class Ransack::Adapters::ActiveRecord::Context

def attribute_method?(str, klass = @klass)
  exists = false
  if ransackable_attribute?(str, klass)
    exists = true
  elsif (segments = str.split(/_/)).size > 1
    remainder = []
    found_assoc = nil
    while !found_assoc && remainder.unshift(segments.pop) && segments.size > 0 do
      assoc, poly_class = unpolymorphize_association(segments.join('_'))
      if found_assoc = get_association(assoc, klass)
        exists = attribute_method?(remainder.join('_'), poly_class || found_assoc.klass)
      end
    end
  end
  exists
end

def attribute_method?(str, klass = @klass)
  exists = false
  if ransackable_attribute?(str, klass)
    exists = true
  elsif (segments = str.split(/_/)).size > 1
    remainder = []
    found_assoc = nil
    while !found_assoc && remainder.unshift(segments.pop) && segments.size > 0 do
      assoc, poly_class = unpolymorphize_association(segments.join('_'))
      if found_assoc = get_association(assoc, klass)
        exists = attribute_method?(remainder.join('_'), poly_class || found_assoc.klass)
      end
    end
  end
  exists
end

def build_join_dependency(relation)
  buckets = relation.joins_values.group_by do |join|
    case join
    when String
      'string_join'
    when Hash, Symbol, Array
      'association_join'
    when ::ActiveRecord::Associations::ClassMethods::JoinDependency::JoinAssociation
      'stashed_join'
    when Arel::Nodes::Join
      'join_node'
    else
      raise 'unknown class: %s' % join.class.name
    end
  end
  association_joins         = buckets['association_join'] || []
  stashed_association_joins = buckets['stashed_join'] || []
  join_nodes                = buckets['join_node'] || []
  string_joins              = (buckets['string_join'] || []).map { |x|
    x.strip
  }.uniq
  join_list = relation.send :custom_join_sql, (string_joins + join_nodes)
  join_dependency = JoinDependency.new(
    relation.klass,
    association_joins,
    join_list
  )
  join_nodes.each do |join|
    join_dependency.table_aliases[join.left.name.downcase] = 1
  end
  join_dependency.graft(*stashed_association_joins)
end

def build_join_dependency(relation)
  buckets = relation.joins_values.group_by do |join|
    case join
    when String
      'string_join'
    when Hash, Symbol, Array
      'association_join'
    when ::ActiveRecord::Associations::JoinDependency::JoinAssociation
      'stashed_join'
    when Arel::Nodes::Join
      'join_node'
    else
      raise 'unknown class: %s' % join.class.name
    end
  end
  association_joins         = buckets['association_join'] || []
  stashed_association_joins = buckets['stashed_join'] || []
  join_nodes                = buckets['join_node'] || []
  string_joins              = (buckets['string_join'] || []).map { |x|
    x.strip
  }.uniq
  join_list = relation.send :custom_join_ast, relation.table.from(relation.table), string_joins
  join_dependency = JoinDependency.new(
    relation.klass,
    association_joins,
    join_list
  )
  join_nodes.each do |join|
    join_dependency.table_aliases[join.left.name.downcase] = 1
  end
  join_dependency.graft(*stashed_association_joins)
end

def build_or_find_association(name, parent = @base, klass = nil)
  found_association = @join_dependency.join_associations.detect do |assoc|
    assoc.reflection.name == name &&
    assoc.parent == parent &&
    (!klass || assoc.klass == klass)
  end
  unless found_association
    @join_dependency.send(:build_polymorphic, name.to_sym, parent, Arel::Nodes::OuterJoin, klass)
    found_association = @join_dependency.join_associations.last
    # Leverage the stashed association functionality in AR
    @object = @object.joins(found_association)
  end
  found_association
end

def build_or_find_association(name, parent = @base, klass = nil)
  found_association = @join_dependency.join_associations.detect do |assoc|
    assoc.reflection.name == name &&
    assoc.parent == parent &&
    (!klass || assoc.klass == klass)
  end
  unless found_association
    @join_dependency.send(:build_polymorphic, name.to_sym, parent, Arel::Nodes::OuterJoin, klass)
    found_association = @join_dependency.join_associations.last
    # Leverage the stashed association functionality in AR
    @object = @object.joins(found_association)
  end
  found_association
end

