rebreak-monorepo/backend/tests/mail/mail-classifier.test.ts

/**
 * Tests für mail-classifier.ts — Mail-Klassifikations-Pipeline.
 *
 * Testet alle Layer-Logiken als pure Funktionen (kein DB-Mock).
 *
 * Abgedeckt:
 *   - extractRelayedDomain() — diverse Relay-Patterns
 *   - normalizeBrand() — Normalisierungs-Logik
 *   - hasRandomTokens() — true/false cases
 *   - computeScore() — Score-Berechnung mit Weights
 *   - classifyMail() — End-to-End Pipeline:
 *       - Gamblezen-Beispiel → Layer 2.5 Hard-Block
 *       - BetandPlay-Beispiel → Layer 2.5 Hard-Block (Apple Hide-My-Email-Pattern)
 *       - Whitelist-Case (wettervorhersage)
 *       - Domain-Block (Layer 2)
 *       - Relay-Decoded Block (Layer 2)
 *       - No-Signal → PASS
 */
import { describe, it, expect, vi } from "vitest";

// gambling-keywords.mjs ist ESM ohne TypeScript — mock before import
vi.mock("../../server/utils/gambling-keywords.mjs", () => ({
  GAMBLING_KEYWORDS: [
    "casino", "bet365", "bwin", "tipico", "unibet", "betway",
    "pokerstars", "jackpot", "freispiel", "free spin", "bonus code",
    "auszahlung", "glücksspiel", "slots", "roulette", "wette",
    "stake", "rolletto", "vbet", "1xbet", "melbet", "mostbet",
    "luckyvibe", "spinz", "casinoly", "rabona", "justcasino",
    "getslots", "rocketplay", "freshcasino", "betano", "leovegas",
  ],
  GAMBLING_WHITELIST: [
    "wettervorhersage",
    "wetter",
    "wetterbericht",
    "wettkampf",
    "wettbewerb",
  ],
}));

import {
  extractRelayedDomain,
  normalizeBrand,
  hasRandomTokens,
  computeScore,
  classifyMail,
  matchesGamblingBrand,
} from "../../server/utils/mail-classifier";

// ─── extractRelayedDomain ────────────────────────────────────────────────────

describe("extractRelayedDomain()", () => {
  it("extrahiert Domain aus SendGrid-bounce-Pattern (user=domain@sendgrid)", () => {
    expect(extractRelayedDomain("bounces+user=gamblezen.com@sendgrid.net"))
      .toBe("gamblezen.com");
  });

  it("extrahiert Domain aus Mailchimp-Track-Pattern (track.user=domain@mc)", () => {
    expect(extractRelayedDomain("track.user=betandplay.com@mailchimp.com"))
      .toBe("betandplay.com");
  });

  it("extrahiert Domain aus _at_-Pattern", () => {
    expect(extractRelayedDomain("a1b2c3_user_at_betandplay.com@em.example.com"))
      .toBe("betandplay.com");
  });

  it("gibt null zurück wenn kein Relay-Pattern erkannt", () => {
    expect(extractRelayedDomain("info@betandplay.com")).toBeNull();
  });

  it("gibt null zurück für direkte Adressen ohne @", () => {
    expect(extractRelayedDomain("noatsign")).toBeNull();
  });

  it("normalisiert extrahierte Domain auf lowercase", () => {
    expect(extractRelayedDomain("bounce=GambleZen.COM@delivery.net"))
      .toBe("gamblezen.com");
  });

  it("gibt null zurück für normale Adressen ohne Relay-Muster", () => {
    expect(extractRelayedDomain("newsletter@example.org")).toBeNull();
  });
});

