#!/bin/sh
##############################################################################
#                      __                                                    #
#      ________ ___   / /  ___     Scala Tools Launch Script                 #
#     / __/ __// _ | / /  / _ |    (c) 2002-2003, LAMP/EPFL                  #
#   __\ \/ /__/ __ |/ /__/ __ |                                              #
#  /____/\___/_/ |_/____/_/ | |                                              #
#                           |/                                               #
##############################################################################

# $Id$

##############################################################################
# Configuration

# The configure function contains all the configurable variables of
# this script. Each of these variables may be overridden by defining
# an environment variable with the same but where the "default_" has
# been replaced by "SCALA_". For example, to start scalaint with a big
# initial heap size, one may run the following command:
#
#   env SCALA_SCALA_ARGS=-Xms1024m scalaint".
#
# These variables must use the Unix form for paths and path lists
# (i.e. use '/' as file separator and ':' as path separator). There
# are two exceptions: JAVA_ARGS and SCALA_ARGS which must use the
# paltform-specific form.
#
# The following environment variables are also read by this script:
#
# - SCALA_CLASSPATH: if defined, it is used as the default classpath
#   by all Scala tools.
#
# - CLASSPATH: if defined and SCALA_CLASSPATH is undefined, it is used
#   as the default classpath by all Scala tools.
#
# - SCALA_SOURCEPATH: if defined, it is used as the default sourcepath
#   by all Scala tools.
#
# - SCALA_BOOTCLASSPATH: if defined, it is used as the default
#   bootclasspath by all Scala tools.
#
# - SCALA_EXTDIRS: if defined, it is used as the default extdirs by
#   all Scala tools.
#
# These variables must use the platform-specific form for paths and
# path lists.

configure() {

    # Location of the Scala library sources.
    default_LIBRARY_SOURCES={#LIBRARY_SOURCES#};

    # Location of the Scala library.
    default_LIBRARY_CLASSES={#LIBRARY_CLASSES#};

    # Location of the Scala tools library.
    default_TOOLS_CLASSES={#TOOLS_CLASSES#};

    # Location of the FJBG library.
    default_FJBG_CLASSES={#FJBG_CLASSES#};

    # Location of the MSIL library.
    default_MSIL_CLASSES={#MSIL_CLASSES#};

    # Command to start the Java VM.
    default_JAVA_CMD={#JAVA_CMD#};

    # Additional arguments to pass to the Java VM.
    default_JAVA_ARGS={#JAVA_ARGS#};

    # Command to start the Scala VM.
    default_SCALA_CMD={#SCALA_CMD#};

    # Additional arguments to pass to the Scala VM.
    default_SCALA_ARGS={#SCALA_ARGS#};

    # Command to start subprocesses. This is mainly for debugging
    # purposes. For example, one may display the Java command that is
    # started by "scala", by running "env SCALA_EXEC=echo scala".
    default_EXEC="exec";

}

##############################################################################
# Error functions

# Prints a warning message on stderr.
warning() {
    echo "$0: warning:" "$@" 1>&2;
}

# Prints an error message on stderr.
error() {
    echo "$0:" "$@" 1>&2;
}

# Prints an error message on stderr and exits with a non-zero status.
abort() {
    error "$@";
    exit 1;
}

##############################################################################
# File name and path list conversion functions

# Prints the OS-specific form of the specified Unix form file name.
get_os_filename() {
    [ $# = 1 ] || abort "internal error";
    case "$UNAME" in
        CYGWIN* ) cygpath --windows "$1";;
        *       ) echo "$@";;
    esac;
}

# Prints the Unix form of the specified OS-specific form file name.
get_unix_filename() {
    [ $# = 1 ] || abort "internal error";
    case "$UNAME" in
        CYGWIN* ) cygpath --unix "$1";;
        *       ) echo "$@";;
    esac;
}

# Prints the OS-specific form of the specified Unix form path list.
get_os_pathlist() {
    [ $# = 1 ] || abort "internal error";
    case "$UNAME" in
        CYGWIN* ) cygpath --window --path "$1";;
        *       ) echo "$@";;
    esac;
}

# Prints the Unix form of the specified OS-specific form path list.
get_unix_pathlist() {
    [ $# = 1 ] || abort "internal error";
    case "$UNAME" in
        CYGWIN* ) cygpath --unix --path "$1";;
        *       ) echo "$@";;
    esac;
}

