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

import { createCursorPaginationRuntime } from "../../src/adapters/query-cache/cursor-pagination-runtime.ts";
import {
  defineMutationIntent,
  isValidIdempotencyKey,
} from "../../src/contracts/mutation-intent.ts";
import type {
  CursorPage,
  CursorPaginationProfile,
} from "../../src/contracts/cursor-pagination.ts";
import type { Result } from "../../src/application/result.ts";

const PROFILE: CursorPaginationProfile = Object.freeze({
  profileId: "TEST_PAGINATION_V1",
  maxPages: 3,
  maxTotalItems: 30,
  maxEstimatedBytes: 32_768,
  maxCursorBytes: 512,
  allowSparsePage: false,
});

function page(
  items: readonly number[],
  nextCursor: string | null,
): CursorPage<number> {
  return Object.freeze({
    items: Object.freeze([...items]),
    nextCursor,
    hasMore: nextCursor !== null,
    snapshotToken: "snapshot-1",
  });
}

/**
 * OPT-NET-01. A loader rejection is evidence about the data source. Reporting
 * it as `PAGINATION_ABORTED` because a signal merely *exists* erases a real
 * network or contract failure and files it under a user decision nobody made.
 */
describe("OPT-NET-01 cursor pagination abort classification", () => {
  it("preserves a loader rejection while the signal is still live", async () => {
    const controller = new AbortController();
    const runtime = createCursorPaginationRuntime<number>({
      definitionId: "TEST_PAGINATION",
      profile: PROFILE,
      loadPage: async () => {
        throw new TypeError("upstream exploded");
      },
    });

    await expect(
      runtime.loadAll({ signal: controller.signal }),
    ).rejects.toThrow("upstream exploded");
  });

  it("keeps the same rejection when no signal is supplied", async () => {
    const runtime = createCursorPaginationRuntime<number>({
      definitionId: "TEST_PAGINATION",
      profile: PROFILE,
      loadPage: async () => {
        throw new TypeError("upstream exploded");
      },
    });

    await expect(runtime.loadAll({})).rejects.toThrow("upstream exploded");
  });

  it("classifies a rejection during a real abort as PAGINATION_ABORTED", async () => {
    const controller = new AbortController();
    const runtime = createCursorPaginationRuntime<number>({
      definitionId: "TEST_PAGINATION",
      profile: PROFILE,
      loadPage: async () => {
        controller.abort();
        throw new TypeError("cancelled upstream");
      },
    });

    const result = await runtime.loadAll({ signal: controller.signal });
    expect(result.ok).toBe(false);
    expect(result.ok ? null : result.error.code).toBe("PAGINATION_ABORTED");
  });

  it("does not admit a page that resolves after the abort", async () => {
    const controller = new AbortController();
    const loadPage = vi.fn(
      async (): Promise<Result<CursorPage<number>>> => {
        controller.abort();
        await new Promise((resolve) => setTimeout(resolve, 5));
        return { ok: true, value: page([1, 2], null) };
      },
    );
    const runtime = createCursorPaginationRuntime<number>({
      definitionId: "TEST_PAGINATION",
      profile: PROFILE,
      loadPage,
    });

    const result = await runtime.loadAll({ signal: controller.signal });
    expect(result.ok).toBe(false);
    expect(result.ok ? null : result.error.code).toBe("PAGINATION_ABORTED");
  });
});

/**
 * OPT-NET-02. One idempotency-key authority. Two validators drift, and the
 * looser one becomes the way a control character reaches a request header.
 */
describe("OPT-NET-02 shared idempotency key validation", () => {
  const rejected = [
    "",
    "   ",
    "key\nwith-newline",
    "key\u0000null",
    "key\u007fdelete",
    "key\u009fc1",
    "a".repeat(257),
  ];

  it("rejects the same values at intent definition and at admission", () => {
    for (const value of rejected) {
      expect(isValidIdempotencyKey(value)).toBe(false);
      expect(() =>
        defineMutationIntent({
          intentId: "intent-1",
          operationId: "OP",
          canonicalInputIdentity: "identity",
          idempotencyKey: value,
          createdAtMonotonicMs: 1,
        }),
      ).toThrow(TypeError);
    }
  });

  it("accepts the bounded printable and Unicode values both sides allow", () => {
    for (const value of ["key-1", "a".repeat(256), "키-값", "ключ"]) {
      expect(isValidIdempotencyKey(value)).toBe(true);
      expect(
        defineMutationIntent({
          intentId: "intent-1",
          operationId: "OP",
          canonicalInputIdentity: "identity",
          idempotencyKey: value,
          createdAtMonotonicMs: 1,
        }).idempotencyKey,
      ).toBe(value);
    }
  });
});