#!/usr/bin/perl

use strict;
#use warnings;  # produces warnings like: Hexadecimal number > 0xffffffff non-portable at ./project2-postScript.pl line 64.

my $DEBUG = 0;

sub fileToString{
    my $file_ = $_[0];
    
    my $msg = "Input file '" . $file_ . "' failed to open.\n" . "Died";

    my $terminator = $/;
    undef $/;
    open INPUT, "<$file_" or die $msg;
    my $str = <INPUT>; # terminator undefined : $str is the whole file.
    close INPUT;

    $/ = $terminator; # Restore for normal behavior later

    return $str;
}

sub stringToFile{
    my ($str, $filename) = @_;
    
    open OUTPUT, ">$filename" or die("ERROR: Unable to create $filename: $!");
    print OUTPUT "$str";
    close OUTPUT;
}



if( $#ARGV + 1 < 1){
    die("Usage $0:  <commandLineArgsFilename> <stdinFilename> <execution_results_filename> [answer_key_filename]");
}


my $commandLineArgsFilename = shift;
my $stdinFilename = shift;
my $resultsFilename = shift;
my $answerKeyFilename = shift;
if( ! defined( $answerKeyFilename)){
    $answerKeyFilename = "";
}

if( $DEBUG == 1){
    print STDERR "commandLineArgsFilename: $commandLineArgsFilename\n";
    print STDERR "stdinFilename: $stdinFilename\n";
    print STDERR "resultsFilename: $resultsFilename\n";
    print STDERR "answerKeyFilename: $answerKeyFilename\n";
}

my $fileContents = fileToString( $resultsFilename);
if( $fileContents !~ m/Free chunk at (0x[0-9A-Fa-f]+)/){
    print "Unable to find base address using 'Free chunk at 0x' as an anchor!\n";
    if( $fileContents !~ m/(0x[0-9A-Fa-f]+)/){
	print "Unable to find base address using '0x' as an anchor!\n";
    }
}
my $baseAddress = hex($1);
# printf( "baseAddress: $baseAddress (0x%X)\n", $baseAddress);
my $offset = $baseAddress - hex('0x100000000');
# printf( "offset: $offset (0x%X)\n", $offset);

my @fileContents = split( /0x/, $fileContents);
for( my $i = 1; $i <= $#fileContents; $i++){
    if( $fileContents[ $i] !~ m/^([0-9A-Fa-f]+)/){
	print "ERROR: Unable to parse address from $fileContents[$i]!\n";
	die();
    }
    if( $1 == "0"){
	# skip over 0x0
	next;
    }
    my $addr = $1;
    my $addrAdjusted = sprintf("%x", hex($addr) - $offset);
    # printf( "$addrAdjusted = hex($addr) - $offset\n");
    # print "fileContents[$i] (before): $fileContents[$i]\n";
    $fileContents[$i] =~ s/^$addr/$addrAdjusted/;
    # print "fileContents[$i] (after): $fileContents[$i]\n";
}

my $fileContentsAdjusted = join('0x', @fileContents);
stringToFile( $fileContentsAdjusted, $resultsFilename );


# echo output
printf("Output (adjusted addresses by -0x%x (-$offset)):\n", $offset);
print "-----------------------------------------------------------------------------\n";
print $fileContentsAdjusted;
print "\n";


my $tmpDiffFile="tmp-$$.diff";
my $tmpDiffSidesFile="tmp-$$-sides.diff";

my $cmd = "diff --text -bd $answerKeyFilename $resultsFilename > $tmpDiffFile";
system( $cmd );

print("\n");  # echo ""

if ( -s "$tmpDiffFile" ){
    print "Diff of answer key (left column) and user program (right column) (side-by-side):\n";
    print "-----------------------------------------------------------------------------\n";
    #diff --text -bd --side-by-side --width=95 $stdoutKeyFilename $stdoutFile  > $tmpDiffSidesFile
    $cmd = "diff --text -bd --side-by-side --width=89 $answerKeyFilename $resultsFilename  > $tmpDiffSidesFile";  # Mac OS X enscript default characters per line
    system( $cmd );
    #system( "truncateFile $tmpDiffSidesFile; cat $tmpDiffSidesFile");
    system( "cat $tmpDiffSidesFile");
    
    print "\n";
    print "Diff of answer key and user program (traditional format):\n";
    print "-----------------------------------------------------------------------------\n";
    #system( "truncateFile $tmpDiffFile; cat $tmpDiffFile");
    system( "cat $tmpDiffFile");

    system( "rm -f $tmpDiffFile $tmpDiffSidesFile");
}

exit(0);