#!/bin/bash
#
# Script de creation d'un media bootable Debian
# Pour l'ACAQB
#
# Dépend : syslinux,wget
#
OPTIND=1

# Default Variables
debian_arch="amd64"
debian_version=$(wget -q --output-document - https://cdimage.debian.org/debian-cd/ | \
    grep -o '[0-9]\{1,2\}\.[0-9]\{1,2\}\.[0.9]\{1,2\}' | head -1)
archive=0
boot_type="efi64"
repo_dir="repo"
tmp_dir="tmp"
current_dir=`pwd`

# In Archlinux, this is default files for syslinux...
conf_file="conf/archlinux.conf"
key_mountpoint="/mnt/usbstick"
device=""

# constant
APP_NAME="Debian USB Creator"
VERSION="1.99.0"
SYSLINUX_EXE=$(command -v syslinux)
PARTED_EXE=$(command -v parted)
MCOPY=$(command -v mtoos)
SYSLINUX_FILES="menu.c32 vesamenu.c32 libutil.c32 libcom32.c32"
SYSLINUX_BIOS_FILES=""
SYSLINUX_EFI_FILES="ldlinux.e64"

process_args() {
    # While getops doesn't handle long parameters
    # I need an personnal function
    # Inspired by http://mywiki.wooledge.org/BashFAQ/035
    while :; do
        case $1 in
            -h|-\?|--help)
                usage
                exit 0
                ;;
            -a|--arch)
                if [[ $2 == "amd64" || $2 == "i386" ]]
                then
                    debian_arch=$2
                    shift
                else
                    printf "Error : CPU architecture must be amd64 or i386"
                    exit 1
                fi
                ;;
            -b|--bios)
                boot_type="bios"
                ;;
            -c|--conf)
                if [ -f $2 ]
                then
                    conf_file=$2
                else
                    printf "%s file not found" $2
                    exit 1
                fi
                shift
                ;;
            -d|--device)
                if [ -b $2 ]
                then
                    device=$2
                    shift
                else
                    printf "%s doesn't a block device, exiting" "$2"
                    exit 1
                fi
                ;;
            --debian-version)
                if [[ $debian_version != $2 ]]
                then
                    archive=1
                    debian_version=$2
                fi
                shift
                ;;
            --repo)
                repo_dir=$2
                shift
                ;;
            --tmp)
                tmp_dir=$2
                shift
                ;;
            -v|--version)
                show_version
                exit 0
                ;;
            *)
            break
        esac
        shift
    done
}

usage() {
cat << EOF
USAGE: ${0} [-a architecture] [-b] 
-a | --arch         Select CPU Architecture amd64 | i386 CPU
-b | --bios         Create a bios bott compatible key 
-d | --device       Device_block USB key to write
--debian-version    Choose Debian Version to download
--repo              Repo directory (defaukt is ./repo)
--temp              Temp directory (default is ./tmp)
-v | --version      Show version

${0} initialize an usb key for Debian automatic install with preseed and a partman recipe.
EOF
}

show_version () {
printf "%s %s 2016-2017 ephase@xieme-art.org\n" "$APP_NAME" "$VERSION"
}

download (){
#Download function
# $1 : filename
# $2 : url
# $3 : 1 if abort download if file exist
printf "Downloading %s :    " "$1"
local url
local http_response
url="$2/$1"
http_response=$(wget --spider --server-response "$url" 2>&1 | grep HTTP/ | tail -1 |  awk ' { printf $2 }')
if [ "$http_response" -eq 200 ]
then
    wget -c --progress=dot "$url" 2>&1 | grep --line-buffered "[0-9]\{1,3\}%" -o | awk '{printf ("\b\b\b\b%4s", $1)}'
    if [ $? -eq 0 ]
    then
        printf " \b\b\b\b\b done\n "
    else
        printf " error, exiting.\n"
        exit 1
    fi
else
    printf "Error 404 : file not found, exiting\n"
    exit 1
fi
}

process_conf_file (){
    while read -r p
    do
        var=$(echo "$p" | awk -F"=" '{print $1}')
        param=$(echo "$p" | awk -F"=" '{print $2}')
        eval "$var"="$param"
    done < <( cat "$1" | grep '^[^#].*')

}

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

# unmount if device is mounted
umount_device (){
    local mounted_part=""
    mounted_part=$(mount | grep "${1}[0-9]" | awk '{print $3}')
    if [ !  "$mounted_part" == "" ]
    then
        for part  in $mounted_part
        do
            if [ -d "$part" ]
            then
                printf "Unmount %s\n " "$part"
                umount "$part" --recursive
            fi
        done
    fi
}

efi_create_key_structure () {
    parted -s "$1" mklabel gpt mkpart EFS fat32 1MiB 128MiB set 1 boot on mkpart debian fat32 128MiB 100%
    sleep 2
    mkfs.vfat "${1}1" -n efi &> /dev/null
    mkfs.vfat "${1}2" -n debian &> /dev/null
    sync
    mount "${1}2" "$2"
    create_dir "$2/efi"
    mount "${1}1" "$2/efi"
}

bios_create_key_structure() {
    parted -s "$1" mklabel msdos mkpart primary fat32 1MiB 100% set 1 boot on
    sleep 2
    mkfs.vfat "${1}1" -n debian &> /dev/null
    mount "${1}1" "$2"
}

