class ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Array

def ==(other)
  other.is_a?(Array) &&
    subtype == other.subtype &&
    delimiter == other.delimiter
end

def cast(value)
  if value.is_a?(::String)
    value = begin
      @pg_decoder.decode(value)
    rescue TypeError
      # malformed array string is treated as [], will raise in PG 2.0 gem
      # this keeps a consistent implementation
      []
    end
  end
  type_cast_array(value, :cast)
end

def changed_in_place?(raw_old_value, new_value)
  deserialize(raw_old_value) != new_value
end

def deserialize(value)
  case value
  when ::String
    type_cast_array(@pg_decoder.decode(value), :deserialize)
  when Data
    type_cast_array(value.values, :deserialize)
  else
    super
  end
end

def force_equality?(value)
  value.is_a?(::Array)
end

def initialize(subtype, delimiter = ",")
  @subtype = subtype
  @delimiter = delimiter
  @pg_encoder = PG::TextEncoder::Array.new name: "#{type}[]", delimiter: delimiter
  @pg_decoder = PG::TextDecoder::Array.new name: "#{type}[]", delimiter: delimiter
end

def map(value, &block)
  value.map { |v| subtype.map(v, &block) }
end

def serialize(value)
  if value.is_a?(::Array)
    casted_values = type_cast_array(value, :serialize)
    Data.new(@pg_encoder, casted_values)
  else
    super
  end
end

def type_cast_array(value, method)
  if value.is_a?(::Array)
    value.map { |item| type_cast_array(item, method) }
  else
    @subtype.public_send(method, value)
  end
end

def type_cast_for_schema(value)
  return super unless value.is_a?(::Array)
  "[" + value.map { |v| subtype.type_cast_for_schema(v) }.join(", ") + "]"
end