#!/bin/bash
#
# Copyright 2014 Hewlett-Packard Development Company, L.P.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

set -eux
set -o pipefail

function build_efiboot_img() {

    cat > "$TMP_BUILD_DIR/grub-embedded.cfg" << END_CONFIG
search --file --set=root /vmlinuz
set prefix=(\$root)/EFI/BOOT/
END_CONFIG

    grub-mkimage --format=x86_64-efi --output=$TMP_BUILD_DIR/bootx64.efi \
    --config=$TMP_BUILD_DIR/grub-embedded.cfg --compression=xz \
    --prefix=/EFI/BOOT part_gpt part_msdos fat ext2 hfs hfsplus \
    iso9660 udf ufs1 ufs2 zfs chain linux boot appleldr ahci \
    configfile normal regexp minicmd reboot halt search \
    search_fs_file search_fs_uuid search_label gfxterm gfxmenu \
    efi_gop efi_uga all_video loadbios gzio echo true probe \
    loadenv bitmap_scale font cat help ls png jpeg tga test \
    at_keyboard usb_keyboard

    # Create a FAT formatted image that contains bootx64.efi in the /EFI/BOOT
    # directory.  This is used to bootstrap GRUB from the ISO image.
    dd if=/dev/zero of=$TMP_BUILD_DIR/efiboot.img bs=1K count=1440
    mkdosfs -F 12 $TMP_BUILD_DIR/efiboot.img

    # Create a temporary mount point:
    MOUNTPOINT=$TMP_BUILD_DIR/tmpmount
    mkdir $MOUNTPOINT
    sudo mount -o loop $TMP_BUILD_DIR/efiboot.img $MOUNTPOINT
    sudo mkdir -p $MOUNTPOINT/EFI/BOOT
    sudo cp $TMP_BUILD_DIR/bootx64.efi $MOUNTPOINT/EFI/BOOT
    sudo umount $MOUNTPOINT
    rmdir $MOUNTPOINT
    cp $TMP_BUILD_DIR/efiboot.img $TMP_IMAGE_DIR/isolinux
}

function build_iso() {

    KERNEL=$1
    INITRD=$2
    KERNEL_CMDLINE_ARGS=$3
    OUTPUT_FILENAME=$4

    SCRIPTNAME=$(basename $0)
    SCRIPTDIR=$(dirname $0)
    MKISOFS="/usr/bin/mkisofs"
    EFI_BOOT_DIR="EFI/BOOT"

    # Create a temporary build directory for holiding the contents of iso
    TMP_IMAGE_DIR="$TMP_BUILD_DIR/image"
    echo "Creating temporary directory $TMP_IMAGE_DIR"
    mkdir -p "$TMP_IMAGE_DIR"

    # Copy isolinux bin to the isolinux directory
    mkdir -p "$TMP_IMAGE_DIR/isolinux"
    echo "Copying isolinux.bin"

    # TODO(rameshg87): Something similar to pkg-map can be used here.
    # But pkg-map doesn't work for cleanup scripts right now.
    if [ $DISTRO_NAME = "fedora" ]; then
        ISOLINUX_BIN=/usr/share/syslinux/isolinux.bin
    else
        ISOLINUX_BIN=/usr/lib/syslinux/isolinux.bin
    fi

    cp $ISOLINUX_BIN "$TMP_IMAGE_DIR/isolinux"

    # Copy initrd, kernel
    echo "Copying kernel to $TMP_IMAGE_DIR/vmlinuz"
    cp $KERNEL "$TMP_IMAGE_DIR/vmlinuz"

    echo "Copying initrd to $TMP_IMAGE_DIR/initrd"
    cp $INITRD "$TMP_IMAGE_DIR/initrd"

    # Generate isolinux.cfg for default booting
    echo "Generating isolinux.cfg"
    cat > "$TMP_IMAGE_DIR/isolinux/isolinux.cfg" << END_CONFIG
DEFAULT install
LABEL install
menu label "Install image"
    kernel /vmlinuz
    append initrd=/initrd $KERNEL_CMDLINE_ARGS --
TIMEOUT 5
PROMPT 0
END_CONFIG


    echo "Creating EFI/BOOT directory"
    mkdir -p "$TMP_IMAGE_DIR/$EFI_BOOT_DIR"

    # Generate grub.cfg for default booting
    echo "Generating grub.cfg"
    cat > "$TMP_IMAGE_DIR/$EFI_BOOT_DIR/grub.cfg" << END_CONFIG
set default="0"
set timeout="5"
set hidden_timeout_quiet=false

menuentry "install" {
    linux /vmlinuz  $KERNEL_CMDLINE_ARGS --
    initrd /initrd
}
END_CONFIG


    DIB_UEFI_ISO_BUILD_EFIBOOT=${DIB_UEFI_ISO_BUILD_EFIBOOT:-}
    if [ -n "$DIB_UEFI_ISO_BUILD_EFIBOOT" ]; then
        build_efiboot_img
    else
        cp $SCRIPTDIR/efiboot.img $TMP_IMAGE_DIR/isolinux
    fi

    # Create the ISO
    echo "Generating the ISO"
    $MKISOFS -r -V "INSTALL_IMAGE" -cache-inodes -J -l \
    -b isolinux/isolinux.bin  -no-emul-boot \
    -boot-load-size 4 -boot-info-table \
    -eltorito-alt-boot -e isolinux/efiboot.img \
    -no-emul-boot -o $OUTPUT_FILENAME $TMP_IMAGE_DIR

}

IMAGE_NAME=${IMAGE_NAME:-'image'}

if echo $IMAGE_ELEMENT | grep -q '\bramdisk\b'; then
    EMITTED_KERNEL=$IMAGE_NAME.kernel
    EMITTED_RAMDISK=$IMAGE_NAME.initramfs
    EMITTED_KERNEL_CMDLINE_ARGS="boot_method=vmedia"
    EMITTED_ISO_FILENAME=$IMAGE_NAME.iso
elif echo $IMAGE_ELEMENT | grep -q '\bbaremetal\b'; then
    EMITTED_KERNEL=${IMAGE_NAME}.vmlinuz
    EMITTED_RAMDISK=${IMAGE_NAME}.initrd
    EMITTED_KERNEL_CMDLINE_ARGS="root=UUID=$DIB_IMAGE_ROOT_FS_UUID"
    DIB_BOOT_ISO_KERNEL_CMDLINE_ARGS=${DIB_BOOT_ISO_KERNEL_CMDLINE_ARGS:-}
    if [ -n "$DIB_BOOT_ISO_KERNEL_CMDLINE_ARGS" ]; then
        EMITTED_KERNEL_CMDLINE_ARGS="$EMITTED_KERNEL_CMDLINE_ARGS $DIB_BOOT_ISO_KERNEL_CMDLINE_ARGS"
    fi
    export EMITTED_ISO_FILENAME="$IMAGE_NAME-boot.iso"
else
    echo "Cannot find the kernel/ramdisk to build the iso image. "
    echo "Please use 'iso' element with either 'baremetal' or 'ramdisk' elements"
fi

build_iso "$EMITTED_KERNEL" "$EMITTED_RAMDISK" "$EMITTED_KERNEL_CMDLINE_ARGS" \
    "$EMITTED_ISO_FILENAME"