#!/bin/bash

set -e -u

# edition-specific strings
iso_edition="SystemD/CLI"                 # default init/wm pair
iso_title="Parabola GNU/Linux-libre Live" # $iso_edition and $iso_version appended
base_group='base'                         # default base package group

# CLI option defaults
archs='i686 x86_64'
iso_arch='dual'
iso_version=$(date +%Y.%m.%d)
iso_label="PARA_$(date +%Y%m)"
iso_dirname='parabola'
enable_offline_install='false'
work_dir=./work
out_dir=./out
target=''
verbose=''
efi_img_kbytes=40000
pacman_conf=${work_dir}/pacman.conf
chroot_customization_script=/root/customize_root_image.sh

# environment
data_dir=/usr/share/parabolaiso/data
releng_dir=$(readlink -f ${0%/*})
initcpio_dir=${releng_dir}/../../parabolaiso/initcpio
packages_dir=${releng_dir}/packages
[ "`which mkparabolaiso 2> /dev/null`" ] || export PATH=$PATH:"${releng_dir}/../../parabolaiso"


_usage ()
{
    echo "usage ${0} [options]"
    echo
    echo " General options:"
    echo "    -E <iso_edition>   Release edition (init/WM pair e.g. 'SystemD/CLI')"
    echo "                        Default: ${iso_edition}"
    echo "    -T <iso_arch>      Target architecture (one of 'i686', 'x86_64', or 'dual')"
    echo "                        Default: ${iso_arch}"
    echo "    -V <iso_version>   Set the iso version in the filename"
    echo "                        Default: ${iso_version}"
    echo "    -L <iso_label>     Set the iso volume label"
    echo "                        Default: ${iso_label}"
    echo "    -D <iso_dirname>   Set the name of the directory inside the ISO"
    echo "                        Default: ${iso_dirname}"
    echo "    -O                 Enable offline install."
    echo "                        Default: '${enable_offline_install}'"
    echo "    -C                 Specify the pacman.conf file used for chroot install."
    echo "                        Default: '${pacman_conf}'"
    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.
make_pacman_conf() {
    sed -r "s|^#?\\s*CacheDir.+|CacheDir = ${work_dir}/${arch}/root-image/isorepo/|g" ${releng_dir}/pacman.conf > ${pacman_conf}
}

# Base installation, plus needed packages (root-image)
make_basefs() {
    setarch ${arch} mkparabolaiso ${verbose} -w ${work_dir}/${arch} -C ${pacman_conf} -D ${iso_dirname} -B ${base_group} init
    setarch ${arch} mkparabolaiso ${verbose} -w ${work_dir}/${arch} -C ${pacman_conf} -D ${iso_dirname} -p "memtest86+ mkinitcpio-nfs-utils nbd" install
}

# Additional packages (root-image)
make_packages() {
    packages=$(grep -h -v ^# ${packages_dir}/packages-{${iso_init},${iso_gui},${iso_wm}}.{both,${arch}} 2> /dev/null || true)
    setarch ${arch} mkparabolaiso ${verbose} -w ${work_dir}/${arch} -C ${pacman_conf} -D ${iso_dirname} -p "${packages}" install

    # create live environment local repo
    if [[ "$enable_offline_install" == 'true' ]]; then
        local iso_repo_dir=${work_dir}/${arch}/root-image/isorepo

        setarch ${arch} repo-add ${iso_repo_dir}/isorepo.db.tar.gz ${iso_repo_dir}/*
    fi
}

# Copy mkinitcpio parabolaiso hooks and build initramfs (root-image)
make_setup_mkinitcpio() {
    local _hook
    for _hook in parabolaiso parabolaiso_shutdown parabolaiso_pxe_common parabolaiso_pxe_nbd parabolaiso_pxe_http parabolaiso_pxe_nfs parabolaiso_loop_mnt; do
        cp ${initcpio_dir}/hooks/${_hook} ${work_dir}/${arch}/root-image/usr/lib/initcpio/hooks
        cp ${initcpio_dir}/install/${_hook} ${work_dir}/${arch}/root-image/usr/lib/initcpio/install
    done
    cp ${initcpio_dir}/install/parabolaiso_kms ${work_dir}/${arch}/root-image/usr/lib/initcpio/install
    cp ${initcpio_dir}/hooks/parabolaiso_shutdown ${work_dir}/${arch}/root-image/usr/lib/initcpio
    cp ${releng_dir}/mkinitcpio.conf ${work_dir}/${arch}/root-image/etc/mkinitcpio-parabolaiso.conf
    setarch ${arch} mkparabolaiso ${verbose} -w ${work_dir}/${arch} -C ${pacman_conf} -D ${iso_dirname} -r 'mkinitcpio -c /etc/mkinitcpio-parabolaiso.conf -k /boot/vmlinuz-linux-libre -g /boot/parabolaiso.img' run
}

