/**
 * What the role card promises, the generated NPC must be holding.
 *
 * Every one of the 36 postings carries a `kit` array, and `generateDialog` prints it
 * on the role card as DRAWS FROM STORES. `generateCharacter` issues it. `generateNPC`
 * did not read it at all, so the card advertised a marksman rifle, a breaching suit
 * and seven other things while the actor was handed whichever of six hardcoded
 * weapons its tier named. Nothing measured the gap, which is why it survived.
 *
 * This guard measures it in two halves, because half of it is a decision over pure
 * data and half of it is whether the engine bothers to ask:
 *
 *   - `drawKitFor()` in postings.mjs decides what a posting issues at a tier. Pure,
 *     so it can be asserted here directly.
 *   - `generateNPC` in ringbrp.mjs must actually call it. A correct decision function
 *     nothing consumes is exactly the defect being fixed, one layer further in, so
 *     the source is scanned as well.
 *
 *   bun tools/check-generator.mjs
 */
import { readFile } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { WEAPONS, ARMOURS, GEAR, DEVICES, SKILL_CATALOGUE } from "./content.mjs";
import * as POSTINGS from "../postings.mjs";

const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
const { ROLES, TRADES, THREATS } = POSTINGS;
const problems = [];

/* Classification comes from catalogue membership, never from the spelling of a key.
 * Containment's `climbing_kit` is "Breaching charges" and its `prybar` is "Entry bar":
 * anything reading meaning out of a key is wrong in that one posting first. */
const CLASSES = [["weapon", WEAPONS], ["armour", ARMOURS], ["gear", [...GEAR, ...(DEVICES ?? [])]]];
const classOf = new Map();
for (const [cls, list] of CLASSES) {
  for (const x of list) {
    if (classOf.has(x.key) && classOf.get(x.key) !== cls) {
      problems.push(`kit key "${x.key}" is in both the ${classOf.get(x.key)} and ${cls} catalogues — `
        + `classification by catalogue membership needs each key to live in exactly one`);
    }
    classOf.set(x.key, cls);
  }
}
const classify = key => classOf.get(key) ?? null;

const SKILLS = new Set(SKILL_CATALOGUE.map(s => (s[1] ? `${s[0]}:${s[1]}` : s[0])));
const WEAPON_BY_KEY = new Map(WEAPONS.map(w => [w.key, w]));
/** The skill a weapon names for itself. The pairing table is the weapon. */
const skillOfWeapon = key => {
  const w = WEAPON_BY_KEY.get(key);
  if (!w) return null;
  return w.spec ? `${w.fam}:${w.spec}` : w.fam;
};

/* ---------- 1. the tier tables must say how much a tier draws ---------- */
for (const [tier, TH] of Object.entries(THREATS)) {
  const d = TH.draw;
  if (!d) { problems.push(`THREATS.${tier} has no draw table — the tier cannot say how much of the posting's stores it takes`); continue; }
  for (const field of ["weapons", "armour", "gear"]) {
    if (!Number.isInteger(d[field]) || d[field] < 0) {
      problems.push(`THREATS.${tier}.draw.${field} is ${JSON.stringify(d[field])}, not a count`);
    }
  }
}

/* ---------- 2. the decision function must exist and be pure ---------- */
const drawKitFor = POSTINGS.drawKitFor;
if (typeof drawKitFor !== "function") {
  problems.push(`postings.mjs does not export drawKitFor() — there is no one place that `
    + `decides what a posting issues at a tier, so the engine and this guard cannot agree on it`);
}

/* ---------- 3. every posting × tier issues from its own stores, usably ---------- */
let pairs = 0, issuedWeapons = 0;
if (typeof drawKitFor === "function") {
  for (const [roleKey, R] of Object.entries({ ...ROLES, ...(TRADES ?? {}) })) {
    const kitSet = new Set(R.kit ?? []);
    const kitWeapons = (R.kit ?? []).filter(k => classify(k) === "weapon");
    const kitArmour  = (R.kit ?? []).filter(k => classify(k) === "armour");
    for (const [tier, TH] of Object.entries(THREATS)) {
      pairs++;
      const where = `${tier} · ${roleKey}`;
      let drawn;
      try { drawn = drawKitFor(roleKey, tier, { classify }); }
      catch (e) { problems.push(`${where}: drawKitFor threw ${e.message}`); continue; }
      if (!drawn) { problems.push(`${where}: drawKitFor returned nothing`); continue; }

