continue fixing

server/utils/vocabularyRisk.ts

@@ -0,0 +1,51 @@
+export type VocabularyRiskTestType = 'chinese-to-english' | 'audio-to-english' | 'multiple-choice';
+
+export const DEFAULT_VOCABULARY_FULL_CORRECT_WORD_THRESHOLD = 50;
+export const VOCABULARY_FULL_CORRECT_RISK_FLAG = 'large_batch_all_correct';
+
+export const INVALIDATING_VOCABULARY_RISK_FLAGS: string[] = [
+  'too_fast',
+  'too_slow',
+  'missing_input_value_trace',
+  'input_value_mismatch',
+  'uniform_answer_intervals',
+  'repeated_whole_second_intervals',
+  VOCABULARY_FULL_CORRECT_RISK_FLAG
+];
+
+const parsePositiveThreshold = (value: unknown): number | undefined => {
+  const parsed = Number(value);
+  return Number.isFinite(parsed) && parsed > 0 ? parsed : undefined;
+};
+
+export const getVocabularyFullCorrectWordThreshold = (): number => {
+  return parsePositiveThreshold(process.env.VOCABULARY_FULL_CORRECT_WORD_THRESHOLD) ??
+    DEFAULT_VOCABULARY_FULL_CORRECT_WORD_THRESHOLD;
+};
+
+export const analyzeVocabularyAttemptResultRisk = ({
+  testType,
+  totalWords,
+  correctWords,
+  threshold = getVocabularyFullCorrectWordThreshold()
+}: {
+  testType: VocabularyRiskTestType | string;
+  totalWords: number;
+  correctWords: number;
+  threshold?: number;
+}): string[] => {
+  const effectiveThreshold = parsePositiveThreshold(threshold) ??
+    DEFAULT_VOCABULARY_FULL_CORRECT_WORD_THRESHOLD;
+  const safeTotalWords = Number.isFinite(totalWords) ? totalWords : 0;
+  const safeCorrectWords = Number.isFinite(correctWords) ? correctWords : 0;
+
+  if (
+    testType !== 'multiple-choice' &&
+    safeTotalWords > effectiveThreshold &&
+    safeTotalWords === safeCorrectWords
+  ) {
+    return [VOCABULARY_FULL_CORRECT_RISK_FLAG];
+  }
+
+  return [];
+};