import {
  EMPTY_MODULE_STORAGE,
  isValidModuleStorageKey,
  MODULE_STORAGE_KEY_MAX_BYTES,
  type ModuleStorageBody,
  ModuleStorageError,
  type ModuleStorageListOptions,
  type ModuleStorageListing,
  type ModuleStorageObject,
  type ModuleStorageObjectMetadata,
  type ModuleStoragePutOptions,
} from "@ekklesia/contracts";
import { describe, expect, it } from "vitest";
import {
  DEFAULT_STORAGE_BUCKET_PREFIX,
  isValidStorageBucketPrefix,
  physicalBucketName,
  resolveModuleStorageBindings,
} from "../src/storage/binding.js";
import { createStorageProviderConfig, describeStorageProvider } from "../src/storage/config.js";
import { createModuleStorage, createModuleStorageLookup } from "../src/storage/module-storage.js";
import type { StorageProvider } from "../src/storage/provider.js";

/** Reads a Web stream to bytes without depending on DOM-only helper types. */
async function collect(stream: ReadableStream<Uint8Array>): Promise<Uint8Array> {
  const reader = stream.getReader();
  const chunks: Uint8Array[] = [];
  let total = 0;
  for (;;) {
    const { done, value } = await reader.read();
    if (done) {
      break;
    }
    chunks.push(value);
    total += value.byteLength;
  }
  const merged = new Uint8Array(total);
  let offset = 0;
  for (const chunk of chunks) {
    merged.set(chunk, offset);
    offset += chunk.byteLength;
  }
  return merged;
}

function streamOf(bytes: Uint8Array): ReadableStream<Uint8Array> {
  return new ReadableStream<Uint8Array>({
    start(controller) {
      controller.enqueue(bytes);
      controller.close();
    },
  });
}

interface RecordedCall {
  readonly operation: string;
  readonly physicalBucket: string;
  readonly key?: string;
}

/**
 * A recording in-memory `StorageProvider`.
 *
 * Deliberately keyed by **physical** bucket, exactly as the real provider is, so a test can assert
 * which physical namespace an operation actually reached — which is the only way to prove isolation
 * rather than assume it.
 */
function fakeProvider(options: { failEnsure?: () => Error } = {}): StorageProvider & {
  readonly calls: readonly RecordedCall[];
  readonly buckets: ReadonlyMap<string, Map<string, { bytes: Uint8Array; contentType?: string }>>;
} {
  const calls: RecordedCall[] = [];
  const buckets = new Map<string, Map<string, { bytes: Uint8Array; contentType?: string }>>();
  const objectsIn = (physicalBucket: string) => {
    const bucket = buckets.get(physicalBucket);
    if (!bucket) {
      throw new ModuleStorageError("STORAGE_BUCKET_UNAVAILABLE");
    }
    return bucket;
  };

