#!/bin/bash

set -e -u

iso_name=talkingparabola
iso_label="PARA_$(date +%Y%m)"
iso_publisher="Parabola GNU/Linux-libre <http://www.parabola.nu>"
iso_application="Parabola GNU/Linux-libre Live/Rescue CD"
iso_version=$(date +%Y.%m.%d)
install_dir=parabola
work_dir=work
out_dir=out
gpg_key=

arch=$(uname -m)
verbose=""
script_path=$(readlink -f ${0%/*})

# Init system. Options are:
# - openrc
# - runit
# - sysvinit
# - systemd
#
# All inits, except for systemd, use OpenRC as the
# daemon manager, so for example runit is in fact
# runit + OpenRC. If this variable is left unset, 
# it will default to systemd
init=systemd

umask 0022

_usage ()
{
    echo "usage ${0} [options]"
    echo
    echo " General options:"
    echo "    -N <iso_name>      Set an iso filename (prefix)"
    echo "                        Default: ${iso_name}"
    echo "    -V <iso_version>   Set an iso version (in filename)"
    echo "                        Default: ${iso_version}"
    echo "    -L <iso_label>     Set an iso label (disk label)"
    echo "                        Default: ${iso_label}"
    echo "    -P <publisher>     Set a publisher for the disk"
    echo "                        Default: '${iso_publisher}'"
    echo "    -A <application>   Set an application name for the disk"
    echo "                        Default: '${iso_application}'"
    echo "    -D <install_dir>   Set an install_dir (directory inside iso)"
    echo "                        Default: ${install_dir}"
    echo "    -w <work_dir>      Set the working directory"
    echo "                        Default: ${work_dir}"
    echo "    -o <out_dir>       Set the output directory"
    echo "                        Default: ${out_dir}"
    echo "    -v                 Enable verbose output"
    echo "    -h                 This help message"
    exit ${1}
}

# Helper function to run make_*() only one time per architecture.
run_once() {
    if [[ ! -e ${work_dir}/build.${1}_${arch} ]]; then
        $1
        touch ${work_dir}/build.${1}_${arch}
    fi
}

# Setup custom pacman.conf with current cache directories and custom mirrorlist.
make_pacman_conf() {
    local _cache_dirs
    _cache_dirs=($(pacman -v 2>&1 | grep '^Cache Dirs:' | sed 's/Cache Dirs:\s*//g'))
    sed -r "s|^#?\\s*CacheDir.+|CacheDir = $(echo -n ${_cache_dirs[@]})|g" ${script_path}/pacman.conf > ${work_dir}/pacman.conf
}

# Base installation, plus needed packages (airootfs)
make_basefs() {
    setarch ${arch} mkparabolaiso ${verbose} -w "${work_dir}/${arch}" -C "${work_dir}/pacman.conf" -D "${install_dir}" -i "${init}" init
    setarch ${arch} mkparabolaiso ${verbose} -w "${work_dir}/${arch}" -C "${work_dir}/pacman.conf" -D "${install_dir}" -i "${init}" -p "haveged memtest86+ mkinitcpio-nfs-utils nbd zsh efitools" install
}

# Additional packages (airootfs)
make_packages() {
    setarch ${arch} mkparabolaiso ${verbose} -w "${work_dir}/${arch}" -C "${work_dir}/pacman.conf" -D "${install_dir}" -p "$(grep -h -v ^# ${script_path}/packages.{both,${arch}})" install
}

# Needed packages for x86_64 EFI boot
make_packages_efi() {
    setarch ${arch} mkparabolaiso ${verbose} -w "${work_dir}/${arch}" -C "${work_dir}/pacman.conf" -D "${install_dir}" -p "efitools" install
}

