From 8f80a64b2120638b35d7b9ceeeb5d2c1b16271a1 Mon Sep 17 00:00:00 2001
From: Mika <kontakt@donau2space.de>
Date: Sun, 29 Mar 2026 03:07:25 +0000
Subject: [PATCH] Add data_visualization/js/ui.js

---
 data_visualization/js/ui.js | 111 ++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 data_visualization/js/ui.js

diff --git a/data_visualization/js/ui.js b/data_visualization/js/ui.js
new file mode 100644
index 0000000..b41732f
--- /dev/null
+++ b/data_visualization/js/ui.js
@@ -0,0 +1,111 @@
+"use strict";
+
+/**
+ * UI Logic for Data Visualization
+ * Handles rendering charts, updating stats, and applying filters.
+ */
+
+import { fetchData } from './api.js';
+
+/**
+ * @typedef {Object} SensorData
+ * @property {string} timestamp - ISO time string
+ * @property {number} intensity - Measured light intensity
+ * @property {number} wavelength - Light wavelength in nm
+ * @property {string} sensor_id - Identifier of the sensor
+ */
+
+/**
+ * Renders chart visualization inside the DOM element with id 'chart-container'.
+ * @param {SensorData[]} dataArray
+ */
+export function renderChart(dataArray) {
+  const container = document.getElementById('chart-container');
+  if (!container) return;
+
+  container.innerHTML = '';
+  
+  // Create canvas for chart
+  const canvas = document.createElement('canvas');
+  canvas.setAttribute('role', 'img');
+  canvas.setAttribute('aria-label', 'Diagramm der Intensitätswerte über Zeit');
+  container.appendChild(canvas);
+
+  const ctx = canvas.getContext('2d');
+  const timestamps = dataArray.map(d => new Date(d.timestamp).toLocaleTimeString());
+  const intensities = dataArray.map(d => d.intensity);
+
+  // Chart.js-like pseudo implementation (no external lib)
+  ctx.beginPath();
+  const maxIntensity = Math.max(...intensities, 1);
+  const minIntensity = Math.min(...intensities, 0);
+  const width = canvas.width = container.offsetWidth;
+  const height = canvas.height = Math.min(400, container.offsetHeight || 300);
+
+  ctx.strokeStyle = '#007acc';
+  ctx.lineWidth = 2;
+
+  intensities.forEach((value, i) => {
+    const x = (i / (intensities.length - 1)) * width;
+    const y = height - ((value - minIntensity) / (maxIntensity - minIntensity)) * height;
+    if (i === 0) ctx.moveTo(x, y);
+    else ctx.lineTo(x, y);
+  });
+  ctx.stroke();
+
+  updateSummary(dataArray);
+}
+
+/**
+ * Updates statistics panel with calculated summary data.
+ * @param {SensorData[]} dataArray
+ */
+export function updateSummary(dataArray) {
+  const avg = dataArray.length ? dataArray.reduce((acc, d) => acc + d.intensity, 0) / dataArray.length : 0;
+  const max = dataArray.length ? Math.max(...dataArray.map(d => d.intensity)) : 0;
+  const min = dataArray.length ? Math.min(...dataArray.map(d => d.intensity)) : 0;
+
+  const summaryEl = document.getElementById('summary-panel');
+  if (!summaryEl) return;
+
+  summaryEl.innerHTML = `
+    <div class="summary__item"><strong>Durchschnitt:</strong> ${avg.toFixed(2)}</div>
+    <div class="summary__item"><strong>Max:</strong> ${max.toFixed(2)}</div>
+    <div class="summary__item"><strong>Min:</strong> ${min.toFixed(2)}</div>
+  `;
+}
+
+/**
+ * Reads filter form values and triggers data reload.
+ */
+export async function applyFilters() {
+  const sensorSelect = document.getElementById('filter-sensor');
+  const timeStart = document.getElementById('filter-start');
+  const timeEnd = document.getElementById('filter-end');
+
+  const params = {};
+  if (sensorSelect?.value) params.sensor = sensorSelect.value;
+  if (timeStart?.value) params.start = timeStart.value;
+  if (timeEnd?.value) params.end = timeEnd.value;
+
+  const data = await fetchData(params).catch(() => []);
+  renderChart(data);
+}
+
+/**
+ * Binds UI event handlers.
+ */
+export function bindUIEvents() {
+  const form = document.getElementById('filter-form');
+  if (form) {
+    form.addEventListener('submit', e => {
+      e.preventDefault();
+      applyFilters();
+    });
+  }
+}
+
+// Auto-bind when DOM is ready
+document.addEventListener('DOMContentLoaded', () => {
+  bindUIEvents();
+});
\ No newline at end of file