#!/bin/bash

CONFIGOK=false
usage () {
   (echo 'Usage:
        checkconfig [ -timeout N ] [ config.ok ] 

    N > 0 in seconds (default is 3).
    config.ok, if mentioned and existing is be used as default configuration.
') >&2
   exit 1
}


TIMEOUT=3
while [ $# -gt 0 ]
do
  case "$1" in
    "") ;;
    -timeout)  
       if expr "$2" : '1[0-9]*' >/dev/null
       then  TIMEOUT="$2"
       else usage
       fi
       shift;;
   config.ok) CONFIGOK=true;;
   *) ;;
  esac
  shift
done

message () { echo -n "$@" '... '; }
warning () { echo; echo '*** Warning:'; echo "$@"; }
ERRORS=false
error () { echo; ERRORS=true; echo '*** Error:'; echo "$@"; false; }
fatal () { 
  echo; echo -n "$@"; 
  echo '
************ They were serious Errors ************

Makefile.config is likely to be incorrect. 
Maybe you just need to reconfigure. Edit Makefile.config or type:

      make config

If you wish to continue, despite errors, type:
   
      make force

Good luck.
'
  exit 1
}

nonempty () {
  message "Checking $1 nonempty"
  if [ -z "$2" ]; then error "$1 is empty" ; else echo ok; fi
}

# Bash configuration
message "Checking that BASH is executanble"
test -x "$BASH" && echo ok || error ERROR

sed -e 's/ *= */=/' -e 's/(\([A-Z][A-Z]*\))/{\1}/' \
    -e 's/^\(.*\)=\(.*[^ \t]\)/\1=\"\2\"/' \
    Makefile.config \
   > config.bash
source config.bash
rm config.bash
if $CONFIGOK && [ -f config.ok ]; then 
  echo 'Using existing configuration config.ok'
  source config.ok; 
fi

# Emacs 
if test -z "$EMACSDIR" -a -n "$EMACS" 
then error "EMACSDIR must be defined when EMACS is"
else echo "XEMACS and XEMACSDIR ok"
fi

if test -z "$XEMACSDIR" -a -n "$XEMACS" 
then error "XEMACSDIR must be defined when XEMACS is"
else echo "XEMACS and XEMACSDIR ok"
fi

# Other directories
nonempty DATADIR "$DATADIR"
nonempty BINDIR "$BINDIR" 
nonempty LATEXDIR "$LATEXDIR" 
nonempty DOCDIR "$DOCDIR" 

# Initex and Latex 
# message "INITEX and LATEX must be defined"

# BEGIN TEX
if
   nonempty INITEX "$INITEX" && \
   nonempty LATEX "$LATEX" && \
   nonempty FORMAT "$FORMAT" 
then
cat << END > dummy.tex
\documentclass{article}
\def \dummy {Testing Your Installation}
\def \dojump{\def \documentclass ##1\dump {\relax}}
\dojump
\dump
\begin{document}
\huge {\bf \dummy}\par Don't worry, feel Lucky!
\end{document}
END

# initex
message "Running INITEX=$INITEX "

if $INITEX '&'$FORMAT 'dummy' > initex.log && [ -f dummy.$FMT ] 
then echo ok
else 
  error "
  Command failed:

      $INITEX '&$FORMAT' dummy > initex.log"' && [ -f dummy.$FMT ]'"

  $INITEX seems to have problems building format $FORMAT for $LATEX
  It could be a problem with $INITEX, format extension $FMT, 
  or the initial $FORMAT.$FMT may not be availableb.
  See initex.log
"
fi 

# latex
message "Running LATEX=$LATEX"
if [ -n "$LATEX" ]; then
  if $LATEX '&dummy' dummy.tex > latex.log && [ -f dummy.dvi ]
  then echo ok
  else
    error "
    Command failed:

      $LATEX '&dummy' dummy.tex > latex.log"' && [ -f dummy.dvi ]'"


    $LATEX installation seem to have problems. 
    See dummy.tex and latex.log
  "
  fi
fi

fi
# END TEX

# if interactive check

if test -z "$DISPLAY"
then
 echo "Skipping viewers check (run with no option to check viewers)"
else
# viewers
echo "Checking viewers"

#begin checkviewers 
checkdvi () {
  DVI="$1"
  EXEC="$2"
  OK="$3"
  if [ -n "$EXEC" ] && [ ! "$EXEC" = "$OK" ]
  then
    echo "Launching $DVI=$EXEC dummy.dvi&"
    $EXEC dummy.dvi &
    sleep "$TIMEOUT"
    PID=$!
    echo -n "Sending USR1 to $DVI ... "
    if kill -USR1 $PID && sleep 1 && kill -CONT $PID 
    then echo ok
    else
      warning "
    $EXEC killed by signal USR1.
    This may be fatal or downgrade the refreshing speed considerably. 

    This may also be due to missing fonts or other latency problem.
    You may try again a longer timeout in second (default is 3).

    Continuing...
"    
     unset $DVI
     fi
     kill -TERM $PID 
  fi
}

if [ -f dummy.dvi ]
then
  ## check for ADVI
  checkdvi ADVI "$ADVI" "$ADVIOK"

  ## check for multiple views with advi
  if $MULTIPLE && [ -n "$ADVI" -a -f dummy.dvi ]
  then
    $ADVI dummy.dvi dummy.dvi &
    sleep "$TIMEOUT"
    PID=$!
    echo -n "Sending USR1 to $DVI ... "
    if kill -USR1 $PID && sleep 1 && kill -CONT $PID 
    then echo ok
    else
      warning "
    $EXEC does not seem to accept multiple files.
    please, set MULTIPLE=false in Makefile.config or
    reconfigure with 

        ./configure -multiple false

    Continuing...
"    
    fi
    kill -TERM $PID 
  fi

  ## check for XDVI
  checkdvi XDVI "$XDVI" "$XDVIOK"
  if [ -n "$DVIPS" -a -n "$GV" -a "$GV" != "$GVOK" ] ; then
    if $DVIPS -o dummy.ps dummy.dvi 2>/dev/null 1>/dev/null
    then 
      $GV dummy.ps &
      PID=$!
      sleep "$TIMEOUT"
      echo -n "Sending HUP to $GV ... "
      if kill -HUP $PID && sleep 1 && kill -CONT $PID
      then echo OK
      else
        warning "
    $GV does not respond to signal HUP.
    This may be fatal or downgrade the refreshing speed considerably. 

    Continuing...
"
        unset GV
      fi
      kill -TERM $PID 
    else 
      warning "
      $DVIPS does not seem to work as expected

    Continuing...
"
      unset DVIPS
      unset GV
    fi
  fi
fi
#end checkviewers 

fi
#end of interactive check

nonempty 'One of ADVI, XDVI or GV' "$ADVI$XDVI$GV" && \
if [ -n "$GV" ]; then
  nonempty 'DVIPS (when GV is nonempty)' "$DVIPS"
fi

if [ -z "$ADVI" ]; then
  warning '
    Active-DVI does not seem to be installed. (You may wish to install it.)
'
fi

if $ERRORS
then
  fatal
else
  echo 'No anomaly detected in Makefile.config.'
  rm -f dummy.{fmt,efmt,tex,aux,log,dvi,ps}
  # config.ok
  (if test -n "$ADVI"; then echo ADVIOK=$ADVI; fi
   if test -n "$XDVI"; then echo XDVIOK=$XDVI; fi
   if test -n "$GV"; then echo GVOK=$GV; fi) > config.ok
fi