package io.company.localhost.common.wrapper;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;
import java.util.Objects;

import org.springframework.util.StreamUtils;
import org.springframework.util.StringUtils;

import com.fasterxml.jackson.core.type.TypeReference;

import io.company.localhost.utils.JacksonUtil;
import io.netty.handler.codec.ValueConverter;
import jakarta.servlet.ReadListener;
import jakarta.servlet.ServletInputStream;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletRequestWrapper;
import lombok.extern.slf4j.Slf4j;

// body 읽어서 cash로 만듬
// 필요하면 filter로 사용
@Slf4j
public class CachedBodyRequestWrapper extends HttpServletRequestWrapper {

    private final Charset encoding;

    private final byte[] cachedBody;

    private ValueConverter targetConvert;

    public CachedBodyRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);

        String characterEncoding = request.getCharacterEncoding();
        if (StringUtils.hasText(characterEncoding) == false) {
            characterEncoding = StandardCharsets.UTF_8.name();
        }

        // XSS 방지를 이곳에서 하지 않을 경우 아래주석 해제 후 아래 //XSS 방지 이후 코드 삭제
        // InputStream requestInputStream = request.getInputStream();
        // this.cachedBody = StreamUtils.copyToByteArray(requestInputStream);
        this.encoding = Charset.forName(characterEncoding);

        // XSS 방지
        String requestBody = null;
        try {
            requestBody = StreamUtils.copyToString(request.getInputStream(), Charset.defaultCharset());
        } catch (IOException e) {
            log.error("StreamUtil.toString Exception", e);
        }


        if (requestBody == null) {
            InputStream requestInputStream = request.getInputStream();
            this.cachedBody = StreamUtils.copyToByteArray(requestInputStream);
            return;
        }

        Object bodyObject = null;
        if (requestBody.startsWith("[")) { // List
            bodyObject = JacksonUtil.fromJson(requestBody, new TypeReference<List<Map<String, Object>>>() {
            });
        } else { // Map
            bodyObject = JacksonUtil.fromJson(requestBody, new TypeReference<Map<String, Object>>() {
            });
        }


        String newRequestBody = JacksonUtil.toJson(bodyObject);
        if (Objects.isNull(newRequestBody)) {
            newRequestBody = new String("");
        }
        this.cachedBody = newRequestBody.getBytes(StandardCharsets.UTF_8);
    }

    /** json body 관련 메소드 START */
    @Override
    public ServletInputStream getInputStream() throws IOException {
        return new CachedBodyServletInputStream(this.cachedBody);
    }

    @Override
    public BufferedReader getReader() throws IOException {
        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(this.cachedBody);
        return new BufferedReader(new InputStreamReader(byteArrayInputStream, encoding));
    }

    /** json body 관련 메소드 END */

    private class CachedBodyServletInputStream extends ServletInputStream {

        private InputStream cachedBodyInputStream;

        public CachedBodyServletInputStream(byte[] cachedBody) {
            this.cachedBodyInputStream = new ByteArrayInputStream(cachedBody);
        }

        @Override
        public boolean isFinished() {
            try {
                return this.cachedBodyInputStream.available() == 0;
            } catch (IOException e) {
                log.error("", e);
                return false;
            }
        }

        @Override
        public boolean isReady() {
            return true;
        }

        @Override
        public void setReadListener(ReadListener listener) {
            throw new UnsupportedOperationException();
        }

        @Override
        public int read() throws IOException {
            return this.cachedBodyInputStream.read();
        }

    }

}