import { NextResponse } from 'next/server';

import { withAuth, withPermission } from '@/lib/api/helpers';
import { errorResponse } from '@/lib/errors';
import { logger } from '@/lib/logger';
import { getResolvedOcrConfig } from '@/lib/services/ocr-config.service';
import { runOcr, type ParsedReceipt } from '@/lib/services/ocr-providers';

const EMPTY: ParsedReceipt = {
  establishment: null,
  date: null,
  amount: null,
  currency: null,
  lineItems: [],
  confidence: 0,
};

export const POST = withAuth(
  withPermission('expenses', 'create', async (req, ctx) => {
    try {
      const formData = await req.formData();
      const file = formData.get('file') as File | null;
      if (!file) {
        return NextResponse.json({ error: 'No file provided' }, { status: 400 });
      }
      const buffer = Buffer.from(await file.arrayBuffer());
      const mimeType = file.type || 'image/jpeg';

      const config = await getResolvedOcrConfig(ctx.portId);
      if (!config.apiKey) {
        // Manual-entry path — no OCR configured. Frontend will show the
        // verify form with empty fields so the user can fill it in.
        return NextResponse.json({
          data: { parsed: EMPTY, source: 'manual', reason: 'no-ocr-configured' },
        });
      }

      try {
        const parsed = await runOcr({
          provider: config.provider,
          model: config.model,
          apiKey: config.apiKey,
          imageBuffer: buffer,
          mimeType,
        });
        return NextResponse.json({
          data: { parsed, source: 'ai', provider: config.provider, model: config.model },
        });
      } catch (err) {
        logger.error({ err, provider: config.provider }, 'OCR provider call failed');
        // Provider hiccup — degrade to manual entry rather than 500-ing.
        return NextResponse.json({
          data: {
            parsed: EMPTY,
            source: 'manual',
            reason: 'provider-error',
            providerError: err instanceof Error ? err.message.slice(0, 200) : 'Unknown error',
          },
        });
      }
    } catch (error) {
      return errorResponse(error);
    }
  }),
);