import { describe, expect, it } from "vitest";

import type {
  OpfsPreparedObject,
  OpfsStorageScope,
} from "../../src/application/ports/browser-file-storage/opfs-ports.ts";
import type {
  BrowserStoragePolicy,
} from "../../src/application/ports/browser-file-storage/shared.ts";
import {
  resolveOpfsRuntimePolicy,
} from "../../src/adapters/storage/opfs/opfs-policy.ts";
import {
  createOpfsWorkerGateway,
  type OpfsWorkerLike,
} from "../../src/adapters/storage/opfs/opfs-worker-client.ts";
import type {
  OpfsWorkerRequest,
  OpfsWorkerResponse,
} from "../../src/adapters/storage/opfs/opfs-worker-protocol.ts";
import {
  createOpfsWorkerRuntime,
  type OpfsMutationLeaseManager,
} from "../../src/adapters/storage/opfs/opfs-worker-runtime.ts";

const scopeA: OpfsStorageScope = Object.freeze({
  namespace: "durable-objects",
  authorityToken: "authority_12345678",
  namespaceToken: "namespace_12345678",
  partitionToken: "partition_12345678",
});
const scopeB: OpfsStorageScope = Object.freeze({
  ...scopeA,
  authorityToken: "authority_87654321",
});
const storagePolicy: BrowserStoragePolicy = Object.freeze({
  owner: "test-owner",
  namespace: scopeA.namespace,
  classification: "PERSONAL",
  authority: "LOCAL_FIRST",
  accountScope: "OPAQUE_PARTITION",
  retention: Object.freeze({ kind: "EXPLICIT_DELETE" }),
  softBudgetBytes: 1024 * 1024,
  hardBudgetBytes: 2 * 1024 * 1024,
  evictionPriority: "USER_AUTHORED",
  logoutAction: "EXPORT_THEN_PURGE",
  accountDeletionAction: "PURGE_PARTITION",
  pressureAction: "RETAIN",
  unavailableFallback: "EXPORT_REQUIRED",
});
const runtimePolicy = resolveOpfsRuntimePolicy({
  chunkSizeBytes: 64 * 1024,
  maxObjectBytes: 64 * 1024,
  maxChunkCount: 1,
  orphanGracePeriodMs: 60_000,
});

type MemoryNode = MemoryDirectory | MemoryFile;

class MemoryFile {
  readonly kind = "file";
  bytes = new Uint8Array();
  lastModified = 0;
}

class MemoryDirectory {
  readonly kind = "directory";
  readonly children = new Map<string, MemoryNode>();

  async getDirectoryHandle(
    name: string,
    options: FileSystemGetDirectoryOptions = {},
  ): Promise<FileSystemDirectoryHandle> {
    const current = this.children.get(name);
    if (current instanceof MemoryDirectory) {
      return current as unknown as FileSystemDirectoryHandle;
    }
    if (current || !options.create) throw notFound();
    const created = new MemoryDirectory();
    this.children.set(name, created);
    return created as unknown as FileSystemDirectoryHandle;
  }

  async getFileHandle(
    name: string,
    options: FileSystemGetFileOptions = {},
  ): Promise<FileSystemFileHandle> {
    const current = this.children.get(name);
    if (current instanceof MemoryFile) {
      return fileHandle(current);
    }
    if (current || !options.create) throw notFound();
    const created = new MemoryFile();
    this.children.set(name, created);
    return fileHandle(created);
  }

  async removeEntry(
    name: string,
    options: FileSystemRemoveOptions = {},
  ): Promise<void> {
    const current = this.children.get(name);
    if (!current) throw notFound();
    if (
      current instanceof MemoryDirectory &&
      current.children.size > 0 &&
      !options.recursive
    ) {
      throw new DOMException("Directory is not empty.", "InvalidModificationError");
    }
    this.children.delete(name);
  }

  async *entries(): AsyncIterableIterator<
    [string, FileSystemDirectoryHandle | FileSystemFileHandle]
  > {
    for (const [name, node] of this.children) {
      yield [
        name,
        node instanceof MemoryDirectory
          ? (node as unknown as FileSystemDirectoryHandle)
          : fileHandle(node),
      ];
    }
  }

