From f9a65e26f2ad435fe1d6d36eceab8612f51cd59a Mon Sep 17 00:00:00 2001
From: Mika <kontakt@donau2space.de>
Date: Sat, 24 Jan 2026 12:03:27 +0000
Subject: [PATCH] Add visualization_tool/js/api.js

---
 visualization_tool/js/api.js | 64 ++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 visualization_tool/js/api.js

diff --git a/visualization_tool/js/api.js b/visualization_tool/js/api.js
new file mode 100644
index 0000000..448a509
--- /dev/null
+++ b/visualization_tool/js/api.js
@@ -0,0 +1,64 @@
+/**
+ * Data Layer for Frozen Runs Visualization Tool
+ * Handles API communication and data transformation.
+ * © 2026 Donau2Space.de
+ */
+
+/**
+ * Fetches metric data from the /metrics API endpoint.
+ * @async
+ * @param {string} [filter] - Optional filter parameter ('pinned' or 'unpinned').
+ * @returns {Promise<Object[]>} Parsed metric data ready for visualization.
+ */
+export async function fetchMetrics(filter) {
+  try {
+    const queryParam = filter ? `?filter=${encodeURIComponent(filter)}` : '';
+    const response = await fetch(`/metrics${queryParam}`, {
+      method: 'GET',
+      headers: {
+        'Accept': 'application/json'
+      }
+    });
+
+    if (!response.ok) {
+      throw new Error(`API request failed with status ${response.status}`);
+    }
+
+    const rawData = await response.json();
+    return parseMetricsData(rawData);
+  } catch (error) {
+    console.error('Error fetching metrics:', error);
+    return [];
+  }
+}
+
+/**
+ * Parses and structures raw metric data from API.
+ * @param {Array} data - Raw metric data from /metrics.
+ * @returns {Array<Object>} Structured metric objects for visualization.
+ */
+export function parseMetricsData(data) {
+  if (!Array.isArray(data)) return [];
+
+  return data.map(entry => {
+    const {
+      metricName = 'unknown',
+      runId = 'N/A',
+      pinned_flag = false,
+      effect_size = null,
+      ci_lower = null,
+      ci_upper = null
+    } = entry ?? {};
+
+    return {
+      name: metricName,
+      runId,
+      pinned: Boolean(pinned_flag),
+      effectSize: typeof effect_size === 'number' ? effect_size : null,
+      confidenceInterval: {
+        lower: typeof ci_lower === 'number' ? ci_lower : null,
+        upper: typeof ci_upper === 'number' ? ci_upper : null
+      }
+    };
+  });
+}