import { beforeEach, describe, expect, it, vi } from "vitest";
import { clampLimit, getHomeFeedPage } from "@/lib/feed";
import { createSession } from "@/lib/session-store";

const json = (body: unknown, status = 200) =>
  new Response(JSON.stringify(body), { status, headers: { "content-type": "application/json" } });

let sid: string;
beforeEach(() => {
  sid = createSession({
    profileAccessToken: "p",
    profileAccessTokenExpiresAt: null,
    profileRefreshToken: "r",
    feedAccessToken: "FEEDTOK",
    feedAccessTokenExpiresAt: null,
    person: { userId: "u", name: "Ann", email: "a@b.co", pictureUrl: null },
    createdAt: Date.now(),
  });
});

describe("getHomeFeedPage", () => {
  it("no session is sign_in and nothing is fetched", async () => {
    const f = vi.fn();
    expect(await getHomeFeedPage(undefined, null, 20, { fetchImpl: f as unknown as typeof fetch }))
      .toEqual({ ok: false, status: 401, error: "sign_in" });
    expect(f).not.toHaveBeenCalled();
  });

  it("first page: items + nextCursor, no cursor upstream, bearer token, home path", async () => {
    const f = vi.fn(async () => json({ data: [{ id: 1 }], metadata: { nextCursor: "C1" } }));
    const r = await getHomeFeedPage(sid, null, 20, { fetchImpl: f as unknown as typeof fetch });
    expect(r).toEqual({ ok: true, items: [{ id: 1 }], nextCursor: "C1" });
    const [url, init] = f.mock.calls[0] as unknown as [string, RequestInit];
    const u = new URL(url);
    expect(u.pathname).toBe("/api/v1/feeds/home/items");
    expect(u.searchParams.get("limit")).toBe("20");
    expect(u.searchParams.has("cursor")).toBe(false);
    expect((init.headers as Record<string, string>).Authorization).toBe("Bearer FEEDTOK");
  });

  it("forwards the cursor on a later page; null nextCursor at the end", async () => {
    const f = vi.fn(async () => json({ data: [], metadata: { nextCursor: null } }));
    const r = await getHomeFeedPage(sid, "X", 20, { fetchImpl: f as unknown as typeof fetch });
    expect(r).toEqual({ ok: true, items: [], nextCursor: null });
    const u = new URL((f.mock.calls[0] as unknown as [string])[0]);
    expect(u.searchParams.get("cursor")).toBe("X");
  });

  it("feed 401 twice is sign_in", async () => {
    const f = vi.fn(async (url: string) =>
      String(url).includes("/feeds/home/items") ? json({}, 401) : json({}, 500),
    );
    const r = await getHomeFeedPage(sid, null, 20, { fetchImpl: f as unknown as typeof fetch });
    expect(r).toEqual({ ok: false, status: 401, error: "sign_in" });
  });

  it("upstream 500 is feed_unavailable", async () => {
    const f = vi.fn(async () => json({}, 500));
    const r = await getHomeFeedPage(sid, null, 20, { fetchImpl: f as unknown as typeof fetch });
    expect(r).toEqual({ ok: false, status: 502, error: "feed_unavailable" });
  });
});

describe("clampLimit", () => {
  it("defaults to 20, caps at 50", () => {
    expect(clampLimit(null)).toBe(20);
    expect(clampLimit("abc")).toBe(20);
    expect(clampLimit("999")).toBe(50);
    expect(clampLimit("10")).toBe(10);
    expect(clampLimit("0")).toBe(20);
  });
});