def evaluate(search, opts = {})
  viz = Visitor.new
  relation = @object.where(viz.accept(search.base)).order(viz.accept(search.sorts))
  opts[:distinct] ? relation.select("DISTINCT #{@klass.quoted_table_name}.*") : relation
end

def evaluate(search, opts = {})
  viz = Visitor.new
  relation = @object.where(viz.accept(search.base)).order(viz.accept(search.sorts))
  opts[:distinct] ? relation.select("DISTINCT #{@klass.quoted_table_name}.*") : relation
end

def get_association(str, parent = @base)
  klass = klassify parent
  ransackable_association?(str, klass) &&
  klass.reflect_on_all_associations.detect {|a| a.name.to_s == str}
end

def get_association(str, parent = @base)
  klass = klassify parent
  ransackable_association?(str, klass) &&
  klass.reflect_on_all_associations.detect {|a| a.name.to_s == str}
end

def get_parent_and_attribute_name(str, parent = @base)
  attr_name = nil
  if ransackable_attribute?(str, klassify(parent))
    attr_name = str
  elsif (segments = str.split(/_/)).size > 1
    remainder = []
    found_assoc = nil
    while remainder.unshift(segments.pop) && segments.size > 0 && !found_assoc do
      assoc, klass = unpolymorphize_association(segments.join('_'))
      if found_assoc = get_association(assoc, parent)
        join = build_or_find_association(found_assoc.name, parent, klass)
        parent, attr_name = get_parent_and_attribute_name(remainder.join('_'), join)
      end
    end
  end
  [parent, attr_name]
end

def get_parent_and_attribute_name(str, parent = @base)
  attr_name = nil
  if ransackable_attribute?(str, klassify(parent))
    attr_name = str
  elsif (segments = str.split(/_/)).size > 1
    remainder = []
    found_assoc = nil
    while remainder.unshift(segments.pop) && segments.size > 0 && !found_assoc do
      assoc, klass = unpolymorphize_association(segments.join('_'))
      if found_assoc = get_association(assoc, parent)
        join = build_or_find_association(found_assoc.name, parent, klass)
        parent, attr_name = get_parent_and_attribute_name(remainder.join('_'), join)
      end
    end
  end
  [parent, attr_name]
end

def join_dependency(relation)
  if relation.respond_to?(:join_dependency) # Squeel will enable this
    relation.join_dependency
  else
    build_join_dependency(relation)
  end
end

def join_dependency(relation)
  if relation.respond_to?(:join_dependency) # Squeel will enable this
    relation.join_dependency
  else
    build_join_dependency(relation)
  end
end

def klassify(obj)
  if Class === obj && ::ActiveRecord::Base > obj
    obj
  elsif obj.respond_to? :klass
    obj.klass
  elsif obj.respond_to? :active_record
    obj.active_record
  else
    raise ArgumentError, "Don't know how to klassify #{obj}"
  end
end

def klassify(obj)
  if Class === obj && ::ActiveRecord::Base > obj
    obj
  elsif obj.respond_to? :klass
    obj.klass
  elsif obj.respond_to? :active_record
    obj.active_record
  else
    raise ArgumentError, "Don't know how to klassify #{obj}"
  end
end

def table_for(parent)
  parent.table
end

def table_for(parent)
  parent.table
end

def type_for(attr)
  return nil unless attr && attr.valid?
  klassify(attr.parent).columns_hash[attr.arel_attribute.name.to_s].type
end

def type_for(attr)
  return nil unless attr && attr.valid?
  name    = attr.arel_attribute.name.to_s
  table   = attr.arel_attribute.relation.table_name
  unless @engine.connection_pool.table_exists?(table)
    raise "No table named #{table} exists"
  end
  @engine.connection_pool.columns_hash[table][name].type
end