Implemented preferences endpoints for apiv4 (#5531)

* implemented preferences endpoints for apiv4

* added user id in preferences endpoints

app/preference.go

@@ -5,12 +5,56 @@ package app
 
 import (
 	"github.com/mattermost/platform/model"
+	"net/http"
 )
 
 func GetPreferencesForUser(userId string) (model.Preferences, *model.AppError) {
 	if result := <-Srv.Store.Preference().GetAll(userId); result.Err != nil {
+		result.Err.StatusCode = http.StatusBadRequest
 		return nil, result.Err
 	} else {
 		return result.Data.(model.Preferences), nil
 	}
 }
+
+func GetPreferenceByCategoryForUser(userId string, category string) (model.Preferences, *model.AppError) {
+	if result := <-Srv.Store.Preference().GetCategory(userId, category); result.Err != nil {
+		result.Err.StatusCode = http.StatusBadRequest
+		return nil, result.Err
+	} else if len(result.Data.(model.Preferences)) == 0 {
+		err := model.NewAppError("getPreferenceCategory", "api.preference.preferences_category.get.app_error", nil, "", http.StatusNotFound)
+		return nil, err
+	} else {
+		return result.Data.(model.Preferences), nil
+	}
+}
+
+func GetPreferenceByCategoryAndNameForUser(userId string, category string, preferenceName string) (*model.Preference, *model.AppError) {
+	if result := <-Srv.Store.Preference().Get(userId, category, preferenceName); result.Err != nil {
+		result.Err.StatusCode = http.StatusBadRequest
+		return nil, result.Err
+	} else {
+		data := result.Data.(model.Preference)
+		return &data, nil
+	}
+}
+
+func UpdatePreferences(preferences model.Preferences) (bool, *model.AppError) {
+	if result := <-Srv.Store.Preference().Save(&preferences); result.Err != nil {
+		result.Err.StatusCode = http.StatusBadRequest
+		return false, result.Err
+	}
+
+	return true, nil
+}
+
+func DeletePreferences(userId string, preferences model.Preferences) (bool, *model.AppError) {
+	for _, preference := range preferences {
+		if result := <-Srv.Store.Preference().Delete(userId, preference.Category, preference.Name); result.Err != nil {
+			result.Err.StatusCode = http.StatusBadRequest
+			return false, result.Err
+		}
+	}
+
+	return true, nil
+}