gas_transfer.dm

/// Test to make sure the pressure pumping proc used by things like portable pumps, pressure pumps, etc actually work.
/datum/unit_test/atmospheric_gas_transfer

/datum/unit_test/atmospheric_gas_transfer/Run()
	for (var/hot_test in list(1e4, 1e6, 1e8, 1e10, 1e12))
		nob_to_trit(hot_test, hot_test, 50, T20C, max(2500, hot_test/100))
	for (var/cold_test in list(1, 1e-2, MOLAR_ACCURACY))
		nob_to_trit(5000, T20C, cold_test, cold_test)
	nob_to_trit(5000, T20C, 100, T20C, 1)

/**
 * Proc to transfer x moles of x temp nob to x moles of x temp trit.
 *
 * Arguments:
 * * nob_moles: Moles for the nob (origin)
 * * nob_temp: Temp for the nob (origin)
 * * trit_moles: Moles for the trit (target)
 * * nob_temp: Temp for the nob (target)
 * * additional_pressure: Optional proc, if unfilled transfer will be 10% of pressure.
 */
/datum/unit_test/atmospheric_gas_transfer/proc/nob_to_trit(nob_moles, nob_temp, trit_moles, trit_temp, additional_pressure)
	var/datum/gas_mixture/first_mix = allocate(/datum/gas_mixture)
	var/datum/gas_mixture/second_mix = allocate(/datum/gas_mixture)

	first_mix.volume = 200
	second_mix.volume = 200

	ASSERT_GAS(/datum/gas/hypernoblium, first_mix)
	ASSERT_GAS(/datum/gas/tritium, second_mix)

	first_mix.gases[/datum/gas/hypernoblium][MOLES] = nob_moles
	first_mix.temperature = nob_temp

	second_mix.gases[/datum/gas/tritium][MOLES] = trit_moles
	second_mix.temperature = trit_temp

	var/initial_pressure = second_mix.return_pressure()
	// A fixed number would mean transfer is too small for high temps. So we make it scaled.

	if(isnull(additional_pressure))
		additional_pressure = first_mix.return_pressure() / 10

	/* ERROR MARGIN CALCULATION
	 * We calculate how much would the pressure change if MOLAR_ACCURACY amount of hothotgas is imparted on the cold mix.
	 * This number gets really big for very high temperatures so it's somewhat meaningless, but our main goal is to ensure the code doesn't break.
	 */
	var/error_margin = first_mix.gas_pressure_minimum_transfer(second_mix) - initial_pressure

	first_mix.pump_gas_to(second_mix, (initial_pressure + additional_pressure))
	var/margin = abs(second_mix.return_pressure() - (initial_pressure+additional_pressure))

	TEST_ASSERT(margin <= error_margin, "Failed to pump [nob_moles] moles of [nob_temp] K Nob to [trit_moles] moles of [trit_temp] K Trit, . Expected pressure = [initial_pressure+additional_pressure] +/- [error_margin]. Got [second_mix.return_pressure()].")