##############################################################################
# Path list construction functions

# Prints the concatenation of two path lists.
append_pathlists() {
    [ $# = 2 ] || abort "internal error";

    if [ -z "$1" ]; then
        echo "$2";
    elif [ -z "$2" ]; then
        echo "$1";
    else
        echo "$1:$2";
    fi;
}

##############################################################################
# Value computation functions

# Computes and stores the value "$1" in the variable "current_$1". If
# the variable "SCALA_$1" is defined, its content is used. Otherwise,
# the content of the variable "default_$1" is used.
compute_value() {
    [ $# = 1 ] || abort "internal error";

    eval current_$1=\"\$default_$1\";
    case "$1" in

        LIBRARY_SOURCES | \
        LIBRARY_CLASSES | \
        TOOLS_CLASSES   | \
        FJBG_CLASSES    | \
        MSIL_CLASSES    )
            if eval [ -n \"\$SCALA_$1\" ]; then
                if eval [ -f \"\$SCALA_$1\" -o -d \"\$SCALA_$1\" ]; then
                    eval current_$1=\"\$SCALA_$1\";
                else
                    eval warning \""File referred by SCALA_$1 (\$SCALA_$1)" \
                        "does not exist, using default value instead."\";
                    unset SCALA_$1;
                fi;
            fi;
            if ! eval [ -f \"\$current_$1\" -o -d \"\$current_$1\" ]; then
                eval abort \""File referred by default_$1 (\$default_$1)" \
                    "does not exist. Please, fix definition of default_$1 in" \
                    "file $SOURCE or define environment variable SCALA_$1."\";
            fi;
            ;;

        JAVA_CMD   | \
        JAVA_ARGS  | \
        SCALA_CMD  | \
        SCALA_ARGS | \
        EXEC       )
            if eval [ -n \"\$SCALA_$1\" ]; then
                eval current_$1=\"\$SCALA_$1\";
            fi;
            ;;

        * )
            abort "internal error: $1";
            ;;

    esac;
}

##############################################################################
# Default paths

# Prints the default scala classpath or nothing if it's unspecified.
get_scala_classpath() {
    if [ -n "$SCALA_CLASSPATH" ]; then
        get_unix_pathlist "$SCALA_CLASSPATH";
    elif [ -n "$CLASSPATH" ]; then
        get_unix_pathlist "$CLASSPATH";
    fi;
}

# Prints the default scala sourcepath or nothing if it's unspecified.
get_scala_sourcepath() {
    if [ -n "$SCALA_SOURCEPATH" ]; then
        get_unix_pathlist "$SCALA_SOURCEPATH";
    fi;
}

# Prints the default scala bootclasspath or nothing if it's unspecified.
get_scala_bootclasspath() {
    if [ -n "$SCALA_BOOTCLASSPATH" ]; then
        get_unix_pathlist "$SCALA_BOOTCLASSPATH";
    fi;
}

# Prints the default scala extdirs or nothing if it's unspecified.
get_scala_extdirs() {
    if [ -n "$SCALA_EXTDIRS" ]; then
        get_unix_pathlist "$SCALA_EXTDIRS";
    fi;
}

##############################################################################
# VM invocation functions

# Prints the VM script-suffix-specific arguments.
vm_get_script_suffix_args() {
    case "$SCRIPT" in
        *-debug* ) echo "-Djava.compiler=NONE -ea";;
    esac;
}

# Starts a Java VM with the specified arguments.
vm_start_java() {
    # compute values
    compute_value EXEC;
    compute_value JAVA_CMD;
    compute_value JAVA_ARGS;

    # start Java VM
    $current_EXEC $current_JAVA_CMD $current_JAVA_ARGS \
        `vm_get_script_suffix_args` "$@";
}

# Starts a Scala VM with the specified arguments.
vm_start_scala() {
    # compute values
    compute_value EXEC;
    compute_value SCALA_CMD;
    compute_value SCALA_ARGS;

    # start Java VM
    $current_EXEC $current_SCALA_CMD $current_SCALA_ARGS \
        `vm_get_script_suffix_args` "$@";
}

##############################################################################
# Scala invocation functions

# Returns true if the given arguments contain a flag -Xbootclasspath.
scala_has_bootclasspath() {
    while [ $# != 0 ]; do
        case "$1" in
            -Xbootclasspath:* ) return 0;;
            -cp | -classpath  ) shift 2;;
            -jar              ) return 1;;
            -*                ) shift 1;;
            *                 ) return 1;;
        esac;
    done;
    return 1;
}

