replace Flot.js with uPlot for server graphs

assets/js/scale.js

@@ -0,0 +1,53 @@
+class RelativeScale {
+  static scale (data, tickCount) {
+    const [min, max] = RelativeScale.calculateBounds(data)
+
+    let factor = 1
+
+    while (true) {
+      const scale = Math.pow(10, factor)
+
+      const scaledMin = min - (min % scale)
+      const scaledMax = max + (max % scale === 0 ? 0 : (scale - (max % scale)))
+
+      const ticks = (scaledMax - scaledMin) / scale
+
+      if (ticks + 1 <= tickCount) {
+        return [scaledMin, scaledMax, scale]
+      } else {
+        // Too many steps between min/max, increase factor and try again
+        factor++
+      }
+    }
+  }
+
+  static generateTicks (min, max, step) {
+    const ticks = []
+    for (let i = min; i <= max; i += step) {
+      ticks.push(i)
+    }
+    return ticks
+  }
+
+  static calculateBounds (data) {
+    if (data.length === 0) {
+      return [0, 0]
+    } else {
+      let min = Number.MAX_VALUE
+      let max = Number.MIN_VALUE
+
+      for (const point of data) {
+        if (point > max) {
+          max = point
+        }
+        if (point < min) {
+          min = point
+        }
+      }
+
+      return [min, max]
+    }
+  }
+}
+
+module.exports = RelativeScale