  const provider: StorageProvider = {
    async close() {},
    async delete(physicalBucket, key) {
      calls.push({ key, operation: "delete", physicalBucket });
      objectsIn(physicalBucket).delete(key);
    },
    async ensureBucket(physicalBucket) {
      calls.push({ operation: "ensureBucket", physicalBucket });
      const failure = options.failEnsure?.();
      if (failure) {
        throw failure;
      }
      if (!buckets.has(physicalBucket)) {
        buckets.set(physicalBucket, new Map());
      }
    },
    async get(physicalBucket, key): Promise<ModuleStorageObject> {
      calls.push({ key, operation: "get", physicalBucket });
      const stored = objectsIn(physicalBucket).get(key);
      if (!stored) {
        throw new ModuleStorageError("STORAGE_OBJECT_NOT_FOUND", key);
      }
      return Object.freeze({
        body: streamOf(stored.bytes),
        contentLength: stored.bytes.byteLength,
        key,
        ...(stored.contentType === undefined ? {} : { contentType: stored.contentType }),
      });
    },
    async head(physicalBucket, key): Promise<ModuleStorageObjectMetadata> {
      calls.push({ key, operation: "head", physicalBucket });
      const stored = objectsIn(physicalBucket).get(key);
      if (!stored) {
        throw new ModuleStorageError("STORAGE_OBJECT_NOT_FOUND", key);
      }
      return Object.freeze({ contentLength: stored.bytes.byteLength, key });
    },
    async list(
      physicalBucket,
      listOptions: ModuleStorageListOptions,
    ): Promise<ModuleStorageListing> {
      calls.push({ operation: "list", physicalBucket });
      const entries = [...objectsIn(physicalBucket).keys()]
        .filter((key) => listOptions.prefix === undefined || key.startsWith(listOptions.prefix))
        .sort();
      return Object.freeze({
        objects: Object.freeze(entries.map((key) => Object.freeze({ key }))),
      });
    },
    async probe() {},
    async put(
      physicalBucket,
      key,
      body: ModuleStorageBody,
      putOptions: ModuleStoragePutOptions,
    ): Promise<ModuleStorageObjectMetadata> {
      calls.push({ key, operation: "put", physicalBucket });
      const bytes =
        typeof body === "string"
          ? new TextEncoder().encode(body)
          : body instanceof Uint8Array
            ? body
            : await collect(body as ReadableStream<Uint8Array>);
      objectsIn(physicalBucket).set(key, {
        bytes,
        ...(putOptions.contentType === undefined ? {} : { contentType: putOptions.contentType }),
      });
      return Object.freeze({ contentLength: bytes.byteLength, key });
    },
  };
  return Object.assign(provider, { buckets: buckets as never, calls: calls as never });
}

describe("physical bucket naming", () => {
  it("is deterministic, so a binding survives restarts and redeployments", () => {
    const first = physicalBucketName("ekklesia", "announcements", "announcement-assets");
    const second = physicalBucketName("ekklesia", "announcements", "announcement-assets");

    expect(first).toBe(second);
    expect(first).toContain("announcements--announcement-assets");
  });

  it("keeps two modules declaring the same logical name in different namespaces", () => {
    const announcements = physicalBucketName("ekklesia", "announcements", "assets");
    const video = physicalBucketName("ekklesia", "video", "assets");

    // The property the whole scheme exists for: `assets` is an obvious name two unrelated modules
    // will both pick.
    expect(announcements).not.toBe(video);
  });

  it("cannot be confused by a hyphen in either identifier", () => {
    // The ambiguity a single-hyphen separator would have produced: module `a-b` + bucket `c` and
    // module `a` + bucket `b-c` would both render as `a-b-c`, silently sharing a namespace.
    const left = physicalBucketName("ekklesia", "a-b", "c");
    const right = physicalBucketName("ekklesia", "a", "b-c");

    expect(left).not.toBe(right);
  });

  it("stays within S3's 63-character bucket-name limit even for maximal identifiers", () => {
    const moduleId = `m${"o".repeat(62)}`.slice(0, 64);
    const bucketId = `b${"u".repeat(46)}`.slice(0, 48);
    const name = physicalBucketName("ekklesia", moduleId, bucketId);

    expect(name.length).toBeLessThanOrEqual(63);
    // Still distinct from a neighbour that truncates to the same readable prefix, because the digest
    // is taken over the full untruncated identity.
    expect(name).not.toBe(physicalBucketName("ekklesia", moduleId, `${bucketId.slice(0, 47)}x`));
  });

  it("always produces a name S3 itself would accept", () => {
    const samples = [
      physicalBucketName("ekklesia", "a", "b"),
      physicalBucketName("ekklesia", `m${"o".repeat(62)}`, `b${"u".repeat(46)}`),
      physicalBucketName("church", "announcements", "announcement-assets"),
      physicalBucketName("ekklesia", "a-b", "c-d"),
    ];
    for (const name of samples) {
      expect(name.length).toBeGreaterThanOrEqual(3);
      expect(name.length).toBeLessThanOrEqual(63);
      expect(name).toMatch(/^[a-z0-9][a-z0-9-]*[a-z0-9]$/u);
      // No dots at all, so S3's adjacent-period and period-next-to-hyphen rules are unreachable and
      // virtual-host-style addressing stays TLS-safe should a provider ever use it. Consecutive
      // hyphens are explicitly fine — `--` is the separator, and the pinned SeaweedFS image accepts
      // such names (verified directly against it in the integration suite).
      expect(name).not.toContain(".");
      // Never IP-shaped, and never a reserved prefix, because it always begins with the validated
      // alphabetic prefix.
      expect(name).not.toMatch(/^\d+-\d+-\d+-\d+$/u);
      expect(name.startsWith("xn--")).toBe(false);
      expect(name.startsWith("sthree-")).toBe(false);
      expect(name.endsWith("-s3alias")).toBe(false);
      expect(name.endsWith("--ol-s3")).toBe(false);
    }
  });

