// @vitest-environment happy-dom
import { beforeEach, describe, expect, it } from "vitest";
import { createMemoryMediaCache, createMemoryStore } from "../../src/browser/storage.js";
import {
  createDisplayController,
  type DisplayChannelStateView,
  type DisplayController,
} from "../../src/display/controller.js";
import { createFakeHost, jsonResponse } from "./support/fake-host.js";

/**
 * The display, driven end to end against a host: register, fetch state, render, report.
 *
 * Every collaborator is injected, so what these prove is the display's own decisions — which frame
 * it keeps when something fails, what it caches and under what key, what it tells the server, and
 * what it never puts on a wall.
 */

const NATIVE_SCENE = {
  backgroundColor: "#000000",
  backgroundImage: false,
  backgroundMode: "none" as const,
  blurPixels: 0,
  darkenOpacity: 0,
  fit: "fill" as const,
  shadow: false,
};

function nativeSelection(id: string, itemRevision = "rev-1") {
  return {
    availableUntilMs: null as number | null,
    deadlineAtMs: 5000,
    durationMs: 5000,
    id,
    itemId: `image-${id}`,
    itemRevision,
    media: {
      display: {
        expiresAtMs: 900_000,
        height: 1080,
        url: `https://cdn.invalid/${id}?sig=a`,
        width: 1920,
      },
      thumbnail: {
        expiresAtMs: 900_000,
        height: 270,
        url: `https://cdn.invalid/${id}-t?sig=a`,
        width: 480,
      },
    },
    payload: { kind: "native-image" },
    presentation: null,
    providerId: "signage.native-images",
    renderer: { kind: "native-image" as const },
    revision: 1,
    scene: NATIVE_SCENE,
    slotId: "slot-1",
    stale: false,
    startedAtMs: 0,
    withdrawn: false,
  };
}

function contributionSelection(id: string, revision = 1) {
  return {
    availableUntilMs: null,
    deadlineAtMs: 5000,
    durationMs: 5000,
    id,
    itemId: "advent",
    itemRevision: String(revision),
    payload: { headline: revision === 1 ? "Sunday, 5pm" : "Cancelled" },
    presentation: null,
    providerId: "fixture.announcements",
    renderer: {
      contributionId: "fixture.announcements.slide",
      contributionVersion: "1.0.0",
      kind: "contribution" as const,
    },
    revision,
    slotId: "slot-1",
    stale: false,
    startedAtMs: 0,
    withdrawn: false,
  };
}

function state(overrides: Partial<DisplayChannelStateView> = {}): DisplayChannelStateView {
  // `??` would fall through on an explicit `null`, which is exactly the case these tests care about.
  const current = "current" in overrides ? overrides.current : nativeSelection("sel-1");
  return {
    channel: { groupId: "group-1", id: "chan-1", key: "default" },
    crossfadeMs: 0,
    current,
    playback: {
      activeTimelineId: "timeline-1" as string | null,
      blackout: false,
      currentSelectionId: current?.id ?? null,
      currentSlotId: current?.slotId ?? null,
      deadlineAtMs: 5000 as number | null,
      pendingTimelineId: null as string | null,
      remainingMs: 5000 as number | null,
      revision: 3,
      selectionRevision: current?.revision ?? null,
      startedAtMs: 0 as number | null,
      transport: "playing",
      ...overrides.playback,
    },
    selections: overrides.selections ?? (current ? [current] : []),
    serverNowMs: 1000,
    staticHold: overrides.staticHold ?? null,
    timeline: overrides.timeline ?? null,
    ...(overrides.channel ? { channel: overrides.channel } : {}),
  };
}

const SESSION = {
  channelId: "chan-1",
  channelKey: "default",
  groupId: "group-1",
  heartbeatIntervalMs: 12_000,
  viewerId: "11111111-1111-4111-8111-111111111111",
};

describe("display controller", () => {
  let root: HTMLElement;

  beforeEach(() => {
    root = document.createElement("div");
    document.body.append(root);
  });

  async function settle(): Promise<void> {
    for (let index = 0; index < 10; index += 1) {
      await new Promise((resolve) => setTimeout(resolve, 0));
    }
  }

  function build(options: {
    readonly host: ReturnType<typeof createFakeHost>;
    readonly media?: ReturnType<typeof createMemoryMediaCache>;
    readonly store?: ReturnType<typeof createMemoryStore>;
    readonly telemetry?: boolean;
  }): DisplayController {
    return createDisplayController({
      context: options.host.context,
      decodeImage: () => Promise.resolve(),
      media: options.media ?? createMemoryMediaCache(),
      newViewerKey: () => "viewer-fixed-key-0001",
      root,
      // No real timers: the refresh schedule is exercised by calling `apply` directly.
      setTimer: () => undefined,
      store: options.store ?? createMemoryStore(),
      ...(options.telemetry === undefined ? {} : { telemetry: options.telemetry }),
    });
  }

  it("registers with a persistent identity and keeps it across restarts", async () => {
    const store = createMemoryStore();
    const keys: unknown[] = [];
    const host = createFakeHost({
      permissions: ["signage.display.view"],
      routes: [
        {
          method: "POST",
          path: "viewers/session",
          respond: ({ init }) => {
            keys.push(JSON.parse(String(init?.body)));
            return jsonResponse(SESSION);
          },
        },
        {
          method: "GET",
          path: "channels/chan-1/display-state",
          respond: () => jsonResponse(state()),
        },
        { method: "POST", path: /^viewers\/.*\/heartbeat$/u, respond: () => jsonResponse({}) },
      ],
    });

    const first = build({ host, store });
    await first.start();
    await settle();
    await first.stop();

    const second = build({ host, store });
    await second.start();
    await settle();
    await second.stop();