  has(path: readonly string[]): boolean {
    let current: MemoryNode = this;
    for (const segment of path) {
      if (!(current instanceof MemoryDirectory)) return false;
      const next = current.children.get(segment);
      if (!next) return false;
      current = next;
    }
    return true;
  }
}

function fileHandle(file: MemoryFile): FileSystemFileHandle {
  return {
    kind: "file",
    name: "memory",
    async getFile() {
      const blob = new Blob([Uint8Array.from(file.bytes)]);
      Object.defineProperty(blob, "lastModified", {
        value: file.lastModified,
      });
      return blob as File;
    },
    async createWritable() {
      let pending = Uint8Array.from(file.bytes);
      return {
        async write(data: FileSystemWriteChunkType) {
          if (!(data instanceof Uint8Array)) {
            throw new TypeError("The test writer accepts Uint8Array only.");
          }
          pending = Uint8Array.from(data);
        },
        async close() {
          file.bytes = pending;
          file.lastModified = Date.now();
        },
        async abort() {},
      } as unknown as FileSystemWritableFileStream;
    },
  } as FileSystemFileHandle;
}

function notFound(): DOMException {
  return new DOMException("Entry was not found.", "NotFoundError");
}

function beginRequest(
  requestId: string,
  transactionId: string,
  scope: OpfsStorageScope,
): OpfsWorkerRequest {
  return {
    requestId,
    kind: "BEGIN_PUT",
    transactionId,
    scope,
    objectId: "object_12345678",
    generation: 1,
    declaredByteLength: 1,
    mediaType: "application/octet-stream",
    createdAtEpochMs: 100,
    storagePolicy,
    chunkSizeBytes: runtimePolicy.chunkSizeBytes,
  };
}

function immediateLeases(releases: { count: number }): OpfsMutationLeaseManager {
  return {
    async acquire() {
      let released = false;
      return {
        release() {
          if (released) return;
          released = true;
          releases.count += 1;
        },
      };
    },
  };
}

function expectFailureCode(
  response: OpfsWorkerResponse | null,
  code: string,
): void {
  expect(response).toMatchObject({ ok: false, failure: { code } });
}

function preparedValue(
  response: OpfsWorkerResponse | null,
): OpfsPreparedObject {
  if (
    !response?.ok ||
    !("value" in response) ||
    !response.value ||
    typeof response.value !== "object" ||
    response.value instanceof ArrayBuffer ||
    !("descriptor" in response.value)
  ) {
    throw new Error("Expected a prepared OPFS object.");
  }
  return response.value;
}

describe("OPFS dedicated worker runtime", () => {
  it("cancels an exact BEGIN while waiting for a lock and releases a late lease", async () => {
    const root = new MemoryDirectory();
    let resolveLease:
      | ((lease: { release(): void }) => void)
      | undefined;
    let acquireSignal: AbortSignal | undefined;
    let releases = 0;
    const leaseManager: OpfsMutationLeaseManager = {
      acquire(signal) {
        acquireSignal = signal;
        return new Promise((resolve) => {
          resolveLease = resolve;
        });
      },
    };
    const runtime = createOpfsWorkerRuntime({
      root: root as unknown as FileSystemDirectoryHandle,
      crypto: globalThis.crypto,
      policy: runtimePolicy,
      leaseManager,
      dedicatedWorker: true,
      supportsSynchronousAccessHandles: false,
    });

    const beginning = runtime.handleRequest(
      beginRequest(
        "request_begin_1234",
        "transaction_12345678",
        scopeA,
      ),
    );
    await Promise.resolve();
    const aborted = await runtime.handleRequest({
      requestId: "request_abort_1234",
      kind: "ABORT_PUT",
      scope: scopeA,
      transactionId: "transaction_12345678",
    });
    expect(aborted).toMatchObject({ ok: true });
    expect(acquireSignal?.aborted).toBe(true);

    resolveLease?.({
      release() {
        releases += 1;
      },
    });
    expectFailureCode(await beginning, "ABORTED");
    expect(releases).toBe(1);
    expect(root.children.size).toBe(0);
  });

