using System.Diagnostics.CodeAnalysis;
using static System.Globalization.CultureInfo;

namespace InnovEnergy.App.Collector.Influx;

internal static class LineProtocolSyntax
{
    private static readonly DateTime Origin = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);


    public static String EscapeName(String nameOrKey)
    {
        return nameOrKey
              .Replace("=", "\\=")
              .Replace(" ", "\\ ")
              .Replace(",", "\\,");
    }

    [SuppressMessage("ReSharper", "RedundantVerbatimPrefix")]
    public static String FormatValue(Object value)
    {
        return value switch
        {
            String   @string   => FormatString  (@string),
            Single   @single   => FormatFloat   (@single),
            Double   @double   => FormatFloat   (@double),
            Int32    @int32    => FormatInteger (@int32),
            UInt32   @uInt32   => FormatInteger (@uInt32),
            Int64    @int64    => FormatInteger (@int64),
            UInt64   @uInt64   => FormatInteger (@uInt64),
            Decimal  @decimal  => FormatFloat   (@decimal),
            Int16    @int16    => FormatInteger (@int16),
            UInt16   @uInt16   => FormatInteger (@uInt16),
            SByte    @sByte    => FormatInteger (@sByte),
            Byte     @byte     => FormatInteger (@byte),
            Boolean  @boolean  => FormatBoolean (@boolean),
            TimeSpan @timeSpan => FormatTimespan(@timeSpan),
            _                  => FormatString  (value.ToString())
        };
    }

    private static String FormatInteger<T>(T i) where T: IFormattable
    {
        return FormatFloat(i) + "i";
    }

    private static String FormatFloat<T>(T f) where T: IFormattable
    {
        return f.ToString(format: null, InvariantCulture);
    }

    private static String FormatTimespan(TimeSpan timeSpan)
    {
        return timeSpan
            .TotalMilliseconds
            .ToString(InvariantCulture);
    }

    private static String FormatBoolean(Boolean b) => b ? "t" : "f";


    private static String FormatString(Object? o)
    {
        var s = o?.ToString();

        return s is null 
             ? "<null>" 
             : "\"" + s.Replace("\"", "\\\"") + "\"";
    }

    public static String FormatTimestamp(DateTime utcTimestamp)
    {
        var t = utcTimestamp - Origin;
        return (t.Ticks * 100L).ToString(InvariantCulture);
    }
}