From a36a0210dba4198c118b1642e83901a1707caea2 Mon Sep 17 00:00:00 2001
From: Mika <kontakt@donau2space.de>
Date: Sun, 18 Jan 2026 16:37:00 +0000
Subject: [PATCH] Add data_visualization/js/chartRenderer.js

---
 data_visualization/js/chartRenderer.js | 137 +++++++++++++++++++++++++
 1 file changed, 137 insertions(+)
 create mode 100644 data_visualization/js/chartRenderer.js

diff --git a/data_visualization/js/chartRenderer.js b/data_visualization/js/chartRenderer.js
new file mode 100644
index 0000000..aca4ae6
--- /dev/null
+++ b/data_visualization/js/chartRenderer.js
@@ -0,0 +1,137 @@
+(() => {
+  /**
+   * chartRenderer.js
+   * Visualization layer rendering measurement data charts.
+   * Uses Chart.js (assumed pre-loaded in the environment)
+   * Handles rendering and updating of multiple measurement charts.
+   */
+
+  let charts = {};
+
+  /**
+   * Converts measurement data into Chart.js datasets
+   * @param {Array<Object>} data - filtered measurement records
+   * @returns {Object} datasets and labels for Chart.js
+   */
+  const prepareDatasets = (data) => {
+    if (!Array.isArray(data)) return { labels: [], datasets: [] };
+    const labels = data.map(d => new Date(d.timestamp).toLocaleTimeString());
+
+    const temperatureData = data.map(d => d.temperature);
+    const humidityData = data.map(d => d.humidity);
+    const brightnessData = data.map(d => d.brightness);
+
+    return {
+      labels,
+      datasets: [
+        {
+          label: 'Temperatur (°C)',
+          data: temperatureData,
+          borderColor: 'rgba(255, 99, 132, 1)',
+          backgroundColor: 'rgba(255, 99, 132, 0.2)',
+          tension: 0.3,
+          yAxisID: 'y',
+        },
+        {
+          label: 'Luftfeuchte (%)',
+          data: humidityData,
+          borderColor: 'rgba(54, 162, 235, 1)',
+          backgroundColor: 'rgba(54, 162, 235, 0.2)',
+          tension: 0.3,
+          yAxisID: 'y1',
+        },
+        {
+          label: 'Signalintensität',
+          data: brightnessData,
+          borderColor: 'rgba(75, 192, 192, 1)',
+          backgroundColor: 'rgba(75, 192, 192, 0.2)',
+          tension: 0.3,
+          yAxisID: 'y',
+        }
+      ]
+    };
+  };
+
+  /**
+   * renderCharts
+   * Visualizes data in line charts and appends them into the .chart-panel.
+   * @param {Array<Object>} data - filtered measurement data
+   */
+  const renderCharts = (data) => {
+    const chartPanel = document.querySelector('.chart-panel');
+    if (!chartPanel) return;
+
+    chartPanel.innerHTML = '';
+
+    const canvas = document.createElement('canvas');
+    canvas.setAttribute('aria-label', 'Messdaten Diagramm');
+    canvas.setAttribute('role', 'img');
+    chartPanel.appendChild(canvas);
+
+    const ctx = canvas.getContext('2d');
+    const { labels, datasets } = prepareDatasets(data);
+
+    const config = {
+      type: 'line',
+      data: { labels, datasets },
+      options: {
+        responsive: true,
+        interaction: { mode: 'index', intersect: false },
+        stacked: false,
+        plugins: {
+          tooltip: {
+            enabled: true,
+            callbacks: {
+              title: (items) => items[0]?.label || '',
+              label: (item) => `${item.dataset.label}: ${item.formattedValue}`
+            }
+          },
+          legend: { labels: { color: '#eee' } },
+        },
+        scales: {
+          y: {
+            type: 'linear',
+            display: true,
+            position: 'left',
+            title: { display: true, text: 'Temperatur / Intensität' },
+            ticks: { color: '#ccc' }
+          },
+          y1: {
+            type: 'linear',
+            display: true,
+            position: 'right',
+            grid: { drawOnChartArea: false },
+            title: { display: true, text: 'Luftfeuchte' },
+            ticks: { color: '#ccc' }
+          },
+          x: {
+            ticks: { color: '#ccc' }
+          }
+        }
+      }
+    };
+
+    charts.main = new Chart(ctx, config);
+  };
+
+  /**
+   * updateChart
+   * Updates existing chart data and re-renders with new dataset.
+   * @param {Array<Object>} newData - new or filtered measurement data
+   */
+  const updateChart = (newData) => {
+    if (!charts.main) {
+      renderCharts(newData);
+      return;
+    }
+
+    const { labels, datasets } = prepareDatasets(newData);
+
+    charts.main.data.labels = labels;
+    charts.main.data.datasets = datasets;
+    charts.main.update('active');
+  };
+
+  // Expose functions globally
+  window.chartRenderer = { renderCharts, updateChart };
+})();
\ No newline at end of file