From 178ad7b3018ea8f16470a002610ae1e18a7401d0 Mon Sep 17 00:00:00 2001
From: Tobias Dammers <tdammers@gmail.com>
Date: Thu, 23 Sep 2021 09:04:13 +0200
Subject: [PATCH] Fuel allocation strategies

---
 addon-config.xml                      |  1 +
 addon-main.nas                        | 50 ++++++++++++++++++++-------
 gui/dialogs/addon-simbrief-dialog.xml | 18 ++++++++++
 3 files changed, 56 insertions(+), 13 deletions(-)

diff --git a/addon-config.xml b/addon-config.xml
index 9fccc47..115d068 100644
--- a/addon-config.xml
+++ b/addon-config.xml
@@ -12,6 +12,7 @@
                 <import-fob type="bool" userarchive="y">0</import-fob>
                 <import-perfinit type="bool" userarchive="y">0</import-perfinit>
                 <import-winds-aloft type="bool" userarchive="y">0</import-winds-aloft>
+                <fuel-strategy type="string" userarchive="y">balanced</fuel-strategy>
             </options>
             <downloading type="bool">0</downloading>
             <text-status type="string"></text-status>
diff --git a/addon-main.nas b/addon-main.nas
index 3669a52..319f398 100644
--- a/addon-main.nas
+++ b/addon-main.nas
@@ -205,9 +205,10 @@ var importFOB = func (ofp) {
     var fob = ofp.getNode('fuel/plan_ramp').getValue() * fuelFactor;
     var unallocated = fob;
     var tankNodes = props.globals.getNode('/consumables/fuel').getChildren('tank');
-    var numTanks = size(tankNodes);
+    var strategy = getprop('sim/simbrief/options/fuel-strategy');
+    printf("Allocating %1.1f kg (%1.1f lbs) of fuel", fob, fob * KG2LB);
 
-    printf("Fuel to allocate: %1.1f kg", fob);
+    var numTanks = size(tankNodes);
 
     var allocate = func(tankNumber, maxAmount = nil) {
         var tankNode = tankNodes[tankNumber];
@@ -243,19 +244,42 @@ var importFOB = func (ofp) {
         allocate(tank2, allocate2);
     }
 
-    var i = 0;
-    while (i < numTanks) {
-        var tankNode = tankNodes[i];
-        var tankName = tankNode.getValue('name') or 'unnamed';
-        if (i >= numTanks - 1 or string.imatch(tankName, "*center*")) {
-            allocate(i);
-            i = i + 1;
-        }
-        else {
-            allocatePair(i, i + 1);
-            i = i + 2;
+    if (strategy == 'first-come-first-serve') {
+        print("Using 'first come, first serve' strategy");
+        var i = 0;
+        while (i < numTanks) {
+            var tankNode = tankNodes[i];
+            var tankName = tankNode.getValue('name') or 'unnamed';
+            if (i >= numTanks - 1 or
+                string.imatch(tankName, "*center*") or
+                string.imatch(tankName, "*front*") or
+                string.imatch(tankName, "*rear*")) {
+                allocate(i);
+                i = i + 1;
+            }
+            else {
+                allocatePair(i, i + 1);
+                i = i + 2;
+            }
         }
     }
+    elsif (strategy == 'balanced') {
+        var totalFuel = unallocated;
+        var totalCapacity = 0;
+        foreach (var tankNode; tankNodes) {
+            var capacity = tankNode.getValue('capacity-m3');
+            totalCapacity = totalCapacity + capacity;
+        }
+        for (var i = 0; i < numTanks; i += 1) {
+            var tankNode = tankNodes[i];
+            var capacity = tankNode.getValue('capacity-m3');
+            allocate(i, totalFuel * capacity / totalCapacity);
+        }
+    }
+    else {
+        printf("Invalid strategy '%s', please allocate fuel manually", strategy);
+    }
+
     printf("Fuel not allocated: %1.1f kg", unallocated);
 };
 
diff --git a/gui/dialogs/addon-simbrief-dialog.xml b/gui/dialogs/addon-simbrief-dialog.xml
index a079832..c14e65a 100644
--- a/gui/dialogs/addon-simbrief-dialog.xml
+++ b/gui/dialogs/addon-simbrief-dialog.xml
@@ -147,6 +147,24 @@
                 <halign>left</halign>
                 <pref-width>100</pref-width>
             </checkbox>
+            <group>
+                <layout>hbox</layout>
+                <text>
+                    <label>Strategy</label>
+                </text>
+                <combo>
+                    <property>/sim/simbrief/options/fuel-strategy</property>
+                    <binding>
+                        <command>dialog-apply</command>
+                    </binding>
+                    <halign>left</halign>
+                    <pref-width>100</pref-width>
+                    <value>first-come-first-serve</value>
+                    <value>balanced</value>
+                </combo>
+                <halign>left</halign>
+                <pref-width>100</pref-width>
+            </group>
         </group>
         <group>
             <layout>hbox</layout>