#!/usr/bin/env node
// embed.mjs — seal what fiapup.js borrows from oskiewar's pipeline into it.
//
// fiapup.js is one global script, like oskiewar.js, because that is all the
// console host loads. It carries three things it doesn't own, each read from
// the file oskiewar uses so the two games share one pipeline:
//
//   xbox/live/object-lisp.mjs   the object compiler (KidLisp → baked sketches)
//   xbox/live/frame-vm.mjs      the frame-program interpreter, run in-game on
//                               hosts that have no `frame` (the console until
//                               R6, and this game's own web shell)
//   xbox/fiapup/objects/*.lisp  the pup, the yard and the props
//
// It writes them between `// <sealed>` and `// </sealed>` and nothing else.
//
//   node xbox/fiapup/embed.mjs          rewrite the block
//   node xbox/fiapup/embed.mjs --check  exit 1 if the block is stale

import { readFileSync, writeFileSync } from "node:fs";
import { fileURLToPath } from "node:url";

const here = new URL("./", import.meta.url);
const live = new URL("../live/", import.meta.url);
const read = (url) => readFileSync(url, "utf8");
export const gamePath = fileURLToPath(new URL("fiapup.js", here));
export const start = "// <sealed>";
export const end = "// </sealed>";

// What the game draws, by the name it asks for, and the file each compiles from.
export const objects = { puppy: "puppy-flat", camp: "camp-flat", ball: "ball-flat",
  rope: "rope-flat", hand: "hand-flat", treat: "treat-flat",
  // the meadow's things, stamped into chunk sketches (flower … birch) or
  // drawn where they move (butterfly, sheep)
  flower: "flower-flat", tuft: "tuft-flat", rock: "rock-flat", pine: "pine-flat", birch: "birch-flat",
  butterfly: "butterfly-flat", sheep: "sheep-flat" };

// A module's source with its `export` keywords taken off, and the names it
// exported. `export default x;` lines go; the named export already covers x.
function unexport(source, file) {
  const names = [];
  const body = source.replace(/^export default .*$/gm, "")
    .replace(/^export (async function\*?|function\*?|const|let|class) (\w+)/gm, (_, kind, name) => {
      names.push(name);
      return `${kind} ${name}`;
    });
  if (/^import /m.test(body)) throw new Error(`${file}: the game can't carry imports`);
  return { body, names };
}

const indent = (text) => text.trimEnd().split("\n").map((line) => (line ? "    " + line : line)).join("\n");

export function generate() {
  const lisp = unexport(read(new URL("object-lisp.mjs", live)), "object-lisp.mjs");
  const vm = unexport(read(new URL("frame-vm.mjs", live)), "frame-vm.mjs");
  const sources = Object.entries(objects).map(([name, file]) =>
    `    ${name}: ${JSON.stringify(read(new URL(`objects/${file}.lisp`, here)))},`);
  return [
    start,
    "// Generated by xbox/fiapup/embed.mjs from xbox/live/object-lisp.mjs,",
    "// xbox/live/frame-vm.mjs and xbox/fiapup/objects/*.lisp. Don't edit here:",
    "// edit those and rerun the tool.",
    "const fiapupObjects = (() => {",
    "  const objectLisp = (() => {",
    indent(lisp.body),
    `    return { ${lisp.names.join(", ")} };`,
    "  })();",
    "  const sources = {",
    ...sources,
    "  };",
    "  const compiled = {};",
    "  for (const name in sources) compiled[name] = objectLisp.compile(sources[name], name);",
    "  return compiled;",
    "})();",
    "const fiapupFrameVm = (() => {",
    indent(vm.body),
    `    return { ${vm.names.join(", ")} };`,
    "})();",
    end,
  ].join("\n");
}

export function embedded(source = read(gamePath)) {
  const a = source.indexOf(start), b = source.indexOf(end);
  return a < 0 || b < 0 ? null : source.slice(a, b + end.length);
}

function write() {
  const source = read(gamePath), block = generate(), current = embedded(source);
  if (!current) throw new Error("fiapup.js: no // <sealed> block to fill");
  const next = source.replace(current, () => block);
  if (next !== source) writeFileSync(gamePath, next);
  return next !== source;
}

if (process.argv[1] && fileURLToPath(import.meta.url) === process.argv[1]) {
  if (process.argv.includes("--check")) {
    const fresh = embedded() === generate();
    console.log(fresh ? "fiapup.js sealed block is current" : "fiapup.js sealed block is stale: run node xbox/fiapup/embed.mjs");
    process.exit(fresh ? 0 : 1);
  }
  console.log(write() ? "sealed the compiler, the frame vm and the objects into fiapup.js" : "sealed block already current");
}