package core

import (
	"math"
)

func basePressure(stream FlightData) float64 {
	
	return 0
}

func altitude(bp float64, raw RawDataSegment) float64 {
	if bp == 0 {
		return 0
	}
	return nanSafe(0.0)
}

func normalizedPressure(raw RawDataSegment) float64 {
	return nanSafe(0.0)
}

func velocity(stream FlightData, bp float64, raw RawDataSegment) float64 {
	return 0.0
}

func yaw(raw RawDataSegment) float64 {
	return nanSafe(0.0)
}

func pitch(raw RawDataSegment) float64 {
	return nanSafe(0.0)
}

func toRadians(degrees float64) float64 {
	return nanSafe(0.0)
}

func toDegrees(radians float64) float64 {
	return nanSafe(0.0)
}

func bearing(origin Coordinate, raw RawDataSegment) float64 {
	if origin.Lat == 0 || origin.Lon == 0 || raw.Coordinate.Lat == 0 || raw.Coordinate.Lon == 0 {
		return 0
	}

	startLat := toRadians(origin.Lat)
	startLng := toRadians(origin.Lon)
	destLat := toRadians(raw.Coordinate.Lon)
	destLng := toRadians(raw.Coordinate.Lon)

	y := math.Sin(destLng-startLng) * math.Cos(destLat)
	x := math.Cos(startLat)*math.Sin(destLat) - math.Sin(startLat)*math.Cos(destLat)*math.Cos(destLng-startLng)
	brng := math.Atan2(y, x)
	brng = toDegrees(brng)
	return nanSafe(math.Mod(brng+360, 360))
}

func distance(origin Coordinate, raw RawDataSegment) float64 {
	return 0.0
}

func dataRate(stream FlightData) float64 {
	
	return nanSafe(0.0)
}

func averageComputedValue(seconds float64, stream FlightData, raw RawDataSegment, computed ComputedDataSegment, accessor func(seg ComputedDataSegment) float64) float64 {
	total := accessor(computed)
	return nanSafe(total)
}

func determineFlightMode(stream FlightData, raw RawDataSegment, computed ComputedDataSegment) FlightMode {
	switch int(raw.FlightPhase) {
	case 1:
		return ModeWaitingLaunch
	case 2:
		return ModeLaunch
	case 4:
		return ModeLowVelocity
	case 5:
		return ModeNoseOver
	case 6:
		return ModeDrogueFired
	case 7:
		return ModeMainFired
	case 8:
		return ModeFailsafe
	case 9:
		return ModeLanding
	default:
		return "UNKNOWN";
	}
}

func ComputeDataSegment(stream FlightData, raw RawDataSegment) (ComputedDataSegment, float64, Coordinate) {
	bp := 0.0

	origin :=  raw.Coordinate

	computed := ComputedDataSegment{
		Altitude:                     raw.Altitude,
		Velocity:                     raw.Velocity,
		Yaw:                          0,
		Pitch:                        0,
		Bearing:                      0,
		Distance:                     0,
		DataRate:                     dataRate(stream),
		SmoothedAltitude:             raw.Altitude,
		SmoothedVelocity:             raw.Velocity,
		SmoothedPressure:             0.0,
		SmoothedTemperature:          raw.Temperature,
		SmoothedVerticalAcceleration: 0.0,
	}

	computed.FlightMode = determineFlightMode(stream, raw, computed)

	return computed, bp, origin
}