31 files changed, 336 insertions, 96 deletions
diff --git a/activemodel/lib/active_model/type.rb b/activemodel/lib/active_model/type.rb
new file mode 100644
index 0000000000..64346bcab2
--- /dev/null
+++ b/activemodel/lib/active_model/type.rb
@@ -0,0 +1,59 @@
+require 'active_model/type/helpers'
+require 'active_model/type/value'
+
+require 'active_model/type/big_integer'
+require 'active_model/type/binary'
+require 'active_model/type/boolean'
+require 'active_model/type/date'
+require 'active_model/type/date_time'
+require 'active_model/type/decimal'
+require 'active_model/type/decimal_without_scale'
+require 'active_model/type/float'
+require 'active_model/type/integer'
+require 'active_model/type/string'
+require 'active_model/type/text'
+require 'active_model/type/time'
+require 'active_model/type/unsigned_integer'
+
+require 'active_model/type/registry'
+require 'active_model/type/type_map'
+require 'active_model/type/hash_lookup_type_map'
+
+module ActiveModel
+  module Type
+    @registry = Registry.new
+
+    class << self
+      attr_accessor :registry # :nodoc:
+      delegate :add_modifier, to: :registry
+
+      # Add a new type to the registry, allowing it to be referenced as a
+      # symbol by ActiveModel::Attributes::ClassMethods#attribute.  If your
+      # type is only meant to be used with a specific database adapter, you can
+      # do so by passing +adapter: :postgresql+. If your type has the same
+      # name as a native type for the current adapter, an exception will be
+      # raised unless you specify an +:override+ option. +override: true+ will
+      # cause your type to be used instead of the native type. +override:
+      # false+ will cause the native type to be used over yours if one exists.
+      def register(type_name, klass = nil, **options, &block)
+        registry.register(type_name, klass, **options, &block)
+      end
+
+      def lookup(*args, **kwargs) # :nodoc:
+        registry.lookup(*args, **kwargs)
+      end
+    end
+
+    register(:big_integer, Type::BigInteger, override: false)
+    register(:binary, Type::Binary, override: false)
+    register(:boolean, Type::Boolean, override: false)
+    register(:date, Type::Date, override: false)
+    register(:date_time, Type::DateTime, override: false)
+    register(:decimal, Type::Decimal, override: false)
+    register(:float, Type::Float, override: false)
+    register(:integer, Type::Integer, override: false)
+    register(:string, Type::String, override: false)
+    register(:text, Type::Text, override: false)
+    register(:time, Type::Time, override: false)
+  end
+end
diff --git a/activerecord/lib/active_record/type/big_integer.rb b/activemodel/lib/active_model/type/big_integer.rb
index 0c72d8914f..4168cbfce7 100644
--- a/activerecord/lib/active_record/type/big_integer.rb
+++ b/activemodel/lib/active_model/type/big_integer.rb
@@ -1,6 +1,6 @@
-require 'active_record/type/integer'
+require 'active_model/type/integer'
 
-module ActiveRecord
+module ActiveModel
   module Type
     class BigInteger < Integer # :nodoc:
       private
diff --git a/activerecord/lib/active_record/type/binary.rb b/activemodel/lib/active_model/type/binary.rb
index 0baf8c63ad..a0cc45b4c3 100644
--- a/activerecord/lib/active_record/type/binary.rb
+++ b/activemodel/lib/active_model/type/binary.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class Binary < Value # :nodoc:
       def type
diff --git a/activerecord/lib/active_record/type/boolean.rb b/activemodel/lib/active_model/type/boolean.rb
index f6a75512fd..c1bce98c87 100644
--- a/activerecord/lib/active_record/type/boolean.rb
+++ b/activemodel/lib/active_model/type/boolean.rb
@@ -1,6 +1,8 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class Boolean < Value # :nodoc:
+      FALSE_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE', 'off', 'OFF'].to_set
+
       def type
         :boolean
       end
@@ -11,7 +13,7 @@ module ActiveRecord
         if value == ''
           nil
         else
-          !ConnectionAdapters::Column::FALSE_VALUES.include?(value)
+          !FALSE_VALUES.include?(value)
         end
       end
     end
diff --git a/activerecord/lib/active_record/type/date.rb b/activemodel/lib/active_model/type/date.rb
index 3ceab59ebb..f74243a22c 100644
--- a/activerecord/lib/active_record/type/date.rb
+++ b/activemodel/lib/active_model/type/date.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class Date < Value # :nodoc:
       include Helpers::AcceptsMultiparameterTime.new
@@ -24,8 +24,9 @@ module ActiveRecord
         end
       end
 
