import { NextRequest, NextResponse } from 'next/server';
import { adminDb } from '@/lib/firebase/admin';

export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ projectId: string }> }
) {
  try {
    const { projectId } = await params;

    // Get all sessions for this project
    const sessionsSnapshot = await adminDb
      .collection('sessions')
      .where('projectId', '==', projectId)
      .get();

    const sessions = sessionsSnapshot.docs
      .map(doc => {
        const data = doc.data();
        return {
          id: doc.id,
          startTime: data.startTime?.toDate?.() || data.startTime,
          endTime: data.endTime?.toDate?.() || data.endTime,
          duration: data.duration || 0,
          filesModified: data.filesModified || [],
          conversationSummary: data.conversationSummary || '',
          workspacePath: data.workspacePath || '',
          conversation: data.conversation || []
        };
      })
      .sort((a, b) => {
        const aTime = a.startTime ? new Date(a.startTime).getTime() : 0;
        const bTime = b.startTime ? new Date(b.startTime).getTime() : 0;
        return aTime - bTime;
      });

    // Analyze activity
    const fileActivity: Record<string, { count: number; dates: string[] }> = {};
    const dailyActivity: Record<string, number> = {};
    
    sessions.forEach(session => {
      if (!session.startTime) return;
      
      const date = new Date(session.startTime).toISOString().split('T')[0];
      dailyActivity[date] = (dailyActivity[date] || 0) + 1;
      
      session.filesModified.forEach((file: string) => {
        if (!fileActivity[file]) {
          fileActivity[file] = { count: 0, dates: [] };
        }
        fileActivity[file].count++;
        if (!fileActivity[file].dates.includes(date)) {
          fileActivity[file].dates.push(date);
        }
      });
    });

    // Get top files
    const topFiles = Object.entries(fileActivity)
      .map(([file, data]) => ({ file, ...data }))
      .sort((a, b) => b.count - a.count)
      .slice(0, 50);

    return NextResponse.json({
      totalSessions: sessions.length,
      sessions,
      fileActivity: topFiles,
      dailyActivity: Object.entries(dailyActivity)
        .map(([date, count]) => ({ date, sessionCount: count }))
        .sort((a, b) => a.date.localeCompare(b.date))
    });

  } catch (error) {
    console.error('Error fetching activity:', error);
    return NextResponse.json(
      { 
        error: 'Failed to fetch activity',
        details: error instanceof Error ? error.message : String(error)
      },
      { status: 500 }
    );
  }
}