Refactor scripts into modules

utils.js

@@ -0,0 +1,92 @@
+(function(){
+  function parseColor(hex) {
+    if (!hex) return [255, 255, 255];
+    let c = hex.replace('#', '');
+    if (c.length === 3) c = c.split('').map(x => x + x).join('');
+    const num = parseInt(c, 16);
+    return [(num >> 16) & 255, (num >> 8) & 255, num & 255];
+  }
+
+  const toHex = v => v.toString(16).padStart(2, '0');
+
+  function hexToRgba(hex, a = 1) {
+    const [r, g, b] = parseColor(hex);
+    return `rgba(${r},${g},${b},${a})`;
+  }
+
+  function getContrastColor(hex) {
+    const [r, g, b] = parseColor(hex);
+    const yiq = (r * 299 + g * 587 + b * 114) / 1000;
+    return yiq >= 128 ? '#000' : '#fff';
+  }
+
+  function lightenColor(hex, p) {
+    const [r, g, b] = parseColor(hex).map(v =>
+      Math.min(255, Math.round(v + (255 - v) * p))
+    );
+    return '#' + [r, g, b].map(toHex).join('');
+  }
+
+  function getHumanDiff(d1, d2) {
+    let start = d1 < d2 ? d1 : d2;
+    let end   = d1 < d2 ? d2 : d1;
+
+    let years  = end.getUTCFullYear()  - start.getUTCFullYear();
+    let months = end.getUTCMonth()     - start.getUTCMonth();
+    let days   = end.getUTCDate()      - start.getUTCDate();
+
+    if (days < 0) {
+      months--;
+      let prevMonthDays = new Date(Date.UTC(
+        end.getUTCFullYear(),
+        end.getUTCMonth(), 0
+      )).getUTCDate();
+      days += prevMonthDays;
+    }
+    if (months < 0) {
+      years--;
+      months += 12;
+    }
+
+    let aligned = new Date(Date.UTC(
+      start.getUTCFullYear() + years,
+      start.getUTCMonth()     + months,
+      start.getUTCDate()      + days,
+      start.getUTCHours(),
+      start.getUTCMinutes(),
+      start.getUTCSeconds()
+    ));
+    let diffMs = end.getTime() - aligned.getTime();
+
+    if (diffMs < 0) {
+      diffMs += 24 * 3600e3;
+      if (days > 0) {
+        days--;
+      } else {
+        months--;
+        if (months < 0) {
+          years--;
+          months += 12;
+        }
+        days = new Date(Date.UTC(
+          end.getUTCFullYear(),
+          end.getUTCMonth(), 0
+        )).getUTCDate();
+      }
+    }
+
+    let hours   = Math.floor(diffMs / 3600e3); diffMs -= hours * 3600e3;
+    let minutes = Math.floor(diffMs /   60e3); diffMs -= minutes *   60e3;
+    let seconds = Math.floor(diffMs /    1e3);
+
+    return { years, months, days, hours, minutes, seconds };
+  }
+
+  window.Utils = {
+    parseColor,
+    hexToRgba,
+    getContrastColor,
+    lightenColor,
+    getHumanDiff
+  };
+})();