence.path(p)
            logger.warning("File %s wasn't restored from backup", safe_path)

        title = FAILED_TO_RESTORE_FROM_BACKUP
        res.extend([(fh, MalwareEvent(title)) for fh in failed_hits])

        return res


def subscribe_to_malware_action(action, coro):
    MalwareAction.add_callback(action, coro)


class HackerTrapHitsSaver:
    BASE_DIR = HackerTrap.DIR
    BASE_PD_DIR = HackerTrap.DIR_PD
    NAME = HackerTrap.NAME
    MAX_HITS_COUNT = 1000  # lets do 1000 files for now, see how it works
    SECONDS_BEFORE_CLEAN = 24 * 60 * 60  # 24 hours between cleanups
    STANDALONE_MARK = "-SA-"
    LOCK = LazyLock()

    @classmethod
    def _filepath(cls, filename=None) -> Path:
        name = filename or cls.NAME
        return Path(cls.BASE_DIR, name)

    @classmethod
    def _clean_filepath(cls) -> Path:
        return Path(cls.BASE_DIR, cls.NAME + ".clean")

    @classmethod
    def _write(cls, file_list: List[Path], filename=None):
        try:
            atomic_rewrite(
                cls._filepath(filename),
                b"\n".join(base64_encode_filename(name) for name in file_list),
                backup=False,
                allow_empty_content=True,
                permissions=0o644,
            )
        except OSError as oe:
            logger.error("Unable to write HackerTrap file: %r", oe)

    @classmethod
    def _extend(cls, file_list: List[T], files_to_add: List[T]) -> List[T]:
        """
        adds files_to_add to file_list
        the method has side_effect (file_list will be modified)
        yet, given that it is private class method -- we can do it
        :param file_list: existing files
        :param files_to_add: files to add
        :return: joined list, limited to MAX_HITS_COUNT
        """
        file_set = set(file_list)  # we will use it to speed up lookups
        _file_list = file_list.copy()
        for file in files_to_add:
            # if we are re-adding file, re-add it at the bottom,
            # so it doesn't rotate out too fast
            if file in file_set:
                _file_list.remove(file)
            _file_list.append(file)
        return _file_list[-cls.MAX_HITS_COUNT :]

    @staticmethod
    def _clean_list(file_list: Iterable[PathLike]) -> List[PathLike]:
        """
        This method checks if any of the files on the list is present
        and removes that entry from the list
        :param file_list: list of files
        :return: new list of files, in the same order, with files that exist
        skipped
        """
        return [file for file in file_list if not os.path.exists(file)]

    @classmethod
    def _should_clean(cls, file_mtime, current_time):
        return current_time - file_mtime > cls.SECONDS_BEFORE_CLEAN

    @classmethod
    def _clean_file(cls, file_list: Iterable[PathLike]):
        """
        We will use extra file to track last time we cleaned
        For that we will use mtime of that file
        :param file_list: list to clean
        :return: cleaned list
        """
        p = cls._clean_filepath()
        if p.exists():
            if cls._should_clean(p.stat().st_mtime, time.time()):
                p.write_bytes(b"")
                file_list = cls._clean_list(file_list)
        else:
            p.write_bytes(b"")

        return file_list

    @classmethod
    def _read(cls, filename=None, skip_exists=True) -> List[Path]:
        try:
            file_list: List[bytes] = (
                cls._filepath(filename).read_bytes().split()
            )
            decoded_file_list: List[Path] = []
            for file in file_list:
                try:
                    decoded_file_list.append(base64_decode_filename(file))
                except binascii.Error as e:
                    logger.error(
                        "Can't decode filepath [%r] with error [%r]", file, e
                    )
            return (
                cls._clean_file(decoded_file_list)
                if skip_exists
                else decoded_file_list
            )

        except FileNotFoundError:
            return []

    @classmethod
    async def add_hits(cls, files_to_add: List[Path], *args, **kwargs):
        """Same behavior as for separate hit."""

        await cls._add_hits(files_to_add, *args, **kwargs)
        await cls.update_sa_hits(files_to_add=[], files_to_remove=files_to_add)

    @classmethod
    async def _add_hits(cls, files_to_add: List[Path], *args, **kwargs):
        try:
            file_list: List[Path] = cls._read()
            result: List[Path] = cls._extend(file_list, files_to_add)
            cls._write(result)
            await cls._copy_to_modsec_rules(cls.NAME)
        except OSError as oe:
            logger.error("Unable to read HackerTrap file %r", oe)

