#!/bin/bash
#
# Copyright (c) 2013-2022 Wind River Systems, Inc.
#
# SPDX-License-Identifier: Apache-2.0
#


usage ()
{
    echo "Usage: `basename $0` [-h|--force|--include-backup]"
    echo "Erases the master boot record on the hard drive."
    echo "WARNING: All data on this hard drive will be lost."
    echo ""
    echo "Options:"
    echo "  -h                  display this help"
    echo "  --force             do not ask for confirmation"
    echo "  --include-backup    removes data from platform backup directory"
    exit 1
}

# Systemd automatically remounts all the mounted filesystems at shutdown
# When we are deleting a partition, we have to unmount its corresponding filesystem
# because remounting deleted filesystems at shutdown will throw errors
unmount_fs()
{
    local fs=$1
    local ret_code=0
    echo "Trying to unmount $fs"
    if findmnt $fs > /dev/null 2>&1 ; then
        if umount -f $fs ; then
            echo "$fs has been successfully unmounted"
        else
            echo "Error! Failed to unmount $fs"
            ret_code=1
        fi
    else
        echo "Warning! $fs is not mounted"
        ret_code=2
    fi
    return $ret_code
}

OPTS=`getopt -o h -l force,include-backup -- "$@"`
if [ $? != 0 ] ; then
    exit 1
fi

eval set -- "$OPTS"

while true ; do
    case "$1" in
        -h) usage; shift;;
        --force) FORCE=1; shift;;
        --include-backup) INCLUDE_BACKUP=1; shift;;
        --) shift; break;;
    esac
done

if [ $# != 0 ] ; then
    echo "Invalid argument. Use -h for help."
    exit 1
fi

declare WIPE_HDD=

# Only wipe the boot device disks
boot_disk_part=$(df --output=source /boot | tail -1)
boot_disk_path=$(find -L /dev/disk/by-path/ -samefile ${boot_disk_part} | sed 's/-part[0-9]*'//)
if [ -z "${boot_disk_path}" ] ; then
    boot_disk_path=$(find -L /dev/disk/by-id/ -samefile ${boot_disk_part} | grep wwn | sed 's/-part[0-9]*'//)
fi
boot_disk=$(readlink -f ${boot_disk_path})

if [ -z "$boot_disk" ] ; then
    echo "Boot disk not found. Failed to wipe disk."
    exit 1
else
    WIPE_HDD="$boot_disk"
fi

# Due to dynamic partitioning, volume groups can have PVs across multiple disks.
# When deleting the boot disk volume groups, we should also delete all PVs
# (across all disks) that are part of volume groups that are also present on the
# boot disk.
boot_disk_vgs=$(pvdisplay -C --separator '  |  ' -o pv_name,vg_name | grep $boot_disk | awk '{print $3}' | sort -u)

pvs_to_delete=""

for vg in $boot_disk_vgs ; do
    pv=$(pvdisplay --select "vg_name=$vg" | awk '/PV Name/{print $3}')
    pvs_to_delete="$pvs_to_delete $pv"
done

WIPE_HDD="$pvs_to_delete $WIPE_HDD"

if [ ! $FORCE ] ; then
    echo "This will result in the loss of all data on the hard drives and"
    echo "will require this node to be re-installed."
    echo "The following disks will be wiped:"
    for dev in $WIPE_HDD ; do
        echo "    $dev"
    done | sort
    echo
    read -p "Are you absolutely sure? [y/n] " -r
    if [[ ! $REPLY =~ ^[Yy]$ ]] ; then
        echo "Aborted"
        exit 1
    fi
    read -p "Type 'wipediskscompletely' to confirm: " -r
    if [[ ! $REPLY = "wipediskscompletely" ]] ; then
        echo "Aborted"
        exit 1
    fi
fi

# Note that the BA5EBA11-0000-1111-2222- is the prefix used by STX and it's defined in sysinv constants.py.
# Since the 000000000001 suffix is used by custom stx LVM partitions,
# the next suffix is used for the persistent backup partition (000000000002)
BACKUP_PART_GUID="BA5EBA11-0000-1111-2222-000000000002"
part_type_guid_str="Partition GUID code"

# get the nodetype variable to check later if this node is a controller
. /etc/platform/platform.conf

for dev in $WIPE_HDD ; do
    if [[ -e $dev ]] ; then
        if [[ "$dev" == "$boot_disk" && "${nodetype}" == "controller" ]] ; then
            part_numbers=( $(parted -s $dev print | awk '$1 == "Number" {i=1; next}; i {print $1}') )
            for part_number in "${part_numbers[@]}" ; do
                part=$dev$part_number
                case $part in
                    *"nvme"*)
                        part=${dev}p${part_number}
                    ;;
                    *"dm-"*)
                        for p in /dev/disk/by-id/wwn-*; do
                            if [ "${dev}" = "$(readlink -f ${p})" ]; then
                                part=${p}-part${part_number}
                                break
                            fi
                        done
                    ;;
                esac
                sgdisk_part_info=$(flock $dev sgdisk -i $part_number $dev)
                part_type_guid=$(echo "$sgdisk_part_info" | grep "$part_type_guid_str" | awk '{print $4;}')
                if [[ "$part_type_guid" == $BACKUP_PART_GUID && ! $INCLUDE_BACKUP ]] ; then
                    echo "Skipping wipe backup partition $part..."
                    continue
                fi
                echo "Wiping partition $part..."
                wipefs -f -a $part

                # Delete the first few bytes at the start and end of the partition. This is required with
                # GPT partitions, they save partition info at the start and the end of the block.
                # Skip / or we will lose access to the tools on the system.
                if [[ $part != $boot_disk_part ]] ; then
                    unmount_fs $part
                    dd if=/dev/zero of=$part bs=512 count=34
                    dd if=/dev/zero of=$part bs=512 count=34 seek=$((`blockdev --getsz $part` - 34))
                fi

                echo "Removing partition $part..."
                sgdisk $dev --delete $part_number
            done

            # Wipe bootloader signature to allow reboot from secondary boot devices (e.g. PXE)
            dd if=/dev/zero of=$dev bs=440 count=1
        else
            echo "Wiping $dev..."
            wipefs -f -a $dev
            unmount_fs $dev

            # Clearing previous GPT tables or LVM data
            # Delete the first few bytes at the start and end of the partition. This is required with
            # GPT partitions, they save partition info at the start and the end of the block.
            dd if=/dev/zero of=$dev bs=512 count=34
            dd if=/dev/zero of=$dev bs=512 count=34 seek=$((`blockdev --getsz $dev` - 34))
        fi
    fi
done

if [[ -z $WIPE_HDD ]] ; then
    echo "No disks were detected."
else
    sync
    echo "The disk(s) have been wiped."
fi