#!/bin/bash
#
# Script de creation d'un media bootable Debian
# Pour l'ACAQB
#
# Dépend : syslinux,wget
#
OPTIND=1
DEBIAN_VERSION="8.6.0"
DEBIAN_ARCH="amd64"
BOOT_TYPE="efi64"
SYSLINUX_EXE=`which syslinux`
SYSLINUX_FILES="menu.c32 vesamenu.c32 libutil.c32 libcom32.c32"
SYSLINUX_BIOS_FILES=""
SYSLINUX_EFI_FILES="ldlinux.e64"
TMP_DIR="tmp"
REPO_DIR="repo"
MOUNT_DIR="/mnt/usbstick"
current_dir=`pwd`

usage() {
    cat << EOF
USAGE: ${0} [-a architecture] [-b] 
    -a  amd64 | i386 CPU architecture
    -b bios boot type (default is efi64)
    -d device_block USB key to write
    
${0} initialize an usb key for Debian automatic install with preseed and a partman recipe.
EOF
}

download (){
    #Download function
    # $1 : filename
    # $2 : url
    # $3 : 1 if abort download if file exist
    echo -ne "Downloading $1 ... "
    if [[ -f $1 && $3 == "1" ]]
    then
        echo file already downloaded.
        return
    fi
    wget ‐‐no-clobber -4 $2/$1 &> /dev/null
    echo "done!"
}

create_dir(){
    # $1 directory to create
    if [ ! -d $1 ]
    then 
        mkdir -p $1
    else
        if [[ $2 == 1 ]]
        then
            rm -rf $1
            create_dir $1
        fi
    fi
}

#Stop script if syslinux is not installed
if [[  $SYSLINUX_EXE == "" ]]
then
    echo "Syslinux not found, script can't continue…"
    exit 1
fi

if [ -d /usr/lib/syslinux/efi64 ]
then    
    syslinux_mod="/usr/lib/syslinux"
else
    if [ -d /usr/lib/syslinux/modules/efi64 ]
    then
        syslinux_mod="/usr/lib/syslinux/modules"
    else
        echo "Syslinux modules folder not found, exiting"
        exit 1
    fi
fi


# Arguments ...
while getopts "ha:bd:" opt; do
    case "$opt" in
        h)
            usage
            exit 0
            ;;
        a)
            if [[ $OPTARG == "amd64" || $OPTARG == "i386" ]]
            then
                DEBIAN_ARCH=$OPTARG
            else
                echo "CPU architecture must be amd64 of i386, bye."
                exit 1
            fi
            ;;
        b)
            BOOT_TYPE="bios"
            ;;
        d)
            if [ -b $OPTARG ]
            then
                dest=$OPTARG
            else
                echo "Destination is not a block device, bye."
                exit 1
            fi
            ;;
    esac
done

bootfiles_Debian="http://ftp.debian.org/debian/dists/jessie/main/installer-${DEBIAN_ARCH}/current/images/hd-media"
iso_url="http://cdimage.debian.org/debian-cd/${DEBIAN_VERSION}/${DEBIAN_ARCH}/iso-cd"
iso_file="debian-${DEBIAN_VERSION}-${DEBIAN_ARCH}-netinst.iso"
repo_path="$REPO_DIR/$DEBIAN_ARCH/$DEBIAN_VERSION"


# Download Debian files (kernel, initrd and iso)
echo -e "\nPrepare Debian files\n---"
# Création du répertoire temporaire
create_dir $repo_path
cd $repo_path
download $iso_file $iso_url 1
for file in "vmlinuz" "initrd.gz" 
do
    download $file $bootfiles_Debian 1
done
cd $current_dir

if [[ -z $dest ]]
then
    echo "No destination device specified, USB key will not be created."
fi
create_dir $TMP_DIR 1
cp $repo_path/$iso_file $TMP_DIR
# Copy wanted syslinux file from archive

case $BOOT_TYPE in
    efi64)
        if [ -f /usr/lib/syslinux/efi64/syslinux.efi ]
        then    
            syslinux_efi="/usr/lib/syslinux/efi64/syslinux.efi"
        else
            if [ -d /usr/lib/SYSLINUX.EFI/modules/efi64/syslinux.efi ]
            then
                 syslinux_efi="/usr/lib/SYSLINUX.EFI/efi64/syslinux.efi"
            else
                echo "Syslinux efi bootlader not found"
                exit 1
            fi
        fi

        syslinux_folder=${TMP_DIR}/efi/EFI/boot
        create_dir $syslinux_folder
        cp -T ${syslinux_efi} $syslinux_folder/bootx64.efi &> /dev/null
        for file in $SYSLINUX_EFI_FILES
        do
            echo "copying $file ..."  
            cp $syslinux_mod/$BOOT_TYPE/$file $syslinux_folder
        done
        for file in $SYSLINUX_FILES
        do
            echo "copie de $file"  
            cp ${syslinux_mod}/${BOOT_TYPE}/${file} $syslinux_folder
        done
        cp $repo_path/{vmlinuz,initrd.gz} $TMP_DIR/efi
        cp -R syslinux/syslinux.cfg  $syslinux_folder &> /dev/null

        ;;
    bios)
        create_dir ${TMP_DIR}/syslinux 1
        for file in $SYSLINUX_FILES
        do
            echo "copie de $file"  
            cp ${syslinux_mod}/${BOOT_TYPE}/${file} ${TMP_DIR}/syslinux/
        done

        for file in $SYSLINUX_BIOS_FILES
        do
            echo "copying $file ..."  
            cp ${syslinux_mod}/${BOOT_TYPE}/${file} ${TMP_DIR}/syslinux/
        done
        cp -R syslinux  $TMP_DIR &> /dev/null
        ;;
esac
echo Copying configurations files 
create_dir $TMP_DIR/partman_recipes
cp -R partman_recipes $TMP_DIR &> /dev/null
create_dir $TMP_DIR/preseeds
cp -R preseeds $TMP_DIR &> /dev/null

if [[ -n $dest ]]
then
    read -p "[WARNING] Disk $dest will be erased continue [Y/N]? " -n 1 -r
    if [[ ! $REPLY =~ ^[Yy]$ ]]
    then
       exit 1
    fi
    #dd if=/dev/zero of=${dest} bs=512 count=1 conv=notrunc &> /dev/null
    echo -e "\nCreating partition"
    parted -s $dest mklabel gpt mkpart EFS fat32 1MiB 128MiB set 1 boot on
    parted -s $dest mkpart EFS fat32 128MiB 100%
    mkfs.vfat ${dest}1 -n efi &> /dev/null
    mkfs.vfat ${dest}2 -n debian &> /dev/null

    # mount and copy
    create_dir $MOUNT_DIR
    mount ${dest}2 $MOUNT_DIR
    create_dir $MOUNT_DIR/efi
    mount ${dest}1 $MOUNT_DIR/efi

    echo "copying all file to USB drive"
    cp -R ${TMP_DIR}/* $MOUNT_DIR
    umount $MOUNT_DIR/efi
    umount $MOUNT_DIR
    echo Unmounting key, please wait ...
    sleep 5
    # Make key bootable if bios.
    if [[ $BOOT_TYPE == "bios" ]]
    then
        # In this mode, we need to write syslinux MBR.
        echo "Writing syslinux mbr.ini fo $dest"
        dd bs=440 count=1 conv=notrunc if=${syslinux_mod}/${BOOT_TYPE}/mbr.bin of=${dest}
        sleep 2
        syslinux --directory /syslinux --install ${dest}1
    fi 
    exit 0
    #rm -rf $TMP_DIR
fi