From 0cfca20ee6529c3d79d998faf9897ede37b3a8e0 Mon Sep 17 00:00:00 2001
From: jweigele <jweigele@local>
Date: Sat, 15 Jul 2023 17:07:09 -0700
Subject: [PATCH] now returns AQI band for later color indicators

---
 aqi_calc.c         | 41 +++++++++++++++++++++++++++++++----------
 include/aqi_calc.h |  1 +
 2 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/aqi_calc.c b/aqi_calc.c
index 97f3bdf..e83575d 100644
--- a/aqi_calc.c
+++ b/aqi_calc.c
@@ -84,10 +84,7 @@ float linear_calc(uint16_t value, aqi_lookup_t lookup_row, int lookup_type){
     return retval;
 }
 
-float aqi_calc_pm10(uint16_t pm10){
-    // precision is integer, so div 100
-    // ex. 2543 / 100 = 25 (real value: 25)
-    pm10 /= 100;
+int get_lookup_int_pm10(uint16_t pm10){
     int i = 0;
     while (i < 6){
         if (pm10 < AQI_LOOKUP_TABLE[i].pm10_high ){
@@ -98,15 +95,20 @@ float aqi_calc_pm10(uint16_t pm10){
     }
     if (pm10 > AQI_LOOKUP_TABLE[i].pm10_high){
         printf("pm10 too high for aqi lookup, this should never happen %d > %d\n", pm10, AQI_LOOKUP_TABLE[i].pm10_high );
-        return 0.0;
+        return -1;
     }
+    return i;    
+}
+
+float aqi_calc_pm10(uint16_t pm10){
+    // precision is integer, so div 100
+    // ex. 2543 / 100 = 25 (real value: 25)
+    pm10 /= 100;
+    int i = get_lookup_int_pm10(pm10);
     return linear_calc(pm10, AQI_LOOKUP_TABLE[i], LOOKUP_PM10);
 }
 
-float aqi_calc_pm25(uint16_t pm25){
-    // precision is one decimal, so div 10:
-    // ex. 2543 / 10 = 254 (real value: 25.4)
-    pm25 /= 10;
+int get_lookup_int_pm25(uint16_t pm25){
     printf("modified pm25: %d\n", pm25);
     int i = 0;
     while (i < 6){
@@ -118,7 +120,26 @@ float aqi_calc_pm25(uint16_t pm25){
     }
     if (pm25 > AQI_LOOKUP_TABLE[i].pm25_high){
         printf("pm25 too high for aqi lookup, this should never happen %d > %d\n", pm25, AQI_LOOKUP_TABLE[i].pm25_high );
-        return 0.0;
+        return -1;
     }
+    return i;
+}
+
+float aqi_calc_pm25(uint16_t pm25){
+    // precision is one decimal, so div 10:
+    // ex. 2543 / 10 = 254 (real value: 25.4)
+    pm25 /= 10;
+    int i = get_lookup_int_pm25(pm25);
     return linear_calc(pm25, AQI_LOOKUP_TABLE[i], LOOKUP_PM25);
 }
+
+int get_lookup_highest(int pm10, int pm25){
+    int pm10_lookup = get_lookup_int_pm10(pm10/100);
+    int pm25_lookup = get_lookup_int_pm25(pm25/10);
+    if (pm25_lookup > pm10_lookup){
+        return pm25_lookup;
+    } else {
+        return pm10_lookup;
+    }
+}
+
diff --git a/include/aqi_calc.h b/include/aqi_calc.h
index 57a21c2..3593de0 100644
--- a/include/aqi_calc.h
+++ b/include/aqi_calc.h
@@ -5,4 +5,5 @@
 
 float aqi_calc_pm10(uint16_t pm10);
 float aqi_calc_pm25(uint16_t pm25);
+int get_lookup_highest(int pm10, int pm25);
 
-- 
2.30.2