package sn.ladoum.bergerie.qr;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.client.j2se.MatrixToImageConfig;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import org.springframework.stereotype.Service;

import java.io.ByteArrayOutputStream;
import java.util.EnumMap;
import java.util.Map;

@Service
public class QrCodeService {

    /** Génère un PNG encodant le texte donné (généralement une URL). */
    public byte[] generatePng(String content, int size) {
        try {
            Map<EncodeHintType, Object> hints = new EnumMap<>(EncodeHintType.class);
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
            hints.put(EncodeHintType.MARGIN, 2);

            QRCodeWriter writer = new QRCodeWriter();
            BitMatrix matrix = writer.encode(content, BarcodeFormat.QR_CODE, size, size, hints);

            // Noir sur blanc (ARGB)
            MatrixToImageConfig config = new MatrixToImageConfig(0xFF2A4030, 0xFFFFFFFF);
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            MatrixToImageWriter.writeToStream(matrix, "PNG", out, config);
            return out.toByteArray();
        } catch (Exception e) {
            throw new IllegalStateException("Erreur génération QR code: " + e.getMessage(), e);
        }
    }
}