feat: initialize project with Next.js, Prisma, and Tailwind CSS

- Add package.json with dependencies and scripts for Next.js and Prisma
- Implement API routes for session management, user authentication, and company configuration
- Create database schema for Company, User, and Session models in Prisma
- Set up authentication with NextAuth and JWT
- Add password reset functionality and user registration endpoint
- Configure Tailwind CSS and PostCSS for styling
- Implement metrics and dashboard settings API endpoints

lib/metrics.ts

@@ -0,0 +1,85 @@
+// Functions to calculate metrics over sessions
+import { ChatSession, DayMetrics, CategoryMetrics, LanguageMetrics, MetricsResult } from './types';
+
+interface CompanyConfig {
+    sentimentAlert?: number;
+}
+
+export function sessionMetrics(sessions: ChatSession[], companyConfig: CompanyConfig = {}): MetricsResult {
+    const total = sessions.length;
+    const byDay: DayMetrics = {};
+    const byCategory: CategoryMetrics = {};
+    const byLanguage: LanguageMetrics = {};
+    let escalated = 0, forwarded = 0;
+    let totalSentiment = 0, sentimentCount = 0;
+    let totalResponse = 0, responseCount = 0;
+    let totalTokens = 0, totalTokensEur = 0;
+
+    // Calculate total session duration in minutes
+    let totalDuration = 0;
+    let durationCount = 0;
+
+    sessions.forEach(s => {
+        const day = s.startTime.toISOString().slice(0, 10);
+        byDay[day] = (byDay[day] || 0) + 1;
+
+        if (s.category) byCategory[s.category] = (byCategory[s.category] || 0) + 1;
+        if (s.language) byLanguage[s.language] = (byLanguage[s.language] || 0) + 1;
+
+        if (s.endTime) {
+            const duration = (s.endTime.getTime() - s.startTime.getTime()) / (1000 * 60); // minutes
+            totalDuration += duration;
+            durationCount++;
+        }
+
+        if (s.escalated) escalated++;
+        if (s.forwardedHr) forwarded++;
+
+        if (s.sentiment != null) {
+            totalSentiment += s.sentiment;
+            sentimentCount++;
+        }
+
+        if (s.avgResponseTime != null) {
+            totalResponse += s.avgResponseTime;
+            responseCount++;
+        }
+
+        totalTokens += s.tokens || 0;
+        totalTokensEur += s.tokensEur || 0;
+    });
+
+    // Now add sentiment alert logic:
+    let belowThreshold = 0;
+    const threshold = companyConfig.sentimentAlert ?? null;
+    if (threshold != null) {
+        for (const s of sessions) {
+            if (s.sentiment != null && s.sentiment < threshold) belowThreshold++;
+        }
+    }
+
+    // Calculate average sessions per day
+    const dayCount = Object.keys(byDay).length;
+    const avgSessionsPerDay = dayCount > 0 ? total / dayCount : 0;
+
+    // Calculate average session length
+    const avgSessionLength = durationCount > 0 ? totalDuration / durationCount : null;
+
+    return {
+        totalSessions: total,
+        avgSessionsPerDay,
+        avgSessionLength,
+        days: byDay,
+        languages: byLanguage,
+        categories: byCategory,
+        belowThresholdCount: belowThreshold,
+        // Additional metrics not in the interface - using type assertion
+        escalatedCount: escalated,
+        forwardedCount: forwarded,
+        avgSentiment: sentimentCount ? totalSentiment / sentimentCount : null,
+        avgResponseTime: responseCount ? totalResponse / responseCount : null,
+        totalTokens,
+        totalTokensEur,
+        sentimentThreshold: threshold,
+    } as MetricsResult;
+}