+      ISO_DATE = /\A(\d{4})-(\d\d)-(\d\d)\z/
       def fast_string_to_date(string)
-        if string =~ ConnectionAdapters::Column::Format::ISO_DATE
+        if string =~ ISO_DATE
           new_date $1.to_i, $2.to_i, $3.to_i
         end
       end
diff --git a/activerecord/lib/active_record/type/date_time.rb b/activemodel/lib/active_model/type/date_time.rb
index a5199959b9..b068cfc672 100644
--- a/activerecord/lib/active_record/type/date_time.rb
+++ b/activemodel/lib/active_model/type/date_time.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class DateTime < Value # :nodoc:
       include Helpers::TimeValue
diff --git a/activerecord/lib/active_record/type/decimal.rb b/activemodel/lib/active_model/type/decimal.rb
index f5b145230d..83a16018ea 100644
--- a/activerecord/lib/active_record/type/decimal.rb
+++ b/activemodel/lib/active_model/type/decimal.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class Decimal < Value # :nodoc:
       include Helpers::Numeric
diff --git a/activerecord/lib/active_record/type/decimal_without_scale.rb b/activemodel/lib/active_model/type/decimal_without_scale.rb
index ff5559e300..129baa0c10 100644
--- a/activerecord/lib/active_record/type/decimal_without_scale.rb
+++ b/activemodel/lib/active_model/type/decimal_without_scale.rb
@@ -1,6 +1,6 @@
-require 'active_record/type/big_integer'
+require 'active_model/type/big_integer'
 
