module ActsAsShardable

# File lib/acts_as_shardable.rb, line 15
def acts_as_shardable(by:, using:, args: {})
  class_attribute :shard_method, :shard_method_using, :shard_args, :module_name, :base_table_name

  case using
  when Symbol
    # built-in functions
  when Proc
    # customized functions
  else
    raise ArgumentError, "unknown sharding function, `using` must be a symbol or proc"
  end

  mutex.synchronize do
    self.shard_method = by
    self.shard_method_using = using
    self.shard_args = args
    self.module_name = self.name.deconstantize.safe_constantize || Object
    self.base_table_name = self.name.demodulize.pluralize.underscore
    self.table_name = "#{self.base_table_name}_0000"
    self.validates self.shard_method.to_sym, presence: true
  end

  include AttributeMethods
  include Shard
end