diff --git a/internal/app/app.go b/internal/app/app.go
index 8f64bf0..43672b5 100644
--- a/internal/app/app.go
+++ b/internal/app/app.go
@@ -3,7 +3,6 @@ package app
 import (
 	"errors"
 	"flag"
-	"fmt"
 	"git.haefelfinger.net/piwigo/PiwigoDirectoryUploader/internal/pkg/localFileStructure"
 	"git.haefelfinger.net/piwigo/PiwigoDirectoryUploader/internal/pkg/piwigo"
 	"github.com/sirupsen/logrus"
@@ -70,12 +69,9 @@ func configureContext() (*appContext, error) {
 	context := new(appContext)
 	context.LocalRootPath = *imagesRootPath
 	context.Piwigo = new(piwigo.PiwigoContext)
-	context.Piwigo.Url = fmt.Sprintf("%s/ws.php?format=json", *piwigoUrl)
-	context.Piwigo.Username = *piwigoUser
-	context.Piwigo.Password = *piwigoPassword
-	context.Piwigo.ChunkSizeInKB = *piwigoUploadChunkSizeInKB
+	err := context.Piwigo.Initialize(*piwigoUrl, *piwigoUser, *piwigoPassword, *piwigoUploadChunkSizeInKB)
 
-	return context, nil
+	return context, err
 }
 
 func loginToPiwigoAndConfigureContext(context *appContext) error {
diff --git a/internal/pkg/piwigo/PiwigoContext.go b/internal/pkg/piwigo/PiwigoContext.go
index e115135..d9bed83 100644
--- a/internal/pkg/piwigo/PiwigoContext.go
+++ b/internal/pkg/piwigo/PiwigoContext.go
@@ -1,25 +1,61 @@
 package piwigo
 
 import (
+	"errors"
+	"fmt"
 	"github.com/sirupsen/logrus"
 	"net/http"
 	"net/http/cookiejar"
 	"net/url"
 )
 
+type PiwigoFormPoster interface {
+	getChunkSizeInKB() int
+	postForm(formData url.Values) (resp *http.Response, err error)
+}
+
 type PiwigoContext struct {
-	Url           string
-	Username      string
-	Password      string
-	ChunkSizeInKB int
+	url           string
+	username      string
+	password      string
+	chunkSizeInKB int
 	Cookies       *cookiejar.Jar
 }
 
-func (context *PiwigoContext) PostForm(formData url.Values) (resp *http.Response, err error) {
+func (context *PiwigoContext) Initialize(baseUrl string, username string, password string, chunkSizeInKB int) error {
+	if baseUrl == "" {
+		return errors.New("Please provide a valid piwigo server base URL")
+	}
+	_, err := url.Parse(baseUrl)
+	if err != nil {
+		return err
+	}
+
+	if username == "" {
+		return errors.New("Please provide a valid username for the given piwigo server.")
+	}
+
+	if chunkSizeInKB < 256 {
+		return errors.New("The minimum chunksize is 256KB. Please provide a value above. Default is 512KB")
+	}
+
+	context.url = fmt.Sprintf("%s/ws.php?format=json", baseUrl)
+	context.username = username
+	context.password = password
+	context.chunkSizeInKB = chunkSizeInKB
+
+	return nil
+}
+
+func (context *PiwigoContext) getChunkSizeInKB() int {
+	return context.chunkSizeInKB
+}
+
+func (context *PiwigoContext) postForm(formData url.Values) (resp *http.Response, err error) {
 	context.initializeCookieJarIfRequired()
 
 	client := http.Client{Jar: context.Cookies}
-	response, err := client.PostForm(context.Url, formData)
+	response, err := client.PostForm(context.url, formData)
 	if err != nil {
 		logrus.Errorln("The HTTP request failed with error %s", err)
 		return nil, err
diff --git a/internal/pkg/piwigo/authentication.go b/internal/pkg/piwigo/authentication.go
index 9b78544..710f557 100644
--- a/internal/pkg/piwigo/authentication.go
+++ b/internal/pkg/piwigo/authentication.go
@@ -39,18 +39,18 @@ type LogoutResponse struct {
 }
 
 func Login(context *PiwigoContext) error {
-	logrus.Debugf("Logging in to %s using user %s", context.Url, context.Username)
+	logrus.Debugf("Logging in to %s using user %s", context.url, context.username)
 
-	if !strings.HasPrefix(context.Url, "https") {
-		logrus.Warnf("The server url %s does not use https! Credentials are not encrypted!", context.Url)
+	if !strings.HasPrefix(context.url, "https") {
+		logrus.Warnf("The server url %s does not use https! Credentials are not encrypted!", context.url)
 	}
 
 	formData := url.Values{}
 	formData.Set("method", "pwg.session.login")
-	formData.Set("username", context.Username)
-	formData.Set("password", context.Password)
+	formData.Set("username", context.username)
+	formData.Set("password", context.password)
 
