Class: Zaptec::MeterReading

Inherits:
Object
  • Object
show all
Defined in:
lib/zaptec/meter_reading.rb

Constant Summary collapse

GOOD = 
"G".freeze
KWH = 
"kWh".freeze
READINGS = 
"RD".freeze
STATUS = 
"ST".freeze
TIMESTAMP = 
"TM".freeze
UNIT = 
"RU".freeze
VALUE = 
"RV".freeze
WH = 
"Wh".freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(reading_kwh:, timestamp:) ⇒ MeterReading 



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# File 'lib/zaptec/meter_reading.rb', line 15

def initialize(reading_kwh:, timestamp:)
  @reading_kwh = reading_kwh
  @timestamp = timestamp
end

Instance Attribute Details

#reading_kwh ⇒ Object (readonly)

github.com/SAFE-eV/OCMF-Open-Charge-Metering-Format/blob/master/OCMF-de.md#json-basiertes-ocmf-format



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# File 'lib/zaptec/meter_reading.rb', line 13

def reading_kwh
  @reading_kwh
end

#timestamp ⇒ Object (readonly)

github.com/SAFE-eV/OCMF-Open-Charge-Metering-Format/blob/master/OCMF-de.md#json-basiertes-ocmf-format



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# File 'lib/zaptec/meter_reading.rb', line 13

def timestamp
  @timestamp
end

Class Method Details

.parse(ocmf_meter_reading) ⇒ Object 



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# File 'lib/zaptec/meter_reading.rb', line 21

def parse(ocmf_meter_reading)
  _prefix, json_payload, _signature = ocmf_meter_reading.split("|")

  data = JSON.parse(json_payload)

  meter_reading = data.fetch(READINGS).detect do |reading|
    reading.fetch(STATUS) == GOOD && reading[UNIT].in?([WH, KWH])
  end

  return if meter_reading.blank?

  timestamp = Time.zone.parse(meter_reading.fetch(TIMESTAMP).split.first)

  kwh_magnitude =
    case meter_reading.fetch(UNIT)
    when KWH then 1
    when WH then 1000.0
    end

  reading_kwh = meter_reading.fetch(VALUE) / kwh_magnitude

  new(reading_kwh:, timestamp:)
end