use strict;
use warnings;

# EX: Change '.' 'char1' 'char2' to 'b' 'char2' 'char1' 's'
my $input_string = 'foo.ra';
my $find         = '\.(.)(.)$';
my $replace      = 'b$2$1s';

my $def_value0 = stringExpressionReplace($input_string,$find,$replace,0);
my $def_value1 = stringExpressionReplace($input_string,$find,$replace,1);
my $def_value2 = stringExpressionReplace($input_string,$find,$replace,2);

# Use varaible-based substitutions in search/replace pattern
sub stringExpressionReplace {
  my $mod_string  = $_[0];
  my $find        = $_[1];
  my $replace     = $_[2];
  my $sr_type     = $_[3];

  print "\nstringExpressionReplace String: $mod_string Find: $find Replace: $replace\n";
  my $orig_string   = $mod_string;
  my $orig_replace  = $replace;
  $replace   = "\"" . $replace . "\"";

  if($sr_type == 1) { # Reorder issue
    #$mod_string =~ s/$find/sprintf($replace,$1,$2,$3,$4,$5)/e; # Example, ordering issue
    print "stringExpressionReplace sr_type = 1 Replace var with substitution hard-coded.\n";
    $mod_string =~ s/$find/sprintf($replace,$2,$1)/e; # Hard-coded order, var list not a string
    print "stringExpressionReplace SR command: s/$find/sprintf($replace,\$2,\$1)/e\n";
    print "stringExpressionReplace String: $orig_string --> $mod_string         Find: $find Replace: $replace\n" if($orig_string ne $mod_string);
  } elsif($sr_type == 2) {
    my @replacements  = ( $replace =~ /(\$\d)/g ); # Store Replacement list in order
    my $replace_count = scalar @replacements;
    $replace   =~ s/\$\d/\%s/g;
    print "stringExpressionReplace Format String: $orig_replace --> $replace\n";
    my $var_list = "";
    if(@replacements) {
      foreach my $var (@replacements) {
        $var_list .= "$var,";
      }
      $var_list =~ s/,$//;
      print "stringExpressionReplace Var    String: $var_list\n";
    }

    if(@replacements) { # perl expression $-based subsitution found
      print "stringExpressionReplace sr_type = 2 Replace and var lists as variables.\n";
      print "stringExpressionReplace SR command: s/$find/sprintf($replace,$var_list)/e\n";
      $mod_string =~ s/$find/sprintf($replace,$var_list)/e;
      #$mod_string =~ s/\.(.)(.)$/sprintf("b%s%ss",$2,$1)/e;
      print "stringExpressionReplace String: $orig_string --> $mod_string Count $replace_count Find: $find Replace: $orig_replace --> $replace $var_list\n";
    } else {
      $mod_string =~ s/$find/$replace/;
      print "stringExpressionReplace                    String: $orig_string --> $mod_string\n" if($orig_string ne $mod_string);
    }
  } else {
    print "stringExpressionReplace completely hard-coded.\n";
    $mod_string =~ s/\.(.)(.)$/b$2$1s/;
    print "stringExpressionReplace sr_type = 0        String: $orig_string --> $mod_string\n" if($orig_string ne $mod_string);
  }
  return $mod_string;
}