initial adjust amounts implemented

src/lib/components/IngredientsPage.svelte

@@ -1,5 +1,82 @@
 <script>
 export let data
+let multiplier = 1
+
+//function multiplyNumbersInString(inputString, constant) {
+//  return inputString.replace(/(\d+(?:[\.,]\d+)?)/g, match => {
+//    const number = match.includes(',') ? match.replace(/\./g, '').replace(',', '.') : match;
+//    const multiplied = (parseFloat(number) * constant).toString();
+//    return match.includes(',') ? multiplied.replace('.', ',') : multiplied;
+//  });
+//}
+function multiplyNumbersInString(inputString, constant) {
+  return inputString.replace(/(\d+(?:[\.,]\d+)?)/g, match => {
+    const number = match.includes(',') ? match.replace(/\./g, '').replace(',', '.') : match;
+    const multiplied = (parseFloat(number) * constant).toString();
+    const rounded = parseFloat(multiplied).toFixed(3);
+    const trimmed = parseFloat(rounded).toString();
+    return match.includes(',') ? trimmed.replace('.', ',') : trimmed;
+  });
+}
+
+
+function convertFloatingPointToFraction(input) {
+  const parts = input.split(/(\d*\.?\d+)/);
+
+  return parts
+    .map(part => {
+      const number = parseFloat(part);
+
+      if (!isNaN(number) && number % 1 !== 0) {
+        const denominator = 10 ** number.toString().split('.')[1].length;
+        const numerator = Math.round(number * denominator);
+
+        if (numerator > 8 || denominator > 8) {
+          const wholeNumber = Math.floor(numerator / denominator);
+          const mixedNumerator = numerator % denominator;
+          const gcd = findGCD(mixedNumerator, denominator);
+          const simplifiedNumerator = mixedNumerator / gcd;
+          const simplifiedDenominator = denominator / gcd;
+
+          if (wholeNumber > 0) {
+            return `${wholeNumber}<sup>${simplifiedNumerator}</sup>&frasl;<sub>${simplifiedDenominator}</sub>`;
+          } else {
+            return `<sup>${simplifiedNumerator}</sup>&frasl;<sub>${simplifiedDenominator}</sub>`;
+          }
+        }
+      }
+
+      return part;
+    })
+    .join('');
+}
+
+function findGCD(a, b) {
+  if (b === 0) {
+    return a;
+  }
+  return findGCD(b, a % b);
+}
+
+// For portions, not sure whether to keep or let it be
+function multiplyFirstNumberInString(inputString, constant) {
+  const firstNumberRegex = /\d+(?:[\.,]\d+)?/;
+  const match = inputString.match(firstNumberRegex);
+  if (match) {
+    const number = match[0].includes(',') ? match[0].replace(/\./g, '').replace(',', '.') : match[0];
+    const multiplied = (parseFloat(number) * constant).toString();
+    const rounded = parseFloat(multiplied).toString();
+    const result = match[0].includes(',') ? rounded.replace('.', ',') : rounded;
+    return inputString.replace(firstNumberRegex, result);
+  }
+  return inputString;
+}
+
+function adjust_amount(string, multiplier){
+	let temp = multiplyNumbersInString(string, multiplier)
+	temp = convertFloatingPointToFraction(temp)
+	return temp
+}
 </script>
 <style>
 *{
@@ -20,16 +97,51 @@ font-family: sans-serif;
 	row-gap: 0.5em;
 	column-gap: 0.5em;
 }
-h4{
-	margin-block: 0;
+.multipliers{
+	display:flex;
+	gap: 0.5rem;
+	justify-content: center;
+}
+.multipliers button{
+	width: 2em;
+	font-size: 1.1rem;
+	border-radius: 0.3rem;
+	border: none;
+	cursor: pointer;
+	transition: 100ms;
+	color: var(--nord0);
+	background-color: var(--nord5);
+	box-shadow: 0px 0px 0.4em 0.05em rgba(0,0,0, 0.2);
+}
+.multipliers button:is(:hover, :focus-visible){
+	scale: 1.2;
+	background-color: var(--orange);
+	box-shadow: 0px 0px 0.5em 0.1em rgba(0,0,0, 0.3);
+}
+button.selected{
+	background-color: var(--nord9);
+	color: white;
+	font-weight: bold;
+	scale: 1.1;
+	box-shadow: 0px 0px 0.4em 0.1em rgba(0,0,0, 0.3);
 }
 </style>
 {#if data.ingredients}
 <div class=ingredients>
 {#if data.portions}
 	<h3>Portionen:</h3>
-	{data.portions}
+	{@html convertFloatingPointToFraction(multiplyFirstNumberInString(data.portions, multiplier))}
 {/if}
+
+<h3>Menge anpassen:</h3>
+<div class=multipliers>
+	<button class:selected={multiplier==0.5} on:click={() => multiplier=0.5}><sup>1</sup>&frasl;<sub>2</sub>x</button>
+	<button class:selected={multiplier==1} on:click={() => multiplier=1}>1x</button>
+	<button class:selected={multiplier==1.5} on:click={() => multiplier=1.5}><sup>3</sup>&frasl;<sub>2</sub>x</button>
+	<button class:selected={multiplier==2} on:click="{() => multiplier=2}">2x</button>
+	<button class:selected={multiplier==3} on:click="{() => multiplier=3}">3x</button>
+</div>
+
 <h2>Zutaten</h2>
 {#each data.ingredients as list}
 {#if list.name}
@@ -37,7 +149,7 @@ h4{
 {/if}
 <div class=ingredients_grid>
 	{#each list.list as item}
-		<div class=amount>{item.amount} {item.unit}</div><div class=name>{@html item.name}</div>
+		<div class=amount>{@html adjust_amount(item.amount, multiplier)} {item.unit}</div><div class=name>{@html item.name}</div>
 	{/each}
 </div>
 {/each}