#!/bin/sh

clear
cat <<EOF

  This script is provided to simplify the installation of GPS,
  the GNAT Programming System.

  You will be asked for confirmation before the actual installation is
  done. You can break out of this script at any time before this.

  Hit RETURN to continue.
EOF

read x

current_dir=`/bin/pwd`

## Read the base directory (absolute path name)
## Sets the variable  $basedir
ask_basedir() {
   clear
   default_dir=`(type gnatmake | cut -d' ' -f3) 2>/dev/null`
   default_dir=`dirname $default_dir`

   if [ "$default_dir " != "." -a "$default_dir " != "/usr/bin" ]; then
      default_dir=`cd $default_dir/..; pwd`
      cat <<EOF

  GNAT has been found in $default_dir.
  Do you want to install GPS there too? Hit RETURN if yes or enter
  the name of the directory in which GPS should be installed:

EOF
   else
     cat <<EOF
  Enter the name of the directory in which you would like to install GPS

EOF
   fi

   while [ "$basedir " = " " ]; do
      printf "[$default_dir] "
      read basedir
      if [ " $basedir" = " " ]; then
         basedir="$default_dir"
      fi
      if echo $basedir | egrep "^[/~]" >/dev/null; then
         true
      else
         basedir=`pwd`/$basedir
      fi
   done

   # Suppress the final / in basedir
   basedir=`echo $basedir | sed -e 's/\/$//'`

   # Check that we have permission to write in $basedir
   if test -d $basedir; then
     if test -w $basedir; then
        if [ -x $basedir/bin/gps ]; then
           echo "  $basedir/bin/gps found."
           printf "  Do you want to overwrite existing installation [Y/n] ? "
           read x
           if [ " $x" = " n" -o " $x" = " N" ]; then
              echo "Aborting the installation process"
	      exit
           fi
        fi
     else
        echo "You do not have permission to write in $basedir"
        echo "Please check whether you should be root to install in that directory."
        echo "Aborting the installation process"
        exit
     fi
   else
     echo ""
     echo "  Directory $basedir does not exist."
     printf "  Do you want to create it [Y/n] ? "
     read x
     if [ " $x" = " n" -o " $x" = " N" ]; then
        echo "Aborting the installation process"
	exit
     fi
     mkdir -p $basedir
   fi

   echo ""
   printf "  Are you now ready to proceed with the installation [Y/n] ? "
   read x
   if [ " $x" = " n" -o " $x" = " N" ]; then
      echo "Aborting the installation process"
      exit
   fi
}

##################################
## Do the actual installation
##################################

install_binaries() {

  echo "Installing the binaries ...."
  cd $basedir

  if [ -f bin/gpr2make ]; then
     rm $current_dir/bin/gpr2make
  fi

  # Do the installation through tar, to preserve symbolic links
  # We also explicitly work on specific directories to avoid
  # copying junk files

  (cd $current_dir; tar cf - bin lib doc share) | tar xf -
}

##
##  Write the end message
##
end_message() {
   clear
   cat <<EOF

   GPS has now been installed on your machine.
   You can start it with the following command:

   $basedir/bin/gps

   Make sure that gps is in your path by typing one of the following
   commands:

   for csh and tcsh shells:
      setenv PATH $basedir/bin:\$PATH
   for sh, bash, ksh and zsh:
      PATH=$basedir/bin:\$PATH
      export PATH

EOF
}

## Main program

ask_basedir
install_binaries
end_message

