#!/bin/bash
set -eu

grub_destination=""
grub_binary=""
rootfs_destination=""
rootfs_targz=""
drive=""

function unmount_drives(){
    echo "Checking if drives are mounted from $1"

    mounts=$(mount | grep $1 | awk '{print $3}')

    for i in $mounts; do
        echo unmounting $i
        umount $i
    done
}

function deploy_installer() {
    rootfs_dest="$1"

    this_script=$(readlink -f $0)

    mkdir -p "$rootfs_dest/usr/bin"
    cp "$this_script" "$rootfs_dest/usr/bin/"
}

function deploy_rootfs_targz(){
    rootfs_destination="$1"
    rootfs_targz="$2"

    echo "Deploying tar.gz"

    echo "Generate random name"
    mount_dir="/tmp/$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 1)"

    echo "Create mount folder"
    mkdir -p "$mount_dir"

    echo "Mount drive to mount folder"
    mount "$rootfs_destination" "$mount_dir"

    echo "Clean up mounted folder"
    rm -rf "$mount_dir"/*

    echo "Untar archive to destination folder"
    tar -zvxf "$rootfs_targz" -C "$mount_dir"

    deploy_installer "$mount_dir"

    echo "Cleanup"
    umount "$mount_dir"
    rm -rf "$mount_dir"

    echo "rootfs deployment done!"
}

function deploy_grub(){
    grub_destination="$1"
    grub_binary="$2"
    rootfs_destination="$3"

    echo "Deploying grub"

    echo "Generate random name"
    mount_dir="/tmp/$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 1)"

    echo "Create mount folder"
    mkdir -p "$mount_dir"

    echo "Mount drive to mount folder"
    mount "$grub_destination" "$mount_dir"

    echo "Create grub path"
    mkdir -p "$mount_dir"/EFI/boot/

    echo "Copy the grub binary"
    cp "$grub_binary" "$mount_dir"/EFI/boot/bootx64.efi

    rootfs_uuid=$(ls -l /dev/disk/by-partuuid/ | grep $(basename "$rootfs_destination") | awk '{print $9}')

    echo "setting root in grub.cfg to: $rootfs_uuid"

    echo "Create grub.cfg"
    cat<<EOT > "$mount_dir"/EFI/boot/grub.cfg
default=1

menuentry "Enea Linux - normal booting" {
    linux (hd0,gpt2)/boot/bzImage root=PARTUUID=${rootfs_uuid} ip=dhcp console=ttyS0,115200 earlyprintk=ttyS0,115200
}

menuentry "Enea Linux - high performance booting" {
    linux (hd0,gpt2)/boot/bzImage root=PARTUUID=${rootfs_uuid} console=ttyS0,115200 earlyprintk=ttyS0,115200 ip=dhcp nohz_full=1-7 isolcpus=1-7 rcu-nocbs=1-7 rcu_nocb_poll intel_pstate=disable clocksource=tsc tsc=reliable nohpet nosoftlockup intel_idle.max_cstate=0 processor.max_cstate=0 mce=ignore_ce audit=0 nmi_watchdog=0 iommu=pt intel_iommu=on  hugepagesz=1GB hugepages=8 default_hugepagesz=1GB hugepagesz=2M hugepages=2048 vfio_iommu_type1.allow_unsafe_interrupts=1
}
EOT
    echo "Cleanup"
    umount "$mount_dir"
    rm -rf "$mount_dir"

    echo "grub deployment done!"
}

function format_drive(){
    unmount_drives "$1"

    sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | fdisk ${1}
       o # clear the in memory partition table
       g # GPT partition type
       n # new partition
       1 # partition number 1
         # default - start at beginning of disk
       +512M # 100 MB boot parttion
       t # change parition type
       1 # set type to EFI System
       n # new partition
       2 # partion number 2
         # default, start immediately after preceding partition
         # default, extend partition to end of disk
       p # print the in-memory partition table
       w # write the partition table
       q # and we're done
EOF

     sleep 1

     unmount_drives "$1"
     mkfs.fat  -F32 -nEFI "$1"1
     unmount_drives "$1"
     yes | mkfs.ext2 -LROOT "$1"2
}

function help(){
cat<<EOH

The purpose of this installer is to guide you through creating a bootable
Enea NFV Access installation on a physical media (e.g. USB stick or HDD).

