module RuboCop::Cop::PrecedingFollowingAlignment

def aligned_comment_lines
  @aligned_comment_lines ||=
    processed_source.comments.map(&:loc).select do |r|
      begins_its_line?(r.expression)
    end.map(&:line)
end

def aligned_equals_operator?(range, lineno)
  # Check that the operator is aligned with a previous assignment or comparison operator
  # ie. an equals sign, an operator assignment (eg. `+=`), a comparison (`==`, `<=`, etc.).
  # Since append operators (`<<`) are a type of assignment, they are allowed as well,
  # despite not ending with a literal equals character.
  line_range = processed_source.buffer.line_range(lineno)
  return false unless line_range
  # Find the specific token to avoid matching up to operators inside strings
  operator_token = processed_source.tokens_within(line_range).detect do |token|
    ASSIGNMENT_OR_COMPARISON_TOKENS.include?(token.type)
  end
  aligned_with_preceding_equals?(range, operator_token) ||
    aligned_with_append_operator?(range, operator_token)
end

def aligned_identical?(range, line)
  range.source == line[range.column, range.size]
end

def aligned_operator?(range, line, lineno)
  aligned_identical?(range, line) || aligned_equals_operator?(range, lineno)
end

def aligned_token?(range, line, lineno)
  aligned_words?(range, line) || aligned_equals_operator?(range, lineno)
end

def aligned_with_adjacent_line?(range, predicate)
  # minus 2 because node.loc.line is zero-based
  pre  = (range.line - 2).downto(0)
  post = range.line.upto(processed_source.lines.size - 1)
  aligned_with_any_line_range?([pre, post], range, &predicate)
end

def aligned_with_any_line?(line_ranges, range, indent = nil, &predicate)
  line_ranges.any? { |line_nos| aligned_with_line?(line_nos, range, indent, &predicate) }
end

def aligned_with_any_line_range?(line_ranges, range, &predicate)
  return true if aligned_with_any_line?(line_ranges, range, &predicate)
  # If no aligned token was found, search for an aligned token on the
  # nearest line with the same indentation as the checked line.
  base_indentation = processed_source.lines[range.line - 1] =~ /\S/
  aligned_with_any_line?(line_ranges, range, base_indentation, &predicate)
end

def aligned_with_append_operator?(range, token)
  return false unless token
  ((range.source == '<<' && token.equal_sign?) ||
    (range.source[-1] == '=' && token.type == :tLSHFT)) &&
    token && range.last_column == token.pos.last_column
end

def aligned_with_equals_sign(token, line_range)
  token_line_indent    = processed_source.line_indentation(token.line)
  assignment_lines     = relevant_assignment_lines(line_range)
  relevant_line_number = assignment_lines[1]
  return :none unless relevant_line_number
  relevant_indent = processed_source.line_indentation(relevant_line_number)
  return :none if relevant_indent < token_line_indent
  return :none unless processed_source.lines[relevant_line_number - 1]
  aligned_equals_operator?(token.pos, relevant_line_number) ? :yes : :no
end

def aligned_with_line?(line_nos, range, indent = nil)
  line_nos.each do |lineno|
    next if aligned_comment_lines.include?(lineno + 1)
    line = processed_source.lines[lineno]
    index = line =~ /\S/
    next unless index
    next if indent && indent != index
    return yield(range, line, lineno + 1)
  end
  false
end

def aligned_with_operator?(range)
  aligned_with_adjacent_line?(range, method(:aligned_operator?))
end

def aligned_with_preceding_equals?(range, token)
  return false unless token
  range.source[-1] == '=' && range.last_column == token.pos.last_column
end

def aligned_with_preceding_equals_operator(token)
  preceding_line_range = token.line.downto(1)
  aligned_with_equals_sign(token, preceding_line_range)
end

def aligned_with_something?(range)
  aligned_with_adjacent_line?(range, method(:aligned_token?))
end

def aligned_with_subsequent_equals_operator(token)
  subsequent_line_range = token.line.upto(processed_source.lines.length)
  aligned_with_equals_sign(token, subsequent_line_range)
end

def aligned_words?(range, line)
  left_edge = range.column
  return true if /\s\S/.match?(line[left_edge - 1, 2])
  token = range.source
  token == line[left_edge, token.length]
end

def allow_for_alignment?
  cop_config['AllowForAlignment']
end

def assignment_lines
  @assignment_lines ||= assignment_tokens.map(&:line)
end

def assignment_tokens
  @assignment_tokens ||= begin
    tokens = processed_source.tokens.select(&:equal_sign?)
    # We don't want to operate on equals signs which are part of an `optarg` in a
    # method definition, or the separator of an endless method definition.
    # For example (the equals sign to ignore is highlighted with ^):
    #     def method(optarg = default_val); end
    #                       ^
    #     def method = foo
    #                ^
    tokens = remove_equals_in_def(tokens, processed_source)
    # Only attempt to align the first = on each line
    Set.new(tokens.uniq(&:line))
  end
end

def relevant_assignment_lines(line_range)
  result                        = []
  original_line_indent          = processed_source.line_indentation(line_range.first)
  relevant_line_indent_at_level = true
  line_range.each do |line_number|
    current_line_indent = processed_source.line_indentation(line_number)
    blank_line          = processed_source.lines[line_number - 1].blank?
    if (current_line_indent < original_line_indent && !blank_line) ||
       (relevant_line_indent_at_level && blank_line)
      break
    end
    result << line_number if assignment_lines.include?(line_number) &&
                             current_line_indent == original_line_indent
    unless blank_line
      relevant_line_indent_at_level = current_line_indent == original_line_indent
    end
  end
  result
end

def remove_equals_in_def(asgn_tokens, processed_source)
  nodes = processed_source.ast.each_node(:optarg, :def)
  eqls_to_ignore = nodes.with_object([]) do |node, arr|
    loc = if node.def_type?
            node.loc.assignment if node.endless?
          else
            node.loc.operator
          end
    arr << loc.begin_pos if loc
  end
  asgn_tokens.reject { |t| eqls_to_ignore.include?(t.begin_pos) }
end