#!/usr/bin/env node
/**
 * Removes stale SRS cards that should not appear in daily typing review:
 * - compact German question cues against full Bisaya questions, e.g.
 *   "wo/wohin" -> "Asa ka padulong?"
 * - German speaking/task prompts against model-answer sentences, e.g.
 *   "Kumusta ka? ..." -> "Begrüße jemanden ..."
 *
 * Default: dry-run. Use --apply to delete matching rows.
 */

import { Op } from 'sequelize';
import { sequelize } from '../utils/sequelize.js';
import VocabSrsItem from '../models/community/vocab_srs_item.js';

function parseArgs(argv) {
  return {
    apply: argv.includes('--apply'),
  };
}

const QUESTION_CUES = new Set([
  'wo',
  'wo wohin',
  'wohin',
  'was',
  'wer',
  'wann',
  'warum',
  'wieso',
  'wie',
]);

function normalizeText(value) {
  return String(value || '')
    .trim()
    .toLowerCase()
    .normalize('NFKC')
    .replace(/[\p{P}\p{S}]+/gu, ' ')
    .replace(/\s+/g, ' ')
    .trim();
}

function wordCount(value) {
  return normalizeText(value).split(/\s+/).filter(Boolean).length;
}

function isQuestionCue(value) {
  return QUESTION_CUES.has(normalizeText(value));
}

function isFullQuestion(value) {
  const text = String(value || '').trim();
  return wordCount(text) >= 2 && /\?\s*$/.test(text);
}

function isStaleQuestionCueCard(left, right) {
  return (isQuestionCue(left) && isFullQuestion(right)) || (isQuestionCue(right) && isFullQuestion(left));
}

function isInstructionLikeText(value) {
  const text = String(value || '').trim();
  if (!text) return false;
  const words = normalizeText(text).split(/\s+/).filter(Boolean);
  if (words.length < 3) return false;

  const normalized = text.toLowerCase().normalize('NFKC');
  const startsWithTaskVerb = /^(sage|sag|frage|frag|bitte|stelle|sprich|erzähle|erzaehle|beschreibe|bilde|wähle|waehle|ordne|übersetze|uebersetze|nenne|nenn|beginne|verwende|nutze|reagiere|kombiniere|spiele|löse|loese|beantworte|ergänze|ergaenze|formuliere|lies|entscheide|zeige|begrüße|begruesse|grüße|gruesse|drücke|druecke)\b/i.test(normalized);
  const containsTaskChain = /\b(und|,)\s*(sage|sag|frage|frag|bitte|stelle|sprich|erzähle|erzaehle|beschreibe|bilde|wähle|waehle|ordne|übersetze|uebersetze|nenne|nenn|verwende|nutze|reagiere|kombiniere|spiele|löse|loese|beantworte|ergänze|ergaenze|formuliere|lies|entscheide|zeige|begrüße|begruesse|grüße|gruesse|drücke|druecke)\b/i.test(normalized);
  const containsPracticeMarker = /\b(laut|jeweils|zu jedem|zu jeder|umgebung|alltagsszene|rollenspiel|mini-dialog|szene)\b/i.test(normalized);

  return startsWithTaskVerb || (containsTaskChain && containsPracticeMarker);
}

function isStaleInstructionCard(left, right) {
  return isInstructionLikeText(left) || isInstructionLikeText(right);
}

async function main() {
  const { apply } = parseArgs(process.argv.slice(2));
  const items = await VocabSrsItem.findAll({
    where: {
      [Op.or]: [
        { learning: { [Op.like]: '%/%' } },
        { reference: { [Op.like]: '%/%' } },
        { learning: { [Op.like]: '%?%' } },
        { reference: { [Op.like]: '%?%' } },
        { learning: { [Op.iLike]: 'Begrüße %' } },
        { reference: { [Op.iLike]: 'Begrüße %' } },
        { learning: { [Op.iLike]: 'Begruesse %' } },
        { reference: { [Op.iLike]: 'Begruesse %' } },
        { learning: { [Op.iLike]: 'Drücke %' } },
        { reference: { [Op.iLike]: 'Drücke %' } },
        { learning: { [Op.iLike]: 'Druecke %' } },
        { reference: { [Op.iLike]: 'Druecke %' } },
      ],
    },
    order: [['id', 'ASC']],
  });

  const matches = items.filter((item) =>
    isStaleQuestionCueCard(item.learning, item.reference) || isStaleInstructionCard(item.learning, item.reference)
  );

  matches.forEach((item) => {
    console.log(
      `SRS ${item.id} course:${item.courseId} lesson:${item.lessonId || '-'} "${item.learning}" | "${item.reference}"`
    );
  });

  if (apply && matches.length) {
    await VocabSrsItem.destroy({
      where: {
        id: {
          [Op.in]: matches.map((item) => item.id),
        },
      },
    });
  }

  console.log(`${apply ? 'Deleted' : 'Would delete'} ${matches.length} invalid SRS item(s).`);
}

main()
  .catch((error) => {
    console.error(error);
    process.exitCode = 1;
  })
  .finally(async () => {
    await sequelize.close();
  });