import { NextRequest, NextResponse } from 'next/server';
import { resolveRange } from '@/lib/ranges';
import { fetchVerbrauch } from '@/lib/influx';
import { RangeKey } from '@/types/strom';

const VALID_RANGES: RangeKey[] = ['24h', '7d', '31d', '365d'];

// GET /api/verbrauch?range=24h&date=YYYY-MM-DD
//                    ?range=7d&date=YYYY-MM-DD
//                    ?range=31d&month=YYYY-MM
//                    ?range=365d&year=YYYY
export async function GET(request: NextRequest) {
  const sp = request.nextUrl.searchParams;
  const range = sp.get('range') as RangeKey | null;

  if (!range || !VALID_RANGES.includes(range)) {
    return NextResponse.json(
      { success: false, error: `Ungueltiger range-Parameter. Erlaubt: ${VALID_RANGES.join(', ')}` },
      { status: 400 }
    );
  }

  try {
    const resolved = resolveRange(range, {
      date: sp.get('date'),
      month: sp.get('month'),
      year: sp.get('year'),
    });
    const data = await fetchVerbrauch(resolved);

    return NextResponse.json(
      { success: true, data },
      {
        headers: {
          'Cache-Control': 'no-store, no-cache, must-revalidate',
          'Pragma': 'no-cache',
          'Expires': '0',
        },
      }
    );
  } catch (error) {
    console.error('InfluxDB error:', error);
    return NextResponse.json(
      { success: false, error: 'Fehler beim Laden der Verbrauchsdaten.' },
      { status: 500 }
    );
  }
}