/// <summary>
/// Decode one report line
/// </summary>
/// <param name="csvLine">The Station report line</param>
/// <param name="lookup">An item lookup table</param>
/// <returns>A MetarData record</returns>
private static MetarTafData DecodeCSVLine(string csvLine, IDictionary <Fields, int> lookup)
{
var rec = new MetarTafData();
try {
string[] e = csvLine.Split(new char[] { ',' });
rec.RAW = e[lookup[Fields.raw_text]].Trim( );
rec.Data = MDEC.MTData.Decode(rec.RAW);
if (double.TryParse(e[lookup[Fields.latitude]], out double dData))
{
rec.Lat = dData;
}
if (double.TryParse(e[lookup[Fields.longitude]], out dData))
{
rec.Lon = dData;
}
if (float.TryParse(e[lookup[Fields.elevation_m]], out float fData))
{
rec.Elevation_m = fData;
}
rec.Valid = true;
}
catch {
rec.Error = $"Unrecognizable TAF record\n{csvLine}";
rec.Valid = false;
}
return(rec);
}
/// <summary>
/// Decodes a METAR / TAF message received as CSV
/// Returns one or more MetarTafData Records as List
/// </summary>
/// <param name="csvData">The Metar/Taf Message</param>
/// <returns>A list of MetarTafData</returns>
internal static MetarTafDataList DecodeCSV(string csvData)
{
// arrives as
/*
* No errors
* No warnings
* 3 ms
* data source=tafs
* N results
* header line
* value line
*/
var ret = new MetarTafDataList();
if (string.IsNullOrEmpty(csvData))
{
var rec = new MetarTafData(); ret.Add(rec);
rec.Error = $"Empty TAF record received";
rec.Valid = false;
return(ret);
}
using (var sr = new StringReader(csvData)) {
try {
var line = sr.ReadLine(); // errors
if (!line.StartsWith("No errors"))
{
var rec = new MetarTafData(); ret.Add(rec);
rec.Error = line;
rec.Valid = false;
return(ret);
}
line = sr.ReadLine( ); // warnings
line = sr.ReadLine( ); // response time
line = sr.ReadLine( ); // data sources
line = sr.ReadLine( ); // N results
string[] e = line.Split(new char[] { ' ' }); // get the N
if (!int.TryParse(e[0], out int nRec))
{
var rec = new MetarTafData(); ret.Add(rec);
rec.Error = $"TAF cannot derive number of records\n{line}";
rec.Valid = false;
return(ret);
}
if (nRec <= 0)
{
var rec = new MetarTafData(); ret.Add(rec);
rec.Error = $"TAF contains 0 records (not a known station?)\n{line}";
rec.Valid = false;
return(ret);
}
line = sr.ReadLine( ); // headers
if (!line.StartsWith($"{Fields.raw_text},"))
{
var rec = new MetarTafData(); ret.Add(rec);
rec.Error = $"Unrecognizable TAF record header format\n{line}";
rec.Valid = false;
return(ret);
}
// Create an item Lookup table
var hList = line.Split(new char[] { ',' }).ToList(); // the list of items from the header
var lookup = CreateLookup(line); // a lookup where the value is the item index in the list (and CSV line)
if (lookup.Count == 0)
{
var rec = new MetarTafData(); ret.Add(rec);
rec.Error = $"Field(s) not found in TAF record header format\n{line}";
rec.Valid = false;
return(ret);
}
// get all station reports
for (int i = 0; i < nRec; i++)
{
line = sr.ReadLine( ); // result line
ret.Add(DecodeCSVLine(line, lookup));
}
}
#pragma warning disable CS0168 // Variable is declared but never used
catch (Exception e) {
#pragma warning restore CS0168 // Variable is declared but never used
var rec = new MetarTafData(); ret.Add(rec);
rec.Error = $"Unrecognizable TAF record\n{csvData}";
rec.Valid = false;
}
return(ret);
}
}