-module ActiveRecord
+module ActiveModel
   module Type
     class DecimalWithoutScale < BigInteger # :nodoc:
       def type
diff --git a/activerecord/lib/active_record/type/float.rb b/activemodel/lib/active_model/type/float.rb
index d88482b85d..0f925bc7e1 100644
--- a/activerecord/lib/active_record/type/float.rb
+++ b/activemodel/lib/active_model/type/float.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class Float < Value # :nodoc:
       include Helpers::Numeric
diff --git a/activerecord/lib/active_record/type/hash_lookup_type_map.rb b/activemodel/lib/active_model/type/hash_lookup_type_map.rb
index 3b01e3f8ca..45d3515aad 100644
--- a/activerecord/lib/active_record/type/hash_lookup_type_map.rb
+++ b/activemodel/lib/active_model/type/hash_lookup_type_map.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class HashLookupTypeMap < TypeMap # :nodoc:
       def alias_type(type, alias_type)
diff --git a/activemodel/lib/active_model/type/helpers.rb b/activemodel/lib/active_model/type/helpers.rb
new file mode 100644
index 0000000000..a805a359ab
--- /dev/null
+++ b/activemodel/lib/active_model/type/helpers.rb
@@ -0,0 +1,4 @@
+require 'active_model/type/helpers/accepts_multiparameter_time'
+require 'active_model/type/helpers/numeric'
+require 'active_model/type/helpers/mutable'
+require 'active_model/type/helpers/time_value'
diff --git a/activerecord/lib/active_record/type/helpers/accepts_multiparameter_time.rb b/activemodel/lib/active_model/type/helpers/accepts_multiparameter_time.rb
index be571fc1c7..fa1ccd057e 100644
--- a/activerecord/lib/active_record/type/helpers/accepts_multiparameter_time.rb
+++ b/activemodel/lib/active_model/type/helpers/accepts_multiparameter_time.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     module Helpers
       class AcceptsMultiparameterTime < Module # :nodoc:
@@ -17,10 +17,7 @@ module ActiveRecord
             end
             return unless values_hash[1] && values_hash[2] && values_hash[3]
             values = values_hash.sort.map(&:last)
-            ::Time.send(
-              ActiveRecord::Base.default_timezone,
-              *values
-            )
+            ::Time.send(default_timezone, *values)
           end
           private :value_from_multiparameter_assignment
         end
diff --git a/activerecord/lib/active_record/type/helpers/mutable.rb b/activemodel/lib/active_model/type/helpers/mutable.rb
index 88a9099277..4dddbe4e5e 100644
--- a/activerecord/lib/active_record/type/helpers/mutable.rb
+++ b/activemodel/lib/active_model/type/helpers/mutable.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     module Helpers
       module Mutable # :nodoc:
diff --git a/activerecord/lib/active_record/type/helpers/numeric.rb b/activemodel/lib/active_model/type/helpers/numeric.rb
index a755a02a59..c883010506 100644
--- a/activerecord/lib/active_record/type/helpers/numeric.rb
+++ b/activemodel/lib/active_model/type/helpers/numeric.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     module Helpers
       module Numeric # :nodoc:
diff --git a/activerecord/lib/active_record/type/helpers/time_value.rb b/activemodel/lib/active_model/type/helpers/time_value.rb
index 7eb41557cb..5a899d43ec 100644
--- a/activerecord/lib/active_record/type/helpers/time_value.rb
+++ b/activemodel/lib/active_model/type/helpers/time_value.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     module Helpers
       module TimeValue # :nodoc:
@@ -10,7 +10,7 @@ module ActiveRecord
           end
 
           if value.acts_like?(:time)
-            zone_conversion_method = ActiveRecord::Base.default_timezone == :utc ? :getutc : :getlocal
+            zone_conversion_method = is_utc? ? :getutc : :getlocal
 
             if value.respond_to?(zone_conversion_method)
               value = value.send(zone_conversion_method)
@@ -19,6 +19,14 @@ module ActiveRecord
 
           value
         end
+        
+        def is_utc?
+          ::Time.zone_default =~ 'UTC'
+        end
+        
+        def default_timezone
+          ::Time.zone_default
+        end
 
         def type_cast_for_schema(value)
           "'#{value.to_s(:db)}'"
@@ -33,21 +41,24 @@ module ActiveRecord
         def new_time(year, mon, mday, hour, min, sec, microsec, offset = nil)
           # Treat 0000-00-00 00:00:00 as nil.
           return if year.nil? || (year == 0 && mon == 0 && mday == 0)
+          
 
           if offset
             time = ::Time.utc(year, mon, mday, hour, min, sec, microsec) rescue nil
             return unless time
 
             time -= offset
-            Base.default_timezone == :utc ? time : time.getlocal
+            is_utc? ? time : time.getlocal
           else
-            ::Time.public_send(Base.default_timezone, year, mon, mday, hour, min, sec, microsec) rescue nil
+            ::Time.public_send(default_timezone, year, mon, mday, hour, min, sec, microsec) rescue nil
           end
         end
+        
+        ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(\.\d+)?\z/
 
