private static void SanitizeConfiguration(CsvDataReaderConfiguration configuration)
{
//Set all the static value indexes to -1 as the index does not matter for static values.
var staticValueColumns = configuration.ColumnDefinitions.Where(cd => cd.ValueSource == ValueSource.StaticValue).ToList();
if (staticValueColumns.Any())
{
staticValueColumns.ForEach(cd => cd.ColumnIndex = -1);
}
}
private static List <TypeCode> GetTypeCodes(CsvDataReaderConfiguration configuration)
{
var typeCodes = new List <TypeCode>(configuration.CsvColumnsCount);
for (int i = 0; i < configuration.CsvColumnsCount; i++)
{
var csvColumn = configuration.ColumnDefinitions.SingleOrDefault(c => c.ColumnIndex == i);
//If a column is not required, then default to empty data type.
typeCodes.Add(csvColumn == null ? TypeCode.Empty : GetTypeCode(csvColumn.ColumnDataType));
}
return(typeCodes);
}
private static IDataReader AddColumnMapping(CsvDataReaderConfiguration configuration, IDataReader dataReader)
{
//Decorate with column mapping functionality - only for columns that require the mapping
var columnValueMappings = new Dictionary <string, int>(configuration.ColumnDefinitions.Count);
configuration.ColumnDefinitions.Where(cd => cd.ColumnIndex >= 0).ToList()
.ForEach(cd => columnValueMappings.Add(cd.ColumnName, cd.ColumnIndex));
if (columnValueMappings.Count > 0)
{
dataReader = new DataReaderColumnMapping(columnValueMappings, dataReader);
}
return(dataReader);
}
private static IDataReader AddValueTransformation(CsvDataReaderConfiguration configuration, IDataReader dataReader)
{
var transformationParamsMappings = new Dictionary <int, Dictionary <string, object> >(configuration.ColumnDefinitions.Count);
configuration.ColumnDefinitions.Where(cd => cd.ValueSource == ValueSource.ColumnValue && cd.Params != null && cd.Params.Count > 0).ToList()
.ForEach(cd => transformationParamsMappings.Add(cd.ColumnIndex, cd.Params));
//Decorate with value transformation if there are any columns with custom parameters
if (transformationParamsMappings.Count > 0)
{
dataReader = new DataReaderValueTransformation(transformationParamsMappings, dataReader);
}
return(dataReader);
}
public IDataReader GetCsvDataReader(CsvDataReaderConfiguration configuration)
{
ValidateConfiguration(configuration);
SanitizeConfiguration(configuration);
//Create the base CSV data reader
IDataReader dataReader = new CsvDataReader(configuration.CsvFilePath, GetTypeCodes(configuration));
//Add decorators
dataReader = AddColumnMapping(configuration, dataReader);
dataReader = AddValueTransformation(configuration, dataReader);
dataReader = AddExtraColumns(configuration, dataReader);
return(dataReader);
}
private static IDataReader AddExtraColumns(CsvDataReaderConfiguration configuration, IDataReader dataReader)
{
var extraColumns = configuration.ColumnDefinitions.Where(cd => cd.ValueSource == ValueSource.StaticValue).ToList();
//Decorate with extra columns if the are any columns with static values
if (extraColumns.Count > 0)
{
var extraColumnsDataReader = new DataReaderExtraColumns(dataReader);
foreach (var extraColumn in extraColumns)
{
extraColumnsDataReader.AddExtraColumn(extraColumn.ColumnName, extraColumn.Params[ParamKeys.Value]);
}
dataReader = extraColumnsDataReader;
}
return(dataReader);
}
private void ValidateConfiguration(CsvDataReaderConfiguration configuration)
{
if (string.IsNullOrWhiteSpace(configuration?.CsvFilePath))
{
throw new ArgumentException("Configuration invalid. FilePath is required.");
}
if (configuration.CsvColumnsCount <= 0)
{
throw new ArgumentException("Configuration invalid. ColumnsCount needs to be positive.");
}
if (configuration.ColumnDefinitions == null || !configuration.ColumnDefinitions.Any())
{
throw new ArgumentException("Configuration invalid. CsvColumnDefinitions are required.");
}
if (configuration.ColumnDefinitions.Any(d => string.IsNullOrWhiteSpace(d.ColumnName) || string.IsNullOrWhiteSpace(d.ColumnDataType)))
{
throw new ArgumentException("Configuration invalid. ColumnName and ColumnDataType fields are required.");
}
if (configuration.ColumnDefinitions.Where(cd => cd.ValueSource != ValueSource.StaticValue).Select(cd => cd.ColumnIndex).Distinct().Count() !=
configuration.ColumnDefinitions.Count(cd => cd.ValueSource != ValueSource.StaticValue))
{
throw new ArgumentException("Configuration invalid. ColumnIndex field has to have a unique value for non-static value sources.");
}
if (configuration.ColumnDefinitions.Select(cd => cd.ColumnName).Distinct().Count() !=
configuration.ColumnDefinitions.Count)
{
throw new ArgumentException("Configuration invalid. ColumnName field has to have a unique value.");
}
var staticValueColumns = configuration.ColumnDefinitions
.Where(cd => cd.ValueSource == ValueSource.StaticValue).ToList();
staticValueColumns.ForEach(cd =>
{
if (cd.Params == null || !cd.Params.ContainsKey(ParamKeys.Value))
{
throw new ArgumentException("Configuration invalid. Static value columns have to have a value parameter.");
}
});
}
