From 3e4e7d6266ea9730508d660ffa35f42cfccdf604 Mon Sep 17 00:00:00 2001
From: Eddy de Vink <github@eddydev.ink>
Date: Sat, 27 Jun 2026 23:51:26 +0200
Subject: [PATCH] feat: separate y-axis scales per metric with three stacked
 charts

---
 src/components/WeightChart.tsx | 126 +++++++++++++++++++--------------
 1 file changed, 72 insertions(+), 54 deletions(-)

diff --git a/src/components/WeightChart.tsx b/src/components/WeightChart.tsx
index 247f1ec..7ea663f 100644
--- a/src/components/WeightChart.tsx
+++ b/src/components/WeightChart.tsx
@@ -11,6 +11,52 @@ const COLORS = {
   muscleMass: '#2196F3',
 }
 
+function SingleChart({
+  title,
+  data,
+  labels,
+  color,
+  unit,
+}: {
+  title: string
+  data: number[]
+  labels: string[]
+  color: string
+  unit: string
+}) {
+  return (
+    <View style={styles.chartBlock}>
+      <Text style={styles.chartTitle}>{title}</Text>
+      <LineChart
+        data={{ labels, datasets: [{ data, color: () => color, strokeWidth: 2 }] }}
+        width={Dimensions.get('window').width - 32}
+        height={180}
+        yAxisSuffix={unit}
+        chartConfig={{
+          backgroundColor: '#ffffff',
+          backgroundGradientFrom: '#ffffff',
+          backgroundGradientTo: '#ffffff',
+          decimalPlaces: 1,
+          color: (opacity = 1) => `rgba(${hexToRgb(color)}, ${opacity})`,
+          labelColor: () => '#666',
+          propsForDots: { r: '3' },
+        }}
+        bezier
+        style={styles.chart}
+        withInnerLines={false}
+        fromZero={false}
+      />
+    </View>
+  )
+}
+
+function hexToRgb(hex: string): string {
+  const r = parseInt(hex.slice(1, 3), 16)
+  const g = parseInt(hex.slice(3, 5), 16)
+  const b = parseInt(hex.slice(5, 7), 16)
+  return `${r}, ${g}, ${b}`
+}
+
 export default function WeightChart({ measurements }: Props) {
   if (measurements.length < 2) {
     return null
@@ -35,57 +81,31 @@ export default function WeightChart({ measurements }: Props) {
 
   return (
     <View style={styles.container}>
-      <Text style={styles.title}>Gewicht & Lichaamssamenstelling</Text>
-      <LineChart
-        data={{
-          labels: sparseLabels,
-          datasets: [
-            {
-              data: dataPoints.map(m => m.weight),
-              color: () => COLORS.weight,
-              strokeWidth: 2,
-            },
-            {
-              data: dataPoints.map(m => m.fatMass),
-              color: () => COLORS.fatMass,
-              strokeWidth: 2,
-            },
-            {
-              data: dataPoints.map(m => m.muscleMass),
-              color: () => COLORS.muscleMass,
-              strokeWidth: 2,
-            },
-          ],
-        }}
-        width={Dimensions.get('window').width - 32}
-        height={240}
-        yAxisSuffix=" kg"
-        chartConfig={{
-          backgroundColor: '#ffffff',
-          backgroundGradientFrom: '#ffffff',
-          backgroundGradientTo: '#ffffff',
-          decimalPlaces: 1,
-          color: (opacity = 1) => `rgba(0, 0, 0, ${opacity})`,
-          labelColor: () => '#666',
-          propsForDots: { r: '3' },
-        }}
-        bezier
-        style={styles.chart}
+      <Text style={styles.title}>Voortgang (30 dagen)</Text>
+
+      <SingleChart
+        title="Gewicht"
+        data={dataPoints.map(m => m.weight)}
+        labels={sparseLabels}
+        color={COLORS.weight}
+        unit=" kg"
+      />
+
+      <SingleChart
+        title="Vetmassa"
+        data={dataPoints.map(m => m.fatMass)}
+        labels={sparseLabels}
+        color={COLORS.fatMass}
+        unit=" kg"
+      />
+
+      <SingleChart
+        title="Spiermassa"
+        data={dataPoints.map(m => m.muscleMass)}
+        labels={sparseLabels}
+        color={COLORS.muscleMass}
+        unit=" kg"
       />
-      <View style={styles.legend}>
-        <View style={styles.legendItem}>
-          <View style={[styles.legendDot, { backgroundColor: COLORS.weight }]} />
-          <Text style={styles.legendLabel}>Gewicht</Text>
-        </View>
-        <View style={styles.legendItem}>
-          <View style={[styles.legendDot, { backgroundColor: COLORS.fatMass }]} />
-          <Text style={styles.legendLabel}>Vetmassa</Text>
-        </View>
-        <View style={styles.legendItem}>
-          <View style={[styles.legendDot, { backgroundColor: COLORS.muscleMass }]} />
-          <Text style={styles.legendLabel}>Spiermassa</Text>
-        </View>
-      </View>
     </View>
   )
 }
@@ -93,9 +113,7 @@ export default function WeightChart({ measurements }: Props) {
 const styles = StyleSheet.create({
   container: { marginHorizontal: 16, marginBottom: 16 },
   title: { fontSize: 18, fontWeight: '700', marginBottom: 8 },
+  chartBlock: { marginBottom: 12 },
+  chartTitle: { fontSize: 13, fontWeight: '600', color: '#555', marginBottom: 4, marginLeft: 4 },
   chart: { borderRadius: 12 },
-  legend: { flexDirection: 'row', justifyContent: 'center', gap: 16, marginTop: 8 },
-  legendItem: { flexDirection: 'row', alignItems: 'center', gap: 4 },
-  legendDot: { width: 10, height: 10, borderRadius: 5 },
-  legendLabel: { fontSize: 12, color: '#666' },
 })