#!/bin/sh
#
# This script runs Processing, using the JDK in the Processing 
# installation directory if possible.
#
# If no JDK was installed with Processing then the script tries to use 
# the preferred Java version of the machine, i.e. what is executed 
# by the "java" console command. This must be a Sun JDK (for details, see
# http://processing.org/reference/environment/platforms.html#java).
#
# In order to run Processing with an already installed JDK that is *not* 
# the preferred Java version of the machine, create a symlink named "java" 
# in the Processing installation directory that points to the JDK home
# directory.
#


# JARs required from JDK (anywhere in/below the JDK home directory)
JDKLIBS="rt.jar tools.jar"

# Set this to non-zero for logging
LOGGING=0

# Logs name and value of a variable to stdout if LOGGING is non-zero.
# Expects the variable name as parameter $1.
log() {
  if [ $LOGGING -ne 0 ]; then
    eval echo $1=\$$1
  fi
}


# Locates JDKLIBS in a directory and its subdirectories and saves their
# absolute paths as list to JDKCP. Expects the directory as parameter $1.
# Sets SUCCESS to 1 if all libraries were found, to 0 otherwise.
make_jdkcp() {
  # Back out of JRE directory if apparently located inside a JDK
  if [ -f "$1/../bin/java" ]; then
    DIR="$1/.."
  else
    DIR="$1"
  fi
  log DIR

  JDKCP=
  SUCCESS=1

  # Locate JDKLIBS
  for L in $JDKLIBS; do
    # Locate only the first library with a matching name
    LIB=`find "$DIR" -name $L 2>/dev/null | head -n 1`
    log L
    log LIB

    # Library found?
    if [ -n "$LIB" ]; then
      JDKCP="$JDKCP"${JDKCP:+:}"$LIB"
    else
      SUCCESS=0
    fi
  done

  log JDKCP
}


# Get absolute path of directory where this script is located
APPDIR=`readlink -f "$0"`
APPDIR=`dirname "$APPDIR"`
log APPDIR

# Try using a local JDK from the same directory as this script
JDKDIR=`readlink -f "$APPDIR/java"`
make_jdkcp "$JDKDIR"
log SUCCESS

# Local JDK found?
if [ $SUCCESS -ne 1 ]; then
  # No, try using the preferred system JRE/JDK (if any)
  JDKDIR=`which java` && JDKDIR=`readlink -e "$JDKDIR"` && JDKDIR=`dirname "$JDKDIR"`/..
  make_jdkcp "$JDKDIR"
  log SUCCESS
fi

# Add all required JARs to CLASSPATH
CLASSPATH="$CLASSPATH"${CLASSPATH:+:}"$JDKCP"
for LIB in "$APPDIR"/lib/*.jar; do
  CLASSPATH="$CLASSPATH"${CLASSPATH:+:}"$LIB"
done
export CLASSPATH
log CLASSPATH

# Make all JDK binaries available in PATH
export PATH="$JDKDIR/bin":"$PATH"
log PATH

# Start Processing in the same directory as this script
cd "$APPDIR"
java processing.app.Base &