  it("serializes APPEND against ABORT so no receipt or generation is resurrected", async () => {
    const root = new MemoryDirectory();
    const releases = { count: 0 };
    let resolveDigest:
      | ((digest: ArrayBuffer) => void)
      | undefined;
    const delayedCrypto = {
      subtle: {
        digest: () =>
          new Promise<ArrayBuffer>((resolve) => {
            resolveDigest = resolve;
          }),
      },
    } as unknown as Crypto;
    const runtime = createOpfsWorkerRuntime({
      root: root as unknown as FileSystemDirectoryHandle,
      crypto: delayedCrypto,
      policy: runtimePolicy,
      leaseManager: immediateLeases(releases),
      dedicatedWorker: true,
      supportsSynchronousAccessHandles: false,
    });
    expect(
      await runtime.handleRequest(
        beginRequest(
          "request_begin_5678",
          "transaction_56785678",
          scopeA,
        ),
      ),
    ).toMatchObject({ ok: true });

    const appending = runtime.handleRequest({
      requestId: "request_append_5678",
      kind: "APPEND_CHUNK",
      scope: scopeA,
      transactionId: "transaction_56785678",
      sequence: 0,
      bytes: new Uint8Array([7]).buffer,
    });
    await Promise.resolve();
    const aborting = runtime.handleRequest({
      requestId: "request_abort_5678",
      kind: "ABORT_PUT",
      scope: scopeA,
      transactionId: "transaction_56785678",
    });
    resolveDigest?.(new Uint8Array(32).buffer);

    expectFailureCode(await appending, "ABORTED");
    expect(await aborting).toMatchObject({ ok: true });
    expect(releases.count).toBe(1);
    expect(
      root.has([
        "authorities",
        scopeA.authorityToken,
        scopeA.namespaceToken,
        scopeA.partitionToken,
        "staging",
        "transaction_56785678",
      ]),
    ).toBe(false);
  });

  it("isolates physical chunks and cancellation tombstones by opaque authority", async () => {
    const root = new MemoryDirectory();
    const releases = { count: 0 };
    const runtime = createOpfsWorkerRuntime({
      root: root as unknown as FileSystemDirectoryHandle,
      crypto: globalThis.crypto,
      policy: runtimePolicy,
      leaseManager: immediateLeases(releases),
      dedicatedWorker: true,
      supportsSynchronousAccessHandles: false,
    });
    const transactionId = "transaction_99999999";
    for (const [index, targetScope] of [scopeA, scopeB].entries()) {
      expect(
        await runtime.handleRequest(
          beginRequest(
            `request_begin_iso_${index}`,
            transactionId,
            targetScope,
          ),
        ),
      ).toMatchObject({ ok: true });
      expect(
        await runtime.handleRequest({
          requestId: `request_append_iso_${index}`,
          kind: "APPEND_CHUNK",
          scope: targetScope,
          transactionId,
          sequence: 0,
          bytes: new Uint8Array([42]).buffer,
        }),
      ).toMatchObject({ ok: true });
    }

    expect(
      await runtime.handleRequest({
        requestId: "request_abort_iso_a",
        kind: "ABORT_PUT",
        scope: scopeA,
        transactionId,
      }),
    ).toMatchObject({ ok: true });
    const finished = await runtime.handleRequest({
      requestId: "request_finish_iso_b",
      kind: "FINISH_PUT",
      scope: scopeB,
      transactionId,
    });
    expect(finished).toMatchObject({ ok: true });
    const preparedObject = preparedValue(finished);
    expect(
      await runtime.handleRequest({
        requestId: "request_verify_iso_b",
        kind: "VERIFY_OBJECT",
        preparedObject,
      }),
    ).toEqual({
      requestId: "request_verify_iso_b",
      ok: true,
      value: true,
    });
  });