  it("isolates two installations sharing one storage service through the prefix", () => {
    const first = physicalBucketName("ekklesia", "announcements", "assets");
    const second = physicalBucketName("stanne", "announcements", "assets");

    expect(first).not.toBe(second);
  });

  it("accepts only a safe bucket prefix", () => {
    expect(isValidStorageBucketPrefix(DEFAULT_STORAGE_BUCKET_PREFIX)).toBe(true);
    for (const bad of ["", "Ekklesia", "ekklesia_", "-ekklesia", "ekklesia--x", "a".repeat(17)]) {
      expect(isValidStorageBucketPrefix(bad)).toBe(false);
    }
  });

  it("resolves every declared bucket in declaration order", () => {
    const bindings = resolveModuleStorageBindings("ekklesia", "announcements", [
      "announcement-assets",
      "thumbnails",
    ]);

    expect(bindings.map((binding) => binding.logicalBucketId)).toEqual([
      "announcement-assets",
      "thumbnails",
    ]);
    expect(new Set(bindings.map((binding) => binding.physicalBucket)).size).toBe(2);
  });
});

describe("object key validation", () => {
  it("accepts ordinary and nested keys", () => {
    for (const key of ["welcome.png", "slides/welcome.png", "a/b/c/deep.webp", "ünïcode.png"]) {
      expect(isValidModuleStorageKey(key)).toBe(true);
    }
  });

  it("rejects keys that would be ambiguous or unrepresentable", () => {
    for (const key of [
      "",
      "/leading-slash.png",
      "back\\slash.png",
      "controlcharacter.png",
      "controlcharacter.png",
      "deletecharacter.png",
      "\ud800lone-surrogate.png",
      "x".repeat(MODULE_STORAGE_KEY_MAX_BYTES + 1),
    ]) {
      expect(isValidModuleStorageKey(key)).toBe(false);
    }
  });

  it("measures the length limit in UTF-8 bytes, not characters", () => {
    // 512 three-byte characters is 1536 bytes — over the limit despite being 512 characters.
    expect(isValidModuleStorageKey("あ".repeat(512))).toBe(false);
    expect(isValidModuleStorageKey("あ".repeat(341))).toBe(true);
  });

  it("does not treat a key as a filesystem path", () => {
    // `..` has no traversal meaning to an object store, and the physical bucket never comes from the
    // key, so this is an ordinary (if odd) object name rather than an escape.
    expect(isValidModuleStorageKey("../still-just-a-name.png")).toBe(true);
  });
});

describe("module storage scoping", () => {
  const provider = () => fakeProvider();

  it("gives a module exactly the buckets its manifest declared", () => {
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["announcement-assets", "thumbnails"],
      moduleId: "announcements",
      provider: provider(),
    });

    expect(storage.buckets()).toEqual(["announcement-assets", "thumbnails"]);
    expect(storage.bucket("announcement-assets").id).toBe("announcement-assets");
  });

  it("refuses a logical bucket the module did not declare", () => {
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["announcement-assets"],
      moduleId: "announcements",
      provider: provider(),
    });

    expect(() => storage.bucket("video-assets")).toThrow(ModuleStorageError);
    try {
      storage.bucket("video-assets");
    } catch (error) {
      expect((error as ModuleStorageError).code).toBe("STORAGE_BUCKET_UNDECLARED");
    }
  });

  it("gives a module no way to reach another module's storage by knowing its name", async () => {
    const shared = fakeProvider();
    const announcements = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["assets"],
      moduleId: "announcements",
      provider: shared,
    });
    const video = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["assets"],
      moduleId: "video",
      provider: shared,
    });

    await announcements.bucket("assets").put("shared-name.txt", "from-announcements");
    await video.bucket("assets").put("shared-name.txt", "from-video");