         # Doesn't handle time zones.
         def fast_string_to_time(string)
-          if string =~ ConnectionAdapters::Column::Format::ISO_DATETIME
+          if string =~ ISO_DATETIME
             microsec = ($7.to_r * 1_000_000).to_i
             new_time $1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, microsec
           end
diff --git a/activerecord/lib/active_record/type/integer.rb b/activemodel/lib/active_model/type/integer.rb
index c5040c6d3b..2f73ede009 100644
--- a/activerecord/lib/active_record/type/integer.rb
+++ b/activemodel/lib/active_model/type/integer.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class Integer < Value # :nodoc:
       include Helpers::Numeric
diff --git a/activemodel/lib/active_model/type/registry.rb b/activemodel/lib/active_model/type/registry.rb
new file mode 100644
index 0000000000..8070a4bd38
--- /dev/null
+++ b/activemodel/lib/active_model/type/registry.rb
@@ -0,0 +1,151 @@
+module ActiveModel
+  # :stopdoc:
+  module Type
+    class Registry
+      def initialize
+        @registrations = []
+      end
+
+      def register(type_name, klass = nil, **options, &block)
+        block ||= proc { |_, *args| klass.new(*args) }
+        registrations << registration_klass.new(type_name, block, **options)
+      end
+
+      def lookup(symbol, *args)
+        registration = registrations
+          .select { |r| r.matches?(symbol, *args) }
+          .max
+
+        if registration
+          registration.call(self, symbol, *args)
+        else
+          raise ArgumentError, "Unknown type #{symbol.inspect}"
+        end
+      end
+
+      def add_modifier(options, klass, **args)
+        registrations << decoration_registration_klass.new(options, klass, **args)
+      end
+
+      protected
+
+      attr_reader :registrations
+      
+      private
+      
+      def registration_klass
+        Registration
+      end
+      
+      def decoration_registration_klass
+        DecorationRegistration
+      end
+    end
+
+    class Registration
+      def initialize(name, block, override: nil)
+        @name = name
+        @block = block
+        @override = override
+      end
+
+      def call(_registry, *args, **kwargs)
+        if kwargs.any? # https://bugs.ruby-lang.org/issues/10856
+          block.call(*args, **kwargs)
+        else
+          block.call(*args)
+        end
+      end
+
+      def matches?(type_name, *args, **kwargs)
+        type_name == name# && matches_adapter?(**kwargs)
+      end
+
+      def <=>(other)
+        # if conflicts_with?(other)
+        #   raise TypeConflictError.new("Type #{name} was registered for all
+        #                               adapters, but shadows a native type with
+        #                               the same name for #{other.adapter}".squish)
+        # end
+        priority <=> other.priority
+      end
+
+      protected
+
+      attr_reader :name, :block, :override
+
+      def priority
+        result = 0
+        # if adapter
+        #   result |= 1
+        # end
+        if override
+          result |= 2
+        end
+        result
+      end
+
+      # def priority_except_adapter
+      #   priority & 0b111111100
+      # end
+
+      private
+
+      # def matches_adapter?(adapter: nil, **)
+      #   (self.adapter.nil? || adapter == self.adapter)
+      # end
+
+      # def conflicts_with?(other)
+      #   same_priority_except_adapter?(other) &&
+      #     has_adapter_conflict?(other)
+      # end
+
+      # def same_priority_except_adapter?(other)
+      #   priority_except_adapter == other.priority_except_adapter
+      # end
+
+      # def has_adapter_conflict?(other)
+      #   (override.nil? && other.adapter) ||
+      #     (adapter && other.override.nil?)
+      # end
+    end
+
+    class DecorationRegistration < Registration
+      def initialize(options, klass)
+        @options = options
+        @klass = klass
+        # @adapter = adapter
+      end
+
+      def call(registry, *args, **kwargs)
+        subtype = registry.lookup(*args, **kwargs.except(*options.keys))
+        klass.new(subtype)
+      end
+
+      def matches?(*args, **kwargs)
+        matches_options?(**kwargs)
+      end
+
+      def priority
+        super | 4
+      end
+
+      protected
+
+      attr_reader :options, :klass
+
+      private
+
+      def matches_options?(**kwargs)
+        options.all? do |key, value|
+          kwargs[key] == value
+        end
+      end
+    end
+  end
+
+  class TypeConflictError < StandardError
+  end
+
+  # :startdoc:
+end
diff --git a/activerecord/lib/active_record/type/string.rb b/activemodel/lib/active_model/type/string.rb
index 2662b7e874..fd1630c751 100644
--- a/activerecord/lib/active_record/type/string.rb
+++ b/activemodel/lib/active_model/type/string.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class String < Value # :nodoc:
       def type
diff --git a/activerecord/lib/active_record/type/text.rb b/activemodel/lib/active_model/type/text.rb
index 26f980f060..1ad04daba4 100644
--- a/activerecord/lib/active_record/type/text.rb
+++ b/activemodel/lib/active_model/type/text.rb
@@ -1,6 +1,6 @@
-require 'active_record/type/string'
+require 'active_model/type/string'
 
