#!/usr/bin/env perl

# A quick script on moving a document with the embedded metadata.
# It uses exiftool for embedding so be sure to have it installed.
# Only needs an argument of a filename to be converted.

# TODO: Create --title (-t) option that automatically skips the title prompt.
# TODO: Create --author (-a) option that automatically skips the author prompt.
# TODO: Create --date (-d) option that automatically skips the date prompt.

use File::Basename;
use File::Copy;
use Modern::Perl;

# Create a simple prompt returning with the given answer.
sub prompt {
  my ($msg) = @_;
  say $msg;
  print ">> ";
  return <STDIN>;
}

# This implementation of kebab-case conversion is opinionated.
# It converts into lowercase and removes all non-alphanumeric characters.
sub kebab_case {
  my ($string) = @_;

  # Convert into lowercase.
  $string = lc($string);

  # Substitute all spaces and extra dashes as one dash.
  $string =~ s/\s+|-+/-/g;

  # Remove all invalid characters.
  $string =~ s/[^a-z0-9-]//g;

  # Remove all leading and trailing dashes.
  $string =~ s/^-+|-+$//g;

  return $string;
}

my $file = $ARGV[0] ? $ARGV[0] : exit 1;

# Prompt for all the required information.
my $title = prompt "Title of the document?";
my $author = prompt "Author?";
my $publication_date = prompt "Publication date?";

# Overwrite the file metadata.
system "exiftool -title=\"${title}\" -author=\"${author}\" -date=\"${publication_date}\" \"$file\"";

# Once the file metadata has been written, it is time to move the file into its kebab-case equivalent.
my ($filename, $dirs, $suffix) = fileparse($file, '\.[^.]+$');
my $file_slug = $dirs . kebab_case($title) . $suffix;
move($file, $file_slug);