#!/bin/bash -eux

case $ARCH in
    amd64|arm64)
        ;;
    *)
        echo "We don't create EFI images for $ARCH."
        exit 0
        ;;
esac

IMAGE_STR="# CLOUD_IMG: This file was created/modified by the Cloud Image build process"
FS_LABEL="cloudimg-rootfs"

. config/functions

create_partitions() {
    disk_image="$1"
    sgdisk "${disk_image}" --zap-all
    case $ARCH in
        arm64)
            sgdisk "${disk_image}" \
                --new=15:0:204800 \
                --typecode=15:ef00 \
                --new=1:
            ;;
        amd64)
            sgdisk "${disk_image}" \
                --new=14::+4M \
                --new=15::+106M \
                --new=1::
            sgdisk "${disk_image}" \
                -t 14:ef02 \
                -t 15:ef00
            ;;
    esac
    sgdisk "${disk_image}" \
        --print
}

create_and_mount_uefi_partition() {
    uefi_dev="/dev/mapper${loop_device///dev/}p15"
    mountpoint="$1"
    mkfs.vfat -F 32 -n UEFI "${uefi_dev}"

    mkdir -p "${mountpoint}"/boot/efi
    mount "${uefi_dev}" "$mountpoint"/boot/efi

    cat << EOF >> "mountpoint/etc/fstab"
LABEL=UEFI	/boot/efi	vfat	defaults	0 0
EOF
}

install_grub() {
    mkdir mountpoint
    mount_partition "${rootfs_dev_mapper}" mountpoint

    create_and_mount_uefi_partition mountpoint

    echo "(hd0) ${loop_device}" > mountpoint/tmp/device.map
    mkdir -p mountpoint/etc/default/grub.d
    efi_boot_dir="/boot/efi/EFI/BOOT"
    chroot mountpoint mkdir -p "${efi_boot_dir}"

    chroot mountpoint apt-get -y update

    # UEFI GRUB modules are meant to be used equally by Secure Boot and
    # non-Secure Boot systems. If you need an extra module not already
    # provided or run into "Secure Boot policy forbids loading X" problems,
    # please file a bug against grub2 to include the affected module.
    case $ARCH in
        arm64)
            chroot mountpoint apt-get -qqy install --no-install-recommends grub-efi-arm64 grub-efi-arm64-bin
            efi_target=arm64-efi
            ;;
        amd64)
            chroot mountpoint apt-get install -qqy grub-efi-amd64-signed grub-efi-amd64 shim-signed
            efi_target=x86_64-efi
            ;;
    esac

    chroot mountpoint grub-install "${loop_device}" \
        --boot-directory=/boot \
        --efi-directory=/boot/efi \
        --target=${efi_target} \
        --removable \
        --uefi-secure-boot \
        --no-nvram

    if [ -f mountpoint/boot/efi/EFI/BOOT/grub.cfg ]; then
        sed -i "s| root| root hd0,gpt1|" mountpoint/boot/efi/EFI/BOOT/grub.cfg
        sed -i "1i${IMAGE_STR}" mountpoint/boot/efi/EFI/BOOT/grub.cfg
        # For some reason the grub disk is looking for /boot/grub/grub.cfg on
        # part 15....
        chroot mountpoint mkdir -p /boot/efi/boot/grub
        chroot mountpoint cp /boot/efi/EFI/BOOT/grub.cfg /boot/efi/boot/grub
    fi

    if [ "$ARCH" = "amd64" ]; then
        # Install the BIOS/GPT bits. Since GPT boots from the ESP partition,
        # it means that we just run this simple command and we're done
        chroot mountpoint grub-install --target=i386-pc "${loop_device}"
    fi

    chroot mountpoint dpkg-divert --local --rename /etc/grub.d/30_os-prober
    chroot mountpoint update-grub
    replace_grub_root_with_label mountpoint
    chroot mountpoint dpkg-divert --remove --local --rename /etc/grub.d/30_os-prober

    chroot mountpoint apt-get -y clean

    rm mountpoint/tmp/device.map
    umount mountpoint/boot/efi
    mount
    umount_partition mountpoint
    rmdir mountpoint
}

disk_image=binary/boot/disk-uefi.ext4

create_empty_disk_image "${disk_image}"
create_partitions "${disk_image}"
mount_image "${disk_image}" 1

# Copy the chroot in to the disk
make_ext4_partition "${rootfs_dev_mapper}"
mkdir mountpoint
mount "${rootfs_dev_mapper}" mountpoint
cp -a chroot/* mountpoint/
umount mountpoint
rmdir mountpoint

install_grub

clean_loops
trap - EXIT