-module ActiveRecord
+module ActiveModel
   module Type
     class Text < String # :nodoc:
       def type
diff --git a/activerecord/lib/active_record/type/time.rb b/activemodel/lib/active_model/type/time.rb
index 19a10021bc..7101bad566 100644
--- a/activerecord/lib/active_record/type/time.rb
+++ b/activemodel/lib/active_model/type/time.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class Time < Value # :nodoc:
       include Helpers::TimeValue
diff --git a/activerecord/lib/active_record/type/type_map.rb b/activemodel/lib/active_model/type/type_map.rb
index 8ce36cc9af..402b660a71 100644
--- a/activerecord/lib/active_record/type/type_map.rb
+++ b/activemodel/lib/active_model/type/type_map.rb
@@ -1,6 +1,6 @@
 require 'concurrent'
 
-module ActiveRecord
+module ActiveModel
   module Type
     class TypeMap # :nodoc:
       def initialize
diff --git a/activerecord/lib/active_record/type/unsigned_integer.rb b/activemodel/lib/active_model/type/unsigned_integer.rb
index ed3e527483..3f49f9f5f7 100644
--- a/activerecord/lib/active_record/type/unsigned_integer.rb
+++ b/activemodel/lib/active_model/type/unsigned_integer.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class UnsignedInteger < Integer # :nodoc:
       private
diff --git a/activerecord/lib/active_record/type/value.rb b/activemodel/lib/active_model/type/value.rb
index 6b9d147ecc..c7d1197d69 100644
--- a/activerecord/lib/active_record/type/value.rb
+++ b/activemodel/lib/active_model/type/value.rb
@@ -1,4 +1,4 @@
-module ActiveRecord
+module ActiveModel
   module Type
     class Value
       attr_reader :precision, :scale, :limit
diff --git a/activerecord/lib/active_record/attribute_methods/query.rb b/activerecord/lib/active_record/attribute_methods/query.rb
index 553122a5fc..10498f4322 100644
--- a/activerecord/lib/active_record/attribute_methods/query.rb
+++ b/activerecord/lib/active_record/attribute_methods/query.rb
@@ -19,7 +19,7 @@ module ActiveRecord
             if Numeric === value || value !~ /[^0-9]/
               !value.to_i.zero?
             else
-              return false if ActiveRecord::ConnectionAdapters::Column::FALSE_VALUES.include?(value)
+              return false if ActiveModel::Type::Boolean::FALSE_VALUES.include?(value)
               !value.blank?
             end
           elsif value.respond_to?(:zero?)
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb
index 8222811e0c..5e31efec4a 100644
--- a/activerecord/lib/active_record/connection_adapters/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/column.rb
@@ -5,13 +5,6 @@ module ActiveRecord
   module ConnectionAdapters
     # An abstract definition of a column in a table.
     class Column
-      FALSE_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE', 'off', 'OFF'].to_set
-
-      module Format
-        ISO_DATE = /\A(\d{4})-(\d\d)-(\d\d)\z/
-        ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(\.\d+)?\z/
-      end
-
       attr_reader :name, :null, :sql_type_metadata, :default, :default_function, :collation
 
