var dive = require('scuba-dive');
// or <script type="text/javascript" src="scuba-dive.js"></script>
dive.feetToMeters(); // 0.3048
dive.feetToMeters(33); // 10.0584
dive.metersToFeet(10); // 3.28084

// check defaults or change them
dive.gravitySamples.current(); // 9.80665 m/s2
dive.gravitySamples.current(9.8);
dive.gravitySamples.current(); // 9.8 m/s2
dive.surfacePressureSamples.current(); // 1 bar
dive.surfacePressureSamples.current(1);
dive.liquidSamples.fresh.density(); // 1000 kg/m3 (1 ton of a m^3)
dive.liquidSamples.salt.density(); // 1030 kg/m3
dive.liquidSamples.mercury.density(); // 13595.1 kg/m3
dive.constants.vapourPressure.lungsBreathing.current(); // 0.056713577314554675 bars (commonly seen in buhlmann deco)
dive.constants.altitudePressure.current(); // 1 bar (for sea level)
dive.constants.altitudePressure.current(0.6600); // (approx. 3000 meters above sea level)
dive.constants.altitudePressure.current(1); // change back to default at sea-level

// calculate dac, sac and rmv rate
dive.dac(2500, 1300, 50); // 24 psi/min
dive.sac(24, 10); // 12.022841322028032 psi/min given 24 psi/min dac rate
dive.rmv(25, 80, 3000); // 0.67 cuft/min given 25 psi/min sac rate

// calculate various depth of 1 cubic meter volume of liquid in atm or bars
dive.depthInMetersToBars(10); // 2.0094000000000003 bar absolute
dive.depthInMetersToAtm(10); // 1.9962003454231434 atm
dive.atmToDepthInMeters(1); // 10.038141470180305 meters
dive.barToDepthInMeters(1); // 9.906875371507827 meters

// calculate depth meters for all calculations above but in fresh water
dive.depthInMetersToBars(10, true); // 1.98 bar absolute (1 above)
dive.depthInMetersToAtm(10, true); // 1.9671848013816926 atm absolute (1 above)
dive.atmToDepthInMeters(1, true); // 10.339285714285714 meters
dive.barToDepthInMeters(1, true); // 10.204081632653061 meters

// calculating partial pressure of a particular gas component mixture
// calculate partial pressure for gas mixture that is 79% nitrogen (N2) and 21% oxygen (O2)
// at 10 meters below sea level, what is partial pressure of each gas?
var p = dive.depthInMetersToBars(10); // 2.0094000000000003 bar absolute
dive.partialPressure(p, 0.79); // 1.5874260000000002 bar absolute
dive.partialPressure(p, 0.21); // 0.42197400000000007 bar absolute

// you can also use the helper function to calculate from depth in meters
dive.partialPressureAtDepth(10, 0.79); // 1.5874260000000002 bar absolute
dive.partialPressureAtDepth(10, 0.21); // 0.42197400000000007 bar absolute

// calculate partial pressures for above but in fresh water
dive.partialPressureAtDepth(10, 0.79, true); // 1.5642 bar absolute
dive.partialPressureAtDepth(10, 0.21, true); // 0.4158 bar absolute

// calculate water vapour pressure at a given temperature (degrees celcius)
// use the conversion tools to calculate in terms of bars
var mmHg = dive.waterVapourPressure(35.2); // 42.538675172399344 mmHg
var pascals = dive.mmHgToPascal(mmHg); // 5671.357731455468 Pascal
dive.pascalToBar(pascals); // 0.056713577314554675 bar
dive.waterVapourPressureInBars(35.2); // 0.056713577314554675 bar
// notice the 0.0567 bar above? we can plug that into the Buhlmann Decompression Algorithm

// calculate maximum operating depth using AIR (21% Oxygen) at 1.4 bars
dive.maxOperatingDepth(1.4, 0.21); // 56.10089197613197 meters
// calculate maximum operating depth using AIR (21% Oxygen) at 1.4 bars in fresh water
dive.maxOperatingDepth(1.4, 0.21, true); // 57.78391873541593 meters

// calculate the narcotic equivalent depth for breathing a gas mixture
// that is 12% Oxygen, 38% Nitrogen and 50% Helium at 100m
dive.equivNarcoticDepth(0.12, 0.38, 0.50, 100); // 56.882888936481194 meters air
dive.equivNarcoticDepth(0.12, 0.38, 0.50, 100, true); // 56.766365121623096 meters air (in fresh water)

// depth change in bars per minute (e.g. 0 to 10 meters in 30 seconds)
dive.depthChangeInBarsPerMinute(0, 10, 0.5); // 2.0201699 bars per minute (in salt water)
dive.depthChangeInBarsPerMinute(0, 10, 0.5, true); // 1.9613300000000002 bars per minute (in fresh water)

// gas rate in bars per minute (e.g. 0 to 10 meters in 30 seconds with 79% Nitrogen)
dive.gasRateInBarsPerMinute(0, 10, 0.5, 0.79); // 1.595934221 bars per minute (in salt water)
dive.gasRateInBarsPerMinute(0, 10, 0.5, 0.79,, true); // 1.5494507 bars per minute (in fresh water)

// gas breathing pressure in bars accounting for water vapour pressure in the lungs
// calculate the pressure at 10 meters breathing 79% N2
dive.gasPressureBreathingInBars(10, 0.79); // 0.7531633844215019 bars (in salt water)
dive.gasPressureBreathingInBars(10, 0.79, true); // 0.729921623921502 bars (in fresh water)

// instantaneous equation (exposed at 20 meters with AIR for 40 minutes)
var pGas = dive.gasPressureBreathingInBars(20, 0.79);
dive.instantaneousEquation(0.79, pGas, 40, 4.0); // 1.5940936555866738 bar

// buhlmann deco algorithm (*this needs review*)
var buhlmannDeco = dive.deco.buhlmann();
var newPlan = new buhlmannDeco.plan(buhlmannDeco.ZH16ATissues); // 1 abs pressure in fresh water
newPlan.addBottomGas("2135", 0.21, 0.35);
newPlan.addDecoGas("50%", 0.5, 0.0);
newPlan.addDepthChange(0, 50, "2135", 5);
newPlan.addFlat(50, "2135", 25);
var decoPlan = newPlan.calculateDecompression(false, 0.2, 0.8, 1.6, 30); //gradientFactorLow = 0.2, gradientFactorHigh=0.8, deco ppO2 = 1.6, and max END allowed: 30 meters.

//No-Deco limit for a gas at a depth
var buhlmann = dive.deco.buhlmann();
var newPlan = new buhlmann.plan(buhlmann.ZH16BTissues);
newPlan.addBottomGas("air", 0.21, 0.0);
var gradientFactor = 1.5; //This was choosen to closely match PADI dive tables.
newPlan.ndl(dive.feetToMeters(140), "air", gradientFactor), "NDL for 140 feet should be close to 7 minutes");