# Customize installation (root-image)
make_customize_root_image() {
    [[ "$enable_offline_install" == 'true' ]] && offline='-O' || offline=''

    cp -af ${releng_dir}/root-image ${work_dir}/${arch}

    echo "Customizing root image"
    iso_title="${iso_title}"                                                       \
    iso_init="${iso_init}"                                                         \
    iso_wm="${iso_wm}"                                                             \
    enable_offline_install="${enable_offline_install}"                             \
    setarch ${arch} mkparabolaiso ${verbose} -w ${work_dir}/${arch}                \
                                             -C ${pacman_conf}                     \
                                             -D ${iso_dirname}                     \
                                             ${offline}                            \
                                             -r ${chroot_customization_script} run
    rm ${work_dir}/${arch}/root-image${chroot_customization_script}
}

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

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

# Prepare /${iso_dirname}/boot/syslinux
make_syslinux() {
    mkdir -p ${work_dir}/iso/${iso_dirname}/boot/syslinux
    for _cfg in ${releng_dir}/syslinux/*.cfg; do
        sed "s|%PARABOLAISO_LABEL%|${iso_label}|g;
             s|%INSTALL_DIR%|${iso_dirname}|g" ${_cfg} > ${work_dir}/iso/${iso_dirname}/boot/syslinux/${_cfg##*/}
    done
    cp ${releng_dir}/syslinux/splash.png ${work_dir}/iso/${iso_dirname}/boot/syslinux
    cp ${work_dir}/${arch}/root-image/usr/lib/syslinux/bios/*.c32 ${work_dir}/iso/${iso_dirname}/boot/syslinux
    cp ${work_dir}/${arch}/root-image/usr/lib/syslinux/bios/lpxelinux.0 ${work_dir}/iso/${iso_dirname}/boot/syslinux
    cp ${work_dir}/${arch}/root-image/usr/lib/syslinux/bios/memdisk ${work_dir}/iso/${iso_dirname}/boot/syslinux
    mkdir -p ${work_dir}/iso/${iso_dirname}/boot/syslinux/hdt
    gzip -c -9 ${work_dir}/${arch}/root-image/usr/share/hwdata/pci.ids > ${work_dir}/iso/${iso_dirname}/boot/syslinux/hdt/pciids.gz
    gzip -c -9 ${work_dir}/${arch}/root-image/usr/lib/modules/*-gnu-*/modules.alias > ${work_dir}/iso/${iso_dirname}/boot/syslinux/hdt/modalias.gz

    # inject edition title
    sed -i "s|_EDITION_TITLE_|${iso_title}|" ${work_dir}/iso/${iso_dirname}/boot/syslinux/parabolaiso_head.cfg

    # prune orphan boot entries for single-architecture ISO
    if [[ "${archs}" == 'i686' ]]; then
        rm ${work_dir}/iso/${iso_dirname}/boot/syslinux/parabolaiso_*64*.cfg
    elif [[ "${archs}" == 'x86_64' ]]; then
        rm ${work_dir}/iso/${iso_dirname}/boot/syslinux/parabolaiso_*32*.cfg
    fi
}

# Prepare /isolinux
make_isolinux() {
    mkdir -p ${work_dir}/iso/isolinux
    sed "s|%INSTALL_DIR%|${iso_dirname}|g" ${releng_dir}/isolinux/isolinux.cfg > ${work_dir}/iso/isolinux/isolinux.cfg
    cp ${work_dir}/${arch}/root-image/usr/lib/syslinux/bios/isolinux.bin ${work_dir}/iso/isolinux/
    cp ${work_dir}/${arch}/root-image/usr/lib/syslinux/bios/isohdpfx.bin ${work_dir}/iso/isolinux/
    cp ${work_dir}/${arch}/root-image/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/root-image/usr/lib/systemd/boot/efi/systemd-bootx64.efi ${work_dir}/iso/EFI/boot/bootx64.efi

