import type { ModuleStorage } from "@ekklesia/module-sdk";
import sharp from "sharp";
import { beforeEach, describe, expect, it } from "vitest";
import { SignageError } from "../src/server/errors.js";
import { SIGNAGE_IMAGE_MAX_BYTES, SIGNAGE_IMAGE_MAX_PIXELS } from "../src/server/images/limits.js";
import { processSignageImage, sha256Hex } from "../src/server/images/processing.js";
import {
  deleteNativeImage,
  ingestNativeImage,
  updateNativeImage,
} from "../src/server/images/service.js";
import { readBoundedBody } from "../src/server/images/streaming.js";
import { isSixteenByNine, resolveNativeScene } from "../src/shared/native-images.js";
import { createFakeStorage, type FakeStorage } from "./support/fake-storage.js";
import {
  bytesOf,
  GIF_DOCUMENT_BASE64,
  makeAnimatedGif,
  makeAnimatedWebp,
  makeImage,
  PDF_DOCUMENT,
  SVG_DOCUMENT,
} from "./support/images.js";
import { createMemorySignageStore, type MemorySignageStore } from "./support/memory-store.js";

async function expectSignageCode(promise: Promise<unknown>, code: string): Promise<SignageError> {
  try {
    await promise;
  } catch (error) {
    expect(error).toBeInstanceOf(SignageError);
    const signageError = error as SignageError;
    expect(signageError.code).toBe(code);
    return signageError;
  }
  throw new Error(`Expected ${code}, but the operation succeeded.`);
}

describe("native image processing", () => {
  it("accepts still PNG, JPEG, and WebP and reports the format the bytes actually are", async () => {
    for (const format of ["png", "jpeg", "webp"] as const) {
      const processed = await processSignageImage(
        await makeImage({ format, height: 720, width: 1280 }),
      );
      expect(processed.format).toBe(format);
      expect(processed.width).toBe(1280);
      expect(processed.height).toBe(720);
      expect(processed.renditions.map((rendition) => rendition.kind)).toEqual([
        "display",
        "thumbnail",
      ]);
    }
  });

  it("refuses SVG, PDF, GIF, animation, and anything that is not an image at all", async () => {
    await expectSignageCode(
      processSignageImage(bytesOf(SVG_DOCUMENT)),
      "SIGNAGE_IMAGE_UNSUPPORTED_FORMAT",
    );
    await expectSignageCode(processSignageImage(bytesOf(PDF_DOCUMENT)), "SIGNAGE_IMAGE_MALFORMED");
    await expectSignageCode(
      processSignageImage(new Uint8Array(Buffer.from(GIF_DOCUMENT_BASE64, "base64"))),
      "SIGNAGE_IMAGE_UNSUPPORTED_FORMAT",
    );
    await expectSignageCode(
      processSignageImage(bytesOf("this is a text file, not a slide")),
      "SIGNAGE_IMAGE_MALFORMED",
    );
    // Animation is detected before format, so an animated GIF reports why it is really refused.
    await expectSignageCode(
      processSignageImage(await makeAnimatedWebp()),
      "SIGNAGE_IMAGE_ANIMATED",
    );
    await expectSignageCode(processSignageImage(await makeAnimatedGif()), "SIGNAGE_IMAGE_ANIMATED");
  });

  it("refuses an image whose decoded pixels exceed the budget, whatever the file size is", async () => {
    // A decompression bomb is small on disk and enormous decoded, which is exactly why the budget
    // is measured in pixels rather than in bytes.
    const bomb = await makeImage({ format: "png", height: 9000, width: 9000 });
    expect(bomb.byteLength).toBeLessThan(SIGNAGE_IMAGE_MAX_BYTES);
    expect(9000 * 9000).toBeGreaterThan(SIGNAGE_IMAGE_MAX_PIXELS);

