package com.ruoyi.payment.infrastructure.channel.wechat;

import com.ruoyi.payment.infrastructure.config.WechatPayConfig;
import com.ruoyi.payment.infrastructure.util.SignUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.*;

/**
 * 微信支付工具类
 * 
 * @author ruoyi
 */
@Slf4j
@Component
public class WxPayUtil {

    @Autowired
    private WechatPayConfig wechatPayConfig;

    /**
     * XML转Map
     */
    public Map<String, String> xmlToMap(String xml) throws Exception {
        Map<String, String> data = new HashMap<>();
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        InputStream is = new ByteArrayInputStream(xml.getBytes("UTF-8"));
        Document doc = builder.parse(is);
        doc.getDocumentElement().normalize();
        NodeList nodeList = doc.getDocumentElement().getChildNodes();
        
        for (int i = 0; i < nodeList.getLength(); i++) {
            Node node = nodeList.item(i);
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                data.put(node.getNodeName(), node.getTextContent());
            }
        }
        return data;
    }

    /**
     * Map转XML
     */
    public String mapToXml(Map<String, String> data) {
        StringBuilder xml = new StringBuilder("<xml>");
        for (Map.Entry<String, String> entry : data.entrySet()) {
            xml.append("<").append(entry.getKey()).append(">");
            xml.append("<![CDATA[").append(entry.getValue()).append("]]>");
            xml.append("</").append(entry.getKey()).append(">");
        }
        xml.append("</xml>");
        return xml.toString();
    }

    /**
     * 生成签名
     */
    public String generateSign(Map<String, String> data) {
        // 1. 参数名ASCII码从小到大排序
        Set<String> keySet = data.keySet();
        String[] keyArray = keySet.toArray(new String[0]);
        Arrays.sort(keyArray);
        
        // 2. 拼接参数
        StringBuilder sb = new StringBuilder();
        for (String k : keyArray) {
            if ("sign".equals(k)) {
                continue;
            }
            String value = data.get(k);
            if (value != null && value.trim().length() > 0) {
                sb.append(k).append("=").append(value).append("&");
            }
        }
        
        // 3. 拼接密钥
        sb.append("key=").append(wechatPayConfig.getMchKey());
        
        // 4. MD5加密并转大写
        return SignUtil.md5(sb.toString());
    }

    /**
     * 验证签名
     */
    public boolean verifySign(Map<String, String> data) {
        if(!wechatPayConfig.getCheckSign()){
            log.info("微信回调不检测验证签名");
            return true;
        }
        String sign = data.get("sign");
        if (sign == null || sign.isEmpty()) {
            return false;
        }
        
        String calculatedSign = generateSign(data);
        return sign.equals(calculatedSign);
    }

    /**
     * 构造成功应答
     */
    public String buildSuccessResponse() {
        Map<String, String> response = new HashMap<>();
        response.put("return_code", "SUCCESS");
        response.put("return_msg", "OK");
        return mapToXml(response);
    }

    /**
     * 构造失败应答
     */
    public String buildFailResponse(String msg) {
        Map<String, String> response = new HashMap<>();
        response.put("return_code", "FAIL");
        response.put("return_msg", msg);
        return mapToXml(response);
    }
}