From d9784bdbd43d6fd325a95df668532c0c3aae80a0 Mon Sep 17 00:00:00 2001
From: Alex Selimov <alex@alexselimov.com>
Date: Wed, 13 May 2026 07:18:04 -0400
Subject: [PATCH] Update heatmap with legend and extra color level

---
 assets/js/build_heatmap.js        | 45 ++++++++++++++++++++++++++++---
 layouts/partials/git-heatmap.html | 41 +++++++++++++++++++++++-----
 2 files changed, 75 insertions(+), 11 deletions(-)

diff --git a/assets/js/build_heatmap.js b/assets/js/build_heatmap.js
index d2bcab5..be78bdb 100644
--- a/assets/js/build_heatmap.js
+++ b/assets/js/build_heatmap.js
@@ -30,9 +30,10 @@ export function constructWeeks() {
 
 function getColor(count) {
   if (count === 0) return "var(--color-empty)";
-  if (count <= 3) return "var(--color-low)";
-  if (count <= 10) return "var(--color-mid)";
-  return "var(--color-high)";
+  if (count <= 2) return "var(--color-l1)";
+  if (count <= 5) return "var(--color-l2)";
+  if (count <= 10) return "var(--color-l3)";
+  return "var(--color-l4)";
 }
 
 export function render(weeks, counts) {
@@ -85,6 +86,42 @@ export function render(weeks, counts) {
   return svg;
 }
 
+export function totalCount(counts) {
+  return Object.values(counts).reduce((s, v) => s + v, 0);
+}
+
+export function renderLegend() {
+  const CELL = 11;
+  const GAP = 3;
+  const SHIFT = CELL + GAP;
+  const svgNS = "http://www.w3.org/2000/svg";
+  const svg = document.createElementNS(svgNS, "svg");
+  svg.setAttribute("width", 5 * SHIFT - GAP);
+  svg.setAttribute("height", CELL);
+  svg.style.display = "inline-block";
+  svg.style.verticalAlign = "middle";
+
+  const colors = [
+    "var(--color-empty)",
+    "var(--color-l1)",
+    "var(--color-l2)",
+    "var(--color-l3)",
+    "var(--color-l4)",
+  ];
+  colors.forEach((color, i) => {
+    const rect = document.createElementNS(svgNS, "rect");
+    rect.setAttribute("x", i * SHIFT);
+    rect.setAttribute("y", 0);
+    rect.setAttribute("width", CELL);
+    rect.setAttribute("height", CELL);
+    rect.setAttribute("fill", color);
+    rect.setAttribute("rx", 2);
+    svg.appendChild(rect);
+  });
+
+  return svg;
+}
+
 export function setupTooltips(svg) {
   const tooltip = document.getElementById("tooltip");
   document.body.appendChild(tooltip);
@@ -94,7 +131,7 @@ export function setupTooltips(svg) {
     const date = e.target.dataset.date;
     const count = e.target.dataset.count;
 
-    tooltip.textContent = `${date} - ${count} commit${count == 1 ? "" : "s"}`;
+    tooltip.textContent = `${date} - ${count} contribution${count == 1 ? "" : "s"}`;
     tooltip.classList.remove("hidden");
   });
 
diff --git a/layouts/partials/git-heatmap.html b/layouts/partials/git-heatmap.html
index ce619a1..25c9e79 100644
--- a/layouts/partials/git-heatmap.html
+++ b/layouts/partials/git-heatmap.html
@@ -4,18 +4,31 @@
 <style>
 :root {
   --color-empty: {{ $p.color_empty_dark }};
-  --color-low:   {{ $p.color_low }};
-  --color-mid:   {{ $p.color_mid }};
-  --color-high:  {{ $p.color_high }};
+  --color-l1: {{ $p.color_max }};
+  --color-l2: {{ $p.color_high }};
+  --color-l3: {{ $p.color_mid }};
+  --color-l4: {{ $p.color_low }};
 }
 @media (prefers-color-scheme: light) {
-    :root {
-      --color-empty: {{ $p.color_empty_light }};
-    }
+  :root {
+    --color-empty: {{ $p.color_empty_light }};
+    --color-l1: {{ $p.color_low }};
+    --color-l2: {{ $p.color_mid }};
+    --color-l3: {{ $p.color_high }};
+    --color-l4: {{ $p.color_max }};
+  }
 }
 #heatmap { overflow-x: auto; }
 #heatmap text { font-family: inherit; fill: currentColor; }
 #heatmap-caption {font-size: 0.8em; text-align: center; margin-top: 0px;}
+#heatmap-footer {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  font-size: 0.75em;
+  margin-top: 4px;
+}
+#heatmap-legend { display: flex; align-items: center; gap: 4px; }
 #tooltip {
   position: fixed;
   background: #333;
@@ -30,7 +43,7 @@
 
 <div id="heatmap"></div>
 <script type="module">
-    import {flattenData, constructWeeks, render, setupTooltips} from "{{ $js.RelPermalink }}"
+    import {flattenData, constructWeeks, render, setupTooltips, totalCount, renderLegend} from "{{ $js.RelPermalink }}"
 
     const data = await fetch("/activity.json").then((r) => r.json());
     const counts = flattenData(data);
@@ -38,7 +51,21 @@
     const svg = render(weeks, counts);
     document.getElementById("heatmap").appendChild(svg);
     setupTooltips(svg);
+
+    document.getElementById("contribution-count").textContent =
+      `${totalCount(counts)} contributions in the last year`;
+
+    const legendEl = document.getElementById("heatmap-legend");
+    legendEl.appendChild(document.createTextNode("Less"));
+    legendEl.appendChild(renderLegend());
+    legendEl.appendChild(document.createTextNode("More"));
 </script>
+
+<div id="heatmap-footer">
+  <span id="contribution-count"></span>
+  <span id="heatmap-legend"></span>
+</div>
+
 {{ with $p.caption }}
 <p id="heatmap-caption"> {{ . | safeHTML }} </p>
 {{ end }}