anouma/components/admin/AdminAnalyticsView.tsx

import type { AdminViewServerProps } from "payload";
import { canViewAnalytics } from "@/access";
import { RANGE_OPTIONS, resolveRange } from "@/lib/analytics/range";
import { getDashboardComparison, percentDelta, type DashboardStats } from "@/lib/analytics/dashboardQueries";
import { topEntries } from "@/lib/analytics/aggregate";
import { analyticsEventLabel } from "@/lib/analytics/events";
import { AnalyticsChart } from "./AnalyticsChart";
import styles from "./AdminAnalyticsView.module.css";

const DEVICE_LABELS: Record<string, string> = { mobile: "Mobile", desktop: "Desktop", tablet: "Tablet" };
const BROWSER_LABELS: Record<string, string> = { chrome: "Chrome", firefox: "Firefox", safari: "Safari", edge: "Edge", other: "Sonstige" };

function fmtInt(n: number): string {
  return n.toLocaleString("de-DE");
}

function DeltaBadge({ delta }: { delta: number | null }) {
  if (delta === null) return null;
  const cls = delta > 0 ? styles.deltaUp : delta < 0 ? styles.deltaDown : styles.deltaFlat;
  const arrow = delta > 0 ? "↑" : delta < 0 ? "↓" : "→";
  return (
    <p className={`${styles.tileDelta} ${cls}`}>
      {arrow} {Math.abs(delta).toLocaleString("de-DE")}%
    </p>
  );
}

function Tile({ label, value, delta }: { label: string; value: number; delta: number | null | undefined }) {
  return (
    <div className={styles.tile}>
      <p className={styles.tileLabel}>{label}</p>
      <p className={styles.tileValue}>{fmtInt(value)}</p>
      {delta !== undefined && <DeltaBadge delta={delta} />}
    </div>
  );
}

function EntryTable({ title, entries }: { title: string; entries: [string, number][] }) {
  return (
    <div>
      <h2 className={styles.sectionTitle}>{title}</h2>
      {entries.length === 0 ? (
        <p className={styles.tableEmpty}>Keine Daten in diesem Zeitraum.</p>
      ) : (
        <table className={styles.table}>
          <tbody>
            {entries.map(([key, count]) => (
              <tr key={key}>
                <td>{key}</td>
                <td style={{ textAlign: "right", fontWeight: 600 }}>{fmtInt(count)}</td>
              </tr>
            ))}
          </tbody>
        </table>
      )}
    </div>
  );
}

function buildHref(base: URLSearchParams, overrides: Record<string, string | null>): string {
  const params = new URLSearchParams(base);
  for (const [key, value] of Object.entries(overrides)) {
    if (value === null) params.delete(key);
    else params.set(key, value);
  }
  const qs = params.toString();
  return qs ? `?${qs}` : "?";
}

export async function AdminAnalyticsView({ initPageResult }: AdminViewServerProps) {
  const req = initPageResult.req;

  if (!canViewAnalytics({ req })) {
    return (
      <div className={styles.page}>
        <h1 className={styles.title}>Analytics</h1>
        <p className={styles.subtitle}>Du hast keine Berechtigung, diesen Bereich zu sehen.</p>
      </div>
    );
  }

  const settings = await req.payload.findGlobal({ slug: "analytics-settings" });
  const maxDaysBack = settings.rawRetentionDays ?? 90;
  const searchParams = req.searchParams;
  const compareEnabled = searchParams.get("compare") === "1";
  const { key: activeRange, range, compareRange } = resolveRange(searchParams, maxDaysBack);

  const { current, previous }: { current: DashboardStats; previous: DashboardStats } = await getDashboardComparison(
    req.payload,
    range,
    compareRange,
  );

  const delta = (metric: keyof Pick<DashboardStats, "sessions" | "pageViews" | "uniqueVisitors" | "avgPagesPerSession">) =>
    compareEnabled ? percentDelta(current[metric], previous[metric]) : undefined;

  const eventDelta = (name: string) =>
    compareEnabled ? percentDelta(current.eventCounts[name] ?? 0, previous.eventCounts[name] ?? 0) : undefined;

  const fromParam = range.from.toISOString().slice(0, 10);
  const toParam = range.to.toISOString().slice(0, 10);

  return (
    <div className={styles.page}>
      <h1 className={styles.title}>Analytics</h1>
      <p className={styles.subtitle}>Datensparsame Reichweitenmessung — keine personenbezogenen Profile. Rohdaten werden {maxDaysBack} Tage aufbewahrt.</p>