// ─── normalizeBrand ──────────────────────────────────────────────────────────

describe("normalizeBrand()", () => {
  it("BetandPlay → betandplay", () => {
    expect(normalizeBrand("BetandPlay")).toBe("betandplay");
  });

  it("bet-and-play → betandplay", () => {
    expect(normalizeBrand("bet-and-play")).toBe("betandplay");
  });

  it("Gamble Zen → gamblezen", () => {
    expect(normalizeBrand("Gamble Zen")).toBe("gamblezen");
  });

  it("Mr. Green → mrgreen", () => {
    expect(normalizeBrand("Mr. Green")).toBe("mrgreen");
  });

  it("lucky_vibe → luckyvibe", () => {
    expect(normalizeBrand("lucky_vibe")).toBe("luckyvibe");
  });

  it("unveränderte Kleinbuchstaben bleiben gleich", () => {
    expect(normalizeBrand("casino")).toBe("casino");
  });
});

// ─── matchesGamblingBrand ────────────────────────────────────────────────────

describe("matchesGamblingBrand()", () => {
  it("'gamblezen' matcht", () => {
    expect(matchesGamblingBrand("gamblezen")).toBe(true);
  });

  it("'betandplay' matcht", () => {
    expect(matchesGamblingBrand("betandplay")).toBe(true);
  });

  it("'casino' matcht (exact)", () => {
    expect(matchesGamblingBrand("casino")).toBe(true);
  });

  it("'mrgreen' matcht", () => {
    expect(matchesGamblingBrand("mrgreen")).toBe(true);
  });

  it("'example' matcht nicht", () => {
    expect(matchesGamblingBrand("example")).toBe(false);
  });

  it("zu kurze Strings (< 4 Zeichen) matchen nie", () => {
    expect(matchesGamblingBrand("bet")).toBe(false);
  });

  it("'googlemail' matcht nicht", () => {
    expect(matchesGamblingBrand("googlemail")).toBe(false);
  });
});

// ─── hasRandomTokens ─────────────────────────────────────────────────────────

describe("hasRandomTokens()", () => {
  it("local-part mit 2+ zufälligen Tokens → true", () => {
    // Gamblezen-typisch: hq3a91_7xmpl2 (2 random-looking tokens)
    expect(hasRandomTokens("hq3a91_7xmpl2")).toBe(true);
  });

  it("local-part mit User-ID + Token → true", () => {
    expect(hasRandomTokens("user123abc_ref456xyz")).toBe(true);
  });

  it("'info' → false (Funktionswort)", () => {
    expect(hasRandomTokens("info")).toBe(false);
  });

  it("'noreply' → false (Funktionswort)", () => {
    expect(hasRandomTokens("noreply")).toBe(false);
  });

  it("'newsletter' → false (Funktionswort, kein Digit-Mix)", () => {
    expect(hasRandomTokens("newsletter")).toBe(false);
  });

  it("normaler Local-Part ohne Zufalls-Tokens → false", () => {
    expect(hasRandomTokens("john.doe")).toBe(false);
  });

  it("nur ein random Token (Grenzfall) → false", () => {
    // Nur ein Token >= 6 mit Digit-Mix → unter Schwelle (braucht >= 2)
    expect(hasRandomTokens("abc123")).toBe(false);
  });

  it("echter BetandPlay-typischer Local-Part → true", () => {
    // z.B. "u7a2b1_offers_ref9x2z" — ein Funktionswort + 2 random tokens
    expect(hasRandomTokens("u7a2b1_offers_ref9x2z")).toBe(true);
  });
});

// ─── computeScore ────────────────────────────────────────────────────────────

describe("computeScore()", () => {
  it("Whitelist-Hit → score=0, whitelistHit=true", () => {
    const result = computeScore(
      "info@wetter.de",
      "Wetter Service",
      "Wettervorhersage für morgen",
      false,
      false,
    );
    expect(result.whitelistHit).toBe(true);
    expect(result.score).toBe(0);
  });

  it("Casino im Betreff → SUBJECT_GAMBLING_KEYWORD += 50", () => {
    const result = computeScore(
      "info@example.com",
      null,
      "Dein Casino-Bonus wartet",
      false,
      false,
    );
    expect(result.keywordHitsSubject).toContain("casino");
    expect(result.score).toBe(50);
  });