# Copy mkinitcpio parabolaiso hooks and build initramfs (airootfs)
make_setup_mkinitcpio() {
    local _hook
    mkdir -p ${work_dir}/${arch}/airootfs/etc/initcpio/hooks
    mkdir -p ${work_dir}/${arch}/airootfs/etc/initcpio/install
    for _hook in parabolaiso parabolaiso_shutdown parabolaiso_pxe_common parabolaiso_pxe_nbd parabolaiso_pxe_http parabolaiso_pxe_nfs parabolaiso_loop_mnt; do
        cp /usr/lib/initcpio/hooks/${_hook} ${work_dir}/${arch}/airootfs/etc/initcpio/hooks
        cp /usr/lib/initcpio/install/${_hook} ${work_dir}/${arch}/airootfs/etc/initcpio/install
    done
    sed -i "s|/usr/lib/initcpio/|/etc/initcpio/|g" ${work_dir}/${arch}/airootfs/etc/initcpio/install/parabolaiso_shutdown
    cp /usr/lib/initcpio/install/parabolaiso_kms ${work_dir}/${arch}/airootfs/etc/initcpio/install
    cp /usr/lib/initcpio/parabolaiso_shutdown ${work_dir}/${arch}/airootfs/etc/initcpio
    cp ${script_path}/mkinitcpio.conf ${work_dir}/${arch}/airootfs/etc/mkinitcpio-parabolaiso.conf
    gnupg_fd=
    if [[ ${gpg_key} ]]; then
      gpg --export ${gpg_key} >${work_dir}/gpgkey
      exec 17<>${work_dir}/gpgkey
    fi
    PARABOLAISO_GNUPG_FD=${gpg_key:+17} setarch ${arch} mkparabolaiso ${verbose} -w "${work_dir}/${arch}" -C "${work_dir}/pacman.conf" -D "${install_dir}" -r 'mkinitcpio -c /etc/mkinitcpio-parabolaiso.conf -k /boot/vmlinuz-linux-libre -g /boot/parabolaiso.img' run
    if [[ ${gpg_key} ]]; then
      exec 17<&-
    fi
}

# Customize installation (airootfs)
make_customize_airootfs() {
    cp -af ${script_path}/airootfs ${work_dir}/${arch}

    cp ${script_path}/pacman.conf ${work_dir}/${arch}/airootfs/etc

    curl -o ${work_dir}/${arch}/airootfs/etc/pacman.d/mirrorlist 'https://www.parabola.nu/mirrorlist/?country=all&protocol=http&use_mirror_status=on'

    lynx -dump -nolist 'https://wiki.parabola.nu/index.php/Installation_Guide?action=render' >> ${work_dir}/${arch}/airootfs/root/install.txt

    setarch ${arch} mkparabolaiso ${verbose} -w "${work_dir}/${arch}" -C "${work_dir}/pacman.conf" -D "${install_dir}" -r '/root/customize_airootfs.sh' run
    rm ${work_dir}/${arch}/airootfs/root/customize_airootfs.sh
}

# Prepare kernel/initramfs ${install_dir}/boot/
make_boot() {
    mkdir -p ${work_dir}/iso/${install_dir}/boot/${arch}
    cp ${work_dir}/${arch}/airootfs/boot/parabolaiso.img ${work_dir}/iso/${install_dir}/boot/${arch}/parabolaiso.img
    cp ${work_dir}/${arch}/airootfs/boot/vmlinuz-linux-libre ${work_dir}/iso/${install_dir}/boot/${arch}/vmlinuz
}

# Add other aditional/extra files to ${install_dir}/boot/
make_boot_extra() {
    cp ${work_dir}/${arch}/airootfs/boot/memtest86+/memtest.bin ${work_dir}/iso/${install_dir}/boot/memtest
    cp ${work_dir}/${arch}/airootfs/usr/share/licenses/common/GPL2/license.txt ${work_dir}/iso/${install_dir}/boot/memtest.COPYING
}

# Prepare /${install_dir}/boot/syslinux
make_syslinux() {
    _uname_r=$(file -b ${work_dir}/${arch}/airootfs/boot/vmlinuz-linux-libre| awk 'f{print;f=0} /version/{f=1}' RS=' ')
    mkdir -p ${work_dir}/iso/${install_dir}/boot/syslinux
    for _cfg in ${script_path}/syslinux/*.cfg; do
        sed "s|%PARABOLAISO_LABEL%|${iso_label}|g;
             s|%INSTALL_DIR%|${install_dir}|g" ${_cfg} > ${work_dir}/iso/${install_dir}/boot/syslinux/${_cfg##*/}
    done
    cp ${script_path}/syslinux/splash.png ${work_dir}/iso/${install_dir}/boot/syslinux
    cp ${work_dir}/${arch}/airootfs/usr/lib/syslinux/bios/*.c32 ${work_dir}/iso/${install_dir}/boot/syslinux
    cp ${work_dir}/${arch}/airootfs/usr/lib/syslinux/bios/lpxelinux.0 ${work_dir}/iso/${install_dir}/boot/syslinux
    cp ${work_dir}/${arch}/airootfs/usr/lib/syslinux/bios/memdisk ${work_dir}/iso/${install_dir}/boot/syslinux
    mkdir -p ${work_dir}/iso/${install_dir}/boot/syslinux/hdt
    gzip -c -9 ${work_dir}/${arch}/airootfs/usr/lib/modules/${_uname_r}/modules.alias > ${work_dir}/iso/${install_dir}/boot/syslinux/hdt/modalias.gz
}

