mattjohnsonpint · October 5, 2024 23:31 · mattjohnsonpint · Aug 21, 2019
diff --git a/Program.cs b/Program.cs
 using System.Text.RegularExpressions;
 using GeoTimeZone;        // Import from Nuget package "GeoTimeZone"  (https://github.com/mattjohnsonpint/GeoTimeZone)
 using TimeZoneConverter;  // Import from Nuget package "TimeZoneConverter"  (https://github.com/mattjohnsonpint/TimeZoneConverter)

 namespace AirportTimeZones;

 internal static class Program
 {
    private static void Main()
    {
        // Get the airports.csv data file from here: http://ourairports.com/data/

        using var reader = File.OpenText("airports.csv");
        var header = reader.ReadLine();
        if (header == null)
            return;

        var csvRegex = new Regex("((?<=\")[^\"]*(?=\"(,|$)+)|(?<=,|^)[^,\"]*(?=,|$))", RegexOptions.Compiled);

        var columns = csvRegex.Matches(header).Select((m, i) => new { m.Value, Index = i }).ToDictionary(x => x.Value, x => x.Index);
        var typeIndex = columns["type"];
        var latIndex = columns["latitude_deg"];
        var lonIndex = columns["longitude_deg"];
        var codeIndex = columns["iata_code"];

        var results = new Dictionary<string, string>();
        string[] badCodes = { "", "-", "---", "0" };

        while (reader.ReadLine() is { } line)
        {
            var values = csvRegex.Matches(line);

            var type = values[typeIndex].Value;
            var code = values[codeIndex].Value;

            if (badCodes.Contains(code) || type == "closed" || results.ContainsKey(code))
                continue;

            var lat = double.Parse(values[latIndex].Value);
            var lon = double.Parse(values[lonIndex].Value);
            var tz = TimeZoneLookup.GetTimeZone(lat, lon).Result;

            results.Add(code, tz);
        }

        using var writer = File.CreateText("timezones.csv");
        
        writer.WriteLine("\"iata_code\",\"iana_tz\",\"windows_tz\"");
        foreach (var item in results.OrderBy(x => x.Key))
        {
            if (!TZConvert.TryIanaToWindows(item.Value, out var windowsTimeZone)) 
                windowsTimeZone = string.Empty;
            
            writer.WriteLine("\"{0}\",\"{1}\",\"{2}\"", item.Key, item.Value, windowsTimeZone);
        }
    }
 }
diff --git a/timezones.csv b/timezones.csv
	using System.Text.RegularExpressions;
	using GeoTimeZone; // Import from Nuget package "GeoTimeZone" (https://github.com/mattjohnsonpint/GeoTimeZone)
	using TimeZoneConverter; // Import from Nuget package "TimeZoneConverter" (https://github.com/mattjohnsonpint/TimeZoneConverter)

	namespace AirportTimeZones;

	internal static class Program
	{
	private static void Main()
	{
	// Get the airports.csv data file from here: http://ourairports.com/data/

	using var reader = File.OpenText("airports.csv");
	var header = reader.ReadLine();
	if (header == null)
	return;

	var csvRegex = new Regex("((?<=\")[^\"](?=\"(,\|$)+)\|(?<=,\|^)[^,\"](?=,\|$))", RegexOptions.Compiled);

	var columns = csvRegex.Matches(header).Select((m, i) => new { m.Value, Index = i }).ToDictionary(x => x.Value, x => x.Index);
	var typeIndex = columns["type"];
	var latIndex = columns["latitude_deg"];
	var lonIndex = columns["longitude_deg"];
	var codeIndex = columns["iata_code"];

	var results = new Dictionary<string, string>();
	string[] badCodes = { "", "-", "---", "0" };

	while (reader.ReadLine() is { } line)
	{
	var values = csvRegex.Matches(line);

	var type = values[typeIndex].Value;
	var code = values[codeIndex].Value;

	if (badCodes.Contains(code) \|\| type == "closed" \|\| results.ContainsKey(code))
	continue;

	var lat = double.Parse(values[latIndex].Value);
	var lon = double.Parse(values[lonIndex].Value);
	var tz = TimeZoneLookup.GetTimeZone(lat, lon).Result;

	results.Add(code, tz);
	}

	using var writer = File.CreateText("timezones.csv");

	writer.WriteLine("\"iata_code\",\"iana_tz\",\"windows_tz\"");
	foreach (var item in results.OrderBy(x => x.Key))
	{
	if (!TZConvert.TryIanaToWindows(item.Value, out var windowsTimeZone))
	windowsTimeZone = string.Empty;

	writer.WriteLine("\"{0}\",\"{1}\",\"{2}\"", item.Key, item.Value, windowsTimeZone);
	}
	}
	}