    @classmethod
    async def add_hit(cls, file_to_add: Path, *args, **kwargs):
        """When storing separate hit it needs to be added to
        malware_found_b64.list
        and excluded from malware_sa_found_b64.list as well from
        proactive/dangerous/[hash]"""
        return await cls.add_hits([file_to_add])

    @classmethod
    async def init(cls):
        await cls.add_hits([])

    @classmethod
    @retry_on(
        FileNotFoundError,
        max_tries=COPY_TO_MODSEC_MAXTRIES,
        on_error=log_failed_to_copy_to_modsec,
        silent=True,
    )
    async def _copy_to_modsec_rules(cls, malware_list_name):
        hp = hosting_panel.HostingPanel()

        try:
            vendor = await hp.get_i360_vendor_name()
        except (ModsecVendorsError, PanelException) as e:
            logger.warning(str(e))
            return False
        try:
            target = await hp.build_vendor_file_path(vendor, malware_list_name)
        except ModsecVendorsError as e:
            logger.exception("Can't get malware found list file: %s", e)
            return False

        found_list = Path(HackerTrap.DIR, malware_list_name)
        target_tmp = target.with_suffix(target.suffix + ".tmp")

        if (
            target.exists()
            and target.stat().st_size == found_list.stat().st_size
            and target.read_bytes() == found_list.read_bytes()
        ):
            logger.info("Nothing to update")
            return False

        try:
            shutil.copy(str(found_list), str(target_tmp))
            target_tmp.rename(target)
            return True
        except FileNotFoundError as e:
            raise e
        except OSError as e:
            logger.error("Failed to copy malware found list: %s", e)
            return False

    @classmethod
    def _get_exists_hash_files(cls):
        with os.scandir(cls.BASE_PD_DIR) as it:
            return [entry.name for entry in it if entry.is_file()]

    @classmethod
    def _create_hash_files(cls, files):
        for fname in files:
            (Path(cls.BASE_PD_DIR) / Path(fname)).touch(0o644)

    @classmethod
    def _remove_hash_files(cls, files):
        for fname in files:
            (Path(cls.BASE_PD_DIR) / Path(fname)).unlink()

    @classmethod
    def _update_sa_hash_files(cls):
        """
        SA hits stored for PD as sha256 hash of full path in
        HackerTrap.DIR_PD. Not more than MAX_HITS_COUNT files in dir.
        Remove older (by mtime) files first.
        """
        try:
            saved_files_list = cls._read(
                filename=HackerTrap.SA_NAME, skip_exists=False
            )
            hash_file_list = [
                hash_path(path) for path in saved_files_list if path
            ]
            exists_hash_file_list = cls._get_exists_hash_files()
            files_to_create = set(hash_file_list) - set(exists_hash_file_list)
            files_to_delete = set(exists_hash_file_list) - set(hash_file_list)
            cls._create_hash_files(files_to_create)
            cls._remove_hash_files(files_to_delete)
        except OSError as e:
            logger.warning(
                "HackerTrap error: %r%s",
                e,
                f" ({e.filename!r})" if e.filename else "",
            )

    @classmethod
    def _update_sa_hit_list(
        cls, files_to_add: List[Path], files_to_remove: List[Path]
    ) -> bool:
        """
        Update file of malware standalone list.
        Return True if malware standalone list was changed otherwise False.
        """
        try:
            saved_list: List[Path] = cls._read(
                filename=HackerTrap.SA_NAME, skip_exists=False
            )
            extended_list: List[Path] = cls._extend(saved_list, files_to_add)
            updated_list = [
                path for path in extended_list if path not in files_to_remove
            ]
            if updated_list != saved_list:
                cls._write(updated_list, filename=HackerTrap.SA_NAME)
                return True
        except OSError as e:
            logger.error("HackerTrap error: %s", e)
        return False

    @classmethod
    async def update_sa_hits(
        cls, files_to_add: List[Path], files_to_remove: List[Path]
    ):
        if files_to_add or files_to_remove:
            async with cls.LOCK:
                if cls._update_sa_hit_list(files_to_add, files_to_remove):
                    if await cls._copy_to_modsec_rules(HackerTrap.SA_NAME):
                        await web_server.graceful_restart()
                    cls._update_sa_hash_files()

