From b256006753b46dcb3858cc86bd5fbd5ff43db58d Mon Sep 17 00:00:00 2001
From: Frank Elsinga <frank@elsinga.de>
Date: Wed, 30 Aug 2023 01:18:21 +0200
Subject: [PATCH] implemented feedback image streaming

---
 server/backend/feedback.go | 65 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/server/backend/feedback.go b/server/backend/feedback.go
index 03a60fe8..16fb9396 100644
--- a/server/backend/feedback.go
+++ b/server/backend/feedback.go
@@ -3,12 +3,16 @@ package backend
 import (
 	"context"
 	"database/sql"
+	"fmt"
 	pb "github.com/TUM-Dev/Campus-Backend/server/api"
 	"github.com/TUM-Dev/Campus-Backend/server/model"
 	log "github.com/sirupsen/logrus"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/emptypb"
+	"io"
+	"os"
+	"path/filepath"
 )
 
 func (s *CampusServer) SendFeedback(ctx context.Context, req *pb.SendFeedbackRequest) (*emptypb.Empty, error) {
@@ -39,3 +43,64 @@ func (s *CampusServer) SendFeedback(ctx context.Context, req *pb.SendFeedbackReq
 
 	return &emptypb.Empty{}, nil
 }
+
+func (s *CampusServer) SendFeedbackImage(stream pb.Campus_SendFeedbackImageServer) error {
+	if err := s.checkDevice(stream.Context()); err != nil {
+		return err
+	}
+
+	// prepare temporary file to save steam to
+	file, err := os.CreateTemp("", "*")
+	defer func(file *os.File) {
+		err := file.Close()
+		if err != nil {
+			log.WithError(err).Error("could not close close file for a feedback-image")
+		}
+	}(file)
+	if err != nil {
+		log.WithError(err).Error("failed to create temporary file for a feedback-image")
+		return status.Error(codes.Internal, err.Error())
+	}
+	// download the file to a temporary file
+	fileSize := 0
+	finalDestination := ""
+	for {
+		req, err := stream.Recv()
+		if finalDestination == "" {
+			finalDestination = fmt.Sprintf("/Storage/feedback/%d/%d.png", req.GetId(), req.GetImageNr())
+		}
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			fields := log.Fields{"finalDestination": finalDestination, "fileSize": fileSize}
+			log.WithError(err).WithFields(fields).Error("failed to recive feedbackImage")
+			return status.Error(codes.Aborted, err.Error())
+		}
+		bytesWritten, err := file.Write(req.GetContent())
+		fileSize += bytesWritten
+		log.Debug("received a chunk with size: ", bytesWritten)
+		if err != nil {
+			fields := log.Fields{"finalDestination": finalDestination, "fileSize": fileSize}
+			log.WithError(err).WithFields(fields).Error("failed to write chunk for feedbackImage")
+			return status.Error(codes.ResourceExhausted, err.Error())
+		}
+	}
+	fields := log.Fields{"finalDestination": finalDestination, "fileSize": fileSize, "temporaryFilename": file.Name()}
+	log.WithFields(fields).Debug("received feedbackImage without issue")
+
+	// move the file to a different directory
+	parent := filepath.Dir(finalDestination)
+	if err = os.MkdirAll(parent, os.ModePerm); err != nil {
+		log.WithError(err).WithField("finalDestination", finalDestination).Error("failed to make all directories")
+		return err
+	}
+	if err := os.Rename(file.Name(), finalDestination); err != nil {
+		fields := log.Fields{"finalDestination": finalDestination, "temporaryFilename": file.Name()}
+		log.WithError(err).WithFields(fields).Error("could not move file to the required location")
+		return status.Error(codes.Internal, err.Error())
+	}
+	log.WithFields(fields).Debug("moved the temporary feedbackImage to the correct location")
+
+	return nil
+}