module Arel::Predications

def between(other)
  if unboundable?(other.begin) == 1 || unboundable?(other.end) == -1
    self.in([])
  elsif open_ended?(other.begin)
    if open_ended?(other.end)
      if infinity?(other.begin) == 1 || infinity?(other.end) == -1
        self.in([])
      else
        not_in([])
      end
    elsif other.exclude_end?
      lt(other.end)
    else
      lteq(other.end)
    end
  elsif open_ended?(other.end)
    gteq(other.begin)
  elsif other.exclude_end?
    gteq(other.begin).and(lt(other.end))
  else
    left = quoted_node(other.begin)
    right = quoted_node(other.end)
    Nodes::Between.new(self, Nodes::And.new([left, right]))
  end
end

def concat(other)
  Nodes::Concat.new self, other
end

def contains(other)
  Arel::Nodes::Contains.new self, quoted_node(other)
end

def does_not_match(other, escape = nil, case_sensitive = false)
  Nodes::DoesNotMatch.new self, quoted_node(other), escape, case_sensitive
end

def does_not_match_all(others, escape = nil)
  grouping_all :does_not_match, others, escape
end

def does_not_match_any(others, escape = nil)
  grouping_any :does_not_match, others, escape
end

def does_not_match_regexp(other, case_sensitive = true)
  Nodes::NotRegexp.new self, quoted_node(other), case_sensitive
end

def eq(other)
  Nodes::Equality.new self, quoted_node(other)
end

def eq_all(others)
  grouping_all :eq, quoted_array(others)
end

def eq_any(others)
  grouping_any :eq, others
end

def grouping_all(method_id, others, *extras)
  nodes = others.map { |expr| send(method_id, expr, *extras) }
  Nodes::Grouping.new Nodes::And.new(nodes)
end

def grouping_any(method_id, others, *extras)
  nodes = others.map { |expr| send(method_id, expr, *extras) }
  Nodes::Grouping.new nodes.inject { |memo, node|
    Nodes::Or.new(memo, node)
  }
end

def gt(right)
  Nodes::GreaterThan.new self, quoted_node(right)
end

def gt_all(others)
  grouping_all :gt, others
end

def gt_any(others)
  grouping_any :gt, others
end

def gteq(right)
  Nodes::GreaterThanOrEqual.new self, quoted_node(right)
end

def gteq_all(others)
  grouping_all :gteq, others
end

def gteq_any(others)
  grouping_any :gteq, others
end

def in(other)
  case other
  when Arel::SelectManager
    Arel::Nodes::In.new(self, other.ast)
  when Enumerable
    Nodes::In.new self, quoted_array(other)
  else
    Nodes::In.new self, quoted_node(other)
  end
end

def in_all(others)
  grouping_all :in, others
end

def in_any(others)
  grouping_any :in, others
end

def infinity?(value)
  value.respond_to?(:infinite?) && value.infinite?
end

def is_distinct_from(other)
  Nodes::IsDistinctFrom.new self, quoted_node(other)
end

def is_not_distinct_from(other)
  Nodes::IsNotDistinctFrom.new self, quoted_node(other)
end

def lt(right)
  Nodes::LessThan.new self, quoted_node(right)
end

def lt_all(others)
  grouping_all :lt, others
end

def lt_any(others)
  grouping_any :lt, others
end

def lteq(right)
  Nodes::LessThanOrEqual.new self, quoted_node(right)
end

def lteq_all(others)
  grouping_all :lteq, others
end

def lteq_any(others)
  grouping_any :lteq, others
end

def matches(other, escape = nil, case_sensitive = false)
  Nodes::Matches.new self, quoted_node(other), escape, case_sensitive
end

def matches_all(others, escape = nil, case_sensitive = false)
  grouping_all :matches, others, escape, case_sensitive
end

def matches_any(others, escape = nil, case_sensitive = false)
  grouping_any :matches, others, escape, case_sensitive
end

def matches_regexp(other, case_sensitive = true)
  Nodes::Regexp.new self, quoted_node(other), case_sensitive
end

def not_between(other)
  if unboundable?(other.begin) == 1 || unboundable?(other.end) == -1
    not_in([])
  elsif open_ended?(other.begin)
    if open_ended?(other.end)
      if infinity?(other.begin) == 1 || infinity?(other.end) == -1
        not_in([])
      else
        self.in([])
      end
    elsif other.exclude_end?
      gteq(other.end)
    else
      gt(other.end)
    end
  elsif open_ended?(other.end)
    lt(other.begin)
  else
    left = lt(other.begin)
    right = if other.exclude_end?
      gteq(other.end)
    else
      gt(other.end)
    end
    left.or(right)
  end
end

def not_eq(other)
  Nodes::NotEqual.new self, quoted_node(other)
end

def not_eq_all(others)
  grouping_all :not_eq, others
end

def not_eq_any(others)
  grouping_any :not_eq, others
end

def not_in(other)
  case other
  when Arel::SelectManager
    Arel::Nodes::NotIn.new(self, other.ast)
  when Enumerable
    Nodes::NotIn.new self, quoted_array(other)
  else
    Nodes::NotIn.new self, quoted_node(other)
  end
end

def not_in_all(others)
  grouping_all :not_in, others
end

def not_in_any(others)
  grouping_any :not_in, others
end

def open_ended?(value)
  value.nil? || infinity?(value) || unboundable?(value)
end

def overlaps(other)
  Arel::Nodes::Overlaps.new self, quoted_node(other)
end

def quoted_array(others)
  others.map { |v| quoted_node(v) }
end

def quoted_node(other)
  Nodes.build_quoted(other, self)
end

def unboundable?(value)
  value.respond_to?(:unboundable?) && value.unboundable?
end

def when(right)
  Nodes::Case.new(self).when quoted_node(right)
end