function isContrastTrainingLesson(lessonType, lessonTitle = '') {
  const normalizedType = String(lessonType || '').toLowerCase();
  if (normalizedType !== 'grammar') {
    return false;
  }

  const title = String(lessonTitle || '').toLowerCase();
  return [
    'kontrast',
    'fehlertraining',
    ' / ',
    'nicht / kein',
    'der / die / das',
    'wo / wohin',
    'du / sie',
    'haben / sein',
    'ich bin / ich habe',
    'ich bin / ich heiße / ich komme'
  ].some((marker) => title.includes(marker));
}

export function getGermanForBisayaLessonPedagogy(lessonNumber, lessonType, lessonTitle = '') {
  const phaseLabel = lessonNumber <= 60 ? 'quickstart' : lessonNumber <= 120 ? 'daily_life' : 'stabilization';
  const blockNumber = Math.ceil(lessonNumber / 10);

  let didacticMode = 'core_input';
  if (lessonType === 'conversation') didacticMode = 'guided_dialogue';
  if (lessonType === 'grammar') didacticMode = 'pattern_drill';
  if (isContrastTrainingLesson(lessonType, lessonTitle)) didacticMode = 'contrast_training';
  if (lessonType === 'review') didacticMode = 'intensive_review';
  if (lessonType === 'culture') didacticMode = 'real_life_scenario';

  const difficultyWeight =
    didacticMode === 'contrast_training' ? 3 :
    lessonType === 'grammar' ? 3 :
    lessonType === 'review' ? 2 :
    lessonType === 'conversation' ? 2 :
    1;

  const newUnitTarget =
    lessonType === 'review' ? 2 :
    didacticMode === 'contrast_training' ? 3 :
    lessonType === 'grammar' ? 4 :
    phaseLabel === 'quickstart' ? 6 :
    phaseLabel === 'daily_life' ? 5 :
    4;

  const reviewWeight =
    lessonType === 'review' ? 90 :
    didacticMode === 'contrast_training' ? 70 :
    lessonType === 'grammar' ? 60 :
    lessonType === 'vocab' ? 55 :
    lessonType === 'culture' ? 20 :
    35;

  return {
    phaseLabel,
    blockNumber,
    didacticMode,
    difficultyWeight,
    newUnitTarget,
    reviewWeight,
    isIntensiveReview: lessonType === 'review'
  };
}

export function getGermanForBisayaProgressTargets(lessonData, pedagogy) {
  const baseMinutes = Number(lessonData?.targetMin || 18);
  const baseScore = Number(lessonData?.targetScore || 80);
  const lessonNumber = Number(lessonData?.num || 1);
  const lessonType = String(lessonData?.type || '');
  const didacticMode = String(pedagogy?.didacticMode || '');
  const isCheckpoint = String(lessonData?.title || '').toLowerCase().includes('checkpoint');

  // Spuerbar steilere Progression: spaetere Wochen bekommen mehr Produktionszeit
  // und hoehere Zielwerte, ohne den Einstieg zu ueberfrachten.
  let minutesBump = 0;
  if (lessonNumber >= 61 && lessonNumber <= 90) minutesBump += 2;
  if (lessonNumber >= 91 && lessonNumber <= 120) minutesBump += 4;
  if (lessonNumber >= 121) minutesBump += 6;

  if (lessonType === 'conversation' && lessonNumber >= 91) minutesBump += 2;
  if (lessonType === 'review') minutesBump += 3;
  if (isCheckpoint) minutesBump += 2;

  let scoreBump = 0;
  if (lessonNumber >= 61 && lessonNumber <= 90) scoreBump += 2;
  if (lessonNumber >= 91 && lessonNumber <= 120) scoreBump += 4;
  if (lessonNumber >= 121) scoreBump += 6;

  if (lessonType === 'grammar') scoreBump += 2;
  if (lessonType === 'review') scoreBump += 2;
  if (didacticMode === 'contrast_training') scoreBump += 1;
  if (isCheckpoint) scoreBump += 3;

  const targetMinutes = Math.min(45, baseMinutes + minutesBump);
  const targetScorePercent = lessonType === 'culture'
    ? 0
    : Math.min(96, baseScore + scoreBump);

  return {
    targetMinutes,
    targetScorePercent
  };
}