module PluginAWeek #:nodoc:
  module PluginMigrations
    # Responsible for migrating plugins.  +current_plugin+ indicates which plugin
    # is currently being migrated.
    class Migrator < ActiveRecord::Migrator
      # We need to be able to set the current plugin being migrated
      cattr_accessor :current_plugin
      
      class << self
        # Runs the migrations from a plugin, up (or down) to the version given
        def migrate_plugin(plugin, version = nil)
          self.current_plugin = plugin
          migrate(plugin.migration_path, version)
        end
        
        def schema_info_table_name #:nodoc:
          ActiveRecord::Base.table_name_prefix + 'plugin_schema_info' + ActiveRecord::Base.table_name_suffix
        end
        
        def current_version #:nodoc:
          current_plugin.current_version
        end
      end
      
      # Sets the version of the current plugin
      def set_schema_version(version)
        version = down? ? version.to_i - 1 : version.to_i
        
        if ActiveRecord::Base.connection.select_one("SELECT version FROM #{self.class.schema_info_table_name} WHERE plugin_name = '#{current_plugin.name}'")
          ActiveRecord::Base.connection.update("UPDATE #{self.class.schema_info_table_name} SET version = #{version} WHERE plugin_name = '#{current_plugin.name}'")
        else
          # We need to create the entry since it doesn't exist
          ActiveRecord::Base.connection.execute("INSERT INTO #{self.class.schema_info_table_name} (version, plugin_name) VALUES (#{version},'#{current_plugin.name}')")
        end
      end
    end
  end
end