# open the class to add methods to apply HVAC efficiency standards
class OpenStudio::Model::AirTerminalSingleDuctParallelPIUReheat

  # Sets the fan power of a PIU fan based on the W/cfm
  # specified in the standard.
  #
  # @param template [String] the standard
  # @return [Bool] returns true if successful, false if not
  def set_performance_rating_method_baseline_fan_power(template)

      OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "Setting PIU fan power for #{self.name}.")
  
      # Determine the fan sizing flow rate, min flow rate,
      # and W/cfm
      sec_flow_frac = 0.5
      min_flow_frac = 0.3
      fan_efficacy_w_per_cfm = 0.35
      # case template
      # when
      # else
      # end
  
      # Get the maximum flow rate through the terminal
      max_primary_air_flow_rate = nil
      if self.autosizedMaximumPrimaryAirFlowRate.is_initialized
        max_primary_air_flow_rate = self.autosizedMaximumPrimaryAirFlowRate.get
      elsif self.maximumPrimaryAirFlowRate.is_initialized
        max_primary_air_flow_rate = self.maximumPrimaryAirFlowRate.get
      end
      
      # Set the max secondary air flow rate
      max_sec_flow_rate_m3_per_s = max_primary_air_flow_rate * sec_flow_frac
      self.setMaximumSecondaryAirFlowRate(max_sec_flow_rate_m3_per_s)
      
      # Set the minimum flow fraction
      #TODO Also compare to min OA requirement
      self.setMinimumPrimaryAirFlowFraction(min_flow_frac)
    
      # Set the fan efficacy
      fan = self.fan.to_FanConstantVolume.get
      fan_rise_pa = fan.pressureRise
      fan_rise_in_wc = OpenStudio.convert(fan_rise_pa, "Pa", "inH_{2}O")
      OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> Pressure Rise = #{fan_rise_pa} Pa")

      max_sec_flow_rate_cfm = OpenStudio.convert(max_sec_flow_rate_m3_per_s, "m^3/s", "ft^3/min").get
      OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> Maximum Fan Flow Rate = #{max_sec_flow_rate_cfm} m3/s")
      OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> Maximum Secondary Air Flow Rate = #{self.maximumSecondaryAirFlowRate.get} m3/s")      
      
      fan_efficiency = fan.fanEfficiency
      OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> Fan Total Efficiency = #{fan_efficiency}")

      fan_power_w = fan_rise_pa * max_sec_flow_rate_m3_per_s / fan_efficiency
      fan_efficacy_calc = fan_power_w / max_sec_flow_rate_m3_per_s
      OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> fan efficacy calculated = #{fan_efficacy_calc} W-s/m3")

      fan_efficacy_w_per_m3_per_s = fan_efficacy_w_per_cfm * OpenStudio.convert(1, 'm^3/s', 'cfm').get

      fan_rise_new_pa = fan_efficacy_w_per_m3_per_s * fan_efficiency
      OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "=> fan pressure rise new = #{fan_rise_new_pa} Pa")
      fan.setPressureRise(fan_rise_new_pa)
      fan_power_new_w = fan_rise_new_pa * max_sec_flow_rate_cfm / fan_efficiency
      fan_efficacy_new_w_per_cfm = fan_power_new_w / max_sec_flow_rate_cfm
      
      OpenStudio::logFree(OpenStudio::Debug, 'openstudio.model.AirTerminalSingleDuctParallelPIUReheat', "For #{self.name}: fan efficacy set to #{fan_efficacy_new_w_per_cfm.round(2)} W/cfm, fan bhp = #{fan.brakeHorsepower} hp, motor efficiency = #{fan.motorEfficiency}.")
      
      return true
    
    end

end