-	response, err := context.PostForm(formData)
+	response, err := context.postForm(formData)
 	if err != nil {
 		return err
 	}
@@ -73,12 +73,12 @@ func Login(context *PiwigoContext) error {
 }
 
 func Logout(context *PiwigoContext) error {
-	logrus.Debugf("Logging out from %s", context.Url)
+	logrus.Debugf("Logging out from %s", context.url)
 
 	formData := url.Values{}
 	formData.Set("method", "pwg.session.logout")
 
-	response, err := context.PostForm(formData)
+	response, err := context.postForm(formData)
 	if err != nil {
 		return err
 	}
@@ -90,21 +90,21 @@ func Logout(context *PiwigoContext) error {
 	}
 
 	if statusResponse.Status != "ok" {
-		logrus.Errorf("Logout from %s failed", context.Url)
+		logrus.Errorf("Logout from %s failed", context.url)
 	} else {
-		logrus.Infof("Successfully logged out from %s", context.Url)
+		logrus.Infof("Successfully logged out from %s", context.url)
 	}
 
 	return nil
 }
 
-func GetStatus(context *PiwigoContext) (*GetStatusResponse, error) {
+func GetStatus(context PiwigoFormPoster) (*GetStatusResponse, error) {
 	logrus.Debugln("Getting current login state...")
 
 	formData := url.Values{}
 	formData.Set("method", "pwg.session.getStatus")
 
-	response, err := context.PostForm(formData)
+	response, err := context.postForm(formData)
 	if err != nil {
 		return nil, err
 	}
@@ -117,7 +117,7 @@ func GetStatus(context *PiwigoContext) (*GetStatusResponse, error) {
 	}
 
 	if statusResponse.Status != "ok" {
-		errorMessage := fmt.Sprintf("Could not get session state from %s", context.Url)
+		errorMessage := fmt.Sprintln("Could not get session state from server")
 		logrus.Errorln(errorMessage)
 		return nil, errors.New(errorMessage)
 	}
diff --git a/internal/pkg/piwigo/category.go b/internal/pkg/piwigo/category.go
index f0ee5e8..2070f03 100644
--- a/internal/pkg/piwigo/category.go
+++ b/internal/pkg/piwigo/category.go
@@ -50,12 +50,12 @@ type createCategoryResponse struct {
 	} `json:"result"`
 }
 
-func GetAllCategories(context *PiwigoContext) (map[string]*PiwigoCategory, error) {
+func GetAllCategories(context PiwigoFormPoster) (map[string]*PiwigoCategory, error) {
 	formData := url.Values{}
 	formData.Set("method", "pwg.categories.getList")
 	formData.Set("recursive", "true")
 
-	response, err := context.PostForm(formData)
+	response, err := context.postForm(formData)
 	if err != nil {
 		return nil, err
 	}
@@ -119,7 +119,7 @@ func buildCategoryKeys(categories map[int]*PiwigoCategory) {
 	}
 }
 
-func CreateCategory(context *PiwigoContext, parentId int, name string) (int, error) {
+func CreateCategory(context PiwigoFormPoster, parentId int, name string) (int, error) {
 	formData := url.Values{}
 	formData.Set("method", "pwg.categories.add")
 	formData.Set("name", name)
@@ -129,7 +129,7 @@ func CreateCategory(context *PiwigoContext, parentId int, name string) (int, err
 		formData.Set("parent", fmt.Sprint(parentId))
 	}
 
-	response, err := context.PostForm(formData)
+	response, err := context.postForm(formData)
 	if err != nil {
 		return 0, err
 	}
@@ -146,7 +146,7 @@ func CreateCategory(context *PiwigoContext, parentId int, name string) (int, err
 		return 0, errors.New("Could not create category")
 	}
 
-	logrus.Infof("Successfully got all categories from %s", context.Url)
+	logrus.Infof("Successfully got all categories from server...")
 
 	return createResponse.Result.ID, nil
 }
diff --git a/internal/pkg/piwigo/picture.go b/internal/pkg/piwigo/picture.go
index c0b27e2..4573217 100644
--- a/internal/pkg/piwigo/picture.go
+++ b/internal/pkg/piwigo/picture.go
@@ -32,7 +32,7 @@ type imageExistResponse struct {
 	Result map[string]string `json:"result"`
 }
 
