#! /usr/bin/perl

use strict;
use warnings;

my $t = Tags->new(
  {
    txt_file  => q{text.txt},
    tag_files => [qw{tag1.txt tag2.txt}],
  }
);

my $count = 3;
for (0..$count){
  print $t->output;
}

package Tags;

sub new {
  my $class = shift;
  my $args = shift;
  my $self = {};
  
  die q{no txt file} unless exists $args->{txt_file};
  die q{no tag files} unless exists $args->{tag_files};
    
  my $txt_file = $args->{txt_file};
  open my $fh, q{<}, $txt_file
    or die qq{cant open *$txt_file* to read: $!};
  $self->{txt} = do{local $\;<$fh>};
  
  my @files = @{$args->{tag_files}};
  die q{no tag files} unless @files;
  
  for my $file (@files){
    open my $fh, q{<}, $file
      or die qq{cant open *$file* to read: $!};
    my @lines = <$fh>;
    chomp @lines;
    my ($tag_name) = $file =~ /([^.]+)\./;
    $self->{$tag_name} = \@lines;
  }
  
  bless $self, $class;
  return $self;
  
}

sub output {
  my $self = shift;
  my $txt = $self->{txt};
  $txt =~ s/{{([^}]+)}}/$self->next({tag => $1})/eg;
  return $txt;
} 

sub next {
  my $self = shift;
  my $args = shift;
  my $tag = $args->{tag};
  die q{bad tag} unless exists $self->{$tag};
  my $tag_txt = shift @{$self->{$tag}};
  push @{$self->{$tag}}, $tag_txt;
  return $tag_txt;
}