// Debug harness: node try.mjs '<snippet>' | node try.mjs -f file.ts [chunkSize]
import fs from "node:fs";
const root = new URL("../..", import.meta.url).pathname.replace(/\/$/, "");
import { createRequire } from "node:module";
const ts = createRequire(root + "/package.json")("typescript");
process.env.TYPESTRIP_ERASE_WASM ??= "build/erase.wasm";
const { blankSourceFile } = await import(root + "/vendor/ts-blank-space/out/index.js");
const { transformSync } = await import(root + "/src/index.js");

let src = process.argv[2];
if (src === "-f") src = fs.readFileSync(process.argv[3], "utf8");
const chunk = Number(process.argv[4] ?? (process.argv[2] === "-f" ? 0 : process.argv[3] ?? 0));

const sf = ts.createSourceFile("input.ts", src, ts.ScriptTarget.ESNext, false, ts.ScriptKind.TS);
const wantErrors = [];
const want = blankSourceFile(sf, (n) => wantErrors.push(n.getStart(sf)));
const gotErrors = [];
let got;
try {
  got = transformSync(src, { onError: (e) => gotErrors.push(e.start) });
} catch (e) {
  console.log("THREW:", e.message);
}
if (got !== undefined) {
  let i = 0;
  while (i < want.length && got[i] === want[i]) i++;
  console.log(i === want.length && got.length === want.length ? "OUTPUT MATCHES oracle byte-for-byte" : `first diff at ${i}`);
  if (src.length < 2000) {
    console.log("want:", JSON.stringify(want));
    console.log("got :", JSON.stringify(got));
  } else if (i < want.length) {
    console.log("want:", JSON.stringify(want.slice(Math.max(0, i - 60), i + 60)));
    console.log("got :", JSON.stringify(got.slice(Math.max(0, i - 60), i + 60)));
  }
  console.log("errors want", JSON.stringify(wantErrors), "got", JSON.stringify(gotErrors));
}
if (chunk > 0 || got !== undefined) {
  const n = chunk || 7;
  let out = "";
  let seed = src.length;
  try {
    function* parts() {
      for (let i = 0; i < src.length; ) {
        let k = n;
        if (chunk === -1) { seed = (seed * 1103515245 + 12345) & 0x7fffffff; k = 1 + (seed % 4096); }
        yield src.slice(i, i + k);
        i += k;
      }
    }
    for (const piece of transformSync(parts())) out += piece;
    if (got !== undefined) {
      let j = 0;
      while (j < got.length && got[j] === out[j]) j++;
      console.log(out === got ? `chunked(${n}) matches whole` : `chunked(${n}) DIFFERS at ${j}: ${JSON.stringify(out.slice(Math.max(0, j - 40), j + 40))}`);
    }
  } catch (e) {
    const { engine } = await import(root + "/src/index.js");
    const d = (i) => engine().dbg?.(i);
    console.log(`chunked(${n}) THREW:`, e.message, "after", JSON.stringify(out.slice(-60)), `state=${d(0)} c=${d(1)} a=${d(2)} sp=${d(3)} ts=${d(4)} tt=${d(5)} emitPos=${d(6)}`);
  }
}