  it("Geld-Pattern (100€) im Betreff → SUBJECT_MONEY_PATTERN += 20", () => {
    const result = computeScore(
      "info@example.com",
      null,
      "100€ Willkommensbonus jetzt sichern",
      false,
      false,
    );
    expect(result.styleFlags).toContain("money-pattern");
    expect(result.score).toBeGreaterThanOrEqual(20);
  });

  it("Brand-Match ohne Random → BRAND_MATCH_NO_RANDOM += 35", () => {
    const result = computeScore(
      "info@example.com",
      null,
      "Normaler Betreff",
      true,  // brandMatch=true
      false, // randomTokens=false
    );
    expect(result.score).toBeGreaterThanOrEqual(35);
  });

  it("Random-Tokens ohne Brand → RANDOM_TOKENS_NO_BRAND += 10", () => {
    const result = computeScore(
      "info@example.com",
      null,
      "Newsletter vom Tag",
      false, // brandMatch=false
      true,  // randomTokens=true
    );
    expect(result.score).toBeGreaterThanOrEqual(10);
  });

  it("Score wird auf max 100 gecapped", () => {
    // Alle Signale gleichzeitig → Score würde > 100 sein
    const result = computeScore(
      "slots@casinobonus.bet",
      "Casino Jackpot",
      "JACKPOT Casino 500€ Freispiele Nur heute Letzte chance",
      true,
      true,
    );
    expect(result.score).toBeLessThanOrEqual(100);
  });
});

// ─── classifyMail() — Pipeline End-to-End ────────────────────────────────────

describe("classifyMail() — End-to-End Pipeline", () => {
  // Leere Domain-Set für die meisten Tests (kein Domain-Hard-Block)
  const emptyDomainSet = new Set<string>();

  // ─── Screenshot-Beispiel 1: Gamblezen via Relay ───────────────────────────
  it("Gamblezen-Beispiel: bounces+user=gamblezen.com@em.sendgrid.net → Layer 2.5 Hard-Block", async () => {
    // Gamblezen leitet über SendGrid-Bounces: Domain "em.sendgrid.net" ist nicht geblockt,
    // aber relay-decoded → "gamblezen.com" + local-part hat random tokens.
    // gamblezen.com ist ein bekannter Gambling-Brand.
    const domainSetWithGamblezen = new Set(["gamblezen.com"]);

    const result = await classifyMail({
      mail: {
        senderEmail: "bounces+user=gamblezen.com@em.sendgrid.net",
        senderName: "Gamble Zen",
        subject: "Dein exklusives Angebot wartet",
      },
      blockedDomainSet: domainSetWithGamblezen,
    });

    // Relay-decoded domain matcht blocklist → Layer 2 (relay-decoded), NICHT Layer 2.5
    expect(result.action).toBe("blocked");
    expect(result.triggerSource).toBe("relay-decoded");
    expect(result.relayDecodedDomain).toBe("gamblezen.com");
  });

  it("Gamblezen-Beispiel ohne Blocklist-Entry → Layer 2.5 Hard-Block via Brand+Random", async () => {
    // Wenn gamblezen.com NICHT in der Blocklist ist: Brand+Random greift trotzdem
    const result = await classifyMail({
      mail: {
        senderEmail: "hq3a91_7xmpl2@em.sendgrid.net",
        senderName: "Gamble Zen", // Brand-Match via Display-Name
        subject: "Dein exklusives Angebot wartet",
      },
      blockedDomainSet: emptyDomainSet,
    });

    expect(result.action).toBe("blocked");
    expect(result.triggerSource).toBe("brand+random");
    expect(result.features.brandMatch).toBe(true);
    expect(result.features.randomTokens).toBe(true);
  });

