/*
 * Copyright 2023 Anton Tananaev (anton@traccar.org)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.traccar.web;

import jakarta.servlet.ServletOutputStream;
import jakarta.servlet.WriteListener;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpServletResponseWrapper;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

public class ResponseWrapper extends HttpServletResponseWrapper {

    private final ByteArrayOutputStream capture;
    private ServletOutputStream output;

    public ResponseWrapper(HttpServletResponse response) {
        super(response);
        capture = new ByteArrayOutputStream(response.getBufferSize());
    }

    @Override
    public ServletOutputStream getOutputStream() {
        if (output == null) {
            output = new ServletOutputStream() {
                @Override
                public boolean isReady() {
                    return true;
                }

                @Override
                public void setWriteListener(WriteListener writeListener) {
                }

                @Override
                public void write(int b) {
                    capture.write(b);
                }

                @Override
                public void flush() throws IOException {
                    capture.flush();
                }

                @Override
                public void close() throws IOException {
                    capture.close();
                }
            };
        }
        return output;
    }

    @Override
    public void flushBuffer() throws IOException {
        super.flushBuffer();
        if (output != null) {
            output.flush();
        }
    }

    public byte[] getCapture() throws IOException {
        if (output != null) {
            output.close();
            return capture.toByteArray();
        }
        return null;
    }

}