class RuboCop::Cop::Layout::HeredocArgumentClosingParenthesis

def add_correct_closing_paren(node, corrector)
  corrector.insert_after(node.arguments.last.source_range, ')')
end

def add_correct_external_trailing_comma(node, corrector)
  return unless external_trailing_comma?(node)
  corrector.insert_after(node.arguments.last.source_range, ',')
end

def autocorrect(node)
  lambda do |corrector|
    fix_closing_parenthesis(node, corrector)
    if internal_trailing_comma?(node)
      remove_internal_trailing_comma(node, corrector)
    end
    if external_trailing_comma?(node)
      fix_external_trailing_comma(node, corrector)
    end
  end
end

def external_trailing_comma?(node)
  !external_trailing_comma_offset_from_loc_end(node).nil?
end

def external_trailing_comma_offset_from_loc_end(node)
  end_pos = node.source_range.end_pos
  offset = 0
  limit = 20
  offset += 1 while offset < limit && space?(end_pos + offset)
  char = processed_source.buffer.source[end_pos + offset]
  return unless char == ','
  offset + 1 # Add one to include the comma.
end

def extract_heredoc(node)
  return node if heredoc_node?(node)
  return node.receiver if single_line_send_with_heredoc_receiver?(node)
  return unless node.hash_type?
  node.values.find do |v|
    heredoc = extract_heredoc(v)
    return heredoc if heredoc
  end
end

def extract_heredoc_argument(node)
  node.arguments.find do |arg_node|
    extract_heredoc(arg_node)
  end
end

def fix_closing_parenthesis(node, corrector)
  remove_incorrect_closing_paren(node, corrector)
  add_correct_closing_paren(node, corrector)
end

def fix_external_trailing_comma(node, corrector)
  remove_incorrect_external_trailing_comma(node, corrector)
  add_correct_external_trailing_comma(node, corrector)
end

def heredoc_node?(node)
  node && STRING_TYPES.include?(node.type) && node.heredoc?
end

def incorrect_parenthesis_removal_begin(node)
  end_pos = node.source_range.end_pos
  if safe_to_remove_line_containing_closing_paren?(node)
    last_line_length = node.source.scan(/\n(.*)$/).last[0].size
    end_pos - last_line_length - 1 # Add one for the line break itself.
  else
    end_pos - 1 # Just the `)` at the end of the string
  end
end

def incorrect_parenthesis_removal_end(node)
  end_pos = node.source_range.end_pos
  if processed_source.buffer.source[end_pos] == ','
    end_pos + 1
  else
    end_pos
  end
end

def internal_trailing_comma?(node)
  !internal_trailing_comma_offset_from_last_arg(node).nil?
end

def internal_trailing_comma_offset_from_last_arg(node)
  source_after_last_arg = range_between(
    node.children.last.source_range.end_pos,
    node.loc.end.begin_pos
  ).source
  first_comma_offset = source_after_last_arg.index(',')
  first_new_line_offset = source_after_last_arg.index("\n")
  return if first_comma_offset.nil?
  return if first_new_line_offset.nil?
  return if first_comma_offset > first_new_line_offset
  first_comma_offset + 1
end

def on_send(node)
  heredoc_arg = extract_heredoc_argument(node)
  return unless heredoc_arg
  outermost_send = outermost_send_on_same_line(heredoc_arg)
  return unless outermost_send
  return unless outermost_send.loc.end
  return unless heredoc_arg.first_line != outermost_send.loc.end.line
  add_offense(outermost_send, location: :end)
end

def outermost_send_on_same_line(heredoc)
  previous = heredoc
  current = previous.parent
  until send_missing_closing_parens?(current, previous, heredoc)
    previous = current
    current = current.parent
    return unless previous && current
  end
  current
end

def remove_incorrect_closing_paren(node, corrector)
  corrector.remove(
    range_between(
      incorrect_parenthesis_removal_begin(node),
      incorrect_parenthesis_removal_end(node)
    )
  )
end

def remove_incorrect_external_trailing_comma(node, corrector)
  end_pos = node.source_range.end_pos
  return unless external_trailing_comma?(node)
  corrector.remove(
    range_between(
      end_pos,
      end_pos + external_trailing_comma_offset_from_loc_end(node)
    )
  )
end

def remove_internal_trailing_comma(node, corrector)
  offset = internal_trailing_comma_offset_from_last_arg(node)
  last_arg_end_pos = node.children.last.source_range.end_pos
  corrector.remove(
    range_between(
      last_arg_end_pos,
      last_arg_end_pos + offset
    )
  )
end

def safe_to_remove_line_containing_closing_paren?(node)
  last_line = processed_source[node.loc.end.line - 1]
  # Safe to remove if last line only contains `)`, `,`, and whitespace.
  last_line.match(/^[ ]*\)[ ]{0,20},{0,1}[ ]*$/)
end

def send_missing_closing_parens?(parent, child, heredoc)
  send_node?(parent) &&
    parent.arguments.include?(child) &&
    parent.loc.begin &&
    parent.loc.end.line != heredoc.last_line
end

def send_node?(node)
  return nil unless node
  node.send_type? || node.csend_type?
end

def single_line_send_with_heredoc_receiver?(node)
  return false unless node.send_type?
  return false unless heredoc_node?(node.receiver)
  node.receiver.location.heredoc_end.end_pos > node.source_range.end_pos
end

def space?(pos)
  processed_source.buffer.source[pos] == ' '
end