package com.ruoyi.im.util;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.math.BigDecimal;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.security.MessageDigest;
import java.util.*;

@Component
public class PayService {

    @Value("${pay.mch-id}")
    private String mchId;

    @Value("${pay.key}")
    private String key;

    @Value("${pay.base-url}")
    private String baseUrl;

    @Value("${pay.call-back-url}")
    private String callBackUrl;

    /**
     * 创建支付订单
     */
    public String createOrder(BigDecimal amount,String orderNo,String payProductId ) {
        try {
            Map<String, Object> params = new HashMap<>();
            params.put("mchId", mchId);
            params.put("productId", 8089);
            params.put("mchOrderNo",orderNo );
            params.put("amount", 3000);
            params.put("notifyUrl", callBackUrl);

            String sign = generateSign(params);
            params.put("sign", sign);

            String url = baseUrl + "/api/pay/create_order";
            return sendPost(url, params);

        } catch (Exception e) {
            return "{\"retCode\":\"FAIL\",\"retMsg\":\"" + e.getMessage() + "\"}";
        }
    }


    /**
     * 查询订单
     */
    public String queryOrder(String orderNo) {
        try {
            Map<String, Object> params = new HashMap<>();
            params.put("mchId", mchId);
            params.put("mchOrderNo", orderNo);

            String sign = generateSign(params);
            params.put("sign", sign);

            String url = baseUrl + "/api/pay/query_order";
            return sendPost(url, params);

        } catch (Exception e) {
            return "{\"retCode\":\"FAIL\",\"retMsg\":\"" + e.getMessage() + "\"}";
        }
    }

    /**
     * 验证回调签名
     */
    public boolean verifySign(Map<String, String> params) {
        try {
            String receivedSign = params.get("sign");
            Map<String, Object> signParams = new HashMap<>(params);
            String calculatedSign = generateSign(signParams);
            return calculatedSign.equals(receivedSign);
        } catch (Exception e) {
            return false;
        }
    }

    /**
     * 生成签名
     */
    private String generateSign(Map<String, Object> params) throws Exception {
        // 移除sign参数
        Map<String, Object> signParams = new HashMap<>(params);
        signParams.remove("sign");

        // 过滤空值并排序
        List<String> keys = new ArrayList<>();
        for (Map.Entry<String, Object> entry : signParams.entrySet()) {
            if (entry.getValue() != null && !entry.getValue().toString().trim().isEmpty()) {
                keys.add(entry.getKey());
            }
        }
        Collections.sort(keys);

        // 拼接字符串
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < keys.size(); i++) {
            String key = keys.get(i);
            String value = signParams.get(key).toString();
            if (i > 0) sb.append("&");
            sb.append(key).append("=").append(value);
        }

        // MD5加密
        String stringSignTemp = sb.toString() + "&key=" + key;
        MessageDigest md = MessageDigest.getInstance("MD5");
        byte[] array = md.digest(stringSignTemp.getBytes("UTF-8"));
        StringBuilder result = new StringBuilder();
        for (byte item : array) {
            result.append(String.format("%02x", item));
        }
        return result.toString().toUpperCase();
    }

    /**
     * 发送POST请求
     */
    private String sendPost(String urlStr, Map<String, Object> params) throws Exception {
        // 构建参数字符串
        StringBuilder postData = new StringBuilder();
        for (Map.Entry<String, Object> param : params.entrySet()) {
            if (postData.length() != 0) postData.append('&');
            postData.append(URLEncoder.encode(param.getKey(), "UTF-8"));
            postData.append('=');
            postData.append(URLEncoder.encode(String.valueOf(param.getValue()), "UTF-8"));
        }

        byte[] postDataBytes = postData.toString().getBytes("UTF-8");

        URL url = new URL(urlStr);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        conn.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
        conn.setDoOutput(true);
        conn.getOutputStream().write(postDataBytes);

        // 读取响应
        Scanner scanner = new Scanner(conn.getInputStream(), "UTF-8");
        String response = scanner.useDelimiter("\\A").next();
        scanner.close();
        return response;
    }
}