namespace ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Actors;

/// <summary>
/// Maps a data connection name to the Akka actor name of its <see cref="DataConnectionActor"/>
/// (review 2026-10-21, lane A M2). Shared by <see cref="DataConnectionManagerActor"/> (which
/// creates the actor) and the site deploy gate (which rejects a config whose connection names
/// would collide once sanitised), so both always agree on the name.
///
/// <para>
/// Every output is a legal Akka path element: ASCII letters and digits plus
/// <c>-_.*+:@&amp;=,!~';()</c> are kept, everything else — spaces, <c>/</c>, <c>#</c>, <c>$</c>
/// and every non-ASCII character — becomes <c>-</c>. The previous sanitiser kept
/// <see cref="char.IsLetterOrDigit(char)"/> (true for non-ASCII letters, which Akka refuses) and
/// <c>$</c> (refused as a leading character), so "Ofen Süd" or "$PLC" threw out of
/// <c>Context.ActorOf</c>. The mapping is NOT injective ("PLC A" and "PLC-A" both give
/// "PLC-A"); callers must treat a collision as an error for the later connection.
/// </para>
/// </summary>
public static class ConnectionActorNames
{
    private const string KeptSymbols = "-_.*+:@&=,!~';()";

    /// <summary>The actor name used for <paramref name="connectionName"/>.</summary>
    /// <param name="connectionName">The data connection's configured name.</param>
    /// <returns>A legal, non-empty Akka actor name.</returns>
    public static string Sanitize(string connectionName)
    {
        if (string.IsNullOrEmpty(connectionName))
            return "-";

        var chars = new char[connectionName.Length];
        for (var i = 0; i < chars.Length; i++)
        {
            var c = connectionName[i];
            chars[i] = (c is >= 'a' and <= 'z' or >= 'A' and <= 'Z' or >= '0' and <= '9') ||
                       KeptSymbols.Contains(c)
                ? c
                : '-';
        }

        return new string(chars);
    }
}