#!/bin/bash

set -e

START_DIR_DONT_CHANGE=`pwd`
SELF=$(basename "$0")

# required config items
CONFFILE=$HOME/.libburnia-releng/${SELF}.conf
GEN_DATA_DIR=releng_generated_data/${SELF}
TMP_DATA_DIR=releng_generated_data
IMG_EXTRACT_DIR=${TMP_DATA_DIR}/${SELF}_extracted_tree

# to be set by the config file
RELENG_XORRISO=""

RELENG_DIR="${IMG_EXTRACT_DIR}"
RELENG_ISOLINUX_BIN="isolinux/isolinux.bin"
RELENG_BOOT_CAT="isolinux/boot.cat"
RELENG_IMG=cimage

KEEP=0
RES=""

REMOTE_URL="http://cdimage.debian.org/cdimage/daily-builds/daily/current/i386/iso-cd"
REMOTE_IMG="debian-testing-i386-businesscard.iso"

print_help() {
 cat << HLP
Usage:
 ${SELF} -help

# using a config file ${CONFFILE}
 ${SELF} -rc [-keep]

# cleanup test generated data directory and exit
 ${SELF} -cleanup
HLP
}

#####################################################################
# cleanup
if [ "${1}" == "-cleanup" ]; then
 cd "${START_DIR_DONT_CHANGE}" || exit 2
 if [ -d "${GEN_DATA_DIR}" ]; then
    rm -rf ${GEN_DATA_DIR}
    printf "${SELF}: removed %s\n" ${GEN_DATA_DIR}
 else
    printf "${SELF}: ${GEN_DATA_DIR} does not exist.\n"
 fi
 exit 0
fi

# help
if [ ! "${1}" ]; then print_help && exit 3; fi
# config file
if [ "${1}" == "-rc" ]; then
 if [ -e ${CONFFILE} ]; then
  . ${CONFFILE}
  printf "${SELF}: Using config file %s\n" ${CONFFILE}
 else
  echo -e "\n${SELF}: Config file ${CONFFILE} not found.\n" && exit 4
 fi
 if [ "${2}" == "-keep" ]; then KEEP=1; fi
# the rest
else
 print_help && exit 5
fi

# data dir
if [ -d "${GEN_DATA_DIR}" ]; then
 printf "\n${SELF}: directory %s exists!" ${GEN_DATA_DIR}
 printf "\n${SELF}: use '${SELF} -cleanup' to remove.\n"
 exit 6
else
 mkdir "${GEN_DATA_DIR}"
fi

if [ "${RELENG_XORRISO}" == "" -o "${RELENG_DIR}" == "" -o "${RELENG_IMG}" == "" ]; then
 echo -e "\n${SELF}: xorriso_cmd IN_dir and OUT_image are required\n"
 exit 7
fi

if [ ! -x "${RELENG_XORRISO}" ]; then
 printf "${SELF}: $RELENG_XORRISO not found or not an executable.\n"
 exit 8
fi

# all must be set at this point
printf "${SELF}: Config items:"
printf "\n\txorriso_cmd=${RELENG_XORRISO}\n\tIN_dir=${RELENG_DIR}\n\tOUT_image=${RELENG_IMG}.iso"
printf "\n\tIN_isolinux=${RELENG_ISOLINUX_BIN}\n\tOUT_bootcat=${RELENG_BOOT_CAT}\n"
RES="${RELENG_IMG}.iso ${RELENG_IMG}.new ${RELENG_IMG}.md5 ${RELENG_IMG}.jigdo ${RELENG_IMG}.template"

# xorriso version details, incl. underlying libraries
"${RELENG_XORRISO}" -version
if ! "${RELENG_XORRISO}" -version | grep libjte >/dev/null 2>&1; then
 printf "\n${SELF}: JTE not supported with this xorriso build. Install jigit and rebuild."
 printf "\n${SELF}: See http://www.einval.com/~steve/software/JTE/\n"
 exit 9
fi

# remove cruft from previous runs
# rm -f ${RES}

# grab remote ISO image, to decompose
if [ ! -f "${TMP_DATA_DIR}"/"${REMOTE_IMG}" ]; then
 printf "\n${SELF}: Downloading ${REMOTE_URL}/${REMOTE_IMG}\n"
 wget --no-check-certificate -T20 -t3 -O \
 "${TMP_DATA_DIR}"/"${REMOTE_IMG}" "${REMOTE_URL}"/"${REMOTE_IMG}"
 WGET_RET="$?"
 case ${WGET_RET} in
     0)
      echo -e "\n${SELF}: Downloading successfully completed.\n"
     ;;
     *)
      echo -e "\n${SELF}: FAIL: wget returned code: $WGET_RET\n"
      exit 10
     ;;
 esac
else
 printf "\n${SELF}: Found ISO image: ${TMP_DATA_DIR}/${REMOTE_IMG}\n"
fi

# check for extraction directory existence
if [ -d "${IMG_EXTRACT_DIR}" ]; then
 printf "\n${SELF}: Found ${IMG_EXTRACT_DIR}. Please cleanup.\n"
 exit 11
else
 mkdir "${IMG_EXTRACT_DIR}"
fi

# extract image content
CMD_EXTRACT="${RELENG_XORRISO} -indev ${TMP_DATA_DIR}/${REMOTE_IMG} \
        -osirrox on:auto_chmod_on \
	-extract / ${IMG_EXTRACT_DIR} \
"
echo -e "${SELF}: Extracting ISO image:\n${CMD_EXTRACT}\n"
set +e
${CMD_EXTRACT}
set -e

