From 7f7506104d9eb4700dc906a76517b7e95cc24567 Mon Sep 17 00:00:00 2001
From: Sven Czarnian <devel@svcz.de>
Date: Tue, 12 Oct 2021 22:29:51 +0200
Subject: [PATCH] extend the inbound

---
 aman/types/Inbound.py | 108 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 106 insertions(+), 2 deletions(-)

diff --git a/aman/types/Inbound.py b/aman/types/Inbound.py
index a670f49..f7663b8 100644
--- a/aman/types/Inbound.py
+++ b/aman/types/Inbound.py
@@ -1,7 +1,111 @@
 #!/usr/bin/env python
 
+import pytz
+
+from datetime import datetime, timedelta
+
 from aman.com import AircraftReport_pb2
+from aman.config.AirportSequencing import AirportSequencing
+from aman.formats.SctEseFormat import SctEseFormat
+from aman.sys.WeatherModel import WeatherModel
+from aman.types.PerformanceData import PerformanceData
+from aman.types.Waypoint import Waypoint
 
 class Inbound:
-    def __init__(self, report : AircraftReport_pb2.AircraftReport):
-        self.report = report
+    def __init__(self, report : AircraftReport_pb2.AircraftReport, sequencingConfig : AirportSequencing, navData : SctEseFormat,
+                 performanceData : PerformanceData, weatherModel : WeatherModel):
+        self.Report = report
+        self.CurrentPosition = report.position
+        self.ReportTime = datetime.strptime(report.reportTime + '+0000', '%Y%m%d%H%M%S%z').replace(tzinfo = pytz.UTC)
+
+        # search performance data -> fallback to A320
+        if self.Report.aircraft.type in performanceData.Aircrafts:
+            self.PerformanceData = performanceData.Aircrafts[self.Report.aircraft.type]
+        if None == self.PerformanceData:
+            self.PerformanceData = performanceData.Aircrafts['A320']
+
+        self.findArrivalRunway(sequencingConfig)
+        self.findArrivalRoute(navData)
+
+        duration = self.secondsUntilTouchdown(weatherModel)
+        self.InitialArrivalTime = self.ReportTime + duration
+        self.EstimatedArrivalTime = self.InitialArrivalTime
+        self.EstimatedStarEntryTime = None
+
+    def findArrivalRunway(self, sequencingConfig : AirportSequencing):
+        self.PlannedRunway = None
+
+        # find the nearest runway for an initial guess
+        distance = 100000.0
+        currentPosition = Waypoint('', self.Report.position.latitude, self.Report.position.longitude)
+        for runway in sequencingConfig.ActiveArrivalRunways:
+            candidateDistance = runway.Runway.start.haversine(currentPosition)
+            if distance > candidateDistance:
+                self.PlannedRunway = runway
+                distance = candidateDistance
+
+    def findArrivalRoute(self, navData : SctEseFormat):
+        self.PlannedStar = None
+        if None == self.PlannedRunway:
+            return
+
+        for arrivalRunway in navData.arrivalRoutes:
+            if arrivalRunway == self.PlannedRunway.Runway.name:
+                stars = navData.arrivalRoutes[arrivalRunway]
+                for star in stars:
+                    if 0 != len(star.route) and self.Report.initialApproachFix == star.iaf.name:
+                        self.PlannedStar = star
+                        return
+
+    def secondsUntilTouchdown(self, weather : WeatherModel):
+        if None == self.PlannedRunway or None == self.PlannedStar:
+            return timedelta(seconds = 0)
+
+        # calculate remaining trackmiles
+        remainingDistanceNM = self.Report.distanceToIAF
+        start = self.PlannedStar.route[0]
+        for i in range(1, len(self.PlannedStar.route)):
+            remainingDistanceNM += start.haversine(self.PlannedStar.route[i]) * 0.539957
+            start = self.PlannedStar.route[i]
+
+        # calculate descend profile
+        flightTimeSeconds = 0
+        currentHeading = Waypoint('', self.Report.position.latitude, self.Report.position.longitude).bearing(self.PlannedStar.route[0])
+        distanceToWaypoint = self.Report.distanceToIAF
+        nextWaypointIndex = 0
+        currentPosition = [ self.Report.dynamics.altitude, self.Report.dynamics.groundSpeed ]
+        while 0 < currentPosition[0]:
+            lastDistance = remainingDistanceNM
+
+            # TODO integrate speed and altitude constraints
+
+            # calculate the next position after 10 seconds
+            if (currentPosition[0] / 1000 * 3) > remainingDistanceNM:
+                oldGroundspeed = currentPosition[1]
+                descendRate = (currentPosition[1] / 60) / 3 * 1000 / 6
+                newAltitude = currentPosition[0] - descendRate
+                if 0 > newAltitude:
+                    newAltitude = 0
+
+                # get the planned IAS and calculate the new altitude and GS out of the predicted information
+                # we assume that the aircraft only decelerates
+                ias = self.PerformanceData.ias(newAltitude, remainingDistanceNM)
+                currentPosition = [ newAltitude, min(weather.calculateGS(newAltitude, int(ias), currentHeading), currentPosition[1]) ]
+
+                # use the average between last and current speed to estimate the remaining distance
+                remainingDistanceNM -= (currentPosition[1] + oldGroundspeed) / 2 / 60 / 6
+            else:
+                remainingDistanceNM -= currentPosition[1] / 60 / 6
+
+            flightTimeSeconds += 10
+            if 0 > remainingDistanceNM:
+                break
+
+            # check if we follow a new waypoint pair
+            distanceToWaypoint -= abs(lastDistance - remainingDistanceNM)
+            if 0 >= distanceToWaypoint:
+                nextWaypointIndex += 1
+                if nextWaypointIndex < len(self.PlannedStar.route):
+                    currentHeading = self.PlannedStar.route[nextWaypointIndex - 1].bearing(self.PlannedStar.route[nextWaypointIndex])
+
+        return timedelta(seconds = flightTimeSeconds)