Deviation Engine

function detectPersistentLowMood(entries: MoodEntry[], baseline: Baseline): boolean {
  const last14Days = entries.slice(-14);
  
  if (last14Days.length < 10) return false; // Need sufficient data
  
  const lowMoodDays = last14Days.filter(e => e.mood < baseline.range.low).length;
  
  // 70%+ of days below typical range
  return lowMoodDays >= 10;
}

return `
  You've been feeling lower than usual for a couple of weeks.
  Persistent low mood can be tough to navigate alone.
  
  Consider talking to a mental health professional:
  • Find a therapist: psychologytoday.com/us/therapists
  • Free/low-cost options: openpathcollective.org
`;

function detectMoodDrop(recentAvg: number, baseline: Baseline): boolean {
  return recentAvg < baseline.average - 1.5;
}

return `
  Your mood has dropped significantly from your usual range.
  If something difficult is happening, you don't have to handle it alone.
  
  Consider reaching out to:
  • A trusted friend or family member
  • A mental health professional
  • Crisis support (988) if you're in immediate distress
`;

function detectHighVariability(entries: MoodEntry[]): boolean {
  const moods = entries.map(e => e.mood);
  const stdDev = standardDeviation(moods);
  
  // Very high fluctuation
  return stdDev > 1.5;
}

return `
  Your mood has been varying quite a bit lately.
  If these ups and downs feel hard to manage, talking to a therapist might help.
`;

function detectIncreasingSymptoms(logs: SymptomLog[]): boolean {
  const recent = logs.slice(-14);
  const previous = logs.slice(-28, -14);
  
  const recentSeverity = mean(recent.map(l => l.severityScore));
  const previousSeverity = mean(previous.map(l => l.severityScore));
  
  // Severity increased by 30%+
  return recentSeverity > previousSeverity * 1.3;
}

return `
  You've been experiencing more intense symptoms lately.
  Consider checking in with a mental health professional to talk about what's been happening.
`;

const CRISIS_KEYWORDS = [
  "suicide", "kill myself", "end my life",
  "self-harm", "hurt myself", "cut myself",
  "not worth living", "want to die"
];
 
function detectCrisisLanguage(text: string): boolean {
  return CRISIS_KEYWORDS.some(keyword => 
    text.toLowerCase().includes(keyword)
  );
}

return `
  🚨 If you're in crisis or considering self-harm:
  
  • Call 988 (Suicide & Crisis Lifeline)
  • Text HOME to 741741 (Crisis Text Line)
  • Call 911 for emergencies
  
  These resources are available 24/7 with trained counselors.
`;

// ❌ BAD
if (mood === 1) {
  alert("Depression detected!"); // One bad day ≠ disorder
}
 
// ✅ GOOD
if (mood === 1) {
  return "Sorry you're having a tough day. Be gentle with yourself.";
}

// ❌ BAD
if (mood < baseline.average && dayOfWeek === "Sunday") {
  alert("Concerning pattern"); // But Sundays are often lower
}
 
// ✅ GOOD
const sundayBaseline = weeklyBaseline["Sunday"];
if (mood < sundayBaseline - 1) {
  // Now comparing to Sunday-specific baseline
}

// ❌ BAD
if (userReports("stressed about work deadline")) {
  return "You may have anxiety disorder."; // Normal stress response
}
 
// ✅ GOOD
if (userReports("stressed about work deadline")) {
  return "Deadlines can be stressful. How are you managing?";
}

return "How are you feeling today? Want to talk about it?";

return `
  You've been feeling a bit lower lately.
  Remember to take care of yourself:
  • Get enough sleep
  • Connect with friends
  • Do something you enjoy
  
  You've got this 💙
`;

return `
  You've been experiencing ${pattern} for ${duration}.
  While difficult feelings are normal, persistent challenges can benefit from professional support.
  
  Consider talking to a mental health professional:
  • Find a therapist: psychologytoday.com/us/therapists
  • Free/low-cost options: openpathcollective.org
  
  You don't have to navigate this alone.
`;

return `
  🚨 If you're in crisis or considering self-harm:
  
  • Call 988 (Suicide & Crisis Lifeline)
  • Text HOME to 741741 (Crisis Text Line)
  • Call 911 for emergencies
  
  These resources are available 24/7.
`;

class DeviationEngine {
  async checkForDeviations(userId: string): Promise<SupportMessage | null> {
    const baseline = await this.getBaseline(userId);
    const recentEntries = await this.getMoodEntries(userId, 14);
    
    // Level 4: Crisis language check (highest priority)
    const latestJournal = await this.getLatestJournal(userId);
    if (latestJournal && detectCrisisLanguage(latestJournal.content)) {
      return {
        level: 4,
        type: "crisis_referral",
        message: this.getCrisisResources()
      };
    }
    
    // Level 3: Persistent low mood
    if (detectPersistentLowMood(recentEntries, baseline)) {
      return {
        level: 3,
        type: "professional_referral",
        message: `
          You've been feeling lower than usual for a couple of weeks.
          Consider talking to a mental health professional:
          • Find a therapist: psychologytoday.com/us/therapists
          • Free/low-cost options: openpathcollective.org
        `
      };
    }
    
    // Level 3: Significant mood drop
    const recentAvg = mean(recentEntries.slice(-7).map(e => e.mood));
    if (detectMoodDrop(recentAvg, baseline)) {
      return {
        level: 3,
        type: "professional_referral",
        message: `
          Your mood has dropped significantly from your usual range.
          Consider reaching out to a mental health professional or trusted friend.
        `
      };
    }
    
    // Level 2: Moderate deviation
    const last3Days = recentEntries.slice(-3);
    const last3Avg = mean(last3Days.map(e => e.mood));
    if (last3Avg < baseline.average - 0.8) {
      return {
        level: 2,
        type: "self_care_suggestion",
        message: `
          You've been feeling a bit lower lately. Remember to take care of yourself:
          • Get enough sleep
          • Connect with supportive people
          • Do activities you enjoy
        `
      };
    }
    
    // Level 1: Gentle check-in
    if (last3Avg < baseline.average - 0.5) {
      return {
        level: 1,
        type: "check_in",
        message: "How are you feeling today? Want to reflect on what's been on your mind?"
      };
    }
    
    return null; // Everything within normal range
  }
  
  private getCrisisResources(): string {
    return `
      🚨 If you're in crisis or considering self-harm:
      
      • Call 988 (Suicide & Crisis Lifeline)
      • Text HOME to 741741 (Crisis Text Line)
      • Call 911 for emergencies
      
      These resources are available 24/7.
    `;
  }
}