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

    sed "s|%PARABOLAISO_LABEL%|${iso_label}|g;
         s|%INSTALL_DIR%|${iso_dirname}|g" \
        ${releng_dir}/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+ ( http://sourceforge.net/apps/mediawiki/tianocore/index.php?title=UEFI_Shell )
    cp ${data_dir}/Shell.efi ${work_dir}/iso/EFI/shellx64_v2.efi
    # EFI Shell 1.0 for non UEFI 2.3+ ( http://sourceforge.net/apps/mediawiki/tianocore/index.php?title=Efi-shell )
    cp ${data_dir}/Shell_Full.efi ${work_dir}/iso/EFI/shellx64_v1.efi
}

# Prepare efiboot.img::/EFI for "El Torito" EFI boot mode
make_efiboot() {
    # cleanup from previous runs
    while mount | grep ${work_dir}/efiboot; do umount ${work_dir}/efiboot; sleep 1; done;
    rm ${work_dir}/iso/EFI/parabolaiso/efiboot.img 2> /dev/null || true

    # create EFI image
    mkdir -p ${work_dir}/iso/EFI/parabolaiso
    truncate -s ${efi_img_kbytes}K ${work_dir}/iso/EFI/parabolaiso/efiboot.img
    mkfs.vfat -n PARABOLAISO_EFI ${work_dir}/iso/EFI/parabolaiso/efiboot.img

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

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

    mkdir -p ${work_dir}/efiboot-staging/EFI/boot
    cp ${work_dir}/x86_64/root-image/usr/lib/systemd/boot/efi/systemd-bootx64.efi ${work_dir}/efiboot-staging/EFI/boot/bootx64.efi

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

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

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

    efi_kbytes=$(($(du -ks ${work_dir}/efiboot-staging | cut -f 1) + 32))
    if [[ ${efi_kbytes} -lt $((${efi_img_kbytes})) ]]; then
        echo "Populating EFI image (${efi_kbytes}KB)"
        cp -rT ${work_dir}/efiboot-staging ${work_dir}/efiboot
        rm -rf ${work_dir}/efiboot-staging
        umount ${work_dir}/efiboot
    else
        echo "Error: Not enough space on EFI image (${efi_img_kbytes}KB - need ${efi_kbytes}KB)"
        umount ${work_dir}/efiboot
        exit 1
    fi
}

# Copy aitab
make_aitab() {
    mkdir -p ${work_dir}/iso/${iso_dirname}
    cp ${releng_dir}/aitab ${work_dir}/iso/${iso_dirname}/aitab
}

# Build all filesystem images specified in aitab (.fs.sfs .sfs)
make_prepare() {
    [[ "$enable_offline_install" == 'true' ]] && offline='-O' || offline=''

    cp -a -l -f ${work_dir}/${arch}/root-image ${work_dir}
    setarch ${arch} mkparabolaiso ${verbose} -w ${work_dir} -D ${iso_dirname} pkglist
    setarch ${arch} mkparabolaiso ${verbose} -w ${work_dir} -D ${iso_dirname} ${offline} prepare

    rm -rf ${work_dir}/root-image
    # rm -rf ${work_dir}/${arch}/root-image (if low space, this helps)
}

# Build ISO
make_iso() {
    mkparabolaiso ${verbose} -w ${work_dir} -D ${iso_dirname} checksum
    mkparabolaiso ${verbose} -w ${work_dir} -D ${iso_dirname} -L ${iso_label} -o ${out_dir} iso ${iso_filename}
}


## prepare state ##

# set CLI options
while getopts 'E:T:V:L:D:OC:w:o:vh' arg; do
    case "${arg}" in
        E) iso_edition="${OPTARG}" ;;
        T) target="${OPTARG}" ;;
        V) iso_version="${OPTARG}" ;;
        L) iso_label="${OPTARG}" ;;
        D) iso_dirname="${OPTARG}" ;;
        O) enable_offline_install='true' ;;
        C) pacman_conf="${OPTARG}" ;;
        w) work_dir="${OPTARG}" ;;
        o) out_dir="${OPTARG}" ;;
        v) verbose="-v" ;;
        h) _usage 0 ;;
        *)
           echo "Invalid argument '${arg}'"
           _usage 1
           ;;
    esac
done

