package com.hanserwei.chat.reader;

import org.springframework.core.io.ByteArrayResource;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.io.UncheckedIOException;
import java.util.Objects;

/**
 * 简单的 {@link ByteArrayResource}，用于保留多部分文件的文件名。
 */
final class MultipartFileResource extends ByteArrayResource {

    private final String filename;

    private MultipartFileResource(byte[] byteArray, String filename) {
        super(byteArray);
        this.filename = filename;
    }

    static MultipartFileResource of(MultipartFile file) {
        try {
            String originalFilename = Objects.requireNonNullElse(file.getOriginalFilename(), "upload");
            return new MultipartFileResource(file.getBytes(), originalFilename);
        }
        catch (IOException ex) {
            throw new UncheckedIOException("读取多部分文件内容失败", ex);
        }
    }

    @Override
    public String getFilename() {
        return filename;
    }
}