class RuboCop::Cop::Layout::ExtraSpacing

def align_column(asgn_token)
  # if we removed unneeded spaces from the beginning of this =,
  # what column would it end from?
  line    = processed_source.lines[asgn_token.pos.line - 1]
  leading = line[0...asgn_token.pos.column]
  spaces  = leading.size - (leading =~ / *\Z/)
  asgn_token.pos.last_column - spaces + 1
end

def align_equal_sign(corrector, token, align_to)
  return unless @corrected.add?(token)
  diff = align_to - token.pos.last_column
  if diff > 0
    corrector.insert_before(token.pos, ' ' * diff)
  elsif diff < 0
    corrector.remove_preceding(token.pos, -diff)
  end
end

def align_equal_signs(range, corrector)
  lines  = contiguous_assignment_lines(range)
  tokens = @asgn_tokens.select { |t| lines.include?(t.pos.line) }
  columns  = tokens.map { |t| align_column(t) }
  align_to = columns.max
  tokens.each { |token| align_equal_sign(corrector, token, align_to) }
end

def aligned_comments?(token)
  ix = processed_source.comments.index do |c|
    c.loc.expression.begin_pos == token.pos.begin_pos
  end
  aligned_with_previous_comment?(ix) || aligned_with_next_comment?(ix)
end

def aligned_tok?(token)
  if token.type == :tCOMMENT
    aligned_comments?(token)
  else
    aligned_with_something?(token.pos)
  end
end

def aligned_with_next_comment?(ix)
  ix < processed_source.comments.length - 1 &&
    comment_column(ix + 1) == comment_column(ix)
end

def aligned_with_previous_comment?(ix)
  ix > 0 && comment_column(ix - 1) == comment_column(ix)
end

def assignment_tokens
  tokens = processed_source.tokens.select { |t| equal_sign?(t) }
  # we don't want to operate on equals signs which are part of an
  #   optarg in a method definition
  # e.g.: def method(optarg = default_val); end
  tokens = remove_optarg_equals(tokens, processed_source)
  # Only attempt to align the first = on each line
  Set.new(tokens.uniq { |t| t.pos.line })
end

def autocorrect(range)
  lambda do |corrector|
    if range.source.end_with?('=')
      align_equal_signs(range, corrector)
    else
      corrector.remove(range)
    end
  end
end

def check_assignment(token)
  assignment_line = ''
  message = ''
  if should_aligned_with_preceding_line?(token)
    assignment_line = preceding_line(token)
    message = format(MSG_UNALIGNED_ASGN, 'preceding')
  else
    assignment_line = following_line(token)
    message = format(MSG_UNALIGNED_ASGN, 'following')
  end
  return if aligned_assignment?(token.pos, assignment_line)
  add_offense(token.pos, token.pos, message)
end

def check_other(t1, t2, ast)
  extra_space_range(t1, t2) do |range|
    # Unary + doesn't appear as a token and needs special handling.
    next if ignored_range?(ast, range.begin_pos)
    next if unary_plus_non_offense?(range)
    add_offense(range, range, MSG_UNNECESSARY)
  end
end

def check_tokens(ast, t1, t2)
  return if t2.type == :tNL
  if force_equal_sign_alignment? &&
     @asgn_tokens.include?(t2) &&
     (@asgn_lines.include?(t2.pos.line - 1) ||
      @asgn_lines.include?(t2.pos.line + 1))
    check_assignment(t2)
  else
    check_other(t1, t2, ast)
  end
end

def comment_column(ix)
  processed_source.comments[ix].loc.column
end

def contiguous_assignment_lines(range)
  result = [range.line]
  range.line.downto(1) do |lineno|
    @asgn_lines.include?(lineno) ? result << lineno : break
  end
  range.line.upto(processed_source.lines.size) do |lineno|
    @asgn_lines.include?(lineno) ? result << lineno : break
  end
  result.sort!
end

def equal_sign?(token)
  token.type == :tEQL || token.type == :tOP_ASGN
end

def extra_space_range(t1, t2)
  return if t1.pos.line != t2.pos.line
  start_pos = t1.pos.end_pos
  end_pos = t2.pos.begin_pos - 1
  return if end_pos <= start_pos
  return if allow_for_alignment? && aligned_tok?(t2)
  yield range_between(start_pos, end_pos)
end

def following_line(token)
  processed_source.lines[token.pos.line]
end

def force_equal_sign_alignment?
  cop_config['ForceEqualSignAlignment']
end

def ignored_range?(ast, start_pos)
  ignored_ranges(ast).any? { |r| r.include?(start_pos) }
end

def ignored_ranges(ast)
  return [] unless ast
  @ignored_ranges ||= on_node(:pair, ast).map do |pair|
    next if pair.parent.single_line?
    key, value = *pair
    key.source_range.end_pos...value.source_range.begin_pos
  end.compact
end

def investigate(processed_source)
  return if processed_source.ast.nil?
  if force_equal_sign_alignment?
    @asgn_tokens = assignment_tokens
    @asgn_lines  = @asgn_tokens.map { |t| t.pos.line }
    # Don't attempt to correct the same = more than once
    @corrected   = Set.new
  end
  processed_source.tokens.each_cons(2) do |t1, t2|
    check_tokens(processed_source.ast, t1, t2)
  end
end

def preceding_line(token)
  processed_source.lines[token.pos.line - 2]
end

def remove_optarg_equals(asgn_tokens, processed_source)
  optargs    = processed_source.ast.each_node(:optarg)
  optarg_eql = optargs.map { |o| o.loc.operator.begin_pos }.to_set
  asgn_tokens.reject { |t| optarg_eql.include?(t.pos.begin_pos) }
end

def should_aligned_with_preceding_line?(token)
  @asgn_lines.include?(token.pos.line - 1)
end

def unary_plus_non_offense?(range)
  range.resize(range.size + 1).source =~ /^ ?\+$/
end