      <div className={styles.filterBar}>
        {RANGE_OPTIONS.map((option) => (
          <a
            key={option.key}
            href={buildHref(searchParams, { range: option.key, from: null, to: null })}
            className={`${styles.rangeLink} ${activeRange === option.key ? styles.rangeLinkActive : ""}`}
          >
            {option.label}
          </a>
        ))}
        <form method="get" className={styles.customForm}>
          <input type="hidden" name="range" value="custom" />
          {compareEnabled && <input type="hidden" name="compare" value="1" />}
          <input type="date" name="from" defaultValue={fromParam} max={toParam} />
          <span>bis</span>
          <input type="date" name="to" defaultValue={toParam} max={new Date().toISOString().slice(0, 10)} />
          <button type="submit">Anwenden</button>
        </form>
        <div className={styles.compareToggle}>
          <a href={buildHref(searchParams, { compare: compareEnabled ? null : "1" })}>
            {compareEnabled ? "Vergleich ausblenden" : "Mit Vorperiode vergleichen"}
          </a>
        </div>
      </div>

      {RANGE_OPTIONS.some((o) => typeof o.days === "number" && o.days > maxDaysBack) && (
        <p style={{ color: "#888", fontSize: 12, marginTop: -16, marginBottom: 20 }}>
          Zeiträume sind auf die konfigurierte Rohdaten-Aufbewahrung von {maxDaysBack} Tagen begrenzt (siehe „Analytics-Einstellungen“).
        </p>
      )}

      <div className={styles.tiles}>
        <Tile label="Sessions" value={current.sessions} delta={delta("sessions")} />
        <Tile label="Seitenaufrufe" value={current.pageViews} delta={delta("pageViews")} />
        <Tile label="Eindeutige Besucher" value={current.uniqueVisitors} delta={delta("uniqueVisitors")} />
        <Tile label="Ø Seiten / Session" value={current.avgPagesPerSession} delta={delta("avgPagesPerSession")} />
        <Tile label="Buchungsstarts" value={current.eventCounts.booking_started ?? 0} delta={eventDelta("booking_started")} />
        <Tile label="Buchungen abgeschlossen" value={current.eventCounts.booking_completed ?? 0} delta={eventDelta("booking_completed")} />
      </div>

      <div className={styles.chartCard}>
        <h2 className={styles.sectionTitle}>Seitenaufrufe &amp; Sessions</h2>
        <AnalyticsChart series={current.series} />
      </div>

      <div className={styles.tableGrid}>
        <EntryTable title="Beliebteste Seiten" entries={topEntries(current.topPaths)} />
        <EntryTable title="Einstiegsseiten" entries={topEntries(current.entryPaths)} />
        <EntryTable title="Ausstiegsseiten" entries={topEntries(current.exitPaths)} />
        <EntryTable
          title="Events"
          entries={topEntries(current.eventCounts).map(([name, count]) => [analyticsEventLabel(name), count])}
        />
        <EntryTable
          title="Geräte"
          entries={topEntries(current.deviceCounts).map(([key, count]) => [DEVICE_LABELS[key] ?? key, count])}
        />
        <EntryTable
          title="Browser"
          entries={topEntries(current.browserCounts).map(([key, count]) => [BROWSER_LABELS[key] ?? key, count])}
        />
      </div>

      <div className={styles.privacyPanel}>
        <h3>Analytics &amp; Datenschutz</h3>
        <p>Erhobene Daten:</p>
        <ul>
          <li>Seitenaufrufe und Events (siehe „Events“-Tabelle)</li>
          <li>Gerätetyp (Mobile/Desktop/Tablet)</li>
          <li>Browser-Familie</li>
          <li>Referrer-Hostname (nur die Domain, keine vollständige URL)</li>
        </ul>
        <p>
          Keine Namen, E-Mail-Adressen, Telefonnummern, vollständigen IP-Adressen oder Formularinhalte. Kein Fingerprinting, keine
          dauerhaften individuellen Nutzerprofile — Besucher:innen werden über einen täglich rotierenden, nicht zurückverfolgbaren Hash
          gruppiert.
        </p>
        <p>
          <strong>Aufbewahrung:</strong> {settings.rawRetentionDays} Tage für Rohdaten, {settings.aggregateRetentionMonths} Monate für
          aggregierte Tagesstatistiken (konfigurierbar unter „Analytics-Einstellungen“).
        </p>
        <p style={{ fontStyle: "italic", color: "#777" }}>
          Rechtliche Einordnung (z. B. ob dies für eure Website ausreichend ist) ist keine technische Aussage dieses Panels — bitte im
          Zweifel rechtlich prüfen lassen, wie auch beim Impressum/Datenschutztext der Website.
        </p>
      </div>
    </div>
  );
}