    // Same logical name, same key, same provider — and two different objects, because the physical
    // namespaces differ.
    const decoder = new TextDecoder();
    const fromAnnouncements = decoder.decode(
      await collect((await announcements.bucket("assets").get("shared-name.txt")).body),
    );
    const fromVideo = decoder.decode(
      await collect((await video.bucket("assets").get("shared-name.txt")).body),
    );

    expect(fromAnnouncements).toBe("from-announcements");
    expect(fromVideo).toBe("from-video");
    expect(shared.buckets.size).toBe(2);
  });

  it("exposes no physical bucket, endpoint, or credential through the module-facing surface", () => {
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["announcement-assets"],
      moduleId: "announcements",
      provider: provider(),
    });
    const bucket = storage.bucket("announcement-assets");

    // The handle names the *logical* bucket, and has no accessor for anything else.
    expect(bucket.id).toBe("announcement-assets");
    expect(Object.keys(bucket).sort()).toEqual(["delete", "get", "head", "id", "list", "put"]);
    expect(Object.keys(storage).sort()).toEqual(["bucket", "buckets"]);
    const serialized = JSON.stringify({ bucket, storage });
    expect(serialized).not.toContain(
      physicalBucketName("ekklesia", "announcements", "announcement-assets"),
    );
    expect(serialized).not.toContain("http");
  });

  it("gives a module declaring no buckets an empty, frozen storage that refuses everything", () => {
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: [],
      moduleId: "calendar",
      provider: provider(),
    });

    expect(storage).toBe(EMPTY_MODULE_STORAGE);
    expect(storage.buckets()).toEqual([]);
    expect(() => storage.bucket("anything")).toThrow(ModuleStorageError);
    expect(Object.isFrozen(storage)).toBe(true);
  });

  it("resolves nothing at all when the host has no provider", () => {
    const lookup = createModuleStorageLookup(undefined, "ekklesia", [
      { logicalBucketIds: ["assets"], moduleId: "announcements" },
    ]);

    expect(lookup.size).toBe(0);
  });

  it.each([
    "__proto__",
    "constructor",
    "prototype",
    "toString",
  ])("treats the reserved property name %s as an ordinary undeclared bucket", (name) => {
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["assets"],
      moduleId: "announcements",
      provider: provider(),
    });

    expect(() => storage.bucket(name)).toThrow(ModuleStorageError);
  });
});

describe("bucket provisioning", () => {
  it("ensures the bucket lazily on first use, not at construction", async () => {
    const shared = fakeProvider();
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["assets"],
      moduleId: "announcements",
      provider: shared,
    });

    // Constructing the facade — which is what startup does — touches the provider zero times, so a
    // storage outage can never stop the platform from booting.
    expect(shared.calls).toHaveLength(0);

    await storage.bucket("assets").list();
    expect(shared.calls.filter((call) => call.operation === "ensureBucket")).toHaveLength(1);
  });

  it("ensures at most once per binding across many operations", async () => {
    const shared = fakeProvider();
    const bucket = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["assets"],
      moduleId: "announcements",
      provider: shared,
    }).bucket("assets");

    await Promise.all([bucket.list(), bucket.list(), bucket.put("a.txt", "a")]);
    await bucket.list();

    expect(shared.calls.filter((call) => call.operation === "ensureBucket")).toHaveLength(1);
  });

  it("retries provisioning after a transient failure rather than poisoning the binding", async () => {
    let failures = 1;
    const shared = fakeProvider({
      failEnsure: () =>
        failures-- > 0 ? new ModuleStorageError("STORAGE_PROVIDER_UNAVAILABLE") : undefined!,
    });
    const bucket = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["assets"],
      moduleId: "announcements",
      provider: shared,
    }).bucket("assets");

