package PVE::QemuConfig;

use strict;
use warnings;

use PVE::AbstractConfig;
use PVE::INotify;
use PVE::JSONSchema;
use PVE::QemuServer::CPUConfig;
use PVE::QemuServer::Drive;
use PVE::QemuServer::Helpers;
use PVE::QemuServer::Monitor qw(mon_cmd);
use PVE::QemuServer;
use PVE::QemuServer::Machine;
use PVE::Storage;
use PVE::Tools;

use base qw(PVE::AbstractConfig);

my $nodename = PVE::INotify::nodename();

mkdir "/etc/pve/nodes/$nodename";
mkdir "/etc/pve/nodes/$nodename/qemu-server";

my $lock_dir = "/var/lock/qemu-server";
mkdir $lock_dir;

sub assert_config_exists_on_node {
    my ($vmid, $node) = @_;

    $node //= $nodename;

    my $filename = __PACKAGE__->config_file($vmid, $node);
    my $exists = -f $filename;

    my $type = guest_type();
    die "unable to find configuration file for $type $vmid on node '$node'\n"
	if !$exists;
}

# BEGIN implemented abstract methods from PVE::AbstractConfig

sub guest_type {
    return "VM";
}

sub __config_max_unused_disks {
    my ($class) = @_;

    return $PVE::QemuServer::Drive::MAX_UNUSED_DISKS;
}

sub config_file_lock {
    my ($class, $vmid) = @_;

    return "$lock_dir/lock-$vmid.conf";
}

sub cfs_config_path {
    my ($class, $vmid, $node) = @_;

    $node = $nodename if !$node;
    return "nodes/$node/qemu-server/$vmid.conf";
}

sub has_feature {
    my ($class, $feature, $conf, $storecfg, $snapname, $running, $backup_only) = @_;

    my $err;
    $class->foreach_volume($conf, sub {
	my ($ds, $drive) = @_;

	return if PVE::QemuServer::drive_is_cdrom($drive);
	return if $backup_only && defined($drive->{backup}) && !$drive->{backup};
	my $volid = $drive->{file};
	$err = 1 if !PVE::Storage::volume_has_feature($storecfg, $feature, $volid, $snapname, $running);
   });

    return $err ? 0 : 1;
}

sub valid_volume_keys {
    my ($class, $reverse) = @_;

    my @keys = PVE::QemuServer::Drive::valid_drive_names();

    return $reverse ? reverse @keys : @keys;
}

# FIXME: adapt parse_drive to use $noerr for better error messages
sub parse_volume {
    my ($class, $key, $volume_string, $noerr) = @_;

    my $volume;
    if ($key eq 'vmstate') {
	eval { PVE::JSONSchema::check_format('pve-volume-id', $volume_string) };
	if (my $err = $@) {
	    return if $noerr;
	    die $err;
	}
	$volume = { 'file' => $volume_string };
    } else {
	$volume = PVE::QemuServer::Drive::parse_drive($key, $volume_string);
    }

    die "unable to parse volume\n" if !defined($volume) && !$noerr;

    return $volume;
}

sub print_volume {
    my ($class, $key, $volume) = @_;

    return PVE::QemuServer::Drive::print_drive($volume);
}

sub volid_key {
    my ($class) = @_;

    return 'file';
}

sub get_replicatable_volumes {
    my ($class, $storecfg, $vmid, $conf, $cleanup, $noerr) = @_;

    my $volhash = {};

    my $test_volid = sub {
	my ($volid, $attr) = @_;

	return if $attr->{cdrom};

	return if !$cleanup && !$attr->{replicate};

	if ($volid =~ m|^/|) {
	    return if !$attr->{replicate};
	    return if $cleanup || $noerr;
	    die "unable to replicate local file/device '$volid'\n";
	}

	my ($storeid, $volname) = PVE::Storage::parse_volume_id($volid, $noerr);
	return if !$storeid;

	my $scfg = PVE::Storage::storage_config($storecfg, $storeid);
	return if $scfg->{shared};

	my ($path, $owner, $vtype) = PVE::Storage::path($storecfg, $volid);
	return if !$owner || ($owner != $vmid);

	if ($vtype ne 'images') {
	    return if $cleanup || $noerr;
	    die "unable to replicate volume '$volid', type '$vtype'\n";
	}

	if (!PVE::Storage::volume_has_feature($storecfg, 'replicate', $volid)) {
	    return if $cleanup || $noerr;
	    die "missing replicate feature on volume '$volid'\n";
	}

	$volhash->{$volid} = 1;
    };

    PVE::QemuServer::foreach_volid($conf, $test_volid);

    return $volhash;
}

sub get_backup_volumes {
    my ($class, $conf) = @_;

    my $return_volumes = [];

    my $test_volume = sub {
	my ($key, $drive) = @_;

	return if PVE::QemuServer::drive_is_cdrom($drive);

	my $included = $drive->{backup} // 1;
	my $reason = "backup=";
	$reason .= defined($drive->{backup}) ? 'no' : 'yes';

	if ($key =~ m/^efidisk/ && (!defined($conf->{bios}) || $conf->{bios} ne 'ovmf')) {
	    $included = 0;
	    $reason = "efidisk but no OMVF BIOS";
	}

	push @$return_volumes, {
	    key => $key,
	    included => $included,
	    reason => $reason,
	    volume_config => $drive,
	};
    };

