package com.by4cloud.platformx.business.utils;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Base64;

public class NetworkFileToBase64 {

	/**
	 * 将网络地址的文件转换为 Base64 字符串
	 *
	 * @param fileUrl 网络文件的 URL 地址
	 * @return Base64 编码字符串，失败返回 null
	 */
	public static String convertNetworkFileToBase64(String fileUrl) {
		InputStream inputStream = null;
		ByteArrayOutputStream outputStream = null;

		try {
			// 1. 创建 URL 对象
			URL url = new URL(fileUrl);

			// 2. 打开连接
			HttpURLConnection conn = (HttpURLConnection) url.openConnection();

			// 3. 设置请求属性和超时时间（防止长时间挂起）
			conn.setRequestMethod("GET");
			conn.setConnectTimeout(5000); // 连接超时 5秒
			conn.setReadTimeout(10000);   // 读取超时 10秒

			// 4. 获取输入流
			int responseCode = conn.getResponseCode();
			if (responseCode != HttpURLConnection.HTTP_OK) {
				System.err.println("HTTP 错误代码: " + responseCode);
				return null;
			}

			inputStream = conn.getInputStream();
			outputStream = new ByteArrayOutputStream();

			// 5. 读取数据到内存
			byte[] buffer = new byte[1024];
			int len;
			while ((len = inputStream.read(buffer)) != -1) {
				outputStream.write(buffer, 0, len);
			}

			// 6. 获取字节数组并编码
			byte[] fileBytes = outputStream.toByteArray();
			return Base64.getEncoder().encodeToString(fileBytes);

		} catch (Exception e) {
			e.printStackTrace();
			return null;
		} finally {
			// 7. 关闭资源
			try {
				if (inputStream != null) inputStream.close();
				if (outputStream != null) outputStream.close();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}

}