    const error = await expectSignageCode(processSignageImage(bomb), "SIGNAGE_IMAGE_PIXEL_LIMIT");
    // The caller learns the limit Signage declared, and nothing about the decoder that enforced it.
    expect(error.detail).toEqual({ maxPixels: SIGNAGE_IMAGE_MAX_PIXELS });
    expect(error.message).not.toMatch(/sharp|vips|pixel limit exceeded/iu);
  });

  it("fits renditions inside their bounds, and never crops or upscales", async () => {
    const tall = await processSignageImage(
      await makeImage({ format: "png", height: 2400, width: 1000 }),
    );
    const display = tall.renditions.find((rendition) => rendition.kind === "display");
    // Inside-fit: the long edge reaches the bound, the short edge is proportional, nothing is cut.
    expect(display?.height).toBe(1080);
    expect(display?.width).toBe(450);

    const small = await processSignageImage(
      await makeImage({ format: "png", height: 90, width: 160 }),
    );
    const smallDisplay = small.renditions.find((rendition) => rendition.kind === "display");
    // Never upscaled: blowing a small image up to 1920 makes it soft, not better.
    expect(smallDisplay?.width).toBe(160);
    expect(smallDisplay?.height).toBe(90);
  });

  it("strips metadata from renditions and flattens transparency against black", async () => {
    const transparent = await processSignageImage(
      await makeImage({ alpha: true, format: "png", height: 200, width: 400 }),
    );
    const display = transparent.renditions.find((rendition) => rendition.kind === "display");
    if (!display) {
      throw new Error("Expected a display rendition.");
    }
    const metadata = await sharp(display.bytes).metadata();

    expect(metadata.format).toBe("webp");
    expect(metadata.hasAlpha).toBe(false);
    // EXIF, GPS coordinates, and camera serial numbers never travel with a published rendition.
    expect(metadata.exif).toBeUndefined();
    expect(metadata.icc).toBeUndefined();
    expect(metadata.xmp).toBeUndefined();
    // The original's own facts are preserved in PostgreSQL instead.
    expect(transparent.hasAlpha).toBe(true);
  });

  it("is deterministic, so a retry of the same bytes produces the same renditions", async () => {
    const bytes = await makeImage({ format: "png", height: 600, width: 800 });
    const first = await processSignageImage(bytes);
    const second = await processSignageImage(bytes);

    expect(first.contentSha256).toBe(second.contentSha256);
    expect(first.contentSha256).toBe(sha256Hex(bytes));
    expect(first.renditions.map((rendition) => rendition.contentSha256)).toEqual(
      second.renditions.map((rendition) => rendition.contentSha256),
    );
  });
});

describe("native image presentation", () => {
  it("lets a true 16:9 image fill the frame, within a documented tolerance", () => {
    expect(isSixteenByNine(1920, 1080)).toBe(true);
    expect(isSixteenByNine(1280, 720)).toBe(true);
    // A one-or-two-pixel export artefact is still 16:9 to a person looking at the wall.
    expect(isSixteenByNine(1918, 1080)).toBe(true);
    expect(isSixteenByNine(1080, 1080)).toBe(false);
    expect(isSixteenByNine(2560, 1080)).toBe(false);
    expect(isSixteenByNine(0, 0)).toBe(false);
  });

  it("shows a 16:9 image whole with no background, blur, or shadow", () => {
    const scene = resolveNativeScene(
      { height: 1080, width: 1920 },
      {
        backgroundColor: "#112233",
        backgroundDarkened: true,
        backgroundMode: "blurred",
        blurPixels: 20,
        foregroundShadow: true,
      },
    );

