#!/usr/bin/env ruby -w

require 'fileutils'

DRAFTS_DIR = File.expand_path("../public/drafts", __dir__).freeze

def usage
  puts "Usage: #{$0} [title]"
  puts
  puts "Examples:"
  puts "  #{$0} Top 5 Ways to Write Clickbait  # using a title without quotes"
  puts "  #{$0} 'Something with punctuation?!' # fancy chars need quotes"
  puts "  #{$0} working-with-databases         # using a slug"
  puts "  #{$0}  # Creates untitled.md (or untitled-2.md, etc.)"
  puts
  puts "Creates a new draft in public/drafts/ directory with proper frontmatter."
end

def draft_path(filename)
  File.join(DRAFTS_DIR, filename)
end

def main
  if ARGV.include?('-h') || ARGV.include?('--help')
    usage
    exit 0
  end

  title, filename =
    if ARGV.empty?
      ['Untitled', next_available_draft]
    else
      given_title = ARGV.join(' ')
      filename = "#{slugify(given_title)}.md"
      path = draft_path(filename)
      if File.exist?(path)
        puts "Error: draft already exists at #{path}"
        exit 1
      end

      [given_title, filename]
    end

  FileUtils.mkdir_p(DRAFTS_DIR)
  path = draft_path(filename)
  content = render_template(title)
  File.write(path, content)

  puts "Created new draft at #{path}"
  puts '>>> Contents below <<<'
  puts
  puts content
end

def slugify(title)
  title.downcase
       .gsub(/[^a-z0-9\s-]/, '')
       .gsub(/\s+/, '-')
       .gsub(/-+/, '-')
       .gsub(/^-|-$/, '')
end

def next_available_draft(base_filename = 'untitled.md')
  return base_filename unless File.exist?(draft_path(base_filename))

  name_without_ext = File.basename(base_filename, '.md')
  counter = 1
  loop do
    numbered_filename = "#{name_without_ext}-#{counter}.md"
    return numbered_filename unless File.exist?(draft_path(numbered_filename))
    counter += 1
  end
end

def render_template(title)
  now = Time.now
  iso_timestamp = now.strftime('%Y-%m-%dT%H:%M:%S%:z')

  <<~FRONTMATTER
    ---
    Author: #{`whoami`.strip}
    Title: #{title}
    Date: unpublished
    Timestamp: #{iso_timestamp}
    Tags:
    ---

    # #{title}

    TKTK
  FRONTMATTER
end

main if $0 == __FILE__