import { parseFreeformFactV2 } from './truthtrance-freeform-facts-v2';
import { parseFreeformFactV3 } from './truthtrance-freeform-facts-v3';
import { parseFreeformFactV4 } from './truthtrance-freeform-facts-v4';
import { parseTruthFreeformFactsV5 } from './truthtrance-freeform-facts-v5';
import { parseFreeformFactV6 } from './truthtrance-freeform-facts-v6';
import { TRUTH_FACT_MAX_TERMS } from './truth-fact-expression';
import type { TruthFact } from './truthtrance';

type Compound = Extract<TruthFact, { kind: 'and' | 'or' }>;
type Separator = { start: number; end: number; kind: 'and' | 'or' };

/** Recognize only a uniquely partitioned, flat current-fact expression.
 * Existing whole questions retain their original parser version. Each atom
 * uses the established public grammar; this parser never inspects game state. */
export function parseTruthFreeformFactsV7(text: string): Compound | null {
  if (typeof text !== 'string' || text.length > 500 || /[\r\n]/.test(text)) return null;
  const input = text.trim();
  if (parseFreeformFactV2(input) || parseFreeformFactV3(input) || parseFreeformFactV4(input) ||
      parseTruthFreeformFactsV5(input) || parseFreeformFactV6(input)) return null;
  const body = input.endsWith('?') ? input.slice(0, -1).trimEnd() : input;
  if (!body || body.includes('?')) return null;
  const separators: Separator[] = [...body.matchAll(/[ \t]+(and|or)[ \t]+/gi)].map(match => ({
    start: match.index!, end: match.index! + match[0].length,
    kind: match[1].toLowerCase() as 'and' | 'or',
  }));
  // Keep the search bounded even if a malicious input contains many words
  // that resemble connectors. A separator may still be part of a card name.
  if (!separators.length || separators.length > 24) return null;
  const shorthand = /^do[ \t]+you[ \t]+have[ \t]+/i.test(body);
  const atomCache = new Map<string, TruthFact | null>();
  const atom = (raw: string, first: boolean): TruthFact | null => {
    const segment = raw.trim();
    if (!segment) return null;
    const key = `${first ? 'first' : 'later'}:${segment}`;
    if (atomCache.has(key)) return atomCache.get(key)!;
    let qualified = segment;
    if (!first && /^not[ \t]+have[ \t]+/i.test(segment)) qualified = `Do you ${segment}`;
    else if (!first && /^have[ \t]+/i.test(segment)) qualified = `Do you ${segment}`;
    else if (!first && shorthand && !/^(?:do|did|is)\b/i.test(segment)) qualified = `Do you have ${segment}`;
    const fact = parseFreeformFactV3(qualified) ?? parseFreeformFactV4(qualified) ?? parseFreeformFactV6(qualified);
    const result = fact && fact.kind !== 'and' && fact.kind !== 'or' ? fact : null;
    atomCache.set(key, result);
    return result;
  };
  // Retain at most two paths per suffix; two prove ambiguity. Memoization
  // bounds repeated exploration even when many separators form card names.
  const memo = new Map<string, TruthFact[][]>();
  const suffix = (offset: number, kind: 'and' | 'or', count: number): TruthFact[][] => {
    const key = `${offset}:${kind}:${count}`;
    const cached = memo.get(key); if (cached) return cached;
    const results: TruthFact[][] = [];
    const final = atom(body.slice(offset), false);
    if (final && count + 1 <= TRUTH_FACT_MAX_TERMS) results.push([final]);
    if (count + 1 < TRUTH_FACT_MAX_TERMS) for (const sep of separators) {
      if (sep.start <= offset || sep.kind !== kind) continue;
      const head = atom(body.slice(offset, sep.start), false);
      if (!head) continue;
      for (const tail of suffix(sep.end, kind, count + 1)) {
        results.push([head, ...tail]);
        if (results.length >= 2) break;
      }
      if (results.length >= 2) break;
    }
    memo.set(key, results);
    return results;
  };
  const matches: Compound[] = [];
  for (const sep of separators) {
    const first = atom(body.slice(0, sep.start), true);
    if (!first) continue;
    for (const tail of suffix(sep.end, sep.kind, 1)) {
      matches.push({kind: sep.kind, terms: [first, ...tail]});
      if (matches.length >= 2) return null;
    }
  }
  return matches.length === 1 ? matches[0] : null;
}