    // An image that already fits needs none of the treatments that exist to frame one that does not.
    expect(scene).toEqual({
      backgroundColor: "#000000",
      backgroundImage: false,
      backgroundMode: "none",
      blurPixels: 0,
      darkenOpacity: 0,
      fit: "fill",
      shadow: false,
    });
  });

  it("shows every other ratio whole, on the background the slot asked for", () => {
    const blurred = resolveNativeScene(
      { height: 1080, width: 1080 },
      {
        backgroundColor: "#112233",
        backgroundDarkened: true,
        backgroundMode: "blurred",
        blurPixels: 24,
        foregroundShadow: true,
      },
    );
    expect(blurred).toMatchObject({
      backgroundImage: true,
      blurPixels: 24,
      darkenOpacity: 0.25,
      fit: "contain",
      shadow: true,
    });

    const solid = resolveNativeScene(
      { height: 1080, width: 1080 },
      {
        backgroundColor: "#112233",
        backgroundDarkened: false,
        backgroundMode: "solid",
        blurPixels: 24,
        foregroundShadow: true,
      },
    );
    // A solid background is not blurred, and an undarkened one is not dimmed.
    expect(solid).toMatchObject({
      backgroundColor: "#112233",
      backgroundImage: false,
      blurPixels: 0,
      darkenOpacity: 0,
      fit: "contain",
    });
  });
});

describe("bounded upload reading", () => {
  function streamedRequest(chunks: readonly Uint8Array[], contentLength?: number): Request {
    const body = new ReadableStream<Uint8Array>({
      start(controller) {
        for (const chunk of chunks) {
          controller.enqueue(chunk);
        }
        controller.close();
      },
    });
    return new Request("http://localhost/images?filename=a.png", {
      body,
      // Required by Node's fetch for a streaming request body.
      duplex: "half",
      headers: contentLength === undefined ? {} : { "content-length": String(contentLength) },
      method: "POST",
    });
  }

  it("refuses a declared length over the limit before the body is even touched", async () => {
    let bodyAccesses = 0;
    // A stand-in rather than a real `Request`, and `body` is a getter: a `ReadableStream` pulls its
    // first chunk as soon as it is constructed, so counting reads would measure the stream rather
    // than the check. Counting *accesses to the body* measures exactly the property under test.
    const request = {
      get body(): ReadableStream<Uint8Array> {
        bodyAccesses += 1;
        return new ReadableStream<Uint8Array>({
          start(controller) {
            controller.enqueue(new Uint8Array(16));
            controller.close();
          },
        });
      },
      headers: new Headers({ "content-length": String(SIGNAGE_IMAGE_MAX_BYTES + 1) }),
    } as unknown as Request;

    await expectSignageCode(
      readBoundedBody(request, SIGNAGE_IMAGE_MAX_BYTES),
      "SIGNAGE_IMAGE_TOO_LARGE",
    );
    expect(bodyAccesses).toBe(0);
  });

  it("counts what actually arrives, so a missing or lying declared length bounds nothing", async () => {
    const chunk = new Uint8Array(1024);
    const chunks = Array.from({ length: 8 }, () => chunk);

    // No `content-length` at all, and a total over a small limit.
    await expectSignageCode(
      readBoundedBody(streamedRequest(chunks), 4096),
      "SIGNAGE_IMAGE_TOO_LARGE",
    );
    // A declared length that lies about being small.
    await expectSignageCode(
      readBoundedBody(streamedRequest(chunks, 10), 4096),
      "SIGNAGE_IMAGE_TOO_LARGE",
    );
  });

  it("reassembles a chunked body exactly", async () => {
    const image = await makeImage({ format: "png", height: 90, width: 160 });
    const half = Math.floor(image.byteLength / 2);
    const bytes = await readBoundedBody(
      streamedRequest([image.slice(0, half), image.slice(half)]),
      SIGNAGE_IMAGE_MAX_BYTES,
    );

    expect(sha256Hex(bytes)).toBe(sha256Hex(image));
  });

  it("refuses an empty body rather than treating it as an image", async () => {
    await expectSignageCode(
      readBoundedBody(streamedRequest([]), SIGNAGE_IMAGE_MAX_BYTES),
      "SIGNAGE_INVALID_REQUEST",
    );
  });
});

describe("native image ingest", () => {
  let store: MemorySignageStore;
  let storage: FakeStorage;
  let counter: number;

