import type { DiscriminatingEventProbe } from "../v9/refinement-packet.ts";
import { candidateIdsFromProbe, distinguishContractErrors } from "./distinguish-contract.ts";
import type { AnswerClass, ConflictProbe, ProbeOutcome } from "./types.ts";

const ANSWER_CLASSES: ReadonlySet<string> = new Set(["yes", "weak_yes", "no", "unsure"]);

export type EngineProbeFields = DiscriminatingEventProbe;

export function probeFromEngine(probe: EngineProbeFields): ConflictProbe | null {
  if (distinguishContractErrors({ ...probe, role: probe.role ?? "distinguish" }).length > 0) {
    return null;
  }
  const semanticKey = probe.semantic_key ?? `${probe.domain}.${probe.year}`;
  const splitHash = probe.candidate_split_hash
    ?? `${probe.candidate_set_version ?? ""}:${probe.domain}:${probe.year}`;
  const outcomes = outcomesFromEngine(probe.expected_outcomes);
  const candidateIds = probe.candidate_ids?.length
    ? [...probe.candidate_ids]
    : candidateIdsFromProbe(probe);
  if (outcomes.length < 2 || candidateIds.length < 2 || (probe.information_gain ?? 0) <= 0) {
    return null;
  }
  const styleOptions = styleOptionsFromEngine(probe.style_options);
  return {
    id: `probe:${semanticKey}:${splitHash}`,
    semantic_key: semanticKey,
    candidate_split_hash: splitHash,
    domain: probe.domain,
    year: probe.year,
    question: probe.user_meaning,
    candidate_ids: candidateIds,
    expected_outcomes: outcomes,
    information_gain: probe.information_gain ?? 0,
    source: probe.source,
    ...(probe.choice_kind === "varga_style"
      || probe.choice_kind === "event_quality"
      || probe.choice_kind === "existence"
      ? { choice_kind: probe.choice_kind }
      : {}),
    ...(styleOptions.length > 0 ? { style_options: styleOptions } : {}),
  };
}

function styleOptionsFromEngine(
  rows: DiscriminatingEventProbe["style_options"],
): NonNullable<ConflictProbe["style_options"]> {
  return (rows ?? []).flatMap((row) => {
    if (!ANSWER_CLASSES.has(row.answer_class)) return [];
    return [{
      label: row.label,
      answer_class: row.answer_class as AnswerClass,
      ...(row.sign ? { sign: row.sign } : {}),
    }];
  });
}

function outcomesFromEngine(
  rows: DiscriminatingEventProbe["expected_outcomes"],
): ProbeOutcome[] {
  if (!rows) return [];
  const parsed: ProbeOutcome[] = [];
  for (const row of rows) {
    if (!ANSWER_CLASSES.has(row.answer_class)) continue;
    parsed.push({
      answer_class: row.answer_class as AnswerClass,
      supports: row.supports,
      conflicts: row.conflicts,
    });
  }
  return parsed;
}