RingBRP/tools/check-rollable.mjs

/**
 * check-rollable — a clue may not hide behind a roll nobody at the table can make.
 *
 * check-scenarios resolves every skill a scenario NAMES against the catalogue, which is a
 * different question from whether anybody present can roll it. CLEAN GROUND shipped four
 * commits with three clue routes gated on Track (base 10), Navigate (base 10) and Science
 * (Botany) — base 1, so the 1% floor was the whole of it — and every guard passed, because
 * all three are perfectly real skills. The defect only surfaced when a desk playtest
 * audited the acts against the sheets the scenario actually casts. That audit is
 * mechanical, so it belongs here rather than in somebody's afternoon.
 *
 * TWO TIERS.
 *
 *   Corpus-wide: for every skill any scenario names, SOMEBODY on the duty roster must be
 *   able to roll it at or above VIABLE. A scenario may bring any roster agent, so a skill
 *   no roster agent can roll is a dead route whoever turns up.
 *
 *   Per scenario: a document that DECLARES its cast is held to that cast instead. This is
 *   the strict check, and the one that catches a scenario recommending six sheets and then
 *   asking for a seventh one's skill. The declaration is a machine-readable line:
 *
 *       <!-- cast: pc_ashcroft, pc_bhattacharya, pc_renshaw -->
 *
 *   It is declared rather than inferred on purpose. The first version of this guard
 *   scraped `pc_` keys out of the prose and swept up the substitutes named in CLEAN
 *   GROUND's player-count scaling — a cast of nine instead of six, which put Sandoval and
 *   his Track 35 in scope and made the guard pass the very bug it was written for. A guard
 *   that guesses the cast is worse than no guard, because it reports success.
 *
 * It does not know any rules. Skill values come from expandFromRegister, the same
 * expansion the packs are built from, so a sheet cannot be checked at numbers it will not
 * be played at.
 *
 *   node tools/check-rollable.mjs            the guard
 *   node tools/check-rollable.mjs --report   every scenario's worst routes, pass or fail
 */
import { readFileSync } from "node:fs";
import { SKILL_CATALOGUE } from "./content.mjs";
import { ROSTER } from "./roster.mjs";
import { expandFromRegister } from "./expand-spec.mjs";
import { scenarioFiles, scenarioText, tagsIn, skillsIn } from "./check-scenarios.mjs";

/**
 * The lowest chance that still counts as a route, in percent.
 *
 * 25 is not arbitrary: it is the commonest base chance in the catalogue — what an
 * untrained agent brings to Spot, Listen or Brawl — so it is the level the game itself
 * treats as "you may reasonably try this". Below it a clue is not gated, it is buried:
 * at 10 a GM is improvising a bridge four times in five, and at 1 the tag is decoration.
 */
const VIABLE = 25;

/** Tag bodies that are telling the GM NOT to roll are not routes and are not checked. */
const NOT_A_ROLL = /\bno roll\b|\bautomatic\b|\bnot Scent\b/i;

/** best[skill name, lowercased] = {val, who} across a set of expanded sheets. */
function rollability(specs) {
  const best = {};
  const offer = (name, val, who) => {
    const k = name.toLowerCase();
    if (!best[k] || val > best[k].val) best[k] = { val, who };
  };
  for (const spec of specs) {
    const e = expandFromRegister(spec);
    for (const sk of e.skills || []) {
      const full = sk.fam + (sk.spec ? `(${sk.spec})` : "");
      // Tags name skills as a GM speaks them: "Repair (Mechanical)", or just "Repair".
      const row = SKILL_CATALOGUE.find(r => r[0] === sk.fam && (r[1] || "") === (sk.spec || ""));
      const label = row ? (row[4] || row[0]) : full;
      offer(label, sk.val, e.name);
      offer(label.replace(/\s*\([^)]*\)\s*$/, "").trim(), sk.val, e.name); // the family alone
    }
  }
  return best;
}

/** Untrained chance for a named skill, so a report can say why something is unrollable. */
const baseFor = name => {
  const n = name.toLowerCase();
  const row = SKILL_CATALOGUE.find(r => (r[4] || r[0]).toLowerCase() === n)
    ?? SKILL_CATALOGUE.find(r => (r[4] || r[0]).replace(/\s*\([^)]*\)\s*$/, "").trim().toLowerCase() === n);
  return row ? row[3] : null;
};

const ROSTER_BEST = rollability(ROSTER);

const problems = [];
const report = [];
let checkedTags = 0;

for (const [label, path] of scenarioFiles()) {
  const raw = readFileSync(path, "utf8");
  const text = scenarioText(raw);

  // Read the declaration off the RAW text: scenarioText strips HTML, comments included.
  const declared = raw.match(/<!--\s*cast:\s*([^>]*?)\s*-->/i);
  const cast = declared
    ? declared[1].split(",").map(x => x.trim()).filter(Boolean).map(k => {
        const spec = ROSTER.find(r => r.key === k);
        if (!spec) {
          problems.push(`${label}: cast declares "${k}", which is not on the duty roster`);
        }
        return spec;
      }).filter(Boolean)
    : [];
  const scope = cast.length ? rollability(cast) : ROSTER_BEST;
  const scopeName = cast.length ? `its declared cast of ${cast.length}` : "the duty roster";

  for (const body of tagsIn(text)) {
    if (NOT_A_ROLL.test(body)) continue;
    checkedTags++;
    for (const cand of skillsIn(body)) {
      const hit = scope[cand.toLowerCase()];
      const base = baseFor(cand);
      const val = hit ? hit.val : (base ?? 0);
      if (val >= VIABLE) continue;
      const held = hit ? `best ${hit.val}% (${hit.who})` : `untrained, base ${base ?? "?"}%`;
      problems.push(`${label}: "${cand}" — ${held}, against ${scopeName}\n`
        + `      ${("[CUS: " + body.trim() + "]").slice(0, 100)}`);
    }
    for (const cand of skillsIn(body)) {
      const hit = scope[cand.toLowerCase()];
      if (hit) report.push([label, cand, hit.val, hit.who, scopeName]);
    }
  }
}

if (process.argv.includes("--report")) {
  const worst = report.sort((a, b) => a[2] - b[2]).slice(0, 20);
  console.log(`check-rollable --report — the twenty thinnest routes in the corpus\n`);
  for (const [file, skill, val, who, scopeName] of worst) {
    console.log(`  ${String(val).padStart(3)}%  ${skill.padEnd(22)} ${who.padEnd(14)} `
      + `${file.replace("docs/scenarios/", "")}  (${scopeName})`);
  }
  process.exit(0);
}

if (problems.length) {
  console.error("check-rollable: FAILED — a clue is behind a roll nobody present can make");
  for (const p of [...new Set(problems)]) console.error("  " + p);
  console.error(`\n  A route must reach ${VIABLE}% for somebody. Move the clue onto a skill `
    + `the cast holds,\n  make it automatic, or cast somebody who has it.`);
  process.exit(1);
}

console.log(`check-rollable: OK — ${checkedTags} rolls across ${scenarioFiles().length} `
  + `scenario files, every one reachable at ${VIABLE}% or better by somebody present`);