    @classmethod
    async def reset_sa_hits(cls):
        """
        Re-populate HackerTrap records using data from database
        """
        # WARN: It is critically important to check the 'resource_type'!
        # In some cases when scanning DB for malwares the results contain
        # '-SA-' mark in the 'type' column. For instance:
        #   SMW-SA-20634-php.bkdr.wp.fakeplugin-0
        # What happens next:
        # 1) New 'MalwareHit' records appear, with 'resource_type'=="DB" and
        # 'orig_file'=="path to a root directory".
        # 2) The config 'malware_standalone_b64.list' gets these paths to root
        # directories, instead of paths to scripts.
        # 3) The action 'pmFromFile' in the modsec rule 77316817 (and some
        # others) matches 'SCRIPT_FILENAME' variable with lines in the config.
        # 4) The matching in the modsec module is not a strict comparison,
        # but the occurrence of a string within a string.
        # For instance, when the config contains the line:
        #   /home/domain/public_html
        # Than all the paths are match with it:
        #   /home/domain/public_html/admin.php
        #   /home/domain/public_html/cms/main.php
        # As the result of all above, the modsec rule makes false-positive
        # conclusion and blocks the request.
        # To prevent that, the 'resource_type' must be equal to 'FILE'.
        resource_type = MalwareScanResourceType.FILE.value
        async with cls.LOCK:
            files = (
                MalwareHit.select(MalwareHit.orig_file)
                .where(
                    # Only standalone malicious files that was found,
                    # but not yet cleared/restored
                    MalwareHit.status.in_(
                        [
                            MalwareHitStatus.FOUND,
                            MalwareHitStatus.CLEANUP_STARTED,
                            MalwareHitStatus.RESTORE_FROM_BACKUP_STARTED,
                        ]
                    ),
                    MalwareHit.malicious,
                    MalwareHit.type.contains(cls.STANDALONE_MARK),
                    MalwareHit.resource_type == resource_type,
                )
                .order_by(MalwareHit.timestamp.desc())
                .limit(cls.MAX_HITS_COUNT)
                .tuples()
            )
            cls._write(
                [os.fsencode(f) for [f] in files], filename=HackerTrap.SA_NAME
            )
            if await cls._copy_to_modsec_rules(HackerTrap.SA_NAME):
                await web_server.graceful_restart()
            cls._update_sa_hash_files()


class MalwareActionIm360(MalwareAction):
    @classmethod
    def _get_handler(cls, action) -> Callable:
        possible_actions = {
            NOTIFY: cls.notify,
            CLEANUP: cls.postpone(
                MalwareCleanupTask,
                post_action=cls.detect,
                action=CLEANUP,
            ),
            CLEANUP_ON_SCHEDULE: cls.postpone(
                MalwareCleanupTask,
                post_action=cls.detect,
                action=CLEANUP_ON_SCHEDULE,
            ),
        }
        try:
            result = possible_actions[action]
        except KeyError:
            result = possible_actions[NOTIFY]
            logger.error(
                "There is no such action '%s'. Config is invalid", action
            )
        return result

    @staticmethod
    def postpone(message, **kwargs):
        async def wrapper(*_, initiator, cause, **__):
            return MalwareEventPostponed(
                message, initiator=initiator, cause=cause, **kwargs
            )

        return wrapper

    @classmethod
    async def detect(cls, scan_id, sink, **_):
        scan = MalwareScan.get(scanid=scan_id)
        await detected_hook(
            sink,
            scan_id,
            scan.type,
            scan.started,
            scan.path,
            scan.total_resources,
        )

    @classmethod
    @bulk_update_malware_history
    async def restore_from_backup(
        cls, hits, **kwargs
    ) -> Dict[MalwareHit, MalwareEvent]:
        to_restore, not_restore = cls._split_hits_on_restore(hits)

        for f in not_restore:
            logger.warning(
                "File %s wasn't restored from backup"
                ", because last restore attempt failed",
                safe_sequence.path(f.orig_file),
            )

        user_hits = {}  # type: Dict[str, List[MalwareHit]]
        for hit in to_restore:
            user_hits.setdefault(hit.user, []).append(hit)

        res = {}  # type: Dict[MalwareHit, MalwareEvent]
        for user, _hits in user_hits.items():
            res.update(
                await cls._restore_from_backup(
                    _hits, file_owner=user, **kwargs
                )
            )
        res.update(
            (hit, MalwareEvent(FAILED_TO_RESTORE_FROM_BACKUP))
            for hit in not_restore
        )
        return res

