import { beforeEach, describe, expect, it } from "vitest";
import { attributionForApi, getAttribution, inferPlatform, parseAttribution } from "@/lib/attribution";

describe("parseAttribution", () => {
  const now = new Date("2026-09-22T12:00:00Z");
  it("captures utm, click ids, variant, referrer and landing url", () => {
    const a = parseAttribution(
      "https://visit.waterschurch.org/?utm_source=facebook&utm_medium=paid_social&utm_campaign=fall-visit&utm_content=video1&utm_term=church+near+me&fbclid=ABC123&v=b",
      "https://l.facebook.com/",
      now,
      "a",
    );
    expect(a.utm_source).toBe("facebook");
    expect(a.utm_medium).toBe("paid_social");
    expect(a.utm_campaign).toBe("fall-visit");
    expect(a.utm_content).toBe("video1");
    expect(a.utm_term).toBe("church near me");
    expect(a.fbclid).toBe("ABC123");
    expect(a.variant).toBe("b");
    expect(a.referrer).toBe("https://l.facebook.com/");
    expect(a.landing_url).toContain("utm_campaign=fall-visit");
    expect(a.first_seen_at).toBe(now.toISOString());
  });
  it("supports Google, TikTok and X identifiers", () => {
    const a = parseAttribution("https://x.test/?gclid=G1&gbraid=GB&wbraid=WB&ttclid=T1&twclid=X1", "", now, "a");
    expect(a).toMatchObject({ gclid: "G1", gbraid: "GB", wbraid: "WB", ttclid: "T1", twclid: "X1" });
  });
  it("accepts tt_click_id as a TikTok alias", () => {
    expect(parseAttribution("https://x.test/?tt_click_id=T9", "", now, "a").ttclid).toBe("T9");
  });
  it("tolerates missing or malformed parameters", () => {
    const a = parseAttribution("not a url", "", now, "a");
    expect(a.variant).toBe("a");
    expect(a.utm_source).toBeUndefined();
    const b = parseAttribution("https://x.test/?utm_source=&gclid=%3Cscript%3Ealert(1)%3C/script%3E", "", now, "a");
    expect(b.utm_source).toBeUndefined();
    expect(b.gclid).toBe("scriptalert(1)/script");
  });
  it("caps overly long values", () => {
    const long = "x".repeat(500);
    expect(parseAttribution(`https://x.test/?utm_campaign=${long}`, "", now, "a").utm_campaign).toHaveLength(200);
  });
});

describe("inferPlatform", () => {
  it("derives the ad platform", () => {
    expect(inferPlatform({ gclid: "1" })).toBe("google");
    expect(inferPlatform({ fbclid: "1" })).toBe("facebook");
    expect(inferPlatform({ utm_source: "instagram" })).toBe("instagram");
    expect(inferPlatform({ ttclid: "1" })).toBe("tiktok");
    expect(inferPlatform({ utm_source: "x" })).toBe("x");
    expect(inferPlatform({})).toBe("direct");
  });
});

describe("getAttribution (browser)", () => {
  beforeEach(() => {
    window.sessionStorage.clear();
    window.history.replaceState({}, "", "/?utm_source=tiktok&utm_campaign=c1&ttclid=T1");
  });
  it("captures once and persists across calls", () => {
    const first = getAttribution("a");
    expect(first.utm_source).toBe("tiktok");
    window.history.replaceState({}, "", "/");
    const second = getAttribution("a");
    expect(second.utm_campaign).toBe("c1");
    expect(second.first_seen_at).toBe(first.first_seen_at);
  });
  it("merges a new click id from a second ad click without losing first-touch data", () => {
    const first = getAttribution("a");
    window.history.replaceState({}, "", "/?utm_source=facebook&fbclid=F1");
    const merged = getAttribution("a");
    expect(merged.fbclid).toBe("F1");
    expect(merged.ttclid).toBe("T1");
    expect(merged.first_seen_at).toBe(first.first_seen_at);
  });
  it("lets an explicit ?v= override the session variant", () => {
    expect(getAttribution("a").variant).toBe("a");
    window.history.replaceState({}, "", "/?v=b");
    expect(getAttribution("a").variant).toBe("b");
  });
  it("flattens to strings for the API", () => {
    const flat = attributionForApi(getAttribution("a"));
    for (const v of Object.values(flat)) expect(typeof v).toBe("string");
    expect(flat.utm_source).toBe("tiktok");
  });
});