# set target arch, GRUB title, and ISO filename
case "${target}" in
    'i686'|'x86_64')
        archs=${target}
        iso_arch=${target}
        launch_msg="Building single-architecture ${iso_edition} ISO for ${archs}"
        ;;
    *)
        launch_msg="Building multi-architecture ${iso_edition} ISO for ${archs}"
        ;;
esac
if [[ "$enable_offline_install" == 'true' ]]; then
    iso_arch="${iso_arch}-complete"
    launch_msg="${launch_msg} (net-install or offline install)"
else
    iso_arch="${iso_arch}-netinstall"
    launch_msg="${launch_msg} (net-install only)"
fi
iso_title="${iso_title}${iso_edition} Edition ${iso_version}"
iso_filename="parabola-${iso_edition}-${iso_arch}-${iso_version}.iso"
iso_filename=$(echo ${iso_filename} | tr '[:upper:]/' '[:lower:]-')
iso_init=$(echo ${iso_edition} | cut -d '/' -f 1 | tr '[:upper:]' '[:lower:]')
iso_wm=$(  echo ${iso_edition} | cut -d '/' -f 2 | tr '[:upper:]' '[:lower:]')
[[ "${iso_wm}" == 'cli'  ]] && iso_gui=''  || iso_gui='gui'
[[ "${archs}"  == 'i686' ]] && arch='i686' || arch='x86_64'


## sanity checks ##

# sanitize paths
iso_label=${iso_label// /}
iso_dirname=${iso_dirname// /}
iso_filename=${iso_filename// /}
iso_init=${iso_init// /}
iso_wm=${iso_wm// /}
work_dir=${work_dir// /}
out_dir=${out_dir// /}
pacman_conf=${pacman_conf// /}

# validate build environment
if [[ "$(uname -m)" != 'x86_64' ]] || ! grep 'ID_LIKE=.*archlinux' /usr/lib/os-release > /dev/null; then
    echo "This script needs to be run on an x86_64 ArchLinux derrivative."
    exit 1
elif [[ ${EUID} -ne 0 ]]; then
    echo "This script needs to be run with root privileges."
    exit 1
elif ! pacman --version | grep libalpm > /dev/null; then
    echo "This script needs the 'pacman' package manager to be installed."
    exit 1
elif ! pacman -Qi parabolaiso-data > /dev/null; then
    echo "This script needs the 'parabolaiso-data' package to be installed."
    exit 1
elif ! ls ${packages_dir}/packages-{${iso_init},${iso_wm}}.both > /dev/null; then
    echo "Invalid init/wm combination: '${iso_edition}'."
    exit 1
fi

# detect previously completed build
prefix=${work_dir}/build.make_
is_done=1
[ ! -f ${prefix}pacman_conf_${arch} -o ! -f ${prefix}boot_extra_${arch} -o    \
  ! -f ${prefix}syslinux_${arch}    -o ! -f ${prefix}isolinux_${arch}   -o    \
  ! -f ${prefix}aitab_${arch}       -o ! -f ${prefix}iso_${arch}         ] && \
    is_done=0
for arch in ${archs}; do
    [ ! -f ${prefix}basefs_${arch}           -o ! -f ${prefix}packages_${arch}             -o    \
      ! -f ${prefix}setup_mkinitcpio_${arch} -o ! -f ${prefix}customize_root_image_${arch} -o    \
      ! -f ${prefix}boot_${arch}             -o ! -f ${prefix}prepare_${arch}               ] && \
        is_done=0
done
if ! (($is_done)); then echo ${launch_msg}; else echo "Nothing to do"; exit; fi;


## build ISO ##

# prepare environment
chown -R 0:0 "${releng_dir}/root-image/"
mkdir -p ${work_dir}

# prepare target filesystems
for arch in ${archs}; do
    run_once make_pacman_conf
    run_once make_basefs
    run_once make_packages
    run_once make_setup_mkinitcpio
    run_once make_customize_root_image
done

# prepare kernels and initrds
for arch in ${archs}; do
    run_once make_boot
done

# prepare ISO
run_once make_boot_extra
run_once make_syslinux
run_once make_isolinux

# prepare EFI
if [[ "`echo ${archs} | grep x86_64`" ]]; then
    run_once make_efi
    run_once make_efiboot
fi

# prepare SFSs
run_once make_aitab
for arch in ${archs}; do
    run_once make_prepare
done

# build ISO
run_once make_iso