import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/lib/auth/authOptions';
import { query } from '@/lib/db-postgres';

export async function GET() {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.email) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const email = session.user.email;

    // Fetch projects joined on user email
    const projects = await query<any>(`
      SELECT p.id, p.data, p.workspace, p.slug
      FROM fs_projects p
      JOIN fs_users u ON u.id = p.user_id
      WHERE u.data->>'email' = $1
      ORDER BY (p.data->>'updatedAt') DESC NULLS LAST
    `, [email]);

    // Fetch session stats per project
    const sessionStats = await query<any>(`
      SELECT
        s.data->>'projectId' AS project_id,
        COUNT(*)::int AS session_count,
        COALESCE(SUM((s.data->>'cost')::float), 0) AS total_cost
      FROM fs_sessions s
      JOIN fs_users u ON u.id = s.user_id
      WHERE u.data->>'email' = $1
      GROUP BY s.data->>'projectId'
    `, [email]);

    const statsByProject = new Map(sessionStats.map((s: any) => [s.project_id, s]));

    const result = projects.map((p: any) => {
      const stats = statsByProject.get(p.id) || { session_count: 0, total_cost: 0 };
      return {
        id: p.id,
        ...p.data,
        stats: {
          sessions: stats.session_count || 0,
          costs: parseFloat(stats.total_cost) || 0,
        },
      };
    });

    return NextResponse.json({ projects: result });
  } catch (error) {
    console.error('[GET /api/projects] Error:', error);
    return NextResponse.json(
      { error: 'Failed to fetch projects', details: error instanceof Error ? error.message : String(error) },
      { status: 500 }
    );
  }
}