"""
Copyright (C) 2024  Michael Ablassmeier <abi@grinser.de>

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/>.
"""

import logging
from typing import List, Any
from argparse import Namespace
from libvirt import virDomain
from libvirtnbdbackup import virt
from libvirtnbdbackup import common as lib
from libvirtnbdbackup import exceptions

log = logging.getLogger()


def arguments(args: Namespace) -> None:
    """Check passed arguments for validity"""
    if args.compress is not False and args.type == "raw":
        raise exceptions.BackupException("Compression not supported with raw output.")

    if args.stdout is True and args.type == "raw":
        raise exceptions.BackupException("Output type raw not supported to stdout.")

    if args.stdout is True and args.raw is True:
        raise exceptions.BackupException(
            "Saving raw images to stdout is not supported."
        )

    if args.type == "raw" and args.level in ("inc", "diff"):
        raise exceptions.BackupException(
            "Stream format raw does not support incremental or differential backup."
        )


def targetDir(args: Namespace) -> None:
    """Check if target directory backup is started to meets
    all requirements based on the backup level executed"""
    if (
        args.level not in ("copy", "full", "auto")
        and not lib.hasFullBackup(args)
        and not args.stdout
    ):
        raise exceptions.BackupException(
            f"Unable to execute [{args.level}] backup: "
            f"No full backup found in target directory: [{args.output}]"
        )

    if lib.targetIsEmpty(args) and args.level == "auto":
        log.info("Backup mode auto, target folder is empty: executing full backup.")
        args.level = "full"
    elif not lib.targetIsEmpty(args) and args.level == "auto":
        if not lib.hasFullBackup(args):
            raise exceptions.BackupException(
                "Can't execute switch to auto incremental backup: "
                f"specified target folder [{args.output}] does not contain full backup.",
            )
        log.info("Backup mode auto: executing incremental backup.")
        args.level = "inc"
    elif not args.stdout and not args.startonly and not args.killonly:
        if not lib.targetIsEmpty(args):
            raise exceptions.BackupException(
                "Target directory already contains full or copy backup."
            )


def vmstate(args, virtClient: virt.client, domObj: virDomain) -> None:
    """Check virtual machine state before executing backup
    and based on situation, either fallback to regular copy
    backup or attempt to bring VM into paused state"""
    if domObj.isActive() == 0:
        args.offline = True
        if args.start_domain is True:
            log.info("Starting domain in paused state")
            if virtClient.startDomain(domObj) == 0:
                args.offline = False
            else:
                log.info("Failed to start VM in paused mode.")

    if args.level == "full" and args.offline is True:
        log.warning("Domain is offline, resetting backup options.")
        args.level = "copy"
        log.warning("New Backup level: [%s].", args.level)
        args.offline = True

    if args.offline is True and args.startonly is True:
        raise exceptions.BackupException(
            "Domain is offline: must be active for this function."
        )


def vmfeature(virtClient: virt.client, domObj: virDomain) -> None:
    """Check if required features are enabled in domain config"""
    if virtClient.hasIncrementalEnabled(domObj) is False:
        raise exceptions.BackupException(
            "Virtual machine does not support required backup features, "
            "please adjust virtual machine configuration."
        )


def diskformat(args: Namespace, disks: List[Any]) -> None:
    """Check if disks meet requirements for backup mode, if not, switch
    backup job to type copy."""
    if args.level != "copy" and lib.hasQcowDisks(disks) is False:
        args.level = "copy"
        raise exceptions.BackupException(
            "Only raw disks attached, switching to backup mode copy."
        )


def blockjobs(
    args, virtClient: virt.client, domObj: virDomain, disks: List[Any]
) -> None:
    """Check if there is an already active backup operation on the domain
    disks. If so, fail accordingly"""
    if (
        not args.killonly
        and not args.offline
        and virtClient.blockJobActive(domObj, disks)
    ):
        raise exceptions.BackupException(
            "Active block job for running domain:"
            f" Check with [virsh domjobinfo {args.domain}] or use option -k to kill the active job."
        )