      for (const group of ["weapons", "armour", "gear"]) {
        for (const key of drawn[group] ?? []) {
          // Assertion 4 of the design: the generator may issue less than the card shows.
          // It may never issue something the card never mentioned.
          if (!kitSet.has(key)) problems.push(`${where}: issued "${key}" as ${group}, which is not in the posting's kit`);
          else if (classify(key) !== group.replace(/s$/, "").replace("armou", "armour")) {
            const want = { weapons: "weapon", armour: "armour", gear: "gear" }[group];
            if (classify(key) !== want) problems.push(`${where}: "${key}" issued as ${group} but the catalogues call it ${classify(key)}`);
          }
        }
      }
      // Assertion 3: a tier that draws weapons, from a posting that has one, gets one.
      const wantW = Math.min(TH.draw?.weapons ?? 0, kitWeapons.length);
      const gotW = (drawn.weapons ?? []).length;
      if (gotW !== wantW) problems.push(`${where}: draws ${TH.draw?.weapons ?? 0} weapon(s) from a kit holding ${kitWeapons.length}, and received ${gotW}`);
      issuedWeapons += gotW;
      const wantA = Math.min(TH.draw?.armour ?? 0, kitArmour.length);
      if ((drawn.armour ?? []).length !== wantA) problems.push(`${where}: expected ${wantA} armour, received ${(drawn.armour ?? []).length}`);
      // Assertion 2: a weapon arrives with the skill it names, or the NPC cannot use it.
      for (const key of drawn.weapons ?? []) {
        const sk = skillOfWeapon(key);
        if (!sk) { problems.push(`${where}: issued weapon "${key}" is in no catalogue`); continue; }
        if (!SKILLS.has(sk)) problems.push(`${where}: weapon "${key}" names skill "${sk}", which is not a skill`);
      }
      // Assertion 1: nothing on the card may be unresolvable.
      for (const key of R.kit ?? []) {
        if (!classify(key)) problems.push(`${where}: the role card prints "${key}", which is in no catalogue`);
      }
    }
  }
}

/* ---------- 4. every path that builds an actor must finish the sheet ---------- */
{
  const src = await readFile(path.join(ROOT, "ringbrp.mjs"), "utf8");
  /* generateCharacter has called grantFullSkillList since it was written, and
     build-packs gives all 62 skills to every packed creature. generateNPC did not, so a
     generated adversary carried about eight rows and a GM asked for Listen or Dodge had
     nothing on the sheet to roll — the first thing reported about this generator. A
     shared finishing step that one of three callers omits is invisible from inside that
     caller, which is what makes it worth naming here rather than remembering. */
  for (const fn of ["generateCharacter", "generateNPC", "generateCreature"]) {
    const at = src.indexOf(`export async function ${fn}(`);
    if (at === -1) { problems.push(`ringbrp.mjs no longer defines ${fn}`); continue; }
    const after = src.slice(at + 10);
    const ends = [after.indexOf("\nexport "), after.indexOf("\nasync function "), after.indexOf("\nfunction ")]
      .filter(i => i !== -1);
    const body = after.slice(0, ends.length ? Math.min(...ends) : after.length);
    if (!/grantFullSkillList\s*\(/.test(body)) {
      problems.push(`${fn} never calls grantFullSkillList — the actor it builds reaches the `
        + `table with only the skills it was explicitly given, and every other actor in the `
        + `game has all 62 with the untrained ones at their printed base`);
    }
  }
}

/* ---------- 5. the engine must actually ask for the kit ---------- */
{
  const src = await readFile(path.join(ROOT, "ringbrp.mjs"), "utf8");
  const start = src.indexOf("export async function generateNPC(");
  if (start === -1) problems.push(`ringbrp.mjs no longer defines generateNPC — this guard is looking at the wrong function`);
  else {
    const after = src.slice(start + 10);
    const ends = [after.indexOf("\nexport "), after.indexOf("\nasync function "), after.indexOf("\nfunction ")]
      .filter(i => i !== -1);
    const body = after.slice(0, ends.length ? Math.min(...ends) : after.length);
    if (!/drawKitFor\s*\(/.test(body)) {
      problems.push(`generateNPC never calls drawKitFor — it builds an NPC without reading the `
        + `posting's kit, so the role card's DRAWS FROM STORES describes stores the actor never visits`);
    }
    // The natural-attack loop must sit inside a creature-tier restriction. Read the
    // text BEFORE the loop, not after it: the condition is upstream of the thing it
    // guards, and the first version of this assertion looked downstream and so
    // reported the fixed code as broken.
    const at = body.indexOf("TH.attacks");
    if (at !== -1 && !/CREATURE_TIER\.has|=== "anomalous"|=== "apex"/.test(body.slice(Math.max(0, at - 400), at))) {
      problems.push(`generateNPC applies THREATS.attacks with no creature-tier restriction above it — `
        + `those six hardcoded weapons are for the two tiers that have no posting to draw from, `
        + `and on a human tier they replace the kit rather than adding to it`);
    }
  }
}

if (problems.length) {
  console.error(`check-generator: FAILED — ${problems.length} problem(s)`);
  for (const p of problems.slice(0, 40)) console.error("  " + p);
  if (problems.length > 40) console.error(`  … and ${problems.length - 40} more`);
  process.exit(1);
}
console.log(`check-generator: OK — ${pairs} posting × tier pairs draw from their own stores, `
  + `${issuedWeapons} weapons issued, each with the skill it names`);