From 030609b45eaf8462d0d38b58c746f75f9cf5beed Mon Sep 17 00:00:00 2001
From: RunasSudo <runassudo@yingtongli.me>
Date: Tue, 27 Aug 2024 17:53:55 +1000
Subject: [PATCH] Refactor bilirubin vs threshold calculation

---
 src/bilirubin_app.js | 30 ++++--------------------------
 src/bilirubin_lib.js | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 26 deletions(-)

diff --git a/src/bilirubin_app.js b/src/bilirubin_app.js
index c1924eb..d7df466 100644
--- a/src/bilirubin_app.js
+++ b/src/bilirubin_app.js
@@ -150,35 +150,13 @@ function updateBilirubin() {
 		return;
 	}
 	
-	// Chronological age in days
-	let d = (document.getElementById('time_measurement').valueAsDate.getTime() - document.getElementById('time_birth').valueAsDate.getTime()) / 1000 / 60 / 60 / 24;
-	
-	let phototherapy_thresh_value = phototherapy_thresh(d, gestation);
-	let exchange_thresh_value = exchange_thresh(d, gestation);
+	let [d, result_text, text_colour, background_colour, accent_colour] = describeBilirubin(gestation, document.getElementById('time_birth').valueAsDate, document.getElementById('time_measurement').valueAsDate, bilirubin);
 	
 	chart.data.datasets[2].data = [{x: d, y: bilirubin}];
 	chart.update();
 	
-	if (bilirubin < phototherapy_thresh_value) {
-		if (bilirubin < phototherapy_thresh_value - 50) {
-			resultDiv.className = 'border-l-4 border-sky-400 bg-sky-50 py-2 px-4';
-			resultP.className = 'text-sm text-sky-800';
-		} else {
-			resultDiv.className = 'border-l-4 border-yellow-400 bg-yellow-50 py-2 px-4';
-			resultP.className = 'text-sm text-yellow-800';
-		}
-		
-		resultP.innerHTML = 'Bilirubin of ' + bilirubin + ' at ' + prettyPrintDays(d) + ' is <span class="font-bold">' + prettyPrintBilirubin(phototherapy_thresh_value - bilirubin) + ' below</span> the phototherapy threshold.';
-	} else if (bilirubin < exchange_thresh_value) {
-		resultDiv.className = 'border-l-4 border-orange-400 bg-orange-50 py-2 px-4';
-		resultP.className = 'text-sm text-orange-800';
-		
-		resultP.innerHTML = 'Bilirubin of ' + bilirubin + ' at ' + prettyPrintDays(d) + ' is <span class="font-bold">' + prettyPrintBilirubin(bilirubin - phototherapy_thresh_value) + ' above</span> the phototherapy threshold, ' + prettyPrintBilirubin(exchange_thresh_value - bilirubin) + ' below the exchange transfusion threshold.';
-	} else {
-		resultDiv.className = 'border-l-4 border-red-400 bg-red-50 py-2 px-4';
-		resultP.className = 'text-sm text-red-800';
-		
-		resultP.innerHTML = 'Bilirubin of ' + bilirubin + ' at ' + prettyPrintDays(d) + ' is ' + prettyPrintBilirubin(bilirubin - exchange_thresh_value) + ' above the <span class="font-bold">exchange transfusion</span> threshold.';
-	}
+	resultDiv.className = 'border-l-4 ' + accent_colour + ' ' + background_colour + ' py-2 px-4';
+	resultP.className = 'text-sm ' + text_colour;
+	resultP.innerHTML = result_text;
 }
 updateBilirubin();
diff --git a/src/bilirubin_lib.js b/src/bilirubin_lib.js
index c55c260..1f5606e 100644
--- a/src/bilirubin_lib.js
+++ b/src/bilirubin_lib.js
@@ -76,6 +76,48 @@ function exchange_thresh(d, gestation) {
 	return thresh_at_3days;
 }
 
+// ----------------------------------
+// Bilirubin vs threshold calculation
+
+function describeBilirubin(gestation, dateBirth, dateMeasurement, bilirubin) {
+	// Chronological age in days
+	let d = (dateMeasurement.getTime() - dateBirth.getTime()) / 1000 / 60 / 60 / 24;
+	
+	let phototherapy_thresh_value = phototherapy_thresh(d, gestation);
+	let exchange_thresh_value = exchange_thresh(d, gestation);
+	
+	// Restate colours separately so Tailwind can detect them
+	let result_text, text_colour, background_colour, accent_colour;
+	
+	if (bilirubin < phototherapy_thresh_value) {
+		if (bilirubin < phototherapy_thresh_value - 50) {
+			text_colour = 'text-sky-800';
+			background_colour = 'bg-sky-50';
+			accent_colour = 'border-sky-400';
+		} else {
+			text_colour = 'text-yellow-800';
+			background_colour = 'bg-yellow-50';
+			accent_colour = 'border-yellow-400';
+		}
+		
+		result_text = 'Bilirubin of ' + bilirubin + ' at ' + prettyPrintDays(d) + ' is <span class="font-bold">' + prettyPrintBilirubin(phototherapy_thresh_value - bilirubin) + ' below</span> the phototherapy threshold.';
+	} else if (bilirubin < exchange_thresh_value) {
+		text_colour = 'text-orange-800';
+		background_colour = 'bg-orange-50';
+		accent_colour = 'border-orange-400';
+		
+		result_text = 'Bilirubin of ' + bilirubin + ' at ' + prettyPrintDays(d) + ' is <span class="font-bold">' + prettyPrintBilirubin(bilirubin - phototherapy_thresh_value) + ' above</span> the phototherapy threshold, ' + prettyPrintBilirubin(exchange_thresh_value - bilirubin) + ' below the exchange transfusion threshold.';
+	} else {
+		text_colour = 'text-red-800';
+		background_colour = 'bg-red-50';
+		accent_colour = 'border-red-400';
+		
+		result_text = 'Bilirubin of ' + bilirubin + ' at ' + prettyPrintDays(d) + ' is ' + prettyPrintBilirubin(bilirubin - exchange_thresh_value) + ' above the <span class="font-bold">exchange transfusion</span> threshold.';
+	}
+	
+	return [d, result_text, text_colour, background_colour, accent_colour];
+}
+
 // --------------
 // Utility functions