#Stop script if syslinux is not installed
if [ -z  "$SYSLINUX_EXE" ]
then
    printf "Syslinux not found, script can't continue.\n"
    exit 1
fi

if [ -z "$PARTED_EXE" ]
then 
    printf "Parted not found, script can't continue.\n"
    exit 1
fi


process_args "$@"
process_conf_file "$conf_file"
if [[ ! -d "$syslinux_mbr_bl_folder" || ! -d "$syslinux_efi_bl_folder" || ! -d "$syslinux_modules_folder" ]]
then
    printf "Bad folder configuration in %s\n" "$conf_file"
    exit 1
fi

if [ "$boot_type" == "bios" ] && [ -z "$MCOPY" ]
then
    printf "Bios key creation need mcopy from mtools packages\n"
    exit 1
fi

bootfiles_Debian="http://ftp.debian.org/debian/dists/stable/main/installer-${debian_arch}/current/images/hd-media"
if [ $archive -eq 1 ]
then
    iso_url="http://cdimage.debian.org/cdimage/archive/${debian_version}/${debian_arch}/iso-cd"
else
    iso_url="http://cdimage.debian.org/debian-cd/${debian_version}/${debian_arch}/iso-cd"
fi 
iso_file="debian-${debian_version}-${debian_arch}-netinst.iso"
repo_path="$repo_dir/$debian_arch/$debian_version"


# Download Debian files (kernel, initrd and iso)
printf "Downloading Debian files\n---\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 "$device" ]
then
    printf "No destination device specified, USB key will not be created.\n"
fi
create_dir "$tmp_dir" 1
cp "$repo_path/$iso_file" "$tmp_dir"
# Copy wanted syslinux file from archive

case $boot_type in
    efi64)
        syslinux_folder=${tmp_dir}/efi/EFI/boot
        create_dir "$syslinux_folder"
        cp -T "$syslinux_efi_bl_folder/$boot_type/syslinux.efi" "$syslinux_folder/bootx64.efi" &> /dev/null
        for file in $SYSLINUX_EFI_FILES
        do
            printf "copying %s \n" "$file"  
            cp "$syslinux_modules_folder/$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)
        syslinux_folder=${tmp_dir}/syslinux
        create_dir "$syslinux_folder"
        for file in $SYSLINUX_BIOS_FILES
        do
            printf "copying %s\n" "$file"   
            cp "$syslinux_modules_folder/$boot_type/$file" "$syslinux_folder"
        done
        cp "$repo_path"/{vmlinuz,initrd.gz} "$tmp_dir"
        cp -R syslinux  "$tmp_dir" &> /dev/null
        ;;
esac

for file in $SYSLINUX_FILES
do
    printf "copying %s\n" "$file"    
    cp "$syslinux_modules_folder/$boot_type/$file" "$syslinux_folder"
done

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 "$device" ]
then
    printf "Partitionning and formating %s\n" "$device"
    read -p "[WARNING] Disk $device will be erased continue [Y/N]? " -n 1 -r
    if [[ ! $REPLY =~ ^[Yy]$ ]]
    then
       exit 1
    fi
    printf "\n\n"
    umount_device "$device"
    create_dir "$key_mountpoint"
    #dd if=/dev/zero of=${dest} bs=512 count=1 conv=notrunc &> /dev/null
    case "$boot_type" in
        "efi64") 
            efi_create_key_structure "$device" "$key_mountpoint"
            ;; 
        "bios")
            bios_create_key_structure "$device" "$key_mountpoint"
            ;;
    esac
    printf "copying all file to USB drive\n"
    cp -R "$tmp_dir"/* "$key_mountpoint"
    umount_device "$device" 
    sleep 5
    # Make key bootable if bios.
    if [ "$boot_type" = "bios" ]
    then
        # In this mode, we need to write syslinux MBR.
        printf "Writing syslinux mbr.ini to %s\n"  "$device"
        dd bs=440 count=1 conv=notrunc if="$syslinux_mbr_bl_folder"/mbr.bin of="$device"
        sleep 2
        "$SYSLINUX_EXE" --directory /syslinux --install "${device}1"
    fi 
    rm -rf "$tmp_dir"
    printf "\nBootable USB key created\n"
    exit 0 
fi