# Prepare /isolinux
make_isolinux() {
    mkdir -p ${work_dir}/iso/isolinux
    sed "s|%INSTALL_DIR%|${install_dir}|g" ${script_path}/isolinux/isolinux.cfg > ${work_dir}/iso/isolinux/isolinux.cfg
    cp ${work_dir}/${arch}/airootfs/usr/lib/syslinux/bios/isolinux.bin ${work_dir}/iso/isolinux/
    cp ${work_dir}/${arch}/airootfs/usr/lib/syslinux/bios/isohdpfx.bin ${work_dir}/iso/isolinux/
    cp ${work_dir}/${arch}/airootfs/usr/lib/syslinux/bios/ldlinux.c32 ${work_dir}/iso/isolinux/
}

# Prepare /EFI
make_efi() {
    mkdir -p ${work_dir}/iso/EFI/boot
    cp ${work_dir}/x86_64/airootfs/usr/share/efitools/efi/PreLoader.efi ${work_dir}/iso/EFI/boot/bootx64.efi
    cp ${work_dir}/x86_64/airootfs/usr/share/efitools/efi/HashTool.efi ${work_dir}/iso/EFI/boot/

    cp ${work_dir}/x86_64/airootfs/usr/lib/systemd/boot/efi/systemd-bootx64.efi ${work_dir}/iso/EFI/boot/loader.efi

    mkdir -p ${work_dir}/iso/loader/entries
    cp ${script_path}/efiboot/loader/loader.conf ${work_dir}/iso/loader/
    cp ${script_path}/efiboot/loader/entries/uefi-shell-v2-x86_64.conf ${work_dir}/iso/loader/entries/
    cp ${script_path}/efiboot/loader/entries/uefi-shell-v1-x86_64.conf ${work_dir}/iso/loader/entries/

    sed "s|%PARABOLAISO_LABEL%|${iso_label}|g;
         s|%INSTALL_DIR%|${install_dir}|g" \
        ${script_path}/efiboot/loader/entries/parabolaiso-x86_64-usb.conf > ${work_dir}/iso/loader/entries/parabolaiso-x86_64.conf

    # EFI Shell 2.0 for UEFI 2.3+
    curl -o ${work_dir}/iso/EFI/shellx64_v2.efi https://raw.githubusercontent.com/tianocore/edk2/master/ShellBinPkg/UefiShell/X64/Shell.efi
    # EFI Shell 1.0 for non UEFI 2.3+
    curl -o ${work_dir}/iso/EFI/shellx64_v1.efi https://raw.githubusercontent.com/tianocore/edk2/master/EdkShellBinPkg/FullShell/X64/Shell_Full.efi
}

# Prepare efiboot.img::/EFI for "El Torito" EFI boot mode
make_efiboot() {
    mkdir -p ${work_dir}/iso/EFI/parabolaiso
    truncate -s 64M ${work_dir}/iso/EFI/parabolaiso/efiboot.img
    mkfs.fat -n PARABOLAISO_EFI ${work_dir}/iso/EFI/parabolaiso/efiboot.img

    mkdir -p ${work_dir}/efiboot
    mount ${work_dir}/iso/EFI/parabolaiso/efiboot.img ${work_dir}/efiboot

    mkdir -p ${work_dir}/efiboot/EFI/parabolaiso
    cp ${work_dir}/iso/${install_dir}/boot/x86_64/vmlinuz ${work_dir}/efiboot/EFI/parabolaiso/vmlinuz.efi
    cp ${work_dir}/iso/${install_dir}/boot/x86_64/parabolaiso.img ${work_dir}/efiboot/EFI/parabolaiso/parabolaiso.img