# Implements the command "scala".
scala() {
    if scala_has_bootclasspath "$@"; then
        vm_start_java "$@";
    else
        compute_value LIBRARY_CLASSES;
        classes="$current_LIBRARY_CLASSES";
        vm_start_java "-Xbootclasspath/a:`get_os_filename "$classes"`" "$@";
    fi;
}

##############################################################################
# Tool invocation functions

# Starts a Scala tool. The first argument is added to the runtime
# classpath. The following ones are passed to vm_start_scala. They
# must, at least, contain the name of the main class.
tool_start() {
    [ $# -gt 1 ] || abort "internal error";
    classpath="$1"; shift 1;

    # compute value
    compute_value LIBRARY_SOURCES;
    compute_value LIBRARY_CLASSES;
    compute_value TOOLS_CLASSES;

    # append tools library to classpath
    classpath=`append_pathlists "$classpath" "$current_TOOLS_CLASSES"`;

    # start Scala VM
    tool_start0 -classpath "`get_os_pathlist "$classpath"`" "$@";
}

tool_start0() {
    if [ -n "`get_scala_extdirs`" ]; then
        tool_start1 -Dscala.ext.dirs="`get_scala_extdirs`" "$@";
    else
        tool_start1 "$@";
    fi;
}

tool_start1() {
    if [ -n "`get_scala_bootclasspath`" ]; then
        tool_start2 -Dscala.boot.class.path="`get_scala_bootclasspath`" "$@";
    else
        tool_start2 "$@";
    fi;
}

tool_start2() {
    if [ -n "`get_scala_sourcepath`" ]; then
        tool_start3 -Dscala.source.path="`get_scala_sourcepath`" "$@";
    else
        tool_start3 "$@";
    fi;
}

tool_start3() {
    if [ -n "`get_scala_classpath`" ]; then
        tool_start4 -Dscala.class.path="`get_scala_classpath`" "$@";
    else
        tool_start4 "$@";
    fi;
}

tool_start4() {
    sources="$current_LIBRARY_SOURCES";
    classes="$current_LIBRARY_CLASSES";
    vm_start_scala \
        -Dscala.product="$SCRIPT" \
        -Dscala.version="$VERSION" \
        -Dscala.home="$PREFIX" \
        -Dscala.library.source.path="`get_os_filename "$sources"`" \
        -Dscala.library.class.path="`get_os_filename "$classes"`" \
        "$@";
}

##############################################################################
# Compiler invocation functions

# Starts a Scala compiler. The first argument is added to the runtime
# classpath. The following ones are passed to vm_start_scala. They
# must, at least, contain the name of the main class.
compiler_start() {
    [ $# -gt 1 ] || abort "internal error";
    classpath="$1"; shift 1;

    # compute values
    compute_value FJBG_CLASSES;
    compute_value MSIL_CLASSES;

    # append FJBG and MSIL libraries to classpath
    classpath=`append_pathlists "$classpath" "$current_FJBG_CLASSES"`;
    classpath=`append_pathlists "$classpath" "$current_MSIL_CLASSES"`;

    # start tool
    tool_start "$classpath" "$@";
}

##############################################################################
# Implementation of scala-info

# Prints given error message, prints usage and exits with error code 1.
info_abort() {
    error "$@";
    info_print_usage 1>&2;
    exit 1;
}

# Prints value of variable $1.
info_print_variable() {
    [ $# = 1 ] || abort "internal error";
    eval echo \"\$$1\";
}

# Prints default value of value $1.
info_print_default_value() {
    [ $# = 1 ] || abort "internal error";
    info_print_variable "default_$1";
}

# Prints current value of value $1.
info_print_current_value() {
    [ $# = 1 ] || abort "internal error";
    compute_value "$1";
    info_print_variable "current_$1";
}

# Implements "scala-info --home".
info_option_home() {
    [ $# -gt 0 ] && abort "too many arguments";
    echo "$PREFIX";
}

# Implements "scala-info --version".
info_option_version() {
    [ $# -gt 0 ] && abort "too many arguments";
    echo "$VERSION";
}

