feat(result): option to copy slow words list with filtering (@vrutant08)

frontend/src/html/pages/test-result.html

@@ -185,6 +185,15 @@
           >
             <i class="fas fa-fw fa-times"></i>
           </button>
+          <button
+            id="copySlowWordsListButton"
+            class="textButton"
+            aria-label="Copy slow words list"
+            data-balloon-pos="up"
+            tabindex="-1"
+          >
+            <i class="fas fa-fw fa-tachometer-alt"></i>
+          </button>
           <button
             id="toggleBurstHeatmap"
             class="textButton"

frontend/src/ts/test/test-ui.ts

@@ -2,6 +2,8 @@ import {
   showNoticeNotification,
   showErrorNotification,
 } from "../states/notifications";
+import { showSimpleModal } from "../states/simple-modal";
+import { z } from "zod";
 
 import { Config } from "../config/store";
 import { setConfig } from "../config/setters";
@@ -1914,10 +1916,78 @@ qs(".pageTest #copyMissedWordsListButton")?.on("click", async () => {
   await copyToClipboard(words);
 });
 
-async function copyToClipboard(content: string): Promise<void> {
+qs(".pageTest #copySlowWordsListButton")?.on("click", () => {
+  const eventLog = getLastEventLog();
+  if (eventLog === null) return;
+
+  const burstHistory = getWordBurstHistory(eventLog);
+  const avgWpm =
+    burstHistory.length > 0
+      ? Math.round(
+          burstHistory.reduce((a, b) => a + b, 0) / burstHistory.length,
+        )
+      : 80;
+
+  showSimpleModal({
+    title: "Copy slow words",
+    buttonText: "copy",
+    buttonAlwaysEnabled: true,
+    schema: z.object({
+      speedThreshold: z.number().positive(),
+    }),
+    inputs: {
+      speedThreshold: {
+        type: "number",
+        label: "WPM threshold:",
+        placeholder: "80",
+        initVal: avgWpm,
+      },
+    },
+    execFn: async ({ speedThreshold }) => {
+      let typedWords: string[];
+      if (Config.mode === "zen") {
+        typedWords = getInputHistory(eventLog);
+      } else {
+        typedWords = TestWords.words
+          .get()
+          .slice(0, getInputHistory(eventLog).length)
+          .map((w) => w.text);
+      }
+
+      const slowWords: string[] = [];
+      typedWords.forEach((word, index) => {
+        const speed = burstHistory[index] ?? Infinity;
+        if (speed < speedThreshold) {
+          slowWords.push(word);
+        }
+      });
+
+      if (slowWords.length === 0) {
+        return {
+          status: "notice",
+          message: `No words typed under ${speedThreshold} WPM`,
+        };
+      }
+
+      await copyToClipboard(
+        slowWords.join(" "),
+        `Copied ${slowWords.length} slow word${slowWords.length > 1 ? "s" : ""} to clipboard`,
+      );
+      return {
+        status: "success",
+        showNotification: false,
+      };
+    },
+  });
+});
+
+async function copyToClipboard(
+  content: string,
+  customMessage?: string,
+): Promise<void> {
   try {
     await navigator.clipboard.writeText(content);
-    showNoticeNotification("Copied to clipboard", {
+    showNoticeNotification(customMessage ?? "Copied to clipboard", {
       durationMs: 2000,
     });
   } catch (e) {