    // The same key both times: a television that reboots is the same screen, not a new one.
    expect(keys).toEqual([
      { viewerKey: "viewer-fixed-key-0001" },
      { viewerKey: "viewer-fixed-key-0001" },
    ]);
  });

  it("renders the server's current selection and reports what it is showing", async () => {
    const host = createFakeHost({
      permissions: ["signage.display.view"],
      routes: [
        { method: "POST", path: "viewers/session", respond: () => jsonResponse(SESSION) },
        {
          method: "GET",
          path: "channels/chan-1/display-state",
          respond: () => jsonResponse(state()),
        },
        { method: "POST", path: /^viewers\/.*\/heartbeat$/u, respond: () => jsonResponse({}) },
      ],
    });
    const controller = build({ host });

    await controller.start();
    await settle();

    const diagnostics = controller.diagnostics();
    expect(diagnostics.renderedSelectionId).toBe("sel-1");
    expect(diagnostics.slate).toBe(false);
    expect(root.querySelectorAll(".signage-layer")).toHaveLength(2);
    await controller.stop();
  });

  it("caches image bytes under a stable key, so a freshly signed URL finds them again", async () => {
    const media = createMemoryMediaCache();
    const stored: string[] = [];
    const wrapped = {
      ...media,
      store: (key: string, url: string) => {
        stored.push(key);
        return media.store(key, url);
      },
    };
    const host = createFakeHost({ permissions: [], routes: [] });
    const controller = build({ host, media: wrapped, telemetry: false });
    await controller.start();

    await controller.apply(state());
    // The same bytes, a new signature — exactly what the next refresh carries.
    const resigned = nativeSelection("sel-1");
    Object.assign(resigned.media.display, { url: "https://cdn.invalid/sel-1?sig=b" });
    await controller.apply(state({ current: resigned }));
    await settle();

    // One store, because the key is built from provider, item, and item revision — never from the
    // URL, which changes every time.
    expect(stored).toEqual(["signage-media/signage.native-images/image-sel-1/rev-1/display"]);
    await controller.stop();
  });

  it("updates a mounted renderer in place when only the payload changed", async () => {
    const mounts: unknown[] = [];
    const updates: unknown[] = [];
    const host = createFakeHost({
      contributions: [
        {
          capability: "signage.slide-renderer",
          id: "fixture.announcements.slide",
          version: "1.0.0",
        },
      ],
      mount: (options) => {
        mounts.push(options.contributionId);
        return {
          contributionId: options.contributionId,
          mounted: true,
          unmount: () => Promise.resolve(),
          update: (input) => {
            updates.push(input);
            return Promise.resolve();
          },
          version: "1.0.0",
        };
      },
      permissions: [],
      routes: [],
    });
    const controller = build({ host, telemetry: false });
    await controller.start();

    await controller.apply(state({ current: contributionSelection("sel-1", 1) }));
    await controller.apply(state({ current: contributionSelection("sel-1", 2) }));
    await settle();

    // One mount, one update: a cancelled event changes the slide without restarting its slot.
    expect(mounts).toEqual(["fixture.announcements.slide"]);
    expect(updates).toHaveLength(1);
    await controller.stop();
  });

  it("keeps the last good frame and records a code when a renderer is not published", async () => {
    const host = createFakeHost({ contributions: [], permissions: [], routes: [] });
    const controller = build({ host, telemetry: false });
    await controller.start();

    await controller.apply(state());
    const good = controller.diagnostics().renderedSelectionId;
    await controller.apply(state({ current: contributionSelection("sel-2", 1) }));
    await settle();

    const diagnostics = controller.diagnostics();
    // Nothing changed on screen, and the reason is a bounded code — never a message on a wall.
    expect(diagnostics.renderedSelectionId).toBe(good);
    expect(diagnostics.lastError?.code).toBe("SLIDE_UNRENDERABLE");
    expect(diagnostics.unusableSelectionIds).toEqual(["sel-2"]);
    await controller.stop();
  });

  it("does not retry a selection it already knows it cannot render", async () => {
    let mountAttempts = 0;
    const host = createFakeHost({
      contributions: [
        {
          capability: "signage.slide-renderer",
          id: "fixture.announcements.slide",
          version: "1.0.0",
        },
      ],
      mount: () => {
        mountAttempts += 1;
        return Promise.reject(new Error("renderer exploded"));
      },
      permissions: [],
      routes: [],
    });
    const controller = build({ host, telemetry: false });
    await controller.start();

    await controller.apply(state({ current: contributionSelection("sel-2", 1) }));
    await controller.apply(state({ current: contributionSelection("sel-2", 1) }));
    await controller.apply(state({ current: contributionSelection("sel-2", 1) }));
    await settle();