# Implements "scala-info --$1 <value>"
info_option_x_value() {
    [ $# -lt 2 ] && abort "missing value name";
    [ $# -gt 2 ] && abort "too many arguments";
    case "$2" in
        LIBRARY_SOURCES     ) value=$2;;
        LIBRARY_CLASSES     ) value=$2;;
        TOOLS_CLASSES       ) value=$2;;
        FJBG_CLASSES        ) value=$2;;
        MSIL_CLASSES        ) value=$2;;
        JAVA_CMD            ) value=$2;;
        JAVA_ARGS           ) value=$2;;
        SCALA_CMD           ) value=$2;;
        SCALA_ARGS          ) value=$2;;
        EXEC                ) value=$2;;
        *                   ) abort "Unknown value \`$2'";;
    esac;
    info_print_$1_value $value;
}

# Implements "scala-info --help".
info_option_help() {
    echo "usage: $0 <option>";
    echo "where possible options include:";
    echo "  --home            Print Scala home directory";
    echo "  --version         Print Scala version";
    echo "  --default <name>  Print default value of value <name>";
    echo "  --current <name>  Print current value of value <name>";
    echo "  -? --help         Print this help message";
    echo "";
    echo "valid value names include:";
    echo "  LIBRARY_SOURCES   Location of the Scala library sources";
    echo "  LIBRARY_CLASSES   Location of the Scala library";
    echo "  TOOLS_CLASSES     Location of the Scala tools";
    echo "  FJBG_CLASSES      Location of the fjbg library";
    echo "  MSIL_CLASSES      Location of the msil library";
    echo "  JAVA_CMD          Command to start the Java VM";
    echo "  JAVA_ARGS         Additional arguments to pass to the Java VM";
    echo "  SCALA_CMD         Command to start the Scala VM";
    echo "  SCALA_ARGS        Additional arguments to pass to the Scala VM";
    echo "  EXEC              Command to start subprocesses";
}

# Entry point of scala-info.
info() {
    [ $# = 0 ] && abort "missing option";

    case "$1" in
        --home      ) shift 1; info_option_home "$@";;
        --version   ) shift 1; info_option_version "$@";;
        --default   ) shift 1; info_option_x_value default "$@";;
        --current   ) shift 1; info_option_x_value current "$@";;
        -? | --help ) shift 1; info_option_help "$@";;
        -*          ) abort "unrecognised option \`$1'";;
        *           ) abort "illegal argument \`$1'";;
    esac;
}

##############################################################################
# Definition of UNAME, SOURCE, SCRIPT, PREFIX and VERSION

unset SCRIPT;
UNAME=`uname`;
SOURCE=$0;
SCRIPT=`basename "$SOURCE"`;
while [ -h "$SOURCE" ]; do
    SCRIPT=`basename "$SOURCE"`;
    LOOKUP=`ls -ld "$SOURCE"`;
    TARGET=`expr "$LOOKUP" : '.*-> \(.*\)$'`;
    if expr "${TARGET:-.}/" : '/.*/$' > /dev/null; then
        SOURCE=${TARGET:-.};
    else
        SOURCE=`dirname "$SOURCE"`/${TARGET:-.};
    fi;
done;
PREFIX=`dirname "$SOURCE"`/..;
PREFIX=`cd "$PREFIX"; pwd`;

VERSION={#VERSION#};
VERSION=${VERSION:-"unknown version"};

##############################################################################
# Test of invocation method

if [ -z "$SCRIPT" ]; then
    abort "Illegal direct invocation; invoke me through a symbolic link.";
fi;

##############################################################################
# Configuration and invocation of $SCRIPT

configure;

case "$SCRIPT" in
    scala-info ) info "$@";;
    scala      ) scala "$@";;
    scala-*    ) scala "$@";;
    scalac*    ) compiler_start "" scala.tools.scalac.Main "$@";;
    scalarun*  ) compiler_start "" scala.tools.scalai.Main "$@";;
    scalaint*  ) compiler_start "" scala.tools.scalai.Main -interactive "$@";;
    scaladoc*  ) tool_start "" scala.tools.scaladoc.Main "$@";;
    scalap*    ) tool_start "" scala.tools.scalap.Main "$@";;
    dtd2scala* ) tool_start "" scala.tools.dtd2scala.Main "$@";;
    scalatest* ) tool_start "" scala.tools.scalatest.Main "$@";;
    *          ) abort "Don't know what to do for $SCRIPT.";;
esac;

##############################################################################