    await expect(bucket.list()).rejects.toMatchObject({ code: "STORAGE_PROVIDER_UNAVAILABLE" });
    // The next call tries again. A memoized *failure* would leave a module permanently broken by one
    // network blip, which is exactly the resilience the real Announcements product depends on.
    await expect(bucket.list()).resolves.toEqual({ objects: [] });
  });

  it("never offers a way to delete a bucket", () => {
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["assets"],
      moduleId: "announcements",
      provider: fakeProvider(),
    });

    const surface = [...Object.keys(storage), ...Object.keys(storage.bucket("assets"))];
    expect(surface.join(" ")).not.toMatch(/deleteBucket|destroy|drop|removeBucket/iu);
  });
});

describe("storage operations through the scoped facade", () => {
  async function announcementsStorage() {
    const provider = fakeProvider();
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: ["announcement-assets"],
      moduleId: "announcements",
      provider,
    });
    return { bucket: storage.bucket("announcement-assets"), provider };
  }

  it("round-trips an object and preserves its content type", async () => {
    const { bucket } = await announcementsStorage();
    const bytes = new Uint8Array([0x89, 0x50, 0x4e, 0x47]);

    await bucket.put("slides/welcome.png", bytes, { contentType: "image/png" });
    const object = await bucket.get("slides/welcome.png");

    expect(object.contentType).toBe("image/png");
    expect(await collect(object.body)).toEqual(bytes);
  });

  it("lists with a prefix and deletes", async () => {
    const { bucket } = await announcementsStorage();
    await bucket.put("slides/a.png", "a");
    await bucket.put("slides/b.png", "b");
    await bucket.put("other/c.png", "c");

    expect((await bucket.list({ prefix: "slides/" })).objects.map((o) => o.key)).toEqual([
      "slides/a.png",
      "slides/b.png",
    ]);

    await bucket.delete("slides/a.png");
    expect((await bucket.list({ prefix: "slides/" })).objects.map((o) => o.key)).toEqual([
      "slides/b.png",
    ]);
  });

  it("reports a missing object as a structured not-found error", async () => {
    const { bucket } = await announcementsStorage();
    await bucket.put("present.png", "x");

    await expect(bucket.get("absent.png")).rejects.toMatchObject({
      code: "STORAGE_OBJECT_NOT_FOUND",
      key: "absent.png",
    });
    await expect(bucket.head("absent.png")).rejects.toMatchObject({
      code: "STORAGE_OBJECT_NOT_FOUND",
    });
  });

  it("rejects an invalid key before reaching the provider", async () => {
    const { bucket, provider } = await announcementsStorage();

    await expect(bucket.get("/leading-slash.png")).rejects.toMatchObject({
      code: "STORAGE_KEY_INVALID",
    });
    // Not even the bucket was ensured: validation happens first.
    expect(provider.calls).toHaveLength(0);
  });

  it("refuses a streamed body with no content length rather than buffering it", async () => {
    const { bucket } = await announcementsStorage();
    const stream = streamOf(new TextEncoder().encode("x"));

    await expect(bucket.put("streamed.bin", stream)).rejects.toMatchObject({
      code: "STORAGE_CONTENT_LENGTH_REQUIRED",
    });
  });

  it("accepts a streamed body when the length is supplied", async () => {
    const { bucket } = await announcementsStorage();
    const stream = streamOf(new TextEncoder().encode("hello"));

    const metadata = await bucket.put("streamed.bin", stream, { contentLength: 5 });
    expect(metadata.key).toBe("streamed.bin");
  });
});

describe("storage provider configuration", () => {
  // Distinctive values, deliberately: a generic `"key"` would make a "no credential leaked"
  // assertion pass or fail on whether a fixed error message happens to use the English word.
  const base = {
    accessKey: "AKIAEXAMPLEACCESSID",
    endpoint: "https://storage.example.test",
    secretKey: "sk-example-secret-material",
  };

  it("treats an absent endpoint as an installation with no object storage", () => {
    expect(createStorageProviderConfig(undefined)).toBeUndefined();
    expect(createStorageProviderConfig({ endpoint: "" })).toBeUndefined();
    expect(createStorageProviderConfig({})).toBeUndefined();
  });