    // One attempt. A broken item never becomes a tight retry loop on an unattended screen.
    expect(mountAttempts).toBe(1);
    await controller.stop();
  });

  it("shows the slate only when it has nothing at all, and never over a good frame", async () => {
    const host = createFakeHost({ permissions: [], routes: [] });
    const controller = build({ host, telemetry: false });
    await controller.start();

    await controller.apply(state({ current: null, selections: [] }));
    await settle();
    expect(root.dataset.slate).toBe("true");
    expect(controller.diagnostics().slate).toBe(true);

    await controller.apply(state());
    await settle();
    expect(root.dataset.slate).toBe("false");

    // Content disappears again — but a good frame is up, so the wall keeps it rather than flashing
    // the slate at a congregation.
    await controller.apply(state({ current: null, selections: [] }));
    await settle();
    expect(root.dataset.slate).toBe("false");
    expect(controller.diagnostics().renderedSelectionId).toBe("sel-1");
    await controller.stop();
  });

  it("covers the output for a blackout while the frame underneath stays prepared", async () => {
    const host = createFakeHost({ permissions: [], routes: [] });
    const controller = build({ host, telemetry: false });
    await controller.start();

    await controller.apply(state());
    await controller.apply(state({ playback: { blackout: true } as never }));
    await settle();

    expect(root.dataset.blackout).toBe("true");
    // The hidden timeline is still what it was: ending the blackout shows this frame, not a slate.
    expect(controller.diagnostics().renderedSelectionId).toBe("sel-1");
    await controller.stop();
  });

  it("reports a bounded, sanitized heartbeat and nothing else", async () => {
    const beats: unknown[] = [];
    const host = createFakeHost({
      permissions: ["signage.display.view"],
      routes: [
        { method: "POST", path: "viewers/session", respond: () => jsonResponse(SESSION) },
        {
          method: "GET",
          path: "channels/chan-1/display-state",
          respond: () => jsonResponse(state()),
        },
        {
          method: "POST",
          path: /^viewers\/.*\/heartbeat$/u,
          respond: ({ init }) => {
            beats.push(JSON.parse(String(init?.body)));
            return jsonResponse({ acknowledged: true, recorded: true });
          },
        },
      ],
    });
    const controller = build({ host });

    await controller.start();
    await settle();

    expect(beats.length).toBeGreaterThan(0);
    const beat = beats[0] as Record<string, unknown>;
    expect(Object.keys(beat).sort()).toEqual([
      "cachedAssetCount",
      "error",
      "offlineReady",
      "reportedContributionId",
      "reportedPlaybackRevision",
      "reportedProviderId",
      "reportedSelectionId",
      "reportedTimelineId",
    ]);
    // Identity, counts, and a code. No URL, no payload, no exception, no credential.
    const serialized = JSON.stringify(beat);
    expect(serialized).not.toContain("https://");
    expect(serialized).not.toContain("payload");
    await controller.stop();
  });

  it("keeps the frame when the server cannot be reached, and says so quietly", async () => {
    const host = createFakeHost({
      permissions: ["signage.display.view"],
      routes: [
        { method: "POST", path: "viewers/session", respond: () => jsonResponse(SESSION) },
        {
          method: "GET",
          path: "channels/chan-1/display-state",
          respond: () => jsonResponse(state()),
        },
        { method: "POST", path: /^viewers\/.*\/heartbeat$/u, respond: () => jsonResponse({}) },
      ],
    });
    const controller = build({ host });
    await controller.start();
    await settle();
    const before = controller.diagnostics().renderedSelectionId;

    // Every request now fails, exactly as a dropped uplink does.
    Object.assign(host.context.api, {
      request: () => Promise.reject(new Error("network is gone")),
    });
    await controller.apply(state());
    await settle();

    expect(controller.diagnostics().renderedSelectionId).toBe(before);
    // Nothing about the failure is on screen: the slate is for having no content, not no network.
    expect(root.dataset.slate).toBe("false");
    await controller.stop();
  });

  it("registers no viewer and sends no heartbeat when telemetry is off", async () => {
    const host = createFakeHost({
      permissions: [],
      routes: [
        { method: "POST", path: "viewers/session", respond: () => jsonResponse(SESSION) },
        { method: "POST", path: /^viewers\//u, respond: () => jsonResponse({}) },
      ],
    });
    const controller = build({ host, telemetry: false });

    await controller.start();
    await controller.apply(state());
    await settle();

    // The management preview renders exactly what a wall renders and appears in no roster.
    expect(host.requests).toEqual([]);
    expect(controller.diagnostics().renderedSelectionId).toBe("sel-1");
    await controller.stop();
  });
});