  it("garbage-collects orphan chunks only inside the requested physical authority", async () => {
    const root = new MemoryDirectory();
    const releases = { count: 0 };
    const runtime = createOpfsWorkerRuntime({
      root: root as unknown as FileSystemDirectoryHandle,
      crypto: globalThis.crypto,
      policy: runtimePolicy,
      leaseManager: immediateLeases(releases),
      dedicatedWorker: true,
      supportsSynchronousAccessHandles: false,
    });
    const preparedByScope = new Map<string, OpfsPreparedObject>();
    for (const [index, targetScope] of [scopeA, scopeB].entries()) {
      const transactionId = `transaction_gc_${index}_1234`;
      await runtime.handleRequest(
        beginRequest(
          `request_gc_begin_${index}`,
          transactionId,
          targetScope,
        ),
      );
      await runtime.handleRequest({
        requestId: `request_gc_append_${index}`,
        kind: "APPEND_CHUNK",
        scope: targetScope,
        transactionId,
        sequence: 0,
        bytes: new Uint8Array([99]).buffer,
      });
      const object = preparedValue(
        await runtime.handleRequest({
          requestId: `request_gc_finish_${index}`,
          kind: "FINISH_PUT",
          scope: targetScope,
          transactionId,
        }),
      );
      preparedByScope.set(targetScope.authorityToken, object);
      await runtime.handleRequest({
        requestId: `request_gc_finalize_${index}`,
        kind: "FINALIZE_PUT",
        transactionId,
        preparedObject: object,
      });
    }
    const digestHex = preparedByScope.get(
      scopeA.authorityToken,
    )!.chunks[0]!.digestHex;
    const cutoff = Date.now() + 10_000;
    expect(
      await runtime.handleRequest({
        requestId: "request_gc_list_a",
        kind: "LIST_ORPHAN_CANDIDATES",
        scope: scopeA,
        olderThanEpochMs: cutoff,
        maxEntries: 10,
      }),
    ).toMatchObject({ ok: true, value: { digests: [digestHex] } });
    expect(
      await runtime.handleRequest({
        requestId: "request_gc_delete_a",
        kind: "DELETE_ORPHAN_CHUNK",
        scope: scopeA,
        digestHex,
        olderThanEpochMs: cutoff,
      }),
    ).toMatchObject({ ok: true, value: { deleted: true } });

    expect(
      await runtime.handleRequest({
        requestId: "request_gc_verify_a",
        kind: "VERIFY_OBJECT",
        preparedObject: preparedByScope.get(scopeA.authorityToken)!,
      }),
    ).toEqual({
      requestId: "request_gc_verify_a",
      ok: true,
      value: false,
    });
    expect(
      await runtime.handleRequest({
        requestId: "request_gc_verify_b",
        kind: "VERIFY_OBJECT",
        preparedObject: preparedByScope.get(scopeB.authorityToken)!,
      }),
    ).toEqual({
      requestId: "request_gc_verify_b",
      ok: true,
      value: true,
    });
  });

  it("reports every required capability and fails closed when the lock is absent", async () => {
    const runtime = createOpfsWorkerRuntime({
      root: new MemoryDirectory() as unknown as FileSystemDirectoryHandle,
      crypto: globalThis.crypto,
      policy: runtimePolicy,
      leaseManager: null,
      dedicatedWorker: true,
      supportsSynchronousAccessHandles: true,
    });
    expect(
      await runtime.handleRequest({
        requestId: "request_caps_1234",
        kind: "CAPABILITIES",
      }),
    ).toEqual({
      requestId: "request_caps_1234",
      ok: true,
      value: {
        available: false,
        dedicatedWorkerRequired: true,
        crossContextMutationLockAvailable: false,
        synchronousAccessHandleAvailable: true,
      },
    });
    expectFailureCode(
      await runtime.handleRequest(
        beginRequest(
          "request_begin_caps",
          "transaction_caps_1234",
          scopeA,
        ),
      ),
      "UNSUPPORTED",
    );
  });
});

describe("OPFS worker client lifecycle", () => {
  it("rejects a colliding concurrent request id without replacing the first RPC", async () => {
    let listener: ((event: MessageEvent<unknown>) => void) | undefined;
    const posted: OpfsWorkerRequest[] = [];
    const worker: OpfsWorkerLike = {
      postMessage(message) {
        posted.push(message);
      },
      addEventListener(_type, next) {
        listener = next;
      },
      removeEventListener() {
        listener = undefined;
      },
    };
    const gateway = createOpfsWorkerGateway({
      worker,
      policy: runtimePolicy,
      createRequestId: () => "request_collision_1234",
    });

    const first = gateway.capabilities();
    const second = gateway.capabilities();
    expect(posted).toHaveLength(1);

    listener?.({
      data: {
        requestId: "request_collision_1234",
        ok: true,
        value: {
          available: true,
          dedicatedWorkerRequired: true,
          crossContextMutationLockAvailable: true,
          synchronousAccessHandleAvailable: true,
        },
      },
    } as MessageEvent<unknown>);
    const secondResult = await second;
    gateway.close();
    await expect(first).resolves.toMatchObject({ ok: true });
    expect(secondResult).toMatchObject({
      ok: false,
      error: { code: "UNAVAILABLE" },
    });
  });