  // ─── Screenshot-Beispiel 2: BetandPlay via Relay ─────────────────────────
  it("BetandPlay-Beispiel: track.user=betandplay.com@mailchimp.com → Layer 2.5 Hard-Block", async () => {
    const domainSetWithBetandPlay = new Set(["betandplay.com"]);

    const result = await classifyMail({
      mail: {
        senderEmail: "track.user=betandplay.com@mailchimp.com",
        senderName: "BetandPlay",
        subject: "100€ Willkommensbonus — Nur heute!",
      },
      blockedDomainSet: domainSetWithBetandPlay,
    });

    expect(result.action).toBe("blocked");
    expect(result.triggerSource).toBe("relay-decoded");
    expect(result.relayDecodedDomain).toBe("betandplay.com");
  });

  it("BetandPlay-Beispiel ohne Blocklist-Entry → Layer 2.5 Hard-Block via Brand+Random", async () => {
    const result = await classifyMail({
      mail: {
        senderEmail: "u7a2b1_offers_ref9x2z@mailchimp.com",
        senderName: "BetandPlay", // Brand-Match via Display-Name
        subject: "100€ Willkommensbonus",
      },
      blockedDomainSet: emptyDomainSet,
    });

    expect(result.action).toBe("blocked");
    expect(result.triggerSource).toBe("brand+random");
    expect(result.features.brandMatch).toBe(true);
    expect(result.features.randomTokens).toBe(true);
  });

  // ─── Layer 1: Whitelist ───────────────────────────────────────────────────
  it("Whitelist-Treffer: 'wettervorhersage' im Betreff → PASS", async () => {
    const result = await classifyMail({
      mail: {
        senderEmail: "service@wetter.de",
        senderName: "Wetter.de",
        subject: "Wettervorhersage für morgen",
      },
      blockedDomainSet: emptyDomainSet,
    });

    expect(result.action).toBe("passed");
    expect(result.triggerSource).toBe("whitelist");
  });

  it("'wettkampf' in Betreff → PASS (kein Gambling trotz 'wette')", async () => {
    const result = await classifyMail({
      mail: {
        senderEmail: "info@sport.de",
        senderName: null,
        subject: "Wettkampf-Ergebnisse dieser Woche",
      },
      blockedDomainSet: emptyDomainSet,
    });

    expect(result.action).toBe("passed");
    expect(result.triggerSource).toBe("whitelist");
  });

  // ─── Layer 2: Domain-Hard-Block ───────────────────────────────────────────
  it("Domain in Blocklist → Layer 2 Hard-Block", async () => {
    const domainSet = new Set(["casinoly.com"]);

    const result = await classifyMail({
      mail: {
        senderEmail: "promo@casinoly.com",
        senderName: "Casinoly",
        subject: "Dein Bonus wartet",
      },
      blockedDomainSet: domainSet,
    });

    expect(result.action).toBe("blocked");
    expect(result.triggerSource).toBe("domain");
    expect(result.features.domainBlocked).toBe(true);
  });

  // ─── Relay-Decoded Block ──────────────────────────────────────────────────
  it("Relay-Decoded: =domain.com in local-part und Domain in Blocklist → relay-decoded Block", async () => {
    const domainSet = new Set(["rabona.com"]);

    const result = await classifyMail({
      mail: {
        senderEmail: "bounce+track=rabona.com@em.sendgrid.net",
        senderName: "Rabona Casino",
        subject: "Exklusiv für dich",
      },
      blockedDomainSet: domainSet,
    });

    expect(result.action).toBe("blocked");
    expect(result.triggerSource).toBe("relay-decoded");
    expect(result.relayDecodedDomain).toBe("rabona.com");
  });

  // ─── Layer 3: Score-Hard-Block ────────────────────────────────────────────
  it("Viele Signale → Score >= 80 → Hard-Block", async () => {
    // Casino im Sender-Name + Jackpot im Betreff + Urgency + Geld-Pattern
    const result = await classifyMail({
      mail: {
        senderEmail: "info@spinz-casino.example",
        senderName: "Casino Jackpot Club",
        subject: "JACKPOT 500€ Freispiele — Nur heute!",
      },
      blockedDomainSet: emptyDomainSet,
    });

    expect(result.action).toBe("blocked");
    expect(result.triggerSource).toMatch(/^score:/);
    expect(result.score).toBeGreaterThanOrEqual(80);
  });

