import 'courses/courses.dart';
import 'models.dart';
import 'speech_compare.dart';

class ReviewCheckResult {
  const ReviewCheckResult({
    required this.complete,
    required this.message,
    this.dictation,
  });

  final bool complete;
  final String message;

  /// Word-by-word comparison with the dictated sentence; null otherwise.
  final SpokenComparison? dictation;
}

/// Checks only the minimum information a learner needs to produce in a
/// review. The rule and the hint come from the core item's course JSON, which
/// accepts contractions and variable slot values instead of one fixed
/// sentence.
class ReviewFeedback {
  const ReviewFeedback._();

  static ReviewCheckResult check(ReviewItem item, String input) {
    final dictation = item.skill == dictationSkill
        ? coreDictationSentences[item.id]
        : null;
    if (dictation != null) {
      final comparison = compareSpoken(dictation.sentence, input);
      final missing = comparison.total - comparison.heardCount;
      final wrong = missing + comparison.extraWords.length;
      return ReviewCheckResult(
        complete: comparison.matches,
        message: comparison.matches
            ? '听写正确。'
            : '有 $wrong 处和听到的句子不一致。再听一次，检查拼写和漏掉的词。',
        dictation: comparison,
      );
    }
    final complete = isCoreItem(item.id)
        ? coreItemUsedIn(item.id, input)
        : RegExp(r"[a-z]+(?:'[a-z]+)?")
                  .allMatches(normalizeAnswer(input))
                  .map((match) => match.group(0))
                  .toSet()
                  .length >=
              2;
    return ReviewCheckResult(
      complete: complete,
      message: complete
          ? '表达已完成，可以进入下一次复习安排。'
          : coreReviewHints[item.id] ?? '再补充本次目标中的关键英文词或句型。',
    );
  }
}