class RuboCop::Cop::Metrics::LineLength

def allow_heredoc?
  allowed_heredoc
end

def allow_uri?
  cop_config['AllowURI']
end

def allowed_heredoc
  cop_config['AllowHeredoc']
end

def allowed_uri_position?(line, uri_range)
  uri_range.begin < max &&
    (uri_range.end == line_length(line) ||
     uri_range.end == line_length(line) - 1)
end

def check_directive_line(line, index)
  return if line_length_without_directive(line) <= max
  range = max..(line_length_without_directive(line) - 1)
  register_offense(
    source_range(
      processed_source.buffer,
      index + 1,
      range
    ),
    line
  )
end

def check_line(line, index, heredocs)
  return if line_length(line) <= max
  return if ignored_line?(line, index, heredocs)
  if ignore_cop_directives? && directive_on_source_line?(index)
    return check_directive_line(line, index)
  end
  return check_uri_line(line, index) if allow_uri?
  register_offense(
    source_range(
      processed_source.buffer, index,
      highligh_start(line)...line_length(line)
    ),
    line
  )
end

def check_uri_line(line, index)
  uri_range = find_excessive_uri_range(line)
  return if uri_range && allowed_uri_position?(line, uri_range)
  register_offense(excess_range(uri_range, line, index), line)
end

def directive_on_source_line?(index)
  source_line_number = index + processed_source.buffer.first_line
  comment =
    processed_source
    .comments
    .detect { |e| e.location.line == source_line_number }
  return false unless comment
  comment.text.match(CommentConfig::COMMENT_DIRECTIVE_REGEXP)
end

def excess_range(uri_range, line, index)
  excessive_position = if uri_range && uri_range.begin < max
                         uri_range.end
                       else
                         highligh_start(line)
                       end
  source_range(processed_source.buffer, index + 1,
               excessive_position...(line_length(line)))
end

def extract_heredocs(ast)
  return [] unless ast
  ast.each_node(:str, :dstr, :xstr).select(&:heredoc?).map do |node|
    body = node.location.heredoc_body
    delimiter = node.location.heredoc_end.source.strip
    [body.first_line...body.last_line, delimiter]
  end
end

def find_excessive_uri_range(line)
  last_uri_match = match_uris(line).last
  return nil unless last_uri_match
  begin_position, end_position = last_uri_match.offset(0)
  return nil if begin_position < max && end_position < max
  begin_position...end_position
end

def highligh_start(line)
  return max unless tab_indentation_width
  max - (tab_indentation_width - 1) * line.count("\t")
end

def ignore_cop_directives?
  cop_config['IgnoreCopDirectives']
end

def ignored_line?(line, index, heredocs)
  matches_ignored_pattern?(line) ||
    heredocs && line_in_whitelisted_heredoc?(heredocs, index.succ)
end

def investigate(processed_source)
  heredocs = extract_heredocs(processed_source.ast) if allow_heredoc?
  processed_source.lines.each_with_index do |line, index|
    check_line(line, index, heredocs)
  end
end

def line_in_whitelisted_heredoc?(heredocs, line_number)
  heredocs.any? do |range, delimiter|
    range.cover?(line_number) &&
      (allowed_heredoc == true || allowed_heredoc.include?(delimiter))
  end
end

def line_length(line)
  if tab_indentation_width
    line = line.gsub("\t", ' ' * tab_indentation_width)
  end
  line.length
end

def line_length_without_directive(line)
  before_comment, = line.split(CommentConfig::COMMENT_DIRECTIVE_REGEXP)
  before_comment.rstrip.length
end

def match_uris(string)
  matches = []
  string.scan(uri_regexp) do
    matches << $LAST_MATCH_INFO if valid_uri?($LAST_MATCH_INFO[0])
  end
  matches
end

def max
  cop_config['Max']
end

def register_offense(loc, line)
  message = format(MSG, length: line_length(line), max: max)
  add_offense(nil, location: loc, message: message) do
    self.max = line_length(line)
  end
end

def tab_indentation_width
  config.for_cop('Layout/Tab')['IndentationWidth']
end

def uri_regexp
  @uri_regexp ||=
    URI::DEFAULT_PARSER.make_regexp(cop_config['URISchemes'])
end

def valid_uri?(uri_ish_string)
  URI.parse(uri_ish_string)
  true
rescue URI::InvalidURIError, NoMethodError
  false
end