  // ─── No-Signal → PASS ────────────────────────────────────────────────────
  it("unauffällige Mail → PASS mit triggerSource 'no-signal'", async () => {
    const result = await classifyMail({
      mail: {
        senderEmail: "newsletter@amazon.de",
        senderName: "Amazon",
        subject: "Deine Bestellung wurde versandt",
      },
      blockedDomainSet: emptyDomainSet,
    });

    expect(result.action).toBe("passed");
    expect(result.triggerSource).toBe("no-signal");
    expect(result.score).toBeLessThan(25);
  });

  // ─── Brand-Match ohne Random → kein Hard-Block, Score-Erhöhung ───────────
  it("Brand-Match ohne Random-Tokens → kein Layer-2.5-Block, aber Score-Erhöhung", async () => {
    const result = await classifyMail({
      mail: {
        senderEmail: "info@betandplay.com", // direktes info@, kein random
        senderName: "BetandPlay",
        subject: "Willkommen",
      },
      blockedDomainSet: emptyDomainSet,
    });

    // Kein Hard-Block Layer 2.5 (kein Random), aber Score erhöht durch Brand-Match
    expect(result.triggerSource).not.toBe("brand+random");
    expect(result.features.brandMatch).toBe(true);
    expect(result.features.randomTokens).toBe(false);
    // Score >= 35 (BRAND_MATCH_NO_RANDOM) — endet je nach anderen Signalen
    expect(result.features.score).toBeGreaterThanOrEqual(35);
  });

  // ─── Korrekte Feature-Struktur im Result ─────────────────────────────────
  it("Result-Features enthalten alle erwarteten Keys", async () => {
    const result = await classifyMail({
      mail: {
        senderEmail: "promo@example.com",
        senderName: null,
        subject: "Test",
      },
      blockedDomainSet: emptyDomainSet,
    });

    expect(result.features).toHaveProperty("score");
    expect(result.features).toHaveProperty("domainBlocked");
    expect(result.features).toHaveProperty("relayDecoded");
    expect(result.features).toHaveProperty("brandMatch");
    expect(result.features).toHaveProperty("randomTokens");
    expect(result.features).toHaveProperty("keywordHitsSubject");
    expect(result.features).toHaveProperty("keywordHitsDomain");
    expect(result.features).toHaveProperty("keywordHitsName");
    expect(result.features).toHaveProperty("styleFlags");
    expect(result.features).toHaveProperty("whitelistHit");
  });

  // ─── Fix 2: SUBJECT_GAMBLING_KEYWORD angehoben auf 50 ────────────────────
  it("Fix 2: 'Casino Bonus' im Betreff, generischer Sender → Score=50 → BLOCK (war vorher PASS)", async () => {
    // Vorher: SUBJECT_GAMBLING_KEYWORD=35 → Score 35 < SCORE_BLOCK_MIDRANGE=50 → PASS
    // Jetzt:  SUBJECT_GAMBLING_KEYWORD=50 → Score 50 >= 50 → BLOCK
    const result = await classifyMail({
      mail: {
        senderEmail: "info@example.com",
        senderName: null,
        subject: "Casino Bonus",
      },
      blockedDomainSet: emptyDomainSet,
    });
    expect(result.action).toBe("blocked");
    expect(result.triggerSource).toMatch(/^score:/);
    expect(result.score).toBe(50);
    expect(result.features.keywordHitsSubject).toContain("casino");
  });

  it("Fix 2: 'Hotel Las Vegas' im Betreff → kein Casino-Keyword → PASS", async () => {
    // 'Las Vegas' enthält nicht 'casino' als Standalone-Wort — kein Keyword-Hit
    const result = await classifyMail({
      mail: {
        senderEmail: "buchung@hotel-example.com",
        senderName: "Hotel Example",
        subject: "Ihre Buchung Hotel Las Vegas",
      },
      blockedDomainSet: emptyDomainSet,
    });
    expect(result.action).toBe("passed");
    expect(result.features.keywordHitsSubject).toHaveLength(0);
  });
});

