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

import { decideChunkRecovery } from "../../src/application/use-cases/decide-chunk-recovery.ts";
import type { StoragePort } from "../../src/application/ports/storage-port.ts";

function memoryStorage(): StoragePort {
  let value: unknown;
  return {
    read: () => ({ ok: true, value }),
    write: (_key: string, next: unknown) => {
      value = next;
      return { ok: true };
    },
    remove: () => ({ ok: true }),
  };
}

describe("controlled chunk recovery", () => {
  it("records the release pair before allowing one reload", () => {
    const storage = memoryStorage();
    const input: Parameters<typeof decideChunkRecovery>[0] = {
      failureKind: "CHUNK_LOAD_FAILURE",
      manifestLoaded: true,
      currentBuildId: "build-a",
      currentReleaseId: "release-a",
      activeBuildId: "build-b",
      activeReleaseId: "release-b",
      storage,
    };
    expect(decideChunkRecovery(input)).toEqual({
      action: "reload-once",
      releasePair: "build-a/release-a->build-b/release-b",
    });
    expect(decideChunkRecovery(input)).toEqual({
      action: "support",
      reason: "reload-already-attempted",
    });
  });

  it.each([
    [{ failureKind: "SERVER_FAILURE" }, "not-recoverable"],
    [{ manifestLoaded: false }, "manifest-unavailable"],
    [
      { activeBuildId: "build-a", activeReleaseId: "release-a" },
      "same-release",
    ],
  ])("stops when a recovery invariant fails: %#", (override, reason) => {
    const result = decideChunkRecovery({
      failureKind: "DEPLOY_MISMATCH",
      manifestLoaded: true,
      currentBuildId: "build-a",
      currentReleaseId: "release-a",
      activeBuildId: "build-b",
      activeReleaseId: "release-b",
      storage: memoryStorage(),
      ...override,
    });
    expect(result).toEqual({ action: "support", reason });
  });
});