s3browser-backend/internal/mutations.go

package s3browser

import (
	"context"
	"fmt"
	"strings"
	"time"

	"github.com/golang-jwt/jwt"
	"github.com/graph-gophers/dataloader"
	"github.com/minio/minio-go/v7"
)

func deleteMutation(ctx context.Context, id string) error {
	s3Client, ok := ctx.Value("s3Client").(*minio.Client)

	if !ok {
		return fmt.Errorf("Failed to get s3Client from context")
	}

	// TODO: it is posible to remove multiple objects with a single call.
	// Is it better to batch this?
	err := s3Client.RemoveObject(ctx, bucketName, id, minio.RemoveObjectOptions{})

	if err != nil {
		return err
	}

	// Invalidate cache
	return invalidateCache(ctx, nomalizeID(id))
}

func copyMutation(ctx context.Context, src, dest string) (*File, error) {
	s3Client, ok := ctx.Value("s3Client").(*minio.Client)

	if !ok {
		return nil, fmt.Errorf("Failed to get s3Client from context")
	}

	// Check if dest is a file or a dir
	if strings.HasSuffix(dest, "/") {
		// create new dest id
		// TODO: What if a file with this id already exists?
		dest += getFilenameFromID(src)
	}

	info, err := s3Client.CopyObject(ctx, minio.CopyDestOptions{
		Bucket: bucketName,
		Object: dest,
	}, minio.CopySrcOptions{
		Bucket: bucketName,
		Object: src,
	})

	if err != nil {
		return nil, err
	}

	// Invalidate cache
	// TODO: check error
	invalidateCache(ctx, nomalizeID(info.Key))

	return &File{
		ID: info.Key,
	}, nil

}

func moveMutation(ctx context.Context, src, dest string) (*File, error) {
	s3Client, ok := ctx.Value("s3Client").(*minio.Client)

	if !ok {
		return nil, fmt.Errorf("Failed to get s3Client from context")
	}

	// Check if dest is a file or a dir
	if strings.HasSuffix(dest, "/") {
		// create new dest id
		// TODO: What if a file with this id already exists?
		dest += getFilenameFromID(src)
	}

	// There is no (spoon) move. Only copy and delete
	info, err := s3Client.CopyObject(ctx, minio.CopyDestOptions{
		Bucket: bucketName,
		Object: dest,
	}, minio.CopySrcOptions{
		Bucket: bucketName,
		Object: src,
	})

	if err != nil {
		return nil, err
	}

	err = deleteMutation(ctx, src)

	if err != nil {
		return nil, err
	}

	invalidateCache(ctx, nomalizeID(info.Key))

	return &File{
		ID: info.Key,
	}, nil

}

func createDirectory(ctx context.Context, path string) (*Directory, error) {
	s3Client, ok := ctx.Value("s3Client").(*minio.Client)

	if !ok {
		return nil, fmt.Errorf("Failed to get s3Client from context")
	}

	if !strings.HasSuffix(path, "/") {
		path += "/"
	}

	info, err := s3Client.PutObject(ctx, bucketName, path, strings.NewReader(""), 0, minio.PutObjectOptions{
		ContentType: "application/x-directory",
	})

	if err != nil {
		return nil, err
	}

	// Invalidate cache
	// TODO: check error
	invalidateCacheForDir(ctx, nomalizeID(info.Key))

	return &Directory{
		ID: info.Key,
	}, nil

}

func deleteDirectory(ctx context.Context, path string) error {
	s3Client, ok := ctx.Value("s3Client").(*minio.Client)

	if !ok {
		return fmt.Errorf("Failed to get s3Client from context")
	}

	loader, ok := ctx.Value("loader").(map[string]*dataloader.Loader)

	if !ok {
		return fmt.Errorf("Failed to get dataloader from context")
	}

	if !strings.HasSuffix(path, "/") {
		path += "/"
	}

	// Get all files inside the directory
	thunk := loader["listObjectsRecursive"].Load(ctx, dataloader.StringKey(nomalizeID(path)))

	result, err := thunk()

	if err != nil {
		return err
	}

	files, ok := result.([]minio.ObjectInfo)
	if !ok {
		return fmt.Errorf("Failed to get parse result from listObjects")
	}

	// Delete all child files
	err = deleteMultiple(ctx, *s3Client, files)

	if err != nil {
		return err
	}

	// If the dir had no children it exists as an object (object with "/" at the end).
	// If it exists as an object and had children it will get delete once the last child has been deleted
	// If it had no children we have to delete it manualy
	// This is at least the behavior when working with minio as s3 backend
	// TODO: check if this is normal behavior when working with s3
	if len(files) == 0 {
		err := s3Client.RemoveObject(ctx, bucketName, path, minio.RemoveObjectOptions{})
		if err != nil {
			return err
		}
	}

	//Invalidate cache
	invalidateCacheForDir(ctx, nomalizeID(path))

	return nil
}

//login Checks for valid username password combination. Returns singed jwt string
func login(ctx context.Context, username, password string) (LoginResult, error) {

	// TODO: replace with propper user management
	if username != "admin" && password != "hunter2" {
		return LoginResult{
			Successful: false,
		}, nil
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, JWTClaims{
		StandardClaims: jwt.StandardClaims{
			Subject:   username,
			ExpiresAt: time.Now().Add(time.Hour * 24).Unix(),
		},
	})

	tokenString, err := token.SignedString([]byte("TODO"))

	if err != nil {
		return LoginResult{
			Successful: false,
		}, err
	}

	return LoginResult{
		Token:      tokenString,
		Successful: true,
	}, nil
}