package cc.mrbird.febs.pay.util;

import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import java.io.*;

public class RequestBodyUtils {

    private static final int BUFFER_SIZE = 1024 * 8;

    /**
     * read string.
     *
     * @param reader Reader instance.
     * @return String.
     * @throws IOException
     */
    public static String read(Reader reader) throws IOException {
        try (StringWriter writer = new StringWriter()) {
            write(reader, writer);
            return writer.getBuffer().toString();
        }
    }

    /**
     * write.
     *
     * @param reader Reader.
     * @param writer Writer.
     * @return count.
     * @throws IOException
     */
    public static long write(Reader reader, Writer writer) throws IOException {

        return write(reader, writer, BUFFER_SIZE);
    }

    /**
     * write.
     *
     * @param reader     Reader.
     * @param writer     Writer.
     * @param bufferSize buffer size.
     * @return count.
     * @throws IOException
     */
    public static long write(Reader reader, Writer writer, int bufferSize) throws IOException {

        int read;
        long total = 0;
        char[] buf = new char[bufferSize];
        while ((read = reader.read(buf)) != -1) {

            writer.write(buf, 0, read);
            total += read;
        }
        return total;
    }

    /**
     * 获取requestBody
     */
    public static String getRequestBody() throws IOException {
        RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
        ServletRequestAttributes servletRequestAttributes = (ServletRequestAttributes) attributes;
        assert servletRequestAttributes != null;
        HttpServletRequest request = servletRequestAttributes.getRequest();
        BufferedReader reader = new BufferedReader(new InputStreamReader(request.getInputStream()));
        //读取输入流的内容转换为String类型IOUtils必须引入org.apache.dubbo.common.utils.IOUtils;包
        return RequestBodyUtils.read(reader);
    }

}