import type { DiscriminatingEventProbe } from "../v9/refinement-packet.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 {
  const semanticKey = probe.semantic_key ?? `${probe.domain}.${probe.year}`;
  const splitHash = probe.candidate_split_hash
    ?? `${probe.domain}:${probe.year}:${[probe.left_time ?? "", probe.right_time ?? ""].sort().join("|")}`;
  return {
    id: `probe:${semanticKey}:${splitHash}`,
    semantic_key: semanticKey,
    candidate_split_hash: splitHash,
    domain: probe.domain,
    year: probe.year,
    question: probe.user_meaning,
    candidate_ids: [probe.left_time, probe.right_time].filter((item): item is string => Boolean(item)),
    expected_outcomes: outcomesFromEngine(
      probe.expected_outcomes,
      probe.left_time,
      probe.right_time,
    ),
    information_gain: probe.information_gain ?? 0,
    source: probe.source,
  };
}

function outcomesFromEngine(
  rows: DiscriminatingEventProbe["expected_outcomes"],
  left?: string,
  right?: string,
): readonly ProbeOutcome[] {
  if (!rows) return defaultOutcomes(left, right);
  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.length > 0 ? parsed : defaultOutcomes(left, right);
}

function defaultOutcomes(left?: string, right?: string): ProbeOutcome[] {
  if (!left || !right || left === right) return [];
  return [
    { answer_class: "yes", supports: [left], conflicts: [right] },
    { answer_class: "no", supports: [right], conflicts: [left] },
    { answer_class: "weak_yes", supports: [left], conflicts: [right] },
    { answer_class: "unsure", supports: [], conflicts: [] },
  ];
}