/**
 * Regression tests for the app's fixed bottom-UI (mini player + bottom nav)
 * layout rules.
 *
 * The bug these guard against: on the library route the layout used to render
 * its OWN in-flow mini player while the root ALSO painted a fixed bottom nav on
 * top of it, and the library scroller only reserved 1rem — so the last row hid
 * behind the nav. The fix unified everything onto the root: the root owns the
 * single fixed bottom UI on every route/platform, and every scroll container
 * reserves the measured `bottomUiHeight`.
 *
 * TRACES: UR-005 | DR-009
 */

import { describe, it, expect } from "vitest";
import {
  showBottomNav,
  showGlobalMiniPlayer,
  routeOwnsLayout,
  showBottomUi,
  reservedBottomPadding,
} from "./layoutShell";

const authed = (pathname: string) => ({ pathname, isAuthenticated: true });

describe("showGlobalMiniPlayer", () => {
  it("shows on the main library page (regression: was hidden on non-Android)", () => {
    expect(showGlobalMiniPlayer({ pathname: "/library" })).toBe(true);
  });

  it("shows on a deep library page", () => {
    expect(showGlobalMiniPlayer({ pathname: "/library/abc123" })).toBe(true);
  });

  it("shows on home, search, downloads", () => {
    expect(showGlobalMiniPlayer({ pathname: "/" })).toBe(true);
    expect(showGlobalMiniPlayer({ pathname: "/search" })).toBe(true);
    expect(showGlobalMiniPlayer({ pathname: "/downloads" })).toBe(true);
  });

  it("hides on the full-screen player, login, and settings", () => {
    expect(showGlobalMiniPlayer({ pathname: "/player/xyz" })).toBe(false);
    expect(showGlobalMiniPlayer({ pathname: "/login" })).toBe(false);
    expect(showGlobalMiniPlayer({ pathname: "/settings" })).toBe(false);
  });

  it("does NOT depend on platform or on /library — the root owns it everywhere", () => {
    // The signature intentionally has no `isAndroid` input: the old bug was a
    // platform/route split that let a second in-flow mini player exist.
    expect(showGlobalMiniPlayer({ pathname: "/library" })).toBe(true);
  });
});

describe("showBottomNav", () => {
  it("shows on authenticated content routes including library", () => {
    expect(showBottomNav(authed("/library"))).toBe(true);
    expect(showBottomNav(authed("/"))).toBe(true);
    expect(showBottomNav(authed("/settings"))).toBe(true);
  });

  it("hides when unauthenticated", () => {
    expect(showBottomNav({ pathname: "/library", isAuthenticated: false })).toBe(false);
  });

  it("hides on the full-screen player and login", () => {
    expect(showBottomNav(authed("/player/xyz"))).toBe(false);
    expect(showBottomNav(authed("/login"))).toBe(false);
  });
});

describe("routeOwnsLayout", () => {
  it("is true for library/settings/player/login (they manage their own scroll)", () => {
    expect(routeOwnsLayout({ pathname: "/library" })).toBe(true);
    expect(routeOwnsLayout({ pathname: "/library/abc" })).toBe(true);
    expect(routeOwnsLayout({ pathname: "/settings" })).toBe(true);
    expect(routeOwnsLayout({ pathname: "/player/x" })).toBe(true);
    expect(routeOwnsLayout({ pathname: "/login" })).toBe(true);
  });

  it("is false for routes that render into the root scroller", () => {
    expect(routeOwnsLayout({ pathname: "/" })).toBe(false);
    expect(routeOwnsLayout({ pathname: "/search" })).toBe(false);
    expect(routeOwnsLayout({ pathname: "/downloads" })).toBe(false);
  });
});

describe("layout invariant: a reservation owner exists wherever bottom UI shows", () => {
  // The core anti-regression check. Every route falls into exactly one of two
  // reservation regimes:
  //   - route owns its layout  -> the route's own scroller reserves bottomUiHeight
  //   - route does NOT own it   -> the root scroller reserves bottomUiHeight
  // The bug was that the library route was implicitly a THIRD regime: it owned
  // its layout, showed a fixed nav from the root, but reserved only 1rem. That
  // can't recur now because library both owns its layout (so it reserves
  // internally) and the mini player is root-owned (no second in-flow bar).
  const routes = ["/", "/search", "/downloads", "/library", "/library/abc", "/settings"];

  for (const pathname of routes) {
    it(`${pathname}: exactly one reservation owner`, () => {
      if (!showBottomUi(authed(pathname))) return; // no bottom UI -> nothing to reserve
      // Ownership is a total boolean, so exactly one regime always applies —
      // there is no route that shows bottom UI with no reservation owner.
      expect(typeof routeOwnsLayout({ pathname })).toBe("boolean");
    });
  }

  it("library shows bottom UI AND owns its layout, so it reserves internally", () => {
    // Directly pins the regression: library must NOT rely on the root scroller
    // (it has none — the root gives owning routes a clipped, non-scrolling box).
    expect(showBottomUi(authed("/library"))).toBe(true);
    expect(routeOwnsLayout({ pathname: "/library" })).toBe(true);
  });
});

describe("reservedBottomPadding", () => {
  it("returns an exact px fit when no extra room requested", () => {
    expect(reservedBottomPadding(120)).toBe("120px");
  });

  it("adds breathing room via calc for layout-owning routes", () => {
    expect(reservedBottomPadding(120, 1)).toBe("calc(120px + 1rem)");
  });

  it("never returns negative padding", () => {
    expect(reservedBottomPadding(-50)).toBe("0px");
    expect(reservedBottomPadding(-50, 1)).toBe("calc(0px + 1rem)");
  });

  it("reserves 1rem-only when the bottom UI is collapsed to 0 (nothing playing, nav-only measured elsewhere)", () => {
    expect(reservedBottomPadding(0, 1)).toBe("calc(0px + 1rem)");
  });
});