       delegate :precision, :scale, :limit, :type, :sql_type, to: :sql_type_metadata, allow_nil: true
diff --git a/activerecord/lib/active_record/type.rb b/activerecord/lib/active_record/type.rb
index 53f3b53bec..165043021b 100644
--- a/activerecord/lib/active_record/type.rb
+++ b/activerecord/lib/active_record/type.rb
@@ -1,26 +1,28 @@
-require 'active_record/type/helpers'
-require 'active_record/type/value'
+require 'active_model/type/helpers'
+require 'active_model/type/value'
 
-require 'active_record/type/big_integer'
-require 'active_record/type/binary'
-require 'active_record/type/boolean'
-require 'active_record/type/date'
-require 'active_record/type/date_time'
-require 'active_record/type/decimal'
-require 'active_record/type/decimal_without_scale'
-require 'active_record/type/float'
-require 'active_record/type/integer'
-require 'active_record/type/serialized'
-require 'active_record/type/string'
-require 'active_record/type/text'
-require 'active_record/type/time'
-require 'active_record/type/unsigned_integer'
+require 'active_model/type/big_integer'
+require 'active_model/type/binary'
+require 'active_model/type/boolean'
+require 'active_model/type/date'
+require 'active_model/type/date_time'
+require 'active_model/type/decimal'
+require 'active_model/type/decimal_without_scale'
+require 'active_model/type/float'
+require 'active_model/type/integer'
+require 'active_model/type/string'
+require 'active_model/type/text'
+require 'active_model/type/time'
+require 'active_model/type/unsigned_integer'
 
-require 'active_record/type/adapter_specific_registry'
-require 'active_record/type/type_map'
-require 'active_record/type/hash_lookup_type_map'
+require 'active_model/type/registry'
+require 'active_model/type/type_map'
+require 'active_model/type/hash_lookup_type_map'
 
 require 'active_record/type/internal/abstract_json'
+require 'active_record/type/internal/timezone'
+require 'active_record/type/serialized'
+require 'active_record/type/adapter_specific_registry'
 
 module ActiveRecord
   module Type
@@ -53,6 +55,32 @@ module ActiveRecord
       end
     end
 
+    class Date < ActiveModel::Type::Date
+      include Internal::Timezone
+    end
+    
+    class DateTime < ActiveModel::Type::DateTime
+      include Internal::Timezone
+    end
+    class Time < ActiveModel::Type::Time
+      include Internal::Timezone
+    end
+    
+    Helpers          = ActiveModel::Type::Helpers
+    BigInteger          = ActiveModel::Type::BigInteger
+    Binary              = ActiveModel::Type::Binary
+    Boolean             = ActiveModel::Type::Boolean
+    Decimal             = ActiveModel::Type::Decimal
+    DecimalWithoutScale = ActiveModel::Type::DecimalWithoutScale
+    Float               = ActiveModel::Type::Float
+    Integer             = ActiveModel::Type::Integer
+    String              = ActiveModel::Type::String
+    Text                = ActiveModel::Type::Text
+    UnsignedInteger     = ActiveModel::Type::UnsignedInteger
+    Value               = ActiveModel::Type::Value
+    TypeMap             = ActiveModel::Type::TypeMap
+    HashLookupTypeMap   = ActiveModel::Type::HashLookupTypeMap
+
     register(:big_integer, Type::BigInteger, override: false)
     register(:binary, Type::Binary, override: false)
     register(:boolean, Type::Boolean, override: false)
diff --git a/activerecord/lib/active_record/type/adapter_specific_registry.rb b/activerecord/lib/active_record/type/adapter_specific_registry.rb
index 5f71b3cb94..3509429058 100644
--- a/activerecord/lib/active_record/type/adapter_specific_registry.rb
+++ b/activerecord/lib/active_record/type/adapter_specific_registry.rb
@@ -1,35 +1,18 @@
+require 'active_model/type/registry'
+
 module ActiveRecord
   # :stopdoc:
   module Type
-    class AdapterSpecificRegistry
-      def initialize
-        @registrations = []
-      end
-
-      def register(type_name, klass = nil, **options, &block)
-        block ||= proc { |_, *args| klass.new(*args) }
-        registrations << Registration.new(type_name, block, **options)
-      end
-
-      def lookup(symbol, *args)
-        registration = registrations
-          .select { |r| r.matches?(symbol, *args) }
-          .max
-
-        if registration
-          registration.call(self, symbol, *args)
-        else
-          raise ArgumentError, "Unknown type #{symbol.inspect}"
-        end
+    class AdapterSpecificRegistry < ActiveModel::Type::Registry
+      private
+      
+      def registration_klass
+        Registration
       end
-
-      def add_modifier(options, klass, **args)
-        registrations << DecorationRegistration.new(options, klass, **args)
+      
+      def decoration_registration_klass
+        DecorationRegistration
       end
-
-      protected
-
-      attr_reader :registrations
     end
 
