/**
 * What this lab can actually materialise, and a refusal for everything else.
 *
 * A declaration the runtime silently ignores is the worst thing this project could ship.
 * The mesh already has that fault catalogued: a firewall key declared in five manifests
 * and read by no code, so a manifest appears to restrict a port and restricts nothing
 * (novox/hq 04-ISSUES/003). A scenario that declares a gateway and raises without one
 * would be the same fault, in the tool built to catch it.
 *
 * So unimplemented parts of the model are refused loudly at raise time rather than
 * ignored. The declaration schema deliberately runs ahead of the runtime — it is the
 * design's shape, and validating against it is useful before any of it can be raised —
 * but the gap between the two has to be visible.
 */

import type { Scenario } from "../declaration/types.ts";
import { PLACEABLE, planPlacements } from "./place.ts";

export class UnsupportedError extends Error {
  readonly missing: string[];

  constructor(missing: string[]) {
    super(
      `this scenario declares things the lab cannot yet materialise:\n  - ${missing.join("\n  - ")}\n\n` +
        `Raising it would produce a mesh that silently lacks them, which is the exact fault ` +
        `this lab exists to catch. Validation accepts them because the declaration model is ` +
        `complete; the runtime is not.`,
    );
    this.name = "UnsupportedError";
    this.missing = missing;
  }
}

export function assertSupported(scenario: Scenario): void {
  const missing: string[] = [];

  // `place: [host]` works. Everything else in the vocabulary is named individually rather
  // than refused as a whole, so a scenario that places a host and a substrate is told exactly
  // which half the lab cannot do.
  const unplaceable = new Set<string>();
  for (const { artifacts } of planPlacements(scenario)) {
    for (const artifact of artifacts) {
      if (!(PLACEABLE as readonly string[]).includes(artifact)) unplaceable.add(artifact);
    }
  }
  for (const artifact of [...unplaceable].sort()) {
    missing.push(
      `place: ${artifact} — only ${PLACEABLE.join(", ")} can be placed; the tiers above ` +
        `tier 0 do not exist yet`,
    );
  }

  if (missing.length > 0) throw new UnsupportedError(missing);
}