/// <summary>
        /// Extracts data off a csv file
        /// </summary>
        /// <param name="file"></param>
        /// <param name="dataStore"></param>
        /// <param name="delimiter"></param>
        /// <param name="hasHeader"></param>
        /// <returns></returns>
        public static List <Dictionary <string, object> > ExtractCsvData(string file, DataStore dataStore, string delimiter = ";", bool hasHeader = true, bool hasGeo = true)
        {
            var data = new List <Dictionary <string, object> >();

            using (var rdr = new StreamReader(file))
                using (var csvRdr = new CsvReader(rdr))
                {
                    csvRdr.Configuration.Delimiter       = delimiter;
                    csvRdr.Configuration.HasHeaderRecord = hasHeader;

                    if (hasHeader)
                    {
                        csvRdr.Read();
                    }
                    csvRdr.ReadHeader();


                    //create col names map from data store, so can match csv header col names to safe db col names
                    var colNamesMap = new Dictionary <string, string>();
                    var colTypesMap = new Dictionary <string, ColumnDataType>();
                    foreach (var c in dataStore.DataSource.Columns)
                    {
                        colNamesMap[c.FriendlyName] = c.Name;
                        colTypesMap[c.Name]         = c.Type;
                    }

                    //data
                    while (csvRdr.Read())
                    {
                        var rec = new Dictionary <string, object>();
                        foreach (var colName in csvRdr.Context.HeaderRecord)
                        {
                            var cName = string.Empty;
                            if (FlatLonProps.Contains(colName))
                            {
                                cName = "lo";
                            }
                            else if (FlatLatProps.Contains(colName))
                            {
                                cName = "la";
                            }
                            else if (FlatGeomProps.Contains(colName))
                            {
                                cName = "wkt";
                            }
                            else
                            {
                                cName = colNamesMap[colName];
                            }

                            rec.Add(cName, ParseToColumnDataType(csvRdr.GetField(colName), colTypesMap.ContainsKey(cName) ? colTypesMap[cName] : ColumnDataType.String));
                        }

                        if (hasGeo && !(rec.ContainsKey("lo") && rec.ContainsKey("la") || rec.ContainsKey("wkt")))
                        {
                            throw MapHive.Core.DataModel.Validation.Utils.GenerateValidationFailedException("FlatData", "no_geo",
                                                                                                            "Flat file does not contain any spatial information (usually lon / lat)");
                        }

                        data.Add(rec);
                    }
                }

            return(data);
        }
        /// <summary>
        /// Processes a flat json file; file has got to have numeric lon / longitude & lat / latitude properties; coords are assumed to be in lon/lat
        /// </summary>
        /// <param name="dbCtx"></param>
        /// <param name="path"></param>
        /// <param name="dsc"></param>
        /// <returns></returns>
        public static async Task <DataStore> ProcessJson(DbContext dbCtx, string path, DataSourceCredentials dsc)
        {
            //assuming a single zip can only be present in a directory, as uploading data for a single layer

            //if there is a zip archive, need to extract it
            ExtractZip(path);


            //test for required shp format files presence...
            var file = Directory.GetFiles(path, "*.json").FirstOrDefault();

            if (string.IsNullOrEmpty(file))
            {
                throw MapHive.Core.DataModel.Validation.Utils.GenerateValidationFailedException("JSON", "no_json_file",
                                                                                                "JSON file has not been found");
            }

            var fName = Path.GetFileNameWithoutExtension(file);

            var output = GetDataStore(fName, "json", dsc);


            var json = JsonConvert.DeserializeObject(File.ReadAllText(file));

            if (json.GetType() != typeof(JArray))
            {
                throw MapHive.Core.DataModel.Validation.Utils.GenerateValidationFailedException("JSON", "not_array",
                                                                                                "JSON file has not been deserialized to array");
            }

            var data = new List <Dictionary <string, object> >(((JArray)json).Count);

            foreach (JObject jRec in (JArray)json)
            {
                var rec = new Dictionary <string, object>();

                foreach (var jProp in jRec.Properties())
                {
                    var propName = jProp.Name.ToLower();

                    //basically looking at a flat json file, BUT allowing convenience parsing for some nested properties
                    if (FlatLonProps.Contains(propName))
                    {
                        rec.Add("lo", GetValueFromJsonProperty(jProp.Value));
                    }
                    else if (FlatLatProps.Contains(propName))
                    {
                        rec.Add("la", GetValueFromJsonProperty(jProp.Value));
                    }
                    else if (FlatGeoLocationProps.Contains(propName))
                    {
                        if (TryExtractLoLaFromJsonObject((JObject)jProp.Value, out var lo, out var la))
                        {
                            rec.Add("lo", lo);
                            rec.Add("la", la);
                        }
                        ;
                    }
                    else if (FlatGeomProps.Contains(propName))
                    {
                        rec.Add("wkt", GetValueFromJsonProperty(jProp.Value));
                    }
                    else
                    {
                        rec.Add(jProp.Name, GetValueFromJsonProperty(jProp.Value));
                    }
                }

                if (rec.ContainsKey("lo") && rec.ContainsKey("la") || rec.ContainsKey("wkt"))
                {
                    data.Add(rec);
                }
            }


            //work out a data model - this is json, so can be totally unpredictable
            foreach (var rec in data)
            {
                foreach (var fProp in rec)
                {
                    //ignore lon/lat, this will be turned into a point
                    //testing for lon/lat only as data is already normalized
                    if (fProp.Key == "lo" || fProp.Key == "la" || fProp.Key == "wkt")
                    {
                        continue;
                    }

                    if (output.DataSource.Columns.Any(c => c.Name == GetSafeDbObjectName(fProp.Key)))
                    {
                        continue;
                    }

                    if (!CheckIfObjectSafe(fProp.Key))
                    {
                        throw MapHive.Core.DataModel.Validation.Utils.GenerateValidationFailedException("ColName", "bad_col_name",
                                                                                                        "Column name contains forbidden words");
                    }

                    var colType = SystemTypeToColumnDataType(fProp.Value.GetType());
                    if (colType != ColumnDataType.Unknown)
                    {
                        output.DataSource.Columns.Add(new Column
                        {
                            Type         = colType,
                            Name         = GetSafeDbObjectName(fProp.Key),
                            FriendlyName = fProp.Key
                        });
                    }
                }
            }

            //create object straight away, so when something goes wrong with import, etc. there is a chance for a cleanup bot
            //to pick it up and cleanup the orphaned data when necessary
            await output.CreateAsync(dbCtx);

            return(await ProcessFlatData(dbCtx, output, data));
        }