Prerequisites:
    - A GRUB .efi binary
    - A drive of 16GB or larger
    - For USB booting you will need:
        - A development based rootfs (e.g. enea-nfv-access-dev-inteld1521.tar.gz)
    - For booting from an SSD or HDD you will need:
        - Any rootfs that needs to be installed on the board
          (e.g. enea-nfv-access.tar.gz)

A bootable media is created after the installer runs the following steps:
    1. Create two partitions on a designated drive (e.g. /dev/sda):
       - a 512MB partition for GRUB
	   - the rest of the drive is reserved for the rootfs.
    2. Configure GRUB on one partition (usually the first one).
    3. Copy a root filesystem on the other partition.

Note: Running step 3 will implicitly copy the installer on that root filesystem
in /usr/bin/install_nfvaccess.sh
----------------------------------------------------------------------------------------
To get a list of what commands are built in the installer, launch it with root
rights and press ENTER, once the "nfv_installer>" console is displayed:
    help              - a guide on how to use the installer
    list-params       - lists parameters
    list-steps        - lists the available steps and the parameters that they depend on
    set               - sets a parameter (e.g. "set drive=/dev/sda")
    clear             - clears a parameter (e.g. "clear drive")
    list-partitions   - lists current drives and partitions
    dry               - describes the steps to be executed and checks if the files exist
    run               - executes the steps
    q or quit         - exits the script

Run 'list-steps' to understand the built-in steps that the installer
can execute and what parameters they depend on in order to be executed.

Running 'list-steps' will print the following:
    1. Format drive - Uses the drive set for the "drive" parameter to create a
    512MB partition for GRUB and another partition for the rootfs. The rootfs
    partition will be as large as the physical media minus 512MB.
        Depends on the following parameter(s):
            drive=
    2. GRUB install - Installs the binary pointed by "grub_binary" on the drive
    set in "grub_destination". A grub.cfg file will be created that will be
    configured to boot off of "rootfs_destination".
        Depends on the following parameters:
            grub_destination=
            grub_binary=
            rootfs_destination=
    3. Root filesystem install - Copies the files found in "rootfs_targz" to
    the drive set in "rootfs_destination".
        Depends on the following parameters:
            rootfs_targz=
            rootfs_destination=

A parameter can be set through the "set" command or cleared through "clear".
As some parameters are common for multiple steps, like rootfs_destination
is for the GRUB and rootfs installation steps, you can get a list of all the
parameters, by running "list-params".

The following parameters can be configured:
    grub_destination=[drive]    - specifies the drive where GRUB will be
                                  installed
    grub_binary=[file]          - points to the GRUB executable to be installed
                                  where grub_destination is set
    rootfs_destination=[drive]  - specifies where the rootfs will be deployed
    rootfs_targz=[.tar.gz file] - what file to unpack to where
                                  rootfs_destination is set
    drive=[/dev/sdaX]            - what drive to partition

Before running the actual partitioning and copying, a dry run can be executed
without affecting the actual layout of the physical media, by running the
"dry" command.

Example of partitioning a drive:
    set drive=/dev/sda
    run

Example of partitioning a drive, installing GRUB and a root filesystem:
    set drive=/dev/sda
    set grub_destination=/dev/sda1
    set grub_binary=/home/user/grub-binary.efi
    set rootfs_destination=/dev/sda2
    set rootfs_targz=/home/user/rootfs.tar.gz
    run

Example of deploying ONLY a root filesystem:
    set rootfs_destination=/dev/sda2
    set rootfs_targz=/home/user/rootfs.tar.gz
    run

EOH
}

function bye(){
    echo "Exiting. Bye!"
    exit 0
}

function list_part(){
    fdisk -l | grep \/dev\/
}

function list_params(){
    echo "    grub_destination=$grub_destination"
    echo "    grub_binary=$grub_binary"
    echo "    rootfs_destination=$rootfs_destination"
    echo "    rootfs_targz=$rootfs_targz"
    echo "    drive=$drive"
}

function clear_param(){
    shift
    case "${1}" in
        grub_destination)
            grub_destination=""
            ;;
        grub_binary)
            grub_binary=""
            ;;
        rootfs_destination)
            rootfs_destination=""
            ;;
        rootfs_targz)
            rootfs_targz=""
            ;;
        drive)
            drive=""
            ;;
        *)
            echo "Unknown parameter: ${1}" >&2
    esac
}

