#!/bin/bash

# crash: Report a problem and exit
crash()
{
    MSG=$1
    echo ${MSG}  >&2
    exit 1
}

# get_value: Return the right hand side of an equals
# statment in swift.properties format: #site sitename option=value
# will return bar
get_value()
{
   for last; do true; done
   eval echo $last |cut -d "=" -f2
}

# Verify an argument is not null
verify_not_null()
{
   argname=$1; shift
   if [ _$1 != _ ]; then
      return 0;
   else
      echo $0: value for $argname can not be null
      exit 1
   fi
}

# Print usage information and exit
usage()
{
   cat << END

   usage: gensites template [-p properties.file] [-L template_directory] [-h] [-T] [-l]
   
   template		 Name of template to use
   -p properties.file	 Specify a swift.properties to use
   -L template_directory Specify a non-standard template directory
   -T			 List all templates available
   -h			 Help / usage information
   -l                    List the contents of a specific template

   Examples:

   Create a site configuration file for sites.xml using default properties.file in current directory
   	$ gensites pads > sites.xml

   Use a specific properties file for a site
        $ gensites -p sites.properties pads > sites.xml

   Specify a non-standard directory where templates are located
   	$ gensites -L template.dir pads > sites.xml


END
exit 0;
}

# Parse command line arguments
while [ $# -gt 0 ]
do
   case "$1" in
      -p) PROPERTIES_FILE=$2; verify_not_null properties_file $PROPERTIES_FILE; shift ;;
      -L) TEMPLATE_DIRECTORY=$2; verify_not_null template_directory $TEMPLATE_DIRECTORY; shift ;;
      -l) LIST_SPECIFIC_TEMPLATE=1 ;;
      -T) LIST_TEMPLATES=1 ;;
      -h|-help|-?) usage ;;
       *) TEMPLATE=$1 ;;
   esac
   shift
done

# Determine SWIFT_HOME
if [ -z "$SWIFT_HOME" ]; then
   SWIFT_BIN_DIR=`which swift`

   if [ ! -d "$SWIFT_HOME" ]; then
      SWIFT_HOME=`dirname $SWIFT_BIN_DIR`"/../etc/sites"
   fi
 
   # Can't find swift path, give up
   if [ ! -d "$SWIFT_HOME" ]; then
      crash "Unable to determine SWIFT_HOME. Please set manually."
   fi            
fi

# List all templates
if [ ! -z $LIST_TEMPLATES ]; then
   # Templates in etc/sites
   for file in `ls -1 $SWIFT_HOME/* 2>/dev/null`
   do
	basename $file
   done
   # Templates in .swift/sites
   for file in `ls -1 $HOME/.swift/sites/* 2>/dev/null`
   do
       basename $file
   done
   exit 0
fi

# Require template name to be specified by user
if [ -z "$TEMPLATE" ]; then
   crash "Not specified: TEMPLATE"
fi

# Use custom template directory if asked
if [ -d "$TEMPLATE_DIRECTORY" ]; then
   TEMPLATE_PATH="$TEMPLATE_DIRECTORY/$TEMPLATE"
fi

# Locate template
if [ ! -f "$TEMPLATE_PATH" ]; then
   if [ -f "$TEMPLATE" ]; then
      $TEMPLATE_PATH = $TEMPLATE
   elif [ -f "$SWIFT_HOME/$TEMPLATE" ]; then
      TEMPLATE_PATH=$SWIFT_HOME/$TEMPLATE
   elif [ -f "$HOME/.swift/sites/$TEMPLATE" ]; then
      TEMPLATE_PATH=$HOME/.swift/sites/$TEMPLATE
   fi
   if [ ! -f "$TEMPLATE_PATH" ]; then
      crash "Cannot find template for $TEMPLATE"
   fi
fi

# List a specific template
if [ ! -z $LIST_SPECIFIC_TEMPLATE ]; then
   cat $TEMPLATE_PATH
   exit 0
fi

# Ensure a properties file exists
if [ ! -f "$PROPERTIES_FILE" ]; then
   PROPERTIES_FILE="swift.properties"
   if [ ! -f "$PROPERTIES_FILE" ]; then
      PROPERTIES_FILE="$HOME/.swift/swift.properties"
      if [ ! -f "$PROPERTIES_FILE" ]; then
         crash "Unable to find a valid properties file! Please specify a valid file with the -p option"
      fi
   fi
fi

# Parse values into variables for later sed processing
WORK=`pwd`"/work"
while read line
do
   case "$line" in
      "#site $TEMPLATE work="*|'#site work='*) 
         WORK=`get_value $line`
         ;;
      "#site $TEMPLATE globus_hostname="*|'#site globus_hostname=') 
         GLOBUS_HOSTNAME=`get_value $line`
         ;;
      "#site $TEMPLATE nodes="*|'#site nodes='*)
         NODES=`get_value $line`
         ;;
      "#site $TEMPLATE project="*|'#site project='*)
         PROJECT=`get_value $line`
         ;;
      "#site $TEMPLATE queue="*|'#site queue='*)
         QUEUE=`get_value $line`
         ;;
      "#site $TEMPLATE n_gran="*|'#site n_gran='*)
         N_GRAN=`get_value $line`
         ;;
      "#site $TEMPLATE n_max="*|'#site n_max='*)
         MAXTIME=`get_value $line`
         ;;
      "#site $TEMPLATE slots="*|'#site slots='*)
         SLOTS=`get_value $line`
         ;;
      "#site $TEMPLATE execution_url="*|'#site slots='*)
        EXECUTION_URL=`get_value $line`
        ;;
   esac
done < $PROPERTIES_FILE

# Test for mandatory variables
[[ ${WORK}   == "" ]] && crash "Not specified: WORK"

# Verify that the variables by the template are defined
for TOKEN in PROJECT QUEUE N_GRAN N_MAX SLOTS
do
   # Need but can't find, due
   if grep _${TOKEN}_ $TEMPLATE_PATH > /dev/null; then
      if [ -z "${!TOKEN}" ]; then
            crash "Not specified: ${TOKEN}"
      fi
   fi
done

# Replace values
SEDFILE=`mktemp`
{
  echo "s/_NODES_/${NODES}/"
  echo "s/_HOST_/${GLOBUS_HOSTNAME}/"
  echo "s@_WORK_@${WORK}@"
  echo "s/_PROJECT_/${PROJECT}/"
  echo "s/_QUEUE_/${QUEUE}/"
  echo "s/_N_GRAN_/${N_GRAN}/"
  echo "s/_N_MAX_/${N_MAX}/"
  echo "s/_SLOTS_/${SLOTS}/"
  echo "s/_MAXTIME_/${MAXTIME}/"
  echo "s@_EXECUTION_URL_@${EXECUTION_URL}@"
  echo "s@_SERVICE_COASTERS_@${SERVICE_COASTERS:-NO_URL_GIVEN}@"
  echo "s@_SERVICE_PORT_@${SERVICE_PORT:-NO_PORT_GIVEN}@"
} > $SEDFILE


sed -f $SEDFILE < $TEMPLATE_PATH
rm $SEDFILE