Merge pull request #64 from TheWisePigeon/8-handle-file-uploads

Handle file uploads

internal/handlers/faces.go

@@ -0,0 +1,48 @@
+package handlers
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"visio/internal/types"
+	"visio/pkg"
+)
+
+type FaceHandler struct {
+	logger *slog.Logger
+}
+
+func NewFaceHandler(logger *slog.Logger) *FaceHandler {
+	return &FaceHandler{
+		logger: logger,
+	}
+}
+
+func (h *FaceHandler) SaveFace(w http.ResponseWriter, r *http.Request) {
+	filePath, err := pkg.HandleFileUpload(w, r)
+	if err != nil {
+		if errors.Is(err, types.ErrFileNotFound) {
+			w.WriteHeader(http.StatusBadRequest)
+			w.Write([]byte(types.ErrFileNotFoundMessage))
+			return
+		}
+		if errors.Is(err, types.ErrUnsupportedFormat) {
+			w.WriteHeader(http.StatusBadRequest)
+			w.Write([]byte(types.ErrUnsupportedFormatMessage))
+			return
+		}
+		if errors.Is(err, types.ErrBodyTooLarge) {
+			w.WriteHeader(http.StatusBadRequest)
+			w.Write([]byte(types.ErrBodyTooLargeMessage))
+			return
+		}
+		h.logger.Error(err.Error())
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	fmt.Println(filePath)
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte("Ok"))
+	return
+}

internal/types/errors.go

@@ -3,7 +3,16 @@ package types
 import "errors"
 
 var (
-	ErrUserNotFound    = errors.New("No user found")
-	ErrSessionNotFound = errors.New("Session not found")
-	ErrDuplicatePrefix = errors.New("Duplicate key prefix")
+	ErrFileNotFoundMessage      = "'face' field not found in request body"
+	ErrUnsupportedFormatMessage = "File type not supported. Only image/jpeg and image/png are."
+	ErrBodyTooLargeMessage      = "Request body too large. Only 5Mb is allowed."
+)
+
+var (
+	ErrUserNotFound      = errors.New("No user found")
+	ErrSessionNotFound   = errors.New("Session not found")
+	ErrDuplicatePrefix   = errors.New("Duplicate key prefix")
+	ErrFileNotFound      = errors.New(ErrFileNotFoundMessage)
+	ErrUnsupportedFormat = errors.New(ErrUnsupportedFormatMessage)
+	ErrBodyTooLarge      = errors.New(ErrBodyTooLargeMessage)
 )

main.go

@@ -38,6 +38,7 @@ func main() {
 	appHandler := handlers.NewAppHandler(keys, appLogger)
 	authHandler := handlers.NewAuthHandler(users, sessions, appLogger)
 	keyHandler := handlers.NewKeyHandler(keys, sessions, appLogger)
+	faceHandler := handlers.NewFaceHandler(appLogger)
 	authMiddleware := middlewares.NewAuthMiddleware(sessions, users, appLogger)
 
 	r := chi.NewRouter()
@@ -68,6 +69,10 @@ func main() {
 		r.With(authMiddleware.CookieAuth).Delete("/{prefix}", keyHandler.Revoke)
 	})
 
+	r.Route("/faces", func(r chi.Router) {
+		r.Post("/", faceHandler.SaveFace)
+	})
+
 	port := os.Getenv("PORT")
 	if port == "" {
 		panic("Unable to read PORT environment variable")

pkg/uploads.go

@@ -0,0 +1,64 @@
+package pkg
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"visio/internal/types"
+)
+
+var imageMimeTypes = []string{
+	"image/jpeg",
+	"image/png",
+}
+
+const MaxFileSize = 5
+
+func HandleFileUpload(w http.ResponseWriter, r *http.Request) (string, error) {
+	r.Body = http.MaxBytesReader(w, r.Body, MaxFileSize<<20)
+	reader, err := r.MultipartReader()
+	if err != nil {
+		return "", fmt.Errorf("Error while reading multipart request body: %w", err)
+	}
+	p, err := reader.NextPart()
+	if err != nil && err != io.EOF {
+		return "", fmt.Errorf("Error while reading multipart body part: %w", err)
+	}
+	if p.FormName() != "face" {
+		return "", types.ErrFileNotFound
+	}
+	buffer := bufio.NewReader(p)
+	sniffedBytes, err := buffer.Peek(512)
+	if err != nil {
+		return "", fmt.Errorf("Error while peeking through bytes: %w", err)
+	}
+	contentType := http.DetectContentType(sniffedBytes)
+	fileIsNotImage := true
+	for _, mimeType := range imageMimeTypes {
+		if contentType == mimeType {
+			fileIsNotImage = false
+			break
+		}
+	}
+	if fileIsNotImage {
+		return "", types.ErrUnsupportedFormat
+	}
+	f, err := os.CreateTemp("", "")
+	if err != nil {
+		return "", fmt.Errorf("Error while creating file: %w", err)
+	}
+	defer f.Close()
+	var maxSize int64 = MaxFileSize << 20
+	lmt := io.MultiReader(buffer, io.LimitReader(p, maxSize-511))
+	written, err := io.Copy(f, lmt)
+	if err != nil && err != io.EOF {
+		return "", types.ErrBodyTooLarge
+	}
+	if written > maxSize {
+		os.Remove(f.Name())
+		return "", fmt.Errorf("Error while deleting file: %w", err)
+	}
+	return f.Name(), nil
+}