package com.infoloop.tianting.utils;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.compress.utils.IOUtils;
import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.Resource;
import org.springframework.web.multipart.MultipartFile;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.Base64;
import java.util.Objects;

@Slf4j
public class FileUtil {

    /**
     * MultipartFile 转 File
     *
     * @param file
     * @throws Exception
     */
    public static File multipartFileToFile(MultipartFile file) throws Exception {
        File toFile;
        if (file == null || file.getSize() <= 0) {
            return null;
        } else {
            InputStream ins;
            ins = file.getInputStream();
            toFile = new File(Objects.requireNonNull(file.getOriginalFilename()));
            inputStreamToFile(ins, toFile);
            ins.close();
        }
        return toFile;
    }

    //获取流文件
    private static void inputStreamToFile(InputStream ins, File file) {
        try {
            OutputStream os = new FileOutputStream(file);
            int bytesRead;
            byte[] buffer = new byte[8192];
            while ((bytesRead = ins.read(buffer, 0, 8192)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
            os.close();
            ins.close();
        } catch (IOException e) {
            log.error("inputStreamToFile error", e);
        }
    }

    public static String convertInputStreamToBase64(InputStream inputStream) throws IOException {
        if (inputStream == null) {
            return null;
        }
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[8192];
        int bytesRead;
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            byteArrayOutputStream.write(buffer, 0, bytesRead);
        }
        byte[] byteArray = byteArrayOutputStream.toByteArray();
        return Base64.getEncoder().encodeToString(byteArray);
    }

    public static Resource downloadFile(String fileName, String fileUrl) throws IOException {
        try (InputStream inputStream = new URL(fileUrl).openStream()) {
            byte[] fileBytes = IOUtils.toByteArray(inputStream);
            return new ByteArrayResource(fileBytes) {
                @Override
                public String getFilename() {
                    return fileName + ".pdf";
                }
            };
        }
    }
}