#!/bin/bash
# 
# ./fastback-unload-receipt RECEIPT
#   where RECEIPT is the name of the file containing the receipt 
#         output by fastback
#
#   will check the md5sum of the file, and decript it if it is encrypted
#   the file must have already been downloaded to the local directory
#
RECEIPT=$1

if [ "$2" = "" ]; then
  DO_FETCH=false
elif [ "$2" = "fetch" ]; then
  DO_FETCH=true
else
  echo >&2 "Error: invalid second argument: $2"
  exit 2
fi  

if [ ! -e $RECEIPT ]; then
  echo >&2 "Error: no such file $RECEIPT"
  exit 2
fi

cat $RECEIPT | while read FIRST REST ; do 
  #echo "FIRST:" $FIRST
  #echo "REST:" $REST

  if [ "$FIRST" = "FILE:" ]; then
    export FILE=$REST
    if [ -z "$FILE" ]; then
      echo >&2 "Error: file name missing from \"FILE:\" line"
      exit 2
    fi  
    #echo found FILE: $FILE
  fi
  if [ "$FIRST" = "MD5SUM:" ]; then
    if ! read MD5LINE; then
      echo >&2 "Error: unable to read MD5SUM"
      exit 2
    fi
    #echo found MD5LINE: $MD5LINE
  fi
  if [ "$FIRST" = "KEY:" ]; then
    KEYCODE=$REST
    if [ -z "$KEYCODE" ]; then
      echo >&2 "Error: key code name missing from \"KEY:\" line"
      exit 2
    fi  
    if ! read KEYLINE; then
      echo >&2 "Error: unable to read encryption key"
      exit 2
    fi
    #echo found KEY: $KEYCODE $KEYLINE
  fi
  if [ "$FIRST" = "END:" ]; then
    if [ -z "$FILE" ]; then 
      echo >&2 "Error: no file name found in receipt: $RECEIPT"
      exit 2
    fi

    if $DO_FETCH; then
        ./fetch-from-indus $FILE
    fi

    if [ -z "$MD5LINE" ]; then 
      echo >&2 "Error: no md5sum found in receipt: $RECEIPT"
      exit 2
    else
      #echo "MD5LINE:$MD5LINE"
      echo "\"md5sum --check\" reports:"
      echo "$MD5LINE" | md5sum --check -
    fi

    if [ ! -z "$KEYLINE" ]; then
      OUTFILE=${FILE%.aes}
      if [ "$OUTFILE" = "$FILE" ]; then
        OUTFILE=$FILE.decoded
      fi
      if openssl $KEYCODE -d -in $FILE -out $OUTFILE  -pass pass:$KEYLINE; then
        echo decode file writen to $OUTFILE
      fi
    fi
  fi
done