    mkdir -p ${work_dir}/efiboot/EFI/boot
    cp ${work_dir}/x86_64/airootfs/usr/share/efitools/efi/PreLoader.efi ${work_dir}/efiboot/EFI/boot/bootx64.efi
    cp ${work_dir}/x86_64/airootfs/usr/share/efitools/efi/HashTool.efi ${work_dir}/efiboot/EFI/boot/

    cp ${work_dir}/x86_64/airootfs/usr/lib/systemd/boot/efi/systemd-bootx64.efi ${work_dir}/efiboot/EFI/boot/loader.efi

    mkdir -p ${work_dir}/efiboot/loader/entries
    cp ${script_path}/efiboot/loader/loader.conf ${work_dir}/efiboot/loader/
    cp ${script_path}/efiboot/loader/entries/uefi-shell-v2-x86_64.conf ${work_dir}/efiboot/loader/entries/
    cp ${script_path}/efiboot/loader/entries/uefi-shell-v1-x86_64.conf ${work_dir}/efiboot/loader/entries/

    sed "s|%PARABOLAISO_LABEL%|${iso_label}|g;
         s|%INSTALL_DIR%|${install_dir}|g" \
        ${script_path}/efiboot/loader/entries/parabolaiso-x86_64-cd.conf > ${work_dir}/efiboot/loader/entries/parabolaiso-x86_64.conf

    cp ${work_dir}/iso/EFI/shellx64_v2.efi ${work_dir}/efiboot/EFI/
    cp ${work_dir}/iso/EFI/shellx64_v1.efi ${work_dir}/efiboot/EFI/

    umount -d ${work_dir}/efiboot
}

# Build airootfs filesystem image
make_prepare() {
    cp -a -l -f ${work_dir}/${arch}/airootfs ${work_dir}
    setarch ${arch} mkparabolaiso ${verbose} -w "${work_dir}" -D "${install_dir}" pkglist
    setarch ${arch} mkparabolaiso ${verbose} -w "${work_dir}" -D "${install_dir}" ${gpg_key:+-g ${gpg_key}} prepare
    rm -rf ${work_dir}/airootfs
    # rm -rf ${work_dir}/${arch}/airootfs (if low space, this helps)
}

# Build ISO
make_iso() {
    mkparabolaiso ${verbose} -w "${work_dir}" -D "${install_dir}" -L "${iso_label}" -P "${iso_publisher}" -A "${iso_application}" -o "${out_dir}" iso "${iso_name}-${iso_version}-dual.iso"
}

if [[ ${EUID} -ne 0 ]]; then
    echo "This script must be run as root."
    _usage 1
fi

if [[ ${arch} != x86_64 ]]; then
    echo "This script needs to be run on x86_64"
    _usage 1
fi

while getopts 'N:V:L:P:A:D:w:o:g:vh' arg; do
    case "${arg}" in
        N) iso_name="${OPTARG}" ;;
        V) iso_version="${OPTARG}" ;;
        L) iso_label="${OPTARG}" ;;
        P) iso_publisher="${OPTARG}" ;;
        A) iso_application="${OPTARG}" ;;
        D) install_dir="${OPTARG}" ;;
        w) work_dir="${OPTARG}" ;;
        o) out_dir="${OPTARG}" ;;
        g) gpg_key="${OPTARG}" ;;
        v) verbose="-v" ;;
        h) _usage 0 ;;
        *)
           echo "Invalid argument '${arg}'"
           _usage 1
           ;;
    esac
done

mkdir -p ${work_dir}

run_once make_pacman_conf

# Do all stuff for each airootfs
for arch in i686 x86_64; do
    run_once make_basefs
    run_once make_packages
done

run_once make_packages_efi

for arch in i686 x86_64; do
    run_once make_setup_mkinitcpio
    run_once make_customize_airootfs
done

for arch in i686 x86_64; do
    run_once make_boot
done

# Do all stuff for "iso"
run_once make_boot_extra
run_once make_syslinux
run_once make_isolinux
run_once make_efi
run_once make_efiboot

for arch in i686 x86_64; do
    run_once make_prepare
done

run_once make_iso