import { createHash } from "node:crypto";

export const LARGE_FIXTURE_COUNT = 1_205;

export const sha256 = (value) =>
  createHash("sha256").update(value).digest("hex");

export const generateLargeFixture = (count = LARGE_FIXTURE_COUNT) => {
  if (!Number.isInteger(count) || count < 1)
    throw new Error("Fixture count must be a positive integer");
  const declarations = Array.from(
    { length: count },
    (_, index) =>
      `__attribute__((noinline, used)) int rea_page_${String(index).padStart(4, "0")}(void) { puts("REA_PAGE_${String(index).padStart(4, "0")}"); return ${index}; }`,
  );
  return [
    "#include <stdio.h>",
    ...declarations,
    "int main(void) { return rea_page_0000(); }",
    "",
  ].join("\n");
};

export const sourceDigest = (sources) => {
  const canonical = [...sources]
    .sort(({ path: left }, { path: right }) => left.localeCompare(right))
    .map(({ path, content }) => `${path}\0${sha256(content)}\n`)
    .join("");
  return sha256(canonical);
};