// ─── Fix 1: Folder-Filter (System-Folder-Ausschluss) ──────────────────────────
// Hinweis: scan-internal ist ein Nitro-Handler (nicht reine Funktion) — die
// specialUse-Filter-Logik wird hier als Unit über die regex-Konstante getestet,
// da ein vollständiger IMAP-Mock außerhalb des Scope dieser Test-Suite liegt.
describe("Fix 1: System-Folder specialUse-Filter-Regex", () => {
  // Repliziert die SKIP_SPECIAL_USE-Konstante aus scan-internal.post.ts
  const SKIP_SPECIAL_USE = /^\\(All|Drafts|Sent|Trash|Flagged)$/;

  type MockMailbox = { path: string; specialUse?: string; flags?: Set<string> };

  function filterScannable(mailboxes: MockMailbox[]): MockMailbox[] {
    return mailboxes.filter((mb) => {
      if (mb.flags?.has("\\Noselect")) return false;
      if (mb.specialUse && SKIP_SPECIAL_USE.test(mb.specialUse)) return false;
      return true;
    });
  }

  it("Gmail All Mail (specialUse='\\\\All') wird ausgeschlossen", () => {
    const mailboxes: MockMailbox[] = [
      { path: "INBOX", specialUse: "\\Inbox" },
      { path: "[Gmail]/All Mail", specialUse: "\\All" },
      { path: "[Gmail]/Spam", specialUse: "\\Junk" },
    ];
    const result = filterScannable(mailboxes);
    expect(result.map((m) => m.path)).toEqual(["INBOX", "[Gmail]/Spam"]);
    expect(result.map((m) => m.path)).not.toContain("[Gmail]/All Mail");
  });

  it("Drafts, Sent, Trash, Flagged werden ausgeschlossen", () => {
    const mailboxes: MockMailbox[] = [
      { path: "INBOX" },
      { path: "Drafts", specialUse: "\\Drafts" },
      { path: "Sent", specialUse: "\\Sent" },
      { path: "Trash", specialUse: "\\Trash" },
      { path: "Starred", specialUse: "\\Flagged" },
      { path: "Spam", specialUse: "\\Junk" },
    ];
    const result = filterScannable(mailboxes);
    const paths = result.map((m) => m.path);
    expect(paths).toContain("INBOX");
    expect(paths).toContain("Spam");
    expect(paths).not.toContain("Drafts");
    expect(paths).not.toContain("Sent");
    expect(paths).not.toContain("Trash");
    expect(paths).not.toContain("Starred");
  });

  it("Folder ohne specialUse (iCloud/GMX) werden NICHT ausgeschlossen", () => {
    // iCloud/GMX liefern kein specialUse-Field — der Filter lässt sie durch
    const mailboxes: MockMailbox[] = [
      { path: "INBOX" },
      { path: "Junk" },        // kein specialUse → bleibt drin (wollen wir)
      { path: "Sent Items" },   // kein specialUse → bleibt drin (suboptimal aber sicher)
    ];
    const result = filterScannable(mailboxes);
    // Alle 3 bleiben — kein false positive ohne specialUse-Info
    expect(result).toHaveLength(3);
  });

  it("Noselect-Folder wird immer ausgeschlossen (unabhängig von specialUse)", () => {
    const mailboxes: MockMailbox[] = [
      { path: "INBOX" },
      { path: "[Gmail]", flags: new Set(["\\Noselect"]) },
    ];
    const result = filterScannable(mailboxes);
    expect(result.map((m) => m.path)).toEqual(["INBOX"]);
  });
});