  it("accepts a valid S3-compatible configuration with safe defaults", () => {
    const config = createStorageProviderConfig(base);

    expect(config).toEqual({
      accessKey: "AKIAEXAMPLEACCESSID",
      bucketPrefix: "ekklesia",
      endpoint: "https://storage.example.test",
      // Path-style by default: every self-hosted S3-compatible service needs it, and virtual-host
      // addressing would require wildcard DNS a typical deployment does not have.
      forcePathStyle: true,
      region: "us-east-1",
      secretKey: "sk-example-secret-material",
    });
  });

  it("requires both credentials once an endpoint is set", () => {
    expect(() => createStorageProviderConfig({ ...base, accessKey: undefined })).toThrow(
      expect.objectContaining({ code: "STORAGE_ACCESS_KEY_MISSING" }),
    );
    expect(() => createStorageProviderConfig({ ...base, secretKey: "  " })).toThrow(
      expect.objectContaining({ code: "STORAGE_SECRET_KEY_MISSING" }),
    );
  });

  it("rejects an endpoint that embeds credentials", () => {
    expect(() =>
      createStorageProviderConfig({ ...base, endpoint: "https://key:secret@storage.example.test" }),
    ).toThrow(expect.objectContaining({ code: "STORAGE_ENDPOINT_WITH_CREDENTIALS" }));
  });

  it.each([
    "not-a-url",
    "ftp://storage.example.test",
    "//storage.example.test",
  ])("rejects the malformed endpoint %s", (endpoint) => {
    expect(() => createStorageProviderConfig({ ...base, endpoint })).toThrow(
      expect.objectContaining({ code: "STORAGE_ENDPOINT_INVALID" }),
    );
  });

  it("requires https in production but allows http in development", () => {
    const http = { ...base, endpoint: "http://127.0.0.1:8333" };

    expect(() => createStorageProviderConfig(http, { environment: "production" })).toThrow(
      expect.objectContaining({ code: "STORAGE_ENDPOINT_INSECURE_IN_PRODUCTION" }),
    );
    expect(createStorageProviderConfig(http, { environment: "development" })?.endpoint).toBe(
      "http://127.0.0.1:8333",
    );
  });

  it("rejects an unsafe bucket prefix", () => {
    expect(() => createStorageProviderConfig({ ...base, bucketPrefix: "Not Valid" })).toThrow(
      expect.objectContaining({ code: "STORAGE_BUCKET_PREFIX_INVALID" }),
    );
  });

  it("never carries a configured value in a configuration error", () => {
    let captured: unknown;
    try {
      createStorageProviderConfig({
        ...base,
        endpoint: "https://super-secret-host.invalid",
        secretKey: undefined,
      });
    } catch (error) {
      captured = error;
    }

    const rendered = `${String(captured)} ${JSON.stringify(captured)}`;
    // No configured *value* survives: not the endpoint, not either credential. (The fixed message
    // legitimately contains the word "key" — what must never appear is a key's value.)
    expect(rendered).not.toContain("super-secret-host.invalid");
    expect(rendered).not.toContain(base.accessKey);
    expect(rendered).not.toContain(base.secretKey);
  });

  it("describes the provider for an operator without printing a credential", () => {
    const config = createStorageProviderConfig({
      ...base,
      accessKey: "AKIAVERYSECRETKEY",
      endpoint: "https://storage.example.test/ignored-path",
      secretKey: "a-very-secret-value",
    });
    if (!config) {
      throw new Error("expected a configuration");
    }

    const description = describeStorageProvider(config);
    expect(description).toContain("https://storage.example.test");
    expect(description).toContain("path-style");
    expect(description).not.toContain("AKIAVERYSECRETKEY");
    expect(description).not.toContain("a-very-secret-value");
  });
});