    PVE::QemuConfig->foreach_volume($conf, $test_volume);

    return $return_volumes;
}

sub __snapshot_save_vmstate {
    my ($class, $vmid, $conf, $snapname, $storecfg, $statestorage, $suspend) = @_;

    # use given storage or search for one from the config
    my $target = $statestorage;

    if (!$target) {
	$target = PVE::QemuServer::find_vmstate_storage($conf, $storecfg);
    }

    my $defaults = PVE::QemuServer::load_defaults();
    my $mem_size = $conf->{memory} // $defaults->{memory};
    my $driver_state_size = 500; # assume 500MB is enough to safe all driver state;
    # our savevm-start does live-save of the memory until the space left in the
    # volume is just enough for the remaining memory content + internal state
    # then it stops the vm and copies the rest so we reserve twice the
    # memory content + state to minimize vm downtime
    my $size = $mem_size*2 + $driver_state_size;
    my $scfg = PVE::Storage::storage_config($storecfg, $target);

    my $name = "vm-$vmid-state-$snapname";
    $name .= ".raw" if $scfg->{path}; # add filename extension for file base storage

    my $statefile = PVE::Storage::vdisk_alloc($storecfg, $target, $vmid, 'raw', $name, $size*1024);
    my $runningmachine = PVE::QemuServer::Machine::get_current_qemu_machine($vmid);

    # get current QEMU -cpu argument to ensure consistency of custom CPU models
    my $runningcpu;
    if (my $pid = PVE::QemuServer::check_running($vmid)) {
	$runningcpu = PVE::QemuServer::CPUConfig::get_cpu_from_running_vm($pid);
    }

    if (!$suspend) {
	$conf = $conf->{snapshots}->{$snapname};
    }

    $conf->{vmstate} = $statefile;
    $conf->{runningmachine} = $runningmachine;
    $conf->{runningcpu} = $runningcpu;

    return $statefile;
}

sub __snapshot_check_running {
    my ($class, $vmid) = @_;
    return PVE::QemuServer::Helpers::vm_running_locally($vmid);
}

sub __snapshot_check_freeze_needed {
    my ($class, $vmid, $config, $save_vmstate) = @_;

    my $running = $class->__snapshot_check_running($vmid);
    if (!$save_vmstate) {
	return ($running, $running && PVE::QemuServer::parse_guest_agent($config)->{enabled} && PVE::QemuServer::qga_check_running($vmid));
    } else {
	return ($running, 0);
    }
}

sub __snapshot_freeze {
    my ($class, $vmid, $unfreeze) = @_;

    if ($unfreeze) {
	eval { mon_cmd($vmid, "guest-fsfreeze-thaw"); };
	warn "guest-fsfreeze-thaw problems - $@" if $@;
    } else {
	eval { mon_cmd($vmid, "guest-fsfreeze-freeze"); };
	warn "guest-fsfreeze-freeze problems - $@" if $@;
    }
}

sub __snapshot_create_vol_snapshots_hook {
    my ($class, $vmid, $snap, $running, $hook) = @_;

    if ($running) {
	my $storecfg = PVE::Storage::config();

	if ($hook eq "before") {
	    if ($snap->{vmstate}) {
		my $path = PVE::Storage::path($storecfg, $snap->{vmstate});
		PVE::Storage::activate_volumes($storecfg, [$snap->{vmstate}]);

		mon_cmd($vmid, "savevm-start", statefile => $path);
		for(;;) {
		    my $stat = mon_cmd($vmid, "query-savevm");
		    if (!$stat->{status}) {
			die "savevm not active\n";
		    } elsif ($stat->{status} eq 'active') {
			sleep(1);
			next;
		    } elsif ($stat->{status} eq 'completed') {
			last;
		    } else {
			die "query-savevm returned status '$stat->{status}'\n";
		    }
		}
	    } else {
		mon_cmd($vmid, "savevm-start");
	    }
	} elsif ($hook eq "after") {
	    eval {
		mon_cmd($vmid, "savevm-end");
		PVE::Storage::deactivate_volumes($storecfg, [$snap->{vmstate}]) if $snap->{vmstate};
	    };
	    warn $@ if $@;
	} elsif ($hook eq "after-freeze") {
	    # savevm-end is async, we need to wait
	    for (;;) {
		my $stat = mon_cmd($vmid, "query-savevm");
		if (!$stat->{bytes}) {
		    last;
		} else {
		    print "savevm not yet finished\n";
		    sleep(1);
		    next;
		}
	    }
	}
    }
}

sub __snapshot_create_vol_snapshot {
    my ($class, $vmid, $ds, $drive, $snapname) = @_;

    return if PVE::QemuServer::drive_is_cdrom($drive);

    my $volid = $drive->{file};
    my $device = "drive-$ds";
    my $storecfg = PVE::Storage::config();

