feat: 新增统一文件模块，统一文件操作

server/internal/file/application/file.go

@@ -0,0 +1,169 @@
+package application
+
+import (
+	"context"
+	"io"
+
+	"mayfly-go/internal/file/config"
+	"mayfly-go/internal/file/domain/entity"
+	"mayfly-go/internal/file/domain/repository"
+	"mayfly-go/pkg/base"
+	"mayfly-go/pkg/errorx"
+	"mayfly-go/pkg/logx"
+	"mayfly-go/pkg/utils/stringx"
+	"mayfly-go/pkg/utils/writerx"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/may-fly/cast"
+)
+
+type File interface {
+	base.App[*entity.File]
+
+	// Upload 上传文件
+	//
+	// @param fileKey 文件key，若存在则使用存在的文件key，否则生成新的文件key。
+	//
+	// @param filename 文件名，带文件后缀
+	//
+	// @return fileKey 文件key
+	Upload(ctx context.Context, fileKey string, filename string, r io.Reader) (string, error)
+
+	// NewWriter 创建文件writer
+	//
+	// @param canEmptyFileKey 文件key，若不为空则使用该文件key，否则生成新的文件key。
+	//
+	// @param filename 文件名，带文件后缀
+	//
+	// @return fileKey 文件key
+	//
+	// @return writer 文件writer
+	//
+	// @return saveFunc 保存文件信息的回调函数 (必须要defer中调用才会入库保存该文件信息)
+	NewWriter(ctx context.Context, canEmptyFileKey string, filename string) (fileKey string, writer *writerx.CountingWriteCloser, saveFunc func() error, err error)
+
+	// GetReader 获取文件reader
+	//
+	// @return filename 文件名
+	//
+	// @return reader 文件reader
+	//
+	// @return err 错误
+	GetReader(ctx context.Context, fileKey string) (string, io.ReadCloser, error)
+
+	// Remove 删除文件
+	Remove(ctx context.Context, fileKey string) error
+}
+
+type fileAppImpl struct {
+	base.AppImpl[*entity.File, repository.File]
+}
+
+func (f *fileAppImpl) InjectFileRepo(repo repository.File) {
+	f.Repo = repo
+}
+
+func (f *fileAppImpl) Upload(ctx context.Context, fileKey string, filename string, r io.Reader) (string, error) {
+	fileKey, writer, saveFileFunc, err := f.NewWriter(ctx, fileKey, filename)
+	if err != nil {
+		return fileKey, err
+	}
+	defer saveFileFunc()
+
+	if _, err := io.Copy(writer, r); err != nil {
+		return fileKey, err
+	}
+	return fileKey, nil
+}
+
+func (f *fileAppImpl) NewWriter(ctx context.Context, canEmptyFileKey string, filename string) (fileKey string, writer *writerx.CountingWriteCloser, saveFunc func() error, err error) {
+	isNewFile := true
+	file := &entity.File{}
+
+	if canEmptyFileKey == "" {
+		canEmptyFileKey = stringx.RandUUID()
+		file.FileKey = canEmptyFileKey
+	} else {
+		file.FileKey = canEmptyFileKey
+		if err := f.GetByCond(file); err == nil {
+			isNewFile = false
+		}
+	}
+	file.Filename = filename
+
+	if !isNewFile {
+		// 先删除旧文件
+		f.remove(ctx, file)
+	}
+
+	// 生产新的文件名
+	newFilename := canEmptyFileKey + filepath.Ext(filename)
+	filepath, w, err := f.newWriter(newFilename)
+	if err != nil {
+		return "", nil, nil, err
+	}
+	file.Path = filepath
+
+	fileKey = canEmptyFileKey
+	writer = writerx.NewCountingWriteCloser(w)
+	// 创建回调函数
+	saveFunc = func() error {
+		// 获取已写入的字节数
+		file.Size = writer.BytesWritten()
+		writer.Close()
+		// 保存文件信息
+		return f.Save(ctx, file)
+	}
+
+	return fileKey, writer, saveFunc, nil
+}
+
+func (f *fileAppImpl) GetReader(ctx context.Context, fileKey string) (string, io.ReadCloser, error) {
+	file := &entity.File{FileKey: fileKey}
+	if err := f.GetByCond(file); err != nil {
+		return "", nil, errorx.NewBiz("文件不存在")
+	}
+	r, err := os.Open(filepath.Join(config.GetFileConfig().BasePath, file.Path))
+	return file.Filename, r, err
+}
+
+func (f *fileAppImpl) Remove(ctx context.Context, fileKey string) error {
+	file := &entity.File{FileKey: fileKey}
+	if err := f.GetByCond(file); err != nil {
+		return errorx.NewBiz("文件不存在")
+	}
+	f.DeleteById(ctx, file.Id)
+	return f.remove(ctx, file)
+}
+
+func (f *fileAppImpl) newWriter(filename string) (string, io.WriteCloser, error) {
+	now := time.Now()
+	filePath := filepath.Join(cast.ToString(now.Year()), cast.ToString(int(now.Month())), cast.ToString(now.Day()), cast.ToString(now.Hour()), filename)
+	fileAbsPath := filepath.Join(config.GetFileConfig().BasePath, filePath)
+
+	// 目录不存在则创建
+	fileDir := filepath.Dir(fileAbsPath)
+	if _, err := os.Stat(fileDir); os.IsNotExist(err) {
+		err = os.MkdirAll(fileDir, os.ModePerm)
+		if err != nil {
+			return "", nil, err
+		}
+	}
+
+	// 创建目标文件
+	out, err := os.OpenFile(fileAbsPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0766)
+	if err != nil {
+		return "", nil, err
+	}
+	return filePath, out, nil
+}
+
+func (f *fileAppImpl) remove(ctx context.Context, file *entity.File) error {
+	if err := os.Remove(filepath.Join(config.GetFileConfig().BasePath, file.Path)); err != nil {
+		logx.ErrorfContext(ctx, "删除旧文件[%s] 失败: %s", file.Path, err.Error())
+		return err
+	}
+	return nil
+}