wegowise/polymorpheus

module Polymorpheus
  class Trigger

    attr_accessor :name, :event, :table, :statement, :timing, :created, :sql_mode,
                  :definer, :charset, :collation_connection, :db_collation

    def initialize(arr)
      raise ArgumentError unless arr.is_a?(Array) && arr.length == 11
      [:name, :event, :table, :statement, :timing, :created, :sql_mode,
        :definer, :charset, :collation_connection, :db_collation].
      each_with_index do |attr, ind|
        self.send("#{attr}=", arr[ind])
      end
    end

    def columns
      /IF\((.*)\) \<\> 1/.match(self.statement) do |match|
        match[1].split(' + ').collect do |submatch|
          /NEW\.([^ ]*)/.match(submatch)[1]
        end
      end
    end

    def schema_statement
      # note that we don't need to worry about unique indices or foreign keys
      # because separate schema statements will be generated for them
      "  add_polymorphic_triggers(:#{table}, #{columns.to_s})"
    end
  end
end