    PVE::QemuServer::qemu_volume_snapshot($vmid, $device, $storecfg, $volid, $snapname);
}

sub __snapshot_delete_remove_drive {
    my ($class, $snap, $remove_drive) = @_;

    if ($remove_drive eq 'vmstate') {
	delete $snap->{$remove_drive};
    } else {
	my $drive = PVE::QemuServer::parse_drive($remove_drive, $snap->{$remove_drive});
	return if PVE::QemuServer::drive_is_cdrom($drive);

	my $volid = $drive->{file};
	delete $snap->{$remove_drive};
	$class->add_unused_volume($snap, $volid);
    }
}

sub __snapshot_delete_vmstate_file {
    my ($class, $snap, $force) = @_;

    my $storecfg = PVE::Storage::config();

    eval {  PVE::Storage::vdisk_free($storecfg, $snap->{vmstate}); };
    if (my $err = $@) {
	die $err if !$force;
	warn $err;
    }
}

sub __snapshot_delete_vol_snapshot {
    my ($class, $vmid, $ds, $drive, $snapname, $unused) = @_;

    return if PVE::QemuServer::drive_is_cdrom($drive);
    my $storecfg = PVE::Storage::config();
    my $volid = $drive->{file};
    my $device = "drive-$ds";

    PVE::QemuServer::qemu_volume_snapshot_delete($vmid, $device, $storecfg, $volid, $snapname);

    push @$unused, $volid;
}

sub __snapshot_rollback_hook {
    my ($class, $vmid, $conf, $snap, $prepare, $data) = @_;

    if ($prepare) {
	# we save the machine of the current config
	$data->{oldmachine} = $conf->{machine};
    } else {
	# if we have a 'runningmachine' entry in the snapshot we use that
	# for the forcemachine parameter, else we use the old logic
	if (defined($conf->{runningmachine})) {
	    $data->{forcemachine} = $conf->{runningmachine};
	    delete $conf->{runningmachine};

	    # runningcpu is newer than runningmachine, so assume it only exists
	    # here, if at all
	    $data->{forcecpu} = delete $conf->{runningcpu}
		if defined($conf->{runningcpu});
	} else {
	    # Note: old code did not store 'machine', so we try to be smart
	    # and guess the snapshot was generated with kvm 1.4 (pc-i440fx-1.4).
	    $data->{forcemachine} = $conf->{machine} || 'pc-i440fx-1.4';

	    # we remove the 'machine' configuration if not explicitly specified
	    # in the original config.
	    delete $conf->{machine} if $snap->{vmstate} && !defined($data->{oldmachine});
	}

	if ($conf->{vmgenid}) {
	    # tell the VM that it's another generation, so it can react
	    # appropriately, e.g. dirty-mark copies of distributed databases or
	    # re-initializing its random number generator
	    $conf->{vmgenid} = PVE::QemuServer::generate_uuid();
	}
    }

    return;
}

sub __snapshot_rollback_vol_possible {
    my ($class, $drive, $snapname) = @_;

    return if PVE::QemuServer::drive_is_cdrom($drive);

    my $storecfg = PVE::Storage::config();
    my $volid = $drive->{file};

    PVE::Storage::volume_rollback_is_possible($storecfg, $volid, $snapname);
}

sub __snapshot_rollback_vol_rollback {
    my ($class, $drive, $snapname) = @_;

    return if PVE::QemuServer::drive_is_cdrom($drive);

    my $storecfg = PVE::Storage::config();
    PVE::Storage::volume_snapshot_rollback($storecfg, $drive->{file}, $snapname);
}

sub __snapshot_rollback_vm_stop {
    my ($class, $vmid) = @_;

    my $storecfg = PVE::Storage::config();
    PVE::QemuServer::vm_stop($storecfg, $vmid, undef, undef, 5, undef, undef);
}

sub __snapshot_rollback_vm_start {
    my ($class, $vmid, $vmstate, $data) = @_;

    my $storecfg = PVE::Storage::config();
    my $params = {
	statefile => $vmstate,
	forcemachine => $data->{forcemachine},
	forcecpu => $data->{forcecpu},
    };
    PVE::QemuServer::vm_start($storecfg, $vmid, $params);
}

sub __snapshot_rollback_get_unused {
    my ($class, $conf, $snap) = @_;

    my $unused = [];

    $class->foreach_volume($conf, sub {
	my ($vs, $volume) = @_;

	return if PVE::QemuServer::drive_is_cdrom($volume);

	my $found = 0;
	my $volid = $volume->{file};

	$class->foreach_volume($snap, sub {
	    my ($ds, $drive) = @_;

	    return if $found;
	    return if PVE::QemuServer::drive_is_cdrom($drive);

	    $found = 1
		if ($drive->{file} && $drive->{file} eq $volid);
	});

	push @$unused, $volid if !$found;
    });

    return $unused;
}

# END implemented abstract methods from PVE::AbstractConfig

1;