import test from "node:test";
import assert from "node:assert/strict";
import {
  D1_MAX_SQL_STATEMENT_BYTES,
  D1_QUERY_MAX_BODY_BYTES,
  JSON_STRING_WORST_CASE_EXPANSION,
  STORAGE_RESOURCE_NAME_MAX_BODY_BYTES,
} from "../resource-limits.js";

test("the recorded D1 statement limit is Cloudflare's documented 100,000 bytes", () => {
  assert.equal(D1_MAX_SQL_STATEMENT_BYTES, 100_000);
});

test("a resource-name body is bounded at 64 KiB", () => {
  assert.equal(STORAGE_RESOURCE_NAME_MAX_BODY_BYTES, 64 * 1024);
});

test("a D1 query body is bounded at 1 MiB", () => {
  assert.equal(D1_QUERY_MAX_BODY_BYTES, 1024 * 1024);
});

// The guard. D1_QUERY_MAX_BODY_BYTES is a flat number rather than a computed
// expression, so nothing but this test holds it to the arithmetic that makes it
// safe. If D1 ever raises its statement limit above 163,840 bytes, the worst-case
// wire form of a legal statement exceeds 1 MiB and the route would begin rejecting
// correct queries with nothing to signal why. This fails first instead.
test("the D1 query body limit clears the worst-case wire form of a legal statement", () => {
  const worstCaseLegalBody =
    JSON_STRING_WORST_CASE_EXPANSION * D1_MAX_SQL_STATEMENT_BYTES +
    STORAGE_RESOURCE_NAME_MAX_BODY_BYTES;
  assert.ok(
    D1_QUERY_MAX_BODY_BYTES > worstCaseLegalBody,
    `D1_QUERY_MAX_BODY_BYTES (${D1_QUERY_MAX_BODY_BYTES}) must exceed the largest legal wire body (${worstCaseLegalBody}), or legal queries are rejected`,
  );
});

// The escape ceiling is the reason the bound is not simply D1's 100,000. Pin the
// factor against the runtime rather than restating the literal: a single ASCII
// control byte serializes to the six characters \uXXXX, which is the worst ratio a
// JSON string can reach over bytes.
test("the JSON worst-case expansion is the six-character \\uXXXX escape", () => {
  assert.equal(JSON_STRING_WORST_CASE_EXPANSION, 6);
  // Written as an escape rather than a literal control byte: a raw 0x01 in source
  // is invisible in most editors and diffs.
  const oneControlByte = "\u0001";
  assert.equal(Buffer.byteLength(oneControlByte), 1);
  // minus the two quotes JSON.stringify wraps the string in
  assert.equal(JSON.stringify(oneControlByte).length - 2, JSON_STRING_WORST_CASE_EXPANSION);
});