#!/usr/bin/perl -w

# Copyright (C) 2008 Julien Chaffraix <jchaffraix@webkit.org>

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions

# are met:

# 1. Redistributions of source code must retain the above copyright

#    notice, this list of conditions and the following disclaimer.

# 2. Redistributions in binary form must reproduce the above copyright

#    notice, this list of conditions and the following disclaimer in the

#    documentation and/or other materials provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

#

use strict;

package InFilesParser;

my $isParsingCommonParameters;

my $hasStartedParsing;

# Helper functions

sub trimComment

{   

    my $string = shift;

    $string =~ s/#.+$//;

    chomp($string);

    return $string;

}

sub trimWS

{

    my $string = shift;

    $string =~ s/^\s+//;

    $string =~ s/\s+$//;

    chomp($string);

    return $string;

}

sub trimQuoteAndWS

{

    my $string = shift;

    $string =~ s/\"([^\"]+)\"/$1/;

    return trimWS($string);

}

# Default constructor

sub new

{

    my $object = shift;

    my $reference = { };

    # Initialize the parser.

    $isParsingCommonParameters = 1;

    $hasStartedParsing = 0;

    bless($reference, $object);

    return $reference;

}

# parse take 3 attributes:

# - the filestream to read from (the caller has to open / close it).

# - the commonParameterHandler called when parsing the first part of the file with the parameter and the value.

# - the perTagHandler called for each optional parameter with the element name, the parameter and its value.

#   If no parameter were provided, it is called once with an empty parameter and value.

sub parse($)

{

    my $object = shift;

    my $fileStream = shift; # IO::File only

    my $commonParameterHandler = shift;

    my $perTagHandler = shift;

    foreach (<$fileStream>) {

        # Ignore whitespace, in case the .in files have the wrong EOL

        # markers and those are getting treated as whitespace.

        $_ = trimWS($_);

        # Empty line, change from common parameter part

        # to per tag part if we have started parsing.

        if (/^$/) {

            if ($hasStartedParsing) {

                $isParsingCommonParameters = 0;

            }

            next;

        }

        # There may be a few empty lines at the beginning of the file

        # so detect the first non empty line which starts the common

        # parameters part.

        $hasStartedParsing = 1;

        if (/^#/) {

            next;

        }

        $_ = trimComment($_);

        if ($isParsingCommonParameters) {

            my ($name, $value) = split '=', $_;

            $name = trimWS($name);

            if (defined($value)) {

                $value = trimQuoteAndWS($value);

            } else {

                # We default to 1 as it eases the syntax.

                $value = "1";

            }

            &$commonParameterHandler($name, $value);

        } else {

            # Parsing per-tag parameters.

            # Split the tag name ($1) from the optionnal parameter(s) ($2)

            /^(\S+)\s*(.*)$/;

            my $elementName = $1;

            if ($2) {

                my @options = split "," , $2;

                my ($option, $value);

                for (my $i = 0; $i < @options; ++$i) {

                    ($option, $value) = split "=", $options[$i];

                    $option = trimWS($option);

                    if (defined($value)) {

                        $value = trimQuoteAndWS($value);

                    } else {

                        # We default to 1 as it eases the syntax.

                        $value = "1";

                    }

                    &$perTagHandler($elementName, $option, $value);

                }

            } else {

                # No parameter was given so call it with empty strings.

                &$perTagHandler($elementName, "", "");

            }

        }

    }

}

1;