  beforeEach(() => {
    store = createMemorySignageStore();
    storage = createFakeStorage();
    counter = 0;
  });

  const newId = () => {
    counter += 1;
    return `00000000-0000-4000-8000-${String(counter).padStart(12, "0")}`;
  };

  async function ingest(bytes: Uint8Array, filename = "welcome.png") {
    return ingestNativeImage({
      bytes,
      displayName: filename,
      expiresAt: null,
      filename,
      newId,
      storage,
      store,
    });
  }

  it("archives the original unchanged and stores both renditions beside it", async () => {
    const bytes = await makeImage({ format: "png", height: 1080, width: 1920 });
    const result = await ingest(bytes);

    expect(result.deduplicated).toBe(false);
    expect([...storage.objects.keys()].sort()).toEqual([
      `native-images/assets/${result.image.id}/display.webp`,
      `native-images/assets/${result.image.id}/original.png`,
      `native-images/assets/${result.image.id}/thumbnail.webp`,
    ]);
    // Byte for byte. It is the church's file, and Signage is not entitled to rewrite it.
    const archived = storage.objects.get(`native-images/assets/${result.image.id}/original.png`);
    expect(sha256Hex(archived?.bytes ?? new Uint8Array())).toBe(sha256Hex(bytes));
    expect(result.image.originalContentType).toBe("image/png");
    expect(result.image.renditions.map((rendition) => rendition.contentType)).toEqual([
      "image/webp",
      "image/webp",
    ]);
  });

  it("returns the existing asset for identical bytes, and writes nothing new", async () => {
    const bytes = await makeImage({ format: "png", height: 1080, width: 1920 });
    const first = await ingest(bytes, "welcome.png");
    const objectCount = storage.objects.size;

    const second = await ingest(bytes, "welcome-copy.png");

    expect(second.deduplicated).toBe(true);
    expect(second.image.id).toBe(first.image.id);
    expect(storage.objects.size).toBe(objectCount);
    expect(store.images.size).toBe(1);
  });

  it("writes nothing at all when the bytes are not an image Signage accepts", async () => {
    await expectSignageCode(
      ingest(bytesOf(SVG_DOCUMENT), "logo.svg"),
      "SIGNAGE_IMAGE_UNSUPPORTED_FORMAT",
    );

    expect(storage.objects.size).toBe(0);
    expect(store.images.size).toBe(0);
  });

  it("removes every object it wrote when a later write fails", async () => {
    const bytes = await makeImage({ format: "png", height: 1080, width: 1920 });
    storage.failPut(`assets/00000000-0000-4000-8000-000000000001/thumbnail.webp`);

    await expectSignageCode(ingest(bytes), "SIGNAGE_STORAGE_UNAVAILABLE");

    // An aborted ingest leaves no orphan bytes and no half-formed asset.
    expect(storage.objects.size).toBe(0);
    expect(store.images.size).toBe(0);
  });

  it("recognizes a sanitized storage failure from the host's separate SDK copy", async () => {
    const bucket = storage.bucket("native-images");
    const externalError = Object.assign(new Error("The storage service could not be reached."), {
      code: "STORAGE_PROVIDER_UNAVAILABLE",
      name: "ModuleStorageError",
    });
    const externalStorage: ModuleStorage = {
      bucket: () => ({ ...bucket, put: () => Promise.reject(externalError) }),
      buckets: () => ["native-images"],
    };

    await expectSignageCode(
      ingestNativeImage({
        bytes: await makeImage({ format: "png", height: 360, width: 640 }),
        displayName: "welcome.png",
        expiresAt: null,
        filename: "welcome.png",
        storage: externalStorage,
        store,
      }),
      "SIGNAGE_STORAGE_UNAVAILABLE",
    );
  });

