#!/bin/sh

case "${1}" in
  list)
    # GET THE INITITAL OUTPUT OF `ls /sys/block`
    BLK_INFO="$(ls -l --color=never /sys/block | grep -v virtual | grep devices | sed 's/  \+/ /g' | cut -d\  -f9-)"
    # STRIP OFF THE PCI BUS LOCATION INFORMATION
    BLK_INFO="$(echo "${BLK_INFO}" | sed 's|\.\.\/devices/pci[0-9a-f:]\{7\}\(/[0-9a-f:.]\{12\}\)\+/||g')"
    # STRIP OFF THE SUPERFLUOUS USB HOST INFORMATION
    BLK_INFO="$(echo "${BLK_INFO}" | sed 's|\(usb[0-9]\+\)/.*/host|\1/host|g')"
    # STRIP OFF THE SUPERFLUOUS HOST AND TARGET INFORMATION
    BLK_INFO="$(echo "${BLK_INFO}" | sed 's|/host[0-9]\+/target\([0-9]\+\):\([0-9]\+\):\([0-9]\+\)/|/|g')"
    # NORMALIZE NVME INFO
    BLK_INFO="$(echo "${BLK_INFO}" | sed 's|nvme/nvme\([0-9]\+\)/nvme\([0-9]\+\)n\([0-9]\+\)|nvme/N:\2:\3:1|g')"
    # STRIP OFF BLOCKS
    BLK_INFO="$(echo "${BLK_INFO}" | sed 's|/block/.*||g')"
    # CONVERT -> TO A SPACE
    BLK_INFO="$(echo "${BLK_INFO}" | sed 's/ -> / /g')"
    # CONVERT / TO A SPACE
    BLK_INFO="$(echo "${BLK_INFO}" | sed 's|/| |g')"
    # NOW GET DEVICE IDs and SIZES
    echo "${BLK_INFO}" | while read -r BLOCKDEV DEV_PORT DEV_HCIL; do
      DEVICE_ID="$(ls -l --color=never /dev/disk/by-id | sed 's/  \+/ /g' | grep -v 'nvme-eui\|wwn-' | grep "${BLOCKDEV}$" | cut -d\  -f9)"
      DEV_BYTES="$(lsblk -bnPo NAME,SIZE | grep "\"${BLOCKDEV}\"" | cut -d\" -f 4)"
      if [ "${DEV_BYTES}" -ge $((1000**5)) ]; then
        DEVICE_SZ="$(awk "BEGIN {print ${DEV_BYTES}/1000^5}" | cut -b1-5)T"
      elif [ "${DEV_BYTES}" -ge $((1000**4)) ]; then
        DEVICE_SZ="$(awk "BEGIN {print ${DEV_BYTES}/1000^4}" | cut -b1-5)T"
      elif [ "${DEV_BYTES}" -ge $((1000**3)) ]; then
        DEVICE_SZ="$(awk "BEGIN {print ${DEV_BYTES}/1000^3}" | cut -b1-5)G"
      elif [ "${DEV_BYTES}" -ge $((1000**2)) ]; then
        DEVICE_SZ="$(awk "BEGIN {print ${DEV_BYTES}/1000^2}" | cut -b1-5)M"
      elif [ "${DEV_BYTES}" -ge 1000 ]; then
        DEVICE_SZ="$(awk "BEGIN {print ${DEV_BYTES}/1000}" | cut -b1-5)K"
      else
        DEVICE_SZ="${DEV_BYTES}B"
      fi
      echo "${DEV_HCIL} ${DEV_PORT} ${BLOCKDEV} ${DEVICE_SZ} ${DEVICE_ID}" >> /tmp/bdmap
    done
    column -N H:C:I:L,PORT,DEV,SIZE,NAME -t -R2,4 -o"   " /tmp/bdmap
    rm /tmp/bdmap
    ;;
  *) echo "Unknown verb '${1}' -- expected delete, list, or rescan"; exit 1;;
esac