/**
 * The Announcements-shaped proof.
 *
 * Modelled on the real product's requirements — a bucket of announcement images, listed and read —
 * and never importing it. The point is what the fixture *cannot* see: it names a logical bucket and
 * object keys, and has no access to SeaweedFS, an endpoint, an access key, or the physical bucket.
 */
describe("an Announcements-shaped module reads its slides without knowing any infrastructure", () => {
  /** Everything this fixture knows. Compare with the real product, which today hardcodes
   * `http://10.40.0.2:9000/announcements?list-type=2` and parses S3 XML by hand. */
  const LOGICAL_BUCKET = "announcement-assets";

  async function loadSlideKeys(storage: {
    bucket: (id: string) => {
      list: (options?: ModuleStorageListOptions) => Promise<ModuleStorageListing>;
    };
  }): Promise<readonly string[]> {
    const listing = await storage.bucket(LOGICAL_BUCKET).list();
    // Extension filtering is the module's own domain logic, exactly as it is today — Core has no
    // opinion about which objects are slides.
    return listing.objects
      .map((object) => object.key)
      .filter((key) => /\.(png|jpe?g|webp)$/iu.test(key));
  }

  it("lists and reads its own images through the logical bucket alone", async () => {
    const provider = fakeProvider();
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: [LOGICAL_BUCKET],
      moduleId: "announcements",
      provider,
    });
    const bucket = storage.bucket(LOGICAL_BUCKET);
    await bucket.put("welcome.png", new Uint8Array([1, 2, 3]), { contentType: "image/png" });
    await bucket.put("notes.txt", "not a slide");

    expect(await loadSlideKeys(storage)).toEqual(["welcome.png"]);

    const slide = await bucket.get("welcome.png");
    expect(slide.contentType).toBe("image/png");
    // Straight into a `Response` — the shape a module route uses to serve an image to a browser
    // without the browser ever learning that object storage exists.
    // The shape a module route uses: the stream and its content type go straight into a `Response`,
    // so a browser receives the image without ever learning that object storage exists.
    const headers = new Headers();
    if (slide.contentType) {
      headers.set("content-type", slide.contentType);
    }
    expect(headers.get("content-type")).toBe("image/png");
    expect(await collect(slide.body)).toEqual(new Uint8Array([1, 2, 3]));
  });

  it("knows the logical bucket and object keys, and nothing about the host", async () => {
    const provider = fakeProvider();
    const storage = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: [LOGICAL_BUCKET],
      moduleId: "announcements",
      provider,
    });
    await storage.bucket(LOGICAL_BUCKET).list();

    const reachable = JSON.stringify({
      bucketHandle: storage.bucket(LOGICAL_BUCKET),
      buckets: storage.buckets(),
      storage,
    });
    for (const infrastructure of [
      "seaweed",
      "SeaweedFS",
      "10.40.0.2",
      "9000",
      "8333",
      "s3",
      "S3",
      "accessKey",
      "secretKey",
      physicalBucketName("ekklesia", "announcements", LOGICAL_BUCKET),
    ]) {
      expect(reachable).not.toContain(infrastructure);
    }
    // The physical bucket exists — the host created it — but only the provider ever saw its name.
    expect([...provider.buckets.keys()]).toEqual([
      physicalBucketName("ekklesia", "announcements", LOGICAL_BUCKET),
    ]);
  });

  it("surfaces a storage outage to the module without any lifecycle state changing", async () => {
    const provider = fakeProvider({
      failEnsure: () => new ModuleStorageError("STORAGE_PROVIDER_UNAVAILABLE"),
    });
    const bucket = createModuleStorage({
      bucketPrefix: "ekklesia",
      logicalBucketIds: [LOGICAL_BUCKET],
      moduleId: "announcements",
      provider,
    }).bucket(LOGICAL_BUCKET);

    // Exactly what the real product does today: catch, keep the previous slides, and retry on the
    // next poll. Nothing here writes anything, anywhere — a transient outage is not an
    // administrative decision (ADR 0030).
    let caught: unknown;
    try {
      await bucket.list();
    } catch (error) {
      caught = error;
    }

    expect(caught).toBeInstanceOf(ModuleStorageError);
    expect((caught as ModuleStorageError).code).toBe("STORAGE_PROVIDER_UNAVAILABLE");
    expect(JSON.stringify(caught)).not.toContain("http");
  });
});