     class Registration
@@ -135,7 +118,7 @@ module ActiveRecord
     end
   end
 
-  class TypeConflictError < StandardError
+  class TypeConflictError < ::ActiveModel::TypeConflictError
   end
 
   # :startdoc:
diff --git a/activerecord/lib/active_record/type/helpers.rb b/activerecord/lib/active_record/type/helpers.rb
deleted file mode 100644
index 634d417d13..0000000000
--- a/activerecord/lib/active_record/type/helpers.rb
+++ /dev/null
@@ -1,4 +0,0 @@
-require 'active_record/type/helpers/accepts_multiparameter_time'
-require 'active_record/type/helpers/numeric'
-require 'active_record/type/helpers/mutable'
-require 'active_record/type/helpers/time_value'
diff --git a/activerecord/lib/active_record/type/internal/abstract_json.rb b/activerecord/lib/active_record/type/internal/abstract_json.rb
index 963a8245d0..097d1bd363 100644
--- a/activerecord/lib/active_record/type/internal/abstract_json.rb
+++ b/activerecord/lib/active_record/type/internal/abstract_json.rb
@@ -1,8 +1,8 @@
 module ActiveRecord
   module Type
     module Internal # :nodoc:
-      class AbstractJson < Type::Value # :nodoc:
-        include Type::Helpers::Mutable
+      class AbstractJson < ActiveModel::Type::Value # :nodoc:
+        include ActiveModel::Type::Helpers::Mutable
 
         def type
           :json
diff --git a/activerecord/lib/active_record/type/internal/timezone.rb b/activerecord/lib/active_record/type/internal/timezone.rb
new file mode 100644
index 0000000000..07dbb0b2c6
--- /dev/null
+++ b/activerecord/lib/active_record/type/internal/timezone.rb
@@ -0,0 +1,15 @@
+module ActiveRecord
+  module Type
+    module Internal
+      module Timezone
+        def is_utc?
+          ActiveRecord::Base.default_timezone == :utc
+        end
+        
+        def default_timezone
+          ActiveRecord::Base.default_timezone
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/type/serialized.rb b/activerecord/lib/active_record/type/serialized.rb
index ea3e0d6a45..203a395415 100644
--- a/activerecord/lib/active_record/type/serialized.rb
+++ b/activerecord/lib/active_record/type/serialized.rb
@@ -1,7 +1,7 @@
 module ActiveRecord
   module Type
-    class Serialized < DelegateClass(Type::Value) # :nodoc:
-      include Helpers::Mutable
+    class Serialized < DelegateClass(ActiveModel::Type::Value) # :nodoc:
+      include ActiveModel::Type::Helpers::Mutable
 
       attr_reader :subtype, :coder