###############################################################################
# Codestriker: Copyright (c) 2001, 2002, 2003 David Sitsky.
# All rights reserved.
# sits@users.sourceforge.net
#
# This program is free software; you can redistribute it and modify it under
# the terms of the GPL.

# Parser object for reading patch diffs in basic form.

package Codestriker::FileParser::PatchBasicDiff;

use strict;
use Codestriker::FileParser::BasicDiffUtils;

# Return the array of filenames, revision number, linenumber and the diff text.
# Return () if the file can't be parsed, meaning it is in another format.
sub parse ($$) {
    my ($type, $fh, $uploaded_filename) = @_;

    # Array of results found.
    my @result = ();

    # The current revision and filename being processed.
    my $revision = $Codestriker::PATCH_REVISION;
    my $filename = $uploaded_filename;

    # Ignore any whitespace at the start of the file.
    my $line = <$fh>;
    while (defined($line)) {

	# Values associated with the diff.
	my $old_linenumber = -1;
	my $new_linenumber = -1;
	my $binary = 0;

	# Skip any heading or trailing whitespace contained in the review
	# text.
	while (defined($line) && $line =~ /^\s*$/) {
	    $line = <$fh>;
	}
	return @result unless defined $line;

	# For basic diffs, the diff line may appear first, but is optional,
	# depending on how the diff was generated.  In any case, the line
	# is ignored.
	if (defined $line && $line =~ /^(diff.*)$/o) {
	    # This isn't right, but it provides some information at least on
	    # the derivative file.
	    $filename = $1;

	    # Read the next line.
	    $line = <$fh>;
	}
	return () unless defined $line;

        # Need to check for binary file differences.
        # Unfortunately, when you provide the "-N" argument to diff,
        # it doesn't indicate new files or removed files properly.  Without
        # the -N argument, it then indicates "Only in ...".
        if ($line =~ /^Binary files .* and (.*) differ$/ ||
	    $line =~ /^Files .* and (.*) differ$/) {
            $filename = $1;
            $binary = 1;
        } elsif ($line =~ /^Only in (.*): (.*)$/) {
            $filename = "$1/$2";
            $binary = 1;
	}
	
	if ($binary == 0) {
	    my $chunk =
		Codestriker::FileParser::BasicDiffUtils->read_diff_text(
		       $fh, $line, $filename, $revision, 0);
	    return () unless defined $chunk;
	    push @result, $chunk;
	} else {
	    # Binary file changed.
	    my $chunk = {};
	    $chunk->{filename} = $filename;
	    $chunk->{revision} = $revision;
	    $chunk->{old_linenumber} = -1;
	    $chunk->{new_linenumber} = -1;
	    $chunk->{binary} = 1;
	    $chunk->{text} = "";
	    $chunk->{description} = "";
	    $chunk->{repmatch} = 0;
	    push @result, $chunk;
	}

	# Read the next line.
	$line = <$fh>;
    }

    # Return the found diff chunks.
    return @result;
}

1;