function set_param(){
    shift
    case "${1}" in
        grub_destination=*)
            grub_destination="${1#*=}"
            ;;
        grub_binary=*)
            grub_binary="${1#*=}"
            ;;
        rootfs_destination=*)
            rootfs_destination="${1#*=}"
            ;;
        rootfs_targz=*)
            rootfs_targz="${1#*=}"
            ;;
        drive=*)
            drive="${1#*=}"
            ;;
        *)
            echo "Unknown parameter: ${1}" >&2
    esac
}

function check_for_file() {
    if [ ! -e "$1" ]; then
        echo "    Warning: $1 does not exist"
    fi
}

function list_steps() {
cat<<EOS
    1. Format drive - Uses the drive set in the 'drive' parameter to create a
    512MB partition for GRUB and another partition for the rootfs. The rootfs
    partition will be as large as the physical media minus 512MB.
        Depends on these parameters:
            drive=$drive
    2. GRUB install - Installs the binary pointed by 'grub_binary' on the drive
    set in 'grub_destination'. A grub.cfg file will be created that will be
    configured to boot off 'rootfs_destination'.
        Depends on these parameters:
            grub_destination=$grub_destination
            grub_binary=$grub_binary
            rootfs_destination=$rootfs_destination
    3. Root filesystem install - Copies the files found in 'rootfs_targz' to
    the drive set in 'rootfs_destination'
        Depends on these parameters:
            rootfs_targz=$rootfs_targz
            rootfs_destination=$rootfs_destination
EOS
}

function run() {
    DRY_RUN="NO"
    step=1
    if [ "$1" == "dry-run" ]; then
        DRY_RUN="YES"
        echo "The following steps will be executed:"
    fi

    if [[ ! -z $drive ]]; then
        echo "    $step. Will format drive $drive"
        step=$((step+1))

        if [[ $DRY_RUN == "NO" ]]; then
            format_drive "$drive"
        else
            check_for_file $drive
        fi
    fi

    if [[ ! -z $grub_destination && ! -z $grub_binary && ! -z $rootfs_destination ]]; then
        echo "    $step. Will deploy GRUB on $grub_destination, using the binary from $grub_binary and will set the rootfs partition to $rootfs_destination"
        step=$((step+1))

        if [[ $DRY_RUN == "NO" ]]; then
            unmount_drives "$grub_destination"
            deploy_grub "$grub_destination" "$grub_binary" "$rootfs_destination"
        else
            check_for_file $grub_destination
            check_for_file $grub_binary
            check_for_file $rootfs_destination
        fi
    fi

    if [[ ! -z $rootfs_targz && ! -z $rootfs_destination ]]; then
        echo "    $step. Will deploy $rootfs_targz on $rootfs_destination"
        step=$((step+1))

        if [[ $DRY_RUN == "NO" ]]; then
            unmount_drives "$rootfs_destination"
            deploy_rootfs_targz "$rootfs_destination" "$rootfs_targz"
        else
            check_for_file $rootfs_destination
            check_for_file $rootfs_targz
        fi
    fi
}

if [[ $EUID -ne 0 ]]; then
    echo "This script must be executed as root. Continue anyway? [y/n]"
    read line
    if [ $line == "n" ]; then
        exit 1
    fi
fi

while IFS="" read -r -e -d $'\n' -p "nfv_installer> " line; do
    case $line in
        q)
            bye;;
        quit)
            bye;;
        list-partitions)
            list_part;;
        list-params)
            list_params;;
        set\ *)
            set_param $line;;
        clear\ *)
            clear_param $line;;
        help)
            help;;
        dry)
            run "dry-run";;
        run)
            run "run-it";;
        list-steps)
            list_steps;;
        *)
            echo "Unknown command $line"
            echo "Commands:"
            echo "    help              - guide on how to use the installer"
            echo "    list-params       - lists parameters"
            echo "    list-steps        - lists the available steps and the parameters that they depend on"
            echo "    set               - set a parameter (e.g. \"set drive=/dev/sda\")"
            echo "    clear             - clears a parameter (e.g. \"clear drive\")"
            echo "    list-partitions   - lists current drives and partitions"
            echo "    dry               - describes the steps to be executed and checks if the files exist"
            echo "    run               - executes the steps"
            echo "    q or quit         - exits the script"
    esac
    history -s "$line"
    echo ""
done