#!/bin/bash

#    linux-deployment-scripts
#    Copyright (C) 2024  VM-Experiments
#
#    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/>.

# hardcoded paths
downloads="downloads/"
output="output/"
chroot="chroot/"
resources="resources/"

# hardcoded package lists
ubuntu_server_packages="nginx grub-pc linux-image-generic"
ubuntu_client_packages="grub-pc linux-image-generic"
ubuntu_client_gnome_packages="ubuntu-desktop"
ubuntu_client_kde_packages="kubuntu-desktop"
installer_packages="linux-image-generic grub-pc parted tar dosfstools util-linux e2fsprogs arch-install-scripts"

# hardcoded links
noble_amd64="https://cdimage.ubuntu.com/ubuntu-base/noble/daily/current/noble-base-amd64.tar.gz"
noble_amd64_name="noble-base-amd64.tar.gz"

jammy_amd64="https://cdimage.ubuntu.com/ubuntu-base/jammy/daily/current/jammy-base-amd64.tar.gz"
jammy_amd64_name="jammy-base-amd64.tar.gz"

# hardcoded names
ubuntu_noble_server_output="noble-server-amd64"
ubuntu_noble_ubuntu_output="noble-ubuntu-amd64"
ubuntu_noble_kubuntu_output="noble-kubuntu-amd64"

ubuntu_jammy_server_output="jammy-server-amd64"
ubuntu_jammy_ubuntu_output="jammy-ubuntu-amd64"
ubuntu_jammy_kubuntu_output="jammy-kubuntu-amd64"

# creates a menu
menu() {
    iter=1
    echo "$1"
    echo ""
    shift
    for arg in "$@"; do
        echo "$iter) $arg"
        iter=$((iter + 1))
    done

    read option
}

# chroot associated functions
prepare_chroot() {
    sudo mount --bind /dev "$chroot/dev"
    sudo mount --bind /proc "$chroot/proc"
    sudo mount --bind /sys "$chroot/sys"
    sudo cp /etc/resolv.conf "$chroot/etc/"

}

do_chroot_command() {
    sudo chroot "$chroot" /bin/bash -c "$*"
}

do_chroot() {
    prepare_chroot "$chroot"
    sudo chroot "$chroot"
    close_chroot "$chroot"
}

close_chroot() {
    sudo umount "$chroot/dev"
    sudo umount "$chroot/proc"
    sudo umount "$chroot/sys"
}

# handle rootfs image from internet
rootfs_downloader() {
    cd "$downloads"
    wget -nc "$1"
    sudo tar -xzf "$2" -C "../$chroot"
    cd ..
}

rootfs_creator() {
    cd $output
    sudo tar -czf "$1" -C "../$chroot" .
    cd ..
}

# packaging rootfs
rootfs_package() {
    infile="$1.tar.gz"
    outfile="$1.iso"

    close_chroot
    sudo rm -rf "$chroot"
    sudo mkdir "$chroot"

    rootfs_downloader "$noble_amd64" "$noble_amd64_name"
    sudo cp "$infile" "$chroot/rootfs.tar.gz"

    prepare_chroot
    do_chroot_command "apt update"
    do_chroot_command "DEBIAN_FRONTEND=noninteractive apt install -y $installer_packages"
    do_chroot_command "mkdir -p /etc/systemd/system/getty@tty1.service.d/"
    do_chroot_command "touch /etc/systemd/system/getty@tty1.service.d/override.conf"
    do_chroot_command "echo -e '[Service]\nExecStart=\nExecStart=/sbin/agetty --noclear --autologin root %I \$TERM' | tee /etc/systemd/system/getty@tty1.service.d/override.conf"
    do_chroot_command "systemctl daemon-reload"
    do_chroot_command "systemctl enable getty@tty1.service"
    close_chroot

    sudo cp "$resources/grub.cfg" "$chroot/boot/grub/grub.cfg"
    sudo cp "$resources/install.sh" "$chroot/root"
    echo "./install.sh" | sudo tee -a "$chroot/root/.profile"
    echo "./install.sh" | sudo tee -a "$chroot/root/.bashrc"
    sudo grub2-mkrescue -o "$outfile" "$chroot"
}

# distro specific
ubuntu_rootfs_prepare() {
    rootfs_downloader "$1" "$2"
    prepare_chroot
    do_chroot_command "apt update -y"
    do_chroot_command "apt full-upgrade -y"
    do_chroot_command "DEBIAN_FRONTEND=noninteractive apt install -y $3"
    close_chroot
    rootfs_creator "$4.tar.gz"
    rootfs_package "$output$4"
}

main() {
    mkdir -p "$downloads" "$output"
    close_chroot
    sudo rm -rf "$chroot"
    sudo mkdir "$chroot"
    clear
    menu "Welcome to the Ubuntu installer creation script. Choose an option." "Ubuntu 24.04" "Ubuntu 22.04"

    case $option in
    1)
        menu "Choose an option." "Server" "Client"

        case $option in
        1)
            ubuntu_rootfs_prepare "$noble_amd64" "$noble_amd64_name" "$ubuntu_server_packages" "$ubuntu_noble_server_output"
            ;;
        2)
            menu "Choose an option." "Ubuntu" "Kubuntu"

            case $option in
            1)
                ubuntu_rootfs_prepare "$noble_amd64" "$noble_amd64_name" "$ubuntu_client_packages $ubuntu_client_gnome_packages" "$ubuntu_noble_ubuntu_output"
                ;;
            2)
                ubuntu_rootfs_prepare "$noble_amd64" "$noble_amd64_name" "$ubuntu_client_packages $ubuntu_client_kde_packages" "$ubuntu_noble_kubuntu_output"
                ;;

            *) ;;

            esac
            ;;

        *) ;;

        esac

        ;;

    2)
        menu "Choose an option." "Server" "Client"

        case $option in
        1)
            ubuntu_rootfs_prepare "$jammy_amd64" "$jammy_amd64_name" "$ubuntu_server_packages" "$ubuntu_jammy_server_output"
            ;;
        2)
            menu "Choose an option." "Ubuntu" "Kubuntu"

            case $option in
            1)
                ubuntu_rootfs_prepare "$jammy_amd64" "$jammy_amd64_name" "$ubuntu_client_packages $ubuntu_client_gnome_packages" "$ubuntu_jammy_ubuntu_output"
                ;;
            2)
                ubuntu_rootfs_prepare "$jammy_amd64" "$jammy_amd64_name" "$ubuntu_client_packages $ubuntu_client_kde_packages" "$ubuntu_jammy_kubuntu_output"
                ;;

            *) ;;

            esac
            ;;

        *) ;;

        esac

        ;;

    *) ;;

    esac
}

main $*