#!/bin/env perl

# Source characters
my @S = qw(p t t͡ʃ k s ʃ);
# Replacement characters
my @Z = qw(b d d͡ʒ g z ʒ);

# Boundaries
my $V = "a|ə|e|o|i|u|ø|y";

use warnings;
use strict;

my $filename = pop;

my $inverted = 0;

while ( $_ = shift )
{
  if(/--invert/)
  {
    $inverted = 1;
  }
}

# Open the file
open(my $fh, "<", $filename);

# Read line by line
while(<$fh>)
{
  # apply early transformations here

  # Go through each "source" => "replacement"
  for(my $i = 0; $i < @S; $i++) {
    # retrieve the source
    my $item = $inverted?$Z[$i]:$S[$i];
    # and replacement
    my $rplc = $inverted?$S[$i]:$Z[$i];

    # replace the source by replacement inside the boundaries
    s/((?:$V)+)$item((?:$V)+)/$1$rplc$2/gi

  }

  # insert any other transformations here


  # print the line after modifications
  print;
}

close($fh);