feat(dashboard): add PR by distance and race comparison table

Made-with: Cursor

frontend/src/pages/DashboardPage.tsx

@@ -5,10 +5,13 @@ import {
   formatDistance,
   formatRaceDate,
   getRaceCountdownLabel,
+  getPaceLabel,
   parseFinishTimeToSeconds,
   splitRacesByDate,
 } from "../lib";
 
+const PR_DISTANCES = [5, 10, 21.1, 42.2] as const;
+
 function getErrorMessage(error: unknown): string {
   if (error instanceof ApiError) {
     return error.message;
@@ -16,6 +19,10 @@ function getErrorMessage(error: unknown): string {
   return "Не удалось загрузить данные dashboard.";
 }
 
+function isSameDistance(left: number, right: number): boolean {
+  return Math.abs(left - right) < 0.05;
+}
+
 export function DashboardPage(): JSX.Element {
   const [races, setRaces] = useState<Race[]>([]);
   const [isLoading, setIsLoading] = useState<boolean>(true);
@@ -86,6 +93,54 @@ export function DashboardPage(): JSX.Element {
     };
   }, [races]);
 
+  const personalRecordsByDistance = useMemo(() => {
+    return PR_DISTANCES.map((distanceKm) => {
+      const candidates = races.filter((race) => {
+        return (
+          race.status === "completed" &&
+          isSameDistance(race.distanceKm, distanceKm) &&
+          Boolean(parseFinishTimeToSeconds(race.finishTime))
+        );
+      });
+
+      let bestRace: Race | null = null;
+      let bestPace = Number.POSITIVE_INFINITY;
+
+      for (const race of candidates) {
+        const totalSeconds = parseFinishTimeToSeconds(race.finishTime);
+        if (!totalSeconds) {
+          continue;
+        }
+
+        const paceSeconds = totalSeconds / race.distanceKm;
+        if (paceSeconds < bestPace) {
+          bestPace = paceSeconds;
+          bestRace = race;
+        }
+      }
+
+      return {
+        distanceKm,
+        bestRace,
+      };
+    });
+  }, [races]);
+
+  const comparisonRows = useMemo(() => {
+    return races
+      .filter((race) => race.status === "completed")
+      .map((race) => ({
+        id: race.id,
+        year: new Date(`${race.date}T00:00:00`).getFullYear(),
+        title: race.title,
+        distance: formatDistance(race.distanceKm),
+        finishTime: race.finishTime ?? "время не указано",
+        pace: getPaceLabel(race.finishTime, race.distanceKm) ?? "не удалось вычислить",
+        place: "нет данных",
+      }))
+      .sort((left, right) => right.year - left.year || left.title.localeCompare(right.title, "ru-RU"));
+  }, [races]);
+
   if (isLoading) {
     return (
       <section className="page page--dashboard" aria-busy="true">
@@ -162,6 +217,60 @@ export function DashboardPage(): JSX.Element {
           <p className="dashboard-card__hint">Завершено: {dashboardMetrics.seasonCompletedCount}</p>
         </article>
       </div>
+
+      <section className="dashboard-section" aria-label="Личные рекорды по дистанциям">
+        <h2 className="dashboard-section__title">PR по дистанциям</h2>
+        <div className="dashboard-grid dashboard-grid--pr">
+          {personalRecordsByDistance.map((item) => (
+            <article key={item.distanceKm} className="dashboard-card">
+              <h3 className="dashboard-card__title">{formatDistance(item.distanceKm)}</h3>
+              {item.bestRace ? (
+                <>
+                  <p className="dashboard-card__value">{item.bestRace.finishTime ?? "время не указано"}</p>
+                  <p className="dashboard-card__meta">{item.bestRace.title}</p>
+                  <p className="dashboard-card__hint">{formatRaceDate(item.bestRace.date)}</p>
+                </>
+              ) : (
+                <p className="dashboard-card__empty">Нет завершённых стартов для этой дистанции.</p>
+              )}
+            </article>
+          ))}
+        </div>
+      </section>
+
+      <section className="dashboard-section" aria-label="Сравнение завершённых стартов">
+        <h2 className="dashboard-section__title">Сравнение стартов</h2>
+        {comparisonRows.length > 0 ? (
+          <div className="comparison-table-wrapper">
+            <table className="comparison-table">
+              <thead>
+                <tr>
+                  <th>Год</th>
+                  <th>Старт</th>
+                  <th>Дистанция</th>
+                  <th>Время</th>
+                  <th>Темп</th>
+                  <th>Место</th>
+                </tr>
+              </thead>
+              <tbody>
+                {comparisonRows.map((row) => (
+                  <tr key={row.id}>
+                    <td>{row.year}</td>
+                    <td>{row.title}</td>
+                    <td>{row.distance}</td>
+                    <td>{row.finishTime}</td>
+                    <td>{row.pace}</td>
+                    <td>{row.place}</td>
+                  </tr>
+                ))}
+              </tbody>
+            </table>
+          </div>
+        ) : (
+          <p className="dashboard-card__empty">Нет completed-стартов для сравнения.</p>
+        )}
+      </section>
     </section>
   );
 }