# grab an MBR
ISOHYBRID_MBR="${GEN_DATA_DIR}/isohybrid.mbr"
dd if="${TMP_DATA_DIR}/${REMOTE_IMG}" bs=1K count=32 of="${ISOHYBRID_MBR}"

# create FAT partition
APPEND_PART="${GEN_DATA_DIR}/fatpart.fat"
/sbin/mkfs.msdos -n Bla -C "${APPEND_PART}" 8192

# GENERAL section
CMD="${RELENG_XORRISO} \
 -as mkisofs \
 -quiet \
 -o ${GEN_DATA_DIR}/${RELENG_IMG}.iso \
 -R \
 -V ISOJIGDO \
 -partition_offset 16 \
 -J -joliet-long \
"

# BOOT section
if [ -f "${IMG_EXTRACT_DIR}"/"${RELENG_ISOLINUX_BIN}" -a -f "${ISOHYBRID_MBR}" -a -f "${APPEND_PART}" ]; then
CMD+="\
 -b ${RELENG_ISOLINUX_BIN} \
 -c ${RELENG_BOOT_CAT} \
 -no-emul-boot -boot-load-size 4 -boot-info-table \
 -isohybrid-mbr ${ISOHYBRID_MBR} \
 -partition_offset 16 \
 -append_partition 2 0x01 ${APPEND_PART} \
"
else
 printf "\n${SELF}: FAIL to compose the boot section.\n"
 exit 12
fi

# JIGDO section
JIGDO_JIGDO=${GEN_DATA_DIR}/${RELENG_IMG}.jigdo
JIGDO_TEMPLATE=${GEN_DATA_DIR}/${RELENG_IMG}.template
JIGDO_MAP_RHV=`realpath ${RELENG_DIR}`
JIGDO_MAP="Debian=${JIGDO_MAP_RHV}"

# create jigdo MD5 list in base64 format
JIGDO_GEN_MD5=${GEN_DATA_DIR}/${RELENG_IMG}.md5
if which jigdo-gen-md5-list >/dev/null 2>&1; then
 printf "${SELF}: Creating MD5 list in hex format in ${JIGDO_GEN_MD5}..."
 jigdo-gen-md5-list ${RELENG_DIR} > ${JIGDO_GEN_MD5}
 printf "Done.\n"
else
 printf "\n${SELF}: Not found: jigdo-gen-md5-list. Install jigit."
 printf "\n${SELF}: See http://www.einval.com/~steve/software/JTE/\n"
 exit 13
fi

CMD+="\
 -jigdo-template-compress gzip \
 -checksum_algorithm_iso md5,sha1,sha256,sha512 \
 -checksum_algorithm_template md5,sha1,sha256,sha512 \
 -jigdo-jigdo ${JIGDO_JIGDO} \
 -jigdo-template ${JIGDO_TEMPLATE} \
 -jigdo-map ${JIGDO_MAP} \
 -md5-list ${JIGDO_GEN_MD5} \
 -jigdo-min-file-size 1024 \
"

CMD+="${RELENG_DIR}"

# Run the whole compound command
echo -e "${SELF}: Creating ISO and jigdo representations:\n$CMD\n"
${CMD}

# Create another imange this time from jigdo files
if which jigit-mkimage >/dev/null 2>&1; then
 printf "${SELF}: Creating new ISO from jigdo files..."
 jigit-mkimage \
  -t ${JIGDO_TEMPLATE} \
  -j ${JIGDO_JIGDO} \
  -m ${JIGDO_MAP} \
  -o ${GEN_DATA_DIR}/${RELENG_IMG}.new
 printf "Done.\n"
else
 printf "\n${SELF}: Not found: jigit-mkimage. Install jigit."
 printf "\n${SELF}: See http://www.einval.com/~steve/software/JTE/\n"
 exit 14
fi

# trap the exit code of diff and let the Universe explode
diff ${GEN_DATA_DIR}/${RELENG_IMG}.iso ${GEN_DATA_DIR}/${RELENG_IMG}.new
DIFF_RET="$?"
case ${DIFF_RET} in
     0)
      echo -e "${SELF}: diff ${GEN_DATA_DIR}/${RELENG_IMG}.iso ${GEN_DATA_DIR}/${RELENG_IMG}.new matched.\n"
     ;;
     *)
      echo -e "${SELF}: FAIL: diff returned code: $DIFF_RET\n"
     ;;
esac

# sort out the cruft
if [ ${KEEP} -eq 0 ]; then
 # safety net, just in case -> we want to be in the starting
 # directory before removing whatever self-generated stuff
 cd "${START_DIR_DONT_CHANGE}" || exit 15
 rm -rf ${GEN_DATA_DIR}
 printf "${SELF}: Removed %s\n" ${GEN_DATA_DIR}
else
 printf "${SELF}: Leaving %s\n" ${GEN_DATA_DIR}
fi

# last hints
printf "\n${SELF}: HINT: manual checks remained to be done:\n"
printf " * ${RELENG_IMG}.img boots from USB stick and/or optical media.\n"
printf " * appended FAT partition is mountable.\n"
printf " * xorriso -indev ${RELENG_IMG}.iso -pvd_info\n"
printf " * fdisk -lu ${RELENG_IMG}.iso\n"

exit 0