class RubyCritic::SourceControlSystem::Perforce

def self.build_file_cache
  # Chun is very slow if files stats are requested one by one
  # this fill a hash with the result of all ruby file in the current directory (and sub-directories)
  {}.tap do |file_cache|
    line_aggregator = []
    `p4 fstat #{PERFORCE_FSTAT_OPTS} #{Dir.getwd}...`.each_line do |line|
      Perforce.compute_line(file_cache, line_aggregator, line)
    end
    # handle remaining lines
    Perforce.insert_file_cache(file_cache, line_aggregator) if line_aggregator.any?
  end
end

def self.child?(root, target)
  root_size = root.size
  target_size = target.size
  return false if target_size < root_size
  target[0...root_size] == root &&
    (target_size == root_size || [File::ALT_SEPARATOR, File::SEPARATOR].include?(target[root_size]))
end

def self.compute_cache_lines(lines)
  perforce_lines = Hash[*lines.map { |line| line.split[1..-1] }.flatten]
  PerforceStats.new(
    Perforce.normalized_file_path(perforce_lines['clientFile']),
    perforce_lines['headRev'],
    perforce_lines['headTime'],
    perforce_lines.key?('action'),
    perforce_lines['headChange']
  )
end

def self.compute_line(file_cache, line_aggregator, line)
  if line.chomp.empty?
    Perforce.insert_file_cache(file_cache, line_aggregator)
  else
    line_aggregator << line
  end
end

def self.in_client_directory?
  p4_info = `p4 info`.each_line.select do |line|
    line.start_with?('Client root', 'Current directory')
  end
  client_directory, current_directory = p4_info.map! { |info| info.split(': ').last.chomp }
  child?(client_directory, current_directory)
end

def self.insert_file_cache(file_cache, lines)
  perforce_stat = Perforce.compute_cache_lines(lines)
  file_cache[perforce_stat.filename] = perforce_stat
  lines.clear
end

def self.key_file(source_file_path)
  Perforce.normalized_file_path(File.join(Dir.getwd, source_file_path))
end

def self.normalized_file_path(file_path)
  file_path.downcase.tr('\\', '/')
end

def self.p4_installed?
  p4_exe = Gem.win_platform? ? 'p4.exe' : 'p4'
  ENV['PATH'].split(File::PATH_SEPARATOR).any? do |directory|
    File.executable?(File.join(directory, p4_exe))
  end
end

def self.supported?
  p4_client = ENV['P4CLIENT'] || ''
  p4_installed? && !p4_client.empty? && in_client_directory?
end

def self.to_s
  'Perforce'
end

def date_of_last_commit(path)
  Time.strptime(perforce_files[Perforce.key_file(path)].last_commit, '%s').strftime('%Y-%m-%d %H:%M:%S %z')
end

def head_reference
  perforce_files.values.map(&:head).max_by(&:to_i)
end

def perforce_files
  @perforce_files ||= Perforce.build_file_cache
end

def revision?
  !perforce_files.values.count(&:opened?).zero?
end

def revisions_count(path)
  perforce_files[Perforce.key_file(path)].revision.to_i
end