    @classmethod
    def _split_hits_on_restore(cls, hits):
        to_restore = []
        not_restore = []
        for hit in hits:
            path = hit.orig_file
            file_ctime = None
            try:
                file_ctime = int(os.path.getctime(path))
            except FileNotFoundError:
                logger.warning(
                    "File %s not found during restore from backup process",
                    safe_sequence.path(path),
                )

            if (
                file_ctime is None
                or MalwareHistory.select()
                .where(
                    MalwareHistory.path == path,
                    MalwareHistory.event == FAILED_TO_RESTORE_FROM_BACKUP,
                    MalwareHistory.ctime >= file_ctime,
                )
                .first()
                is None
            ):
                to_restore.append(hit)
            else:
                not_restore.append(hit)

        return to_restore, not_restore

    @classmethod
    async def _restore_from_backup(
        cls, hits, file_owner, sink=None, **_
    ) -> List[Tuple[MalwareHit, MalwareEvent]]:
        paths = [h.orig_file for h in hits]

        tmp_dir = cls._get_tmp_dir(file_owner)

        restored, failed = await restore_files(
            files=paths,
            until=choose_use_backups_start_from_date(file_owner),
            sink=sink,
            tmp_dir=tmp_dir,
        )
        res = []

        restored_hits = [h for h in hits if h.orig_file in restored]
        failed_hits = [h for h in hits if h.orig_file in failed]

        for p in restored:
            safe_path = safe_sequence.path(p)
            logger.info("File %s was restored from backup", safe_path)

        title = RESTORED_FROM_BACKUP
        res.extend([(rh, MalwareEvent(title)) for rh in restored_hits])

        for p in failed:
            safe_path = safe_sequence.path(p)
            logger.warning("File %s wasn't restored from backup", safe_path)

        title = FAILED_TO_RESTORE_FROM_BACKUP
        res.extend([(fh, MalwareEvent(title)) for fh in failed_hits])

        return res

    @classmethod
    def _get_tmp_dir(cls, file_owner):
        hp = hosting_panel.HostingPanel()
        try:
            user = pwd.getpwnam(file_owner)
        except (KeyError, TypeError):
            return Core.TMPDIR
        try:
            tmp_dir = str(hp.base_home_dir(user.pw_dir))
        except (RuntimeError, FileNotFoundError):
            return Core.TMPDIR

        return tmp_dir

    @classmethod
    async def apply_default_action(
        cls,
        hits: Collection[HitInfoType],
        initiator=None,
        cause=None,
        sink=None,
        resource_type=None,
        **kwargs,
    ) -> List[Tuple[HitInfoType, MalwareEvent, str, bool]]:
        """Perform action with malware which user set in the config"""

        to_restore = [
            hit
            for hit in hits
            if should_try_autorestore_malicious(hit.user)
            # restore from backup does not apply to db scans
            and not isinstance(hit, MalwareDatabaseHitInfo)
        ]
        restore_events = await cls.restore_from_backup(
            to_restore, initiator=initiator, sink=sink, cause=cause, **kwargs
        )
        # FIXME: remove this mapping
        # when we start to store UID instead of username in the db
        panel_users = set(await hosting_panel.HostingPanel().get_users())
        uid_to_name = {
            pw.pw_uid: pw.pw_name
            for pw in pwd.getpwall()
            if pw.pw_name in panel_users
        }
        res = []
        for hit in hits:
            if isinstance(hit, MalwareDatabaseHitInfo):
                owner = uid_to_name.get(hit.owner, str(hit.owner))
                user = uid_to_name.get(hit.user, str(hit.user))
                path = cast(MalwareDatabaseHitInfo, hit).path
            else:
                owner = hit.owner
                user = hit.user
                path = cast(MalwareHitAlternate, hit).orig_file

            action, config_owner = choose_action_for_malicious(user)

            if hit in restore_events and restore_events[hit].successful:
                res.append((hit, restore_events[hit], action, True))
                continue

            handler_kw_args = kwargs.copy()
            if isinstance(hit, MalwareDatabaseHitInfo):
                handler_kw_args["db_name"] = hit.db_name
                handler_kw_args["db_host"] = hit.db_host
                handler_kw_args["db_port"] = hit.db_port

                handler_kw_args["table_name"] = hit.table_name
                handler_kw_args["table_field"] = hit.table_field
                handler_kw_args["table_row_inf"] = hit.table_row_inf

                handler_kw_args["scan_id"] = hit.scan_id

            handler = cls._get_handler(action)
            event = await handler(
                path=path,
                file_owner=owner,
                file_user=user,
                cause=cause,
                initiator=initiator or config_owner,
                sink=sink,
                app_name=hit.app_name,
                resource_type=resource_type,
                **handler_kw_args,
            )

            res.append((hit, event, action, False))

        return res