-func ImageUploadRequired(context *PiwigoContext, md5sums []string) ([]string, error) {
+func ImageUploadRequired(context PiwigoFormPoster, md5sums []string) ([]string, error) {
 	//TODO: make sure to split to multiple queries -> to honor max upload queries
 	//TODO: Make sure to return the found imageIds of the found sums to update the local image nodes
 
@@ -44,7 +44,7 @@ func ImageUploadRequired(context *PiwigoContext, md5sums []string) ([]string, er
 
 	logrus.Tracef("Looking up missing files: %s", md5sumList)
 
-	response, err := context.PostForm(formData)
+	response, err := context.postForm(formData)
 	if err != nil {
 		return nil, err
 	}
@@ -68,8 +68,8 @@ func ImageUploadRequired(context *PiwigoContext, md5sums []string) ([]string, er
 	return missingFiles, nil
 }
 
-func UploadImage(context *PiwigoContext, filePath string, md5sum string, category int) (int, error) {
-	if context.ChunkSizeInKB <= 0 {
+func UploadImage(context PiwigoFormPoster, filePath string, md5sum string, category int) (int, error) {
+	if context.getChunkSizeInKB() <= 0 {
 		return 0, errors.New("Uploadchunk size is less or equal to zero. 512 is a recommendet value to begin with.")
 	}
 
@@ -79,7 +79,7 @@ func UploadImage(context *PiwigoContext, filePath string, md5sum string, categor
 	}
 
 	fileSizeInKB := fileInfo.Size() / 1024
-	logrus.Infof("Uploading %s using chunksize of %d KB and total size of %d KB", filePath, context.ChunkSizeInKB, fileSizeInKB)
+	logrus.Infof("Uploading %s using chunksize of %d KB and total size of %d KB", filePath, context.getChunkSizeInKB(), fileSizeInKB)
 
 	err = uploadImageChunks(filePath, context, fileSizeInKB, md5sum)
 	if err != nil {
@@ -94,7 +94,7 @@ func UploadImage(context *PiwigoContext, filePath string, md5sum string, categor
 	return imageId, nil
 }
 
-func uploadImageChunks(filePath string, context *PiwigoContext, fileSizeInKB int64, md5sum string) error {
+func uploadImageChunks(filePath string, context PiwigoFormPoster, fileSizeInKB int64, md5sum string) error {
 	file, err := os.Open(filePath)
 	if err != nil {
 		return err
@@ -102,8 +102,9 @@ func uploadImageChunks(filePath string, context *PiwigoContext, fileSizeInKB int
 	defer file.Close()
 
 	reader := bufio.NewReader(file)
-	buffer := make([]byte, context.ChunkSizeInKB*1024)
-	numberOfChunks := (fileSizeInKB / int64(context.ChunkSizeInKB)) + 1
+	bufferSize := 1024 * context.getChunkSizeInKB()
+	buffer := make([]byte, bufferSize)
+	numberOfChunks := (fileSizeInKB / int64(context.getChunkSizeInKB())) + 1
 	currentChunk := int64(0)
 
 	for {
@@ -130,7 +131,7 @@ func uploadImageChunks(filePath string, context *PiwigoContext, fileSizeInKB int
 	return nil
 }
 
-func uploadImageChunk(context *PiwigoContext, base64chunk string, md5sum string, position int64) error {
+func uploadImageChunk(context PiwigoFormPoster, base64chunk string, md5sum string, position int64) error {
 	formData := url.Values{}
 	formData.Set("method", "pwg.images.addChunk")
 	formData.Set("data", base64chunk)
@@ -141,7 +142,7 @@ func uploadImageChunk(context *PiwigoContext, base64chunk string, md5sum string,
 
 	logrus.Tracef("Uploading chunk %d of file with sum %s", position, md5sum)
 
-	response, err := context.PostForm(formData)
+	response, err := context.postForm(formData)
 	if err != nil {
 		return err
 	}
@@ -161,7 +162,7 @@ func uploadImageChunk(context *PiwigoContext, base64chunk string, md5sum string,
 	return nil
 }
 
-func uploadImageFinal(context *PiwigoContext, originalFilename string, md5sum string, categoryId int) (int, error) {
+func uploadImageFinal(context PiwigoFormPoster, originalFilename string, md5sum string, categoryId int) (int, error) {
 	formData := url.Values{}
 	formData.Set("method", "pwg.images.add")
 	formData.Set("original_sum", md5sum)
@@ -171,7 +172,7 @@ func uploadImageFinal(context *PiwigoContext, originalFilename string, md5sum st
 
 	logrus.Debugf("Finalizing upload of file %s with sum %s to category %d", originalFilename, md5sum, categoryId)
 
-	response, err := context.PostForm(formData)
+	response, err := context.postForm(formData)
 	if err != nil {
 		return 0, err
 	}