Viatom/Wellue Check Me O2 [interface cable]

Code:
[TestMethod]

public void ReadViatomBinaryFile()

{

    const int HEADER_SIZE = 40;

    const int RECORD_SIZE = 5;



    string path = @"[REDACTED, CHANGES ACCORDING TO WHICH FILE I WANT TO TEST]";



    Assert.IsTrue( File.Exists( path ) );



    using var file   = File.OpenRead( path );

    using var reader = new BinaryReader( file );



    int fileVersion = reader.ReadInt16();

    Assert.IsTrue( fileVersion is 3 or 5 ); // Never actually encountered FileVersion=5, but apparently someone else has and it's binary compatible



    int year = reader.ReadInt16();

    Assert.AreEqual( 2023, year );



    int month = reader.ReadByte();

    Assert.IsTrue( month >= 1 && month <= 12 );

            

    int day = reader.ReadByte();

    Assert.IsTrue( day is >= 1 and <= 31 );

            

    int hour = reader.ReadByte();

    Assert.IsTrue( hour is >= 0 and <= 24 );

            

    int minute = reader.ReadByte();

    Assert.IsTrue( minute is >= 0 and <= 60 );

            

    int second = reader.ReadByte();

    Assert.IsTrue( second is >= 0 and <= 60 );



    var expectedTimestamp = DateTime.Parse( "2023-10-04 03:17:47.000" );

    var headerTimestamp   = new DateTime( year, month, day, hour, minute, second );

    Assert.AreEqual( expectedTimestamp, headerTimestamp );



    // Read timestamp (NOTE: The filename also appears to be a timestamp. Do they always match?)

    var filenameTimestamp = DateTime.ParseExact( Path.GetFileName( path ), "yyyyMMddHHmmsss", CultureInfo.InvariantCulture );

    Assert.AreEqual( expectedTimestamp, filenameTimestamp );



    // Read and validate file size 

    int fileSize = reader.ReadInt32();

    Assert.AreEqual( file.Length, fileSize );

            

    // Read duration of recording 

    var duration = TimeSpan.FromSeconds( reader.ReadInt16() );

    Assert.AreEqual( TimeSpan.FromSeconds( 5316 ), duration );



    // Skip the rest of the header, as it doesn't provide any useful information for us. 

    file.Position = HEADER_SIZE;

    

    // The rest of the file should be an exact multiple of RECORD_SIZE

    Assert.AreEqual( 0, (fileSize - HEADER_SIZE) % RECORD_SIZE );



    int    recordCount = (fileSize - HEADER_SIZE) / RECORD_SIZE;

    double frequency   = 1.0 / (duration.TotalSeconds / recordCount);



    for( int i = 0; i < recordCount; i++ )

    {

        var spO2      = reader.ReadByte();

        var pulse     = reader.ReadByte();

        var isInvalid = reader.ReadByte();

        var motion    = reader.ReadByte();

        var vibration = reader.ReadByte();

        

        Debug.WriteLine( $"OX: {spO2}, PULSE: {pulse}, MOT: {motion}, INVALID: {isInvalid}, VIB: {vibration}" );

    }

}