  it("rejects pending RPCs immediately when the worker reports a fatal event", async () => {
    let failureListener: ((event: Event) => void) | undefined;
    const worker: OpfsWorkerLike = {
      postMessage() {},
      addEventListener() {},
      removeEventListener() {},
      addFailureEventListener(listener) {
        failureListener = listener;
      },
      removeFailureEventListener() {
        failureListener = undefined;
      },
    };
    const gateway = createOpfsWorkerGateway({
      worker,
      policy: runtimePolicy,
      createRequestId: () => "request_crash_1234",
    });
    const pending = gateway.capabilities();

    expect(failureListener).toBeTypeOf("function");
    if (!failureListener) {
      gateway.close();
      return;
    }
    failureListener(new Event("error"));
    await expect(pending).resolves.toMatchObject({
      ok: false,
      error: { code: "UNAVAILABLE" },
    });
    await expect(gateway.capabilities()).resolves.toMatchObject({
      ok: false,
      error: { code: "UNAVAILABLE" },
    });
  });

  it("scopes the open signal to verification and leaves the acquired source readable", async () => {
    let listener:
      | ((event: MessageEvent<unknown>) => void)
      | undefined;
    const worker: OpfsWorkerLike = {
      postMessage(message) {
        const response: OpfsWorkerResponse =
          message.kind === "VERIFY_OBJECT"
            ? {
                requestId: message.requestId,
                ok: true,
                value: true,
              }
            : {
                requestId: message.requestId,
                ok: true,
                value: new Uint8Array([4, 2]).buffer,
              };
        queueMicrotask(() =>
          listener?.({ data: response } as MessageEvent<unknown>),
        );
      },
      addEventListener(_type, nextListener) {
        listener = nextListener;
      },
      removeEventListener() {
        listener = undefined;
      },
    };
    let requestSequence = 0;
    const gateway = createOpfsWorkerGateway({
      worker,
      policy: runtimePolicy,
      createRequestId: () => `request_open_${++requestSequence}_1234`,
    });
    const preparedObject: OpfsPreparedObject = {
      physicalSchemaVersion: 1,
      descriptor: {
        objectId: "object_open_12345678",
        scope: scopeA,
        generation: 1,
        byteLength: 2,
        mediaType: "application/octet-stream",
        createdAtEpochMs: 100,
        integrity: {
          algorithm: "SHA-256-TREE-V1",
          rootDigestHex: "a".repeat(64),
          chunkSizeBytes: runtimePolicy.chunkSizeBytes,
        },
        storagePolicy,
      },
      chunks: [
        {
          sequence: 0,
          byteLength: 2,
          digestHex: "b".repeat(64),
        },
      ],
    };
    const openController = new AbortController();
    const opened = await gateway.openObject(
      preparedObject,
      openController.signal,
    );
    expect(opened.ok).toBe(true);
    openController.abort();

    const chunks: number[][] = [];
    if (opened.ok) {
      for await (const result of opened.value.stream(
        new AbortController().signal,
      )) {
        expect(result.ok).toBe(true);
        if (result.ok) chunks.push([...result.value]);
      }
    }
    expect(chunks).toEqual([[4, 2]]);
    gateway.close();
  });

  it("removes its listener and rejects all pending RPCs before Worker termination", async () => {
    const listeners = new Set<(event: MessageEvent<unknown>) => void>();
    const worker: OpfsWorkerLike = {
      postMessage() {},
      addEventListener(_type, listener) {
        listeners.add(listener);
      },
      removeEventListener(_type, listener) {
        listeners.delete(listener);
      },
    };
    const gateway = createOpfsWorkerGateway({
      worker,
      policy: runtimePolicy,
      createRequestId: () => "request_pending_1234",
    });
    const pending = gateway.capabilities();
    expect(listeners.size).toBe(1);
    gateway.close();
    expect(listeners.size).toBe(0);
    await expect(pending).resolves.toMatchObject({
      ok: false,
      error: { code: "UNAVAILABLE" },
    });
    await expect(gateway.capabilities()).resolves.toMatchObject({
      ok: false,
      error: { code: "UNAVAILABLE" },
    });
  });
});