module DomainVariations

# File lib/domain_variations.rb, line 41
def candidates(domain, wordnet: nil)
  flat = flatten(domain)
  return [domain.to_s.downcase] if flat.length < 2

  orig_pos = split_position(domain)
  seen = {}
  list = []

  add = lambda do |candidate|
    return if seen[candidate]

    parsed = DomainParse.parse(candidate)
    return if parsed[:error]

    seen[candidate] = true
    list << parsed[:domain]
  end

  add_dot_splits = lambda do |host|
    host_flat = flatten(host)
    return if host_flat.length < 2

    host_pos = split_position(host)
    positions = []
    ((host_flat.length - 2).downto(1)).each do |position|
      positions << position unless position == host_pos
    end
    tail = host_flat.length - 1
    positions << tail unless tail == host_pos || positions.include?(tail)

    positions.each { |position| add.call(split_at(host_flat, position)) }
  end

  add.call(domain.to_s.downcase)
  add_dot_splits.call(domain.to_s.downcase)

  unless wordnet == false
    lookup = wordnet || DomainVariationsWordnet.default_lookup
    DomainVariationsWordnet.creative_domains(domain, lookup: lookup).each do |creative|
      add.call(creative)
      add_dot_splits.call(creative)
    end
  end

  list.take(MAX_CANDIDATES)
end

# File lib/domain_variations.rb, line 13
def eligible?(parsed)
  return false if parsed[:error]
  return false unless parsed[:dotted]

  domain = parsed[:domain]
  DomainParse::MULTI_PART_TLDS.none? { |suffix| domain.end_with?(".#{suffix}") }
end

# File lib/domain_variations.rb, line 21
def flatten(domain)
  domain.to_s.downcase.delete(".")
end

# File lib/domain_variations.rb, line 88
def no_results?(rdap:, quotes:)
  return false if rdap[:available] == false
  return true if quotes.empty?

  quotes.all? { |quote| quote[:supported] == false }
end

# File lib/domain_variations.rb, line 33
def split_at(flat, position)
  return nil if position <= 0 || position >= flat.length

  left = flat[0, position]
  right = flat[position..]
  "#{left}.#{right}"
end

# File lib/domain_variations.rb, line 25
def split_position(domain)
  host = domain.to_s.downcase
  label, = host.split(".", 2)
  return nil if label.nil? || label.empty?

  label.length
end