  it("treats a race with an identical upload as a success rather than a failure", async () => {
    const bytes = await makeImage({ format: "png", height: 1080, width: 1920 });
    const first = await ingest(bytes);
    // The second ingest is forced past the dedup check by clearing the hash lookup once, exactly as
    // a concurrent commit would: the write happens, and the unique index refuses the insert.
    const originalLookup = store.findReadyImageByContentHash.bind(store);
    let lookups = 0;
    store.findReadyImageByContentHash = (hash: string) => {
      lookups += 1;
      return lookups === 1 ? Promise.resolve(undefined) : originalLookup(hash);
    };

    const second = await ingest(bytes);

    expect(second.deduplicated).toBe(true);
    expect(second.image.id).toBe(first.image.id);
    // The losing attempt cleaned up after itself.
    expect(storage.objects.size).toBe(3);
  });

  it("refuses bytes past Signage's own limit even if the caller read them", async () => {
    await expectSignageCode(
      ingestNativeImage({
        bytes: new Uint8Array(SIGNAGE_IMAGE_MAX_BYTES + 1),
        displayName: "huge.png",
        expiresAt: null,
        filename: "huge.png",
        storage,
        store,
      }),
      "SIGNAGE_IMAGE_TOO_LARGE",
    );
  });
});

describe("native image maintenance", () => {
  let store: MemorySignageStore;
  let storage: FakeStorage;

  async function seed() {
    return ingestNativeImage({
      bytes: await makeImage({ format: "png", height: 1080, width: 1920 }),
      displayName: "welcome.png",
      expiresAt: null,
      filename: "welcome.png",
      storage,
      store,
    });
  }

  beforeEach(() => {
    store = createMemorySignageStore();
    storage = createFakeStorage();
  });

  it("writes nothing for an exact no-op", async () => {
    const { image } = await seed();
    let writes = 0;
    const original = store.updateImage.bind(store);
    store.updateImage = (id, changes) => {
      writes += 1;
      return original(id, changes);
    };

    const unchanged = await updateNativeImage({
      assetId: image.id,
      displayName: image.displayName,
      expiresAt: null,
      store,
    });

    expect(unchanged.displayName).toBe(image.displayName);
    expect(writes).toBe(0);
  });

  it("renames and expires an image, and treats a null expiration as permanent", async () => {
    const { image } = await seed();
    const expires = new Date("2027-01-01T00:00:00.000Z");

    const renamed = await updateNativeImage({
      assetId: image.id,
      displayName: "Welcome slide",
      expiresAt: expires,
      store,
    });
    expect(renamed.displayName).toBe("Welcome slide");
    expect(renamed.expiresAt?.toISOString()).toBe(expires.toISOString());

    const permanent = await updateNativeImage({ assetId: image.id, expiresAt: null, store });
    expect(permanent.expiresAt).toBeNull();
  });

  it("deletes an unreferenced image and every object it owned", async () => {
    const { image } = await seed();

    await deleteNativeImage({ assetId: image.id, storage, store });

    expect(store.images.size).toBe(0);
    expect(storage.objects.size).toBe(0);
  });

  it("refuses to delete an image a slot or a live static hold still refers to", async () => {
    const { image } = await seed();
    store.addImageReference(image.id, "slot");
    store.addImageReference(image.id, "static-hold");

    const error = await expectSignageCode(
      deleteNativeImage({ assetId: image.id, storage, store }),
      "SIGNAGE_ASSET_IN_USE",
    );

    // Counts an operator can act on — never a slot id, a timeline name, or a channel group's name.
    expect(error.detail).toEqual({ heldByChannelGroups: 1, referencedBySlots: 1 });
    expect(store.images.size).toBe(1);
    expect(storage.objects.size).toBe(3);
  });

  it("refuses an unknown image without saying whether it ever existed", async () => {
    await expectSignageCode(
      deleteNativeImage({
        assetId: "11111111-1111-4111-8111-111111111111",
        storage,
        store,
      }),
      "SIGNAGE_NOT_FOUND",
    );
  });
});