class ActiveRecord::InsertAll::Builder

def columns_list
  format_columns(insert_all.keys_including_timestamps)
end

def conflict_target
  if index = insert_all.unique_by
    sql = +"(#{format_columns(index.columns)})"
    sql << " WHERE #{index.where}" if index.where
    sql
  elsif update_duplicates?
    "(#{format_columns(insert_all.primary_keys)})"
  end
end

def extract_types_from_columns_on(table_name, keys:)
  columns = @model.schema_cache.columns_hash(table_name)
  unknown_column = (keys - columns.keys).first
  raise UnknownAttributeError.new(model.new, unknown_column) if unknown_column
  keys.index_with { |key| model.type_for_attribute(key) }
end

def format_columns(columns)
  columns.respond_to?(:map) ? quote_columns(columns).join(",") : columns
end

def initialize(insert_all)
  @insert_all, @model, @connection = insert_all, insert_all.model, insert_all.connection
end

def into
  "INTO #{model.quoted_table_name} (#{columns_list})"
end

def quote_column(column)
  connection.quote_column_name(column)
end

def quote_columns(columns)
  columns.map { |column| quote_column(column) }
end

def raw_update_sql
  insert_all.update_sql
end

def returning
  return unless insert_all.returning
  if insert_all.returning.is_a?(String)
    insert_all.returning
  else
    Array(insert_all.returning).map do |attribute|
      if model.attribute_alias?(attribute)
        "#{quote_column(model.attribute_alias(attribute))} AS #{quote_column(attribute)}"
      else
        quote_column(attribute)
      end
    end.join(",")
  end
end

def touch_model_timestamps_unless(&block)
  return "" unless update_duplicates? && record_timestamps?
  model.timestamp_attributes_for_update_in_model.filter_map do |column_name|
    if touch_timestamp_attribute?(column_name)
      "#{column_name}=(CASE WHEN (#{updatable_columns.map(&block).join(" AND ")}) THEN #{model.quoted_table_name}.#{column_name} ELSE #{connection.high_precision_current_timestamp} END),"
    end
  end.join
end

def touch_timestamp_attribute?(column_name)
  insert_all.updatable_columns.exclude?(column_name)
end

def updatable_columns
  quote_columns(insert_all.updatable_columns)
end

def values_list
  types = extract_types_from_columns_on(model.table_name, keys: keys_including_timestamps)
  values_list = insert_all.map_key_with_value do |key, value|
    next value if Arel::Nodes::SqlLiteral === value
    ActiveModel::Type::SerializeCastValue.serialize(type = types[key], type.cast(value))
  end
  connection.visitor.compile(Arel::Nodes::ValuesList.new(values_list))
end