.NET events

GenAIEventsILogger.cs

private string GetFinishReason(ChatFinishReason finishReason) => finishReason switch
{
    ChatFinishReason.Stop => "stop",
    ChatFinishReason.Length => "length",
    ChatFinishReason.ToolCalls => "tool_calls",
    // ...
    _ => finishReason.ToString(),
};

private void LogChoice(ChatCompletion message)
{
    if (_logger.IsEnabled(LogLevel.Information))
    {
        var eventBody = new
        {
            id = message.Id,
            index = 0,
            finish_reason = GetFinishReason(message.FinishReason),
            message = new
            {
                content = new 
                { 
                    role = "assistant", 
                    content = IsContentLoggingEnabled ? 
                        message.Content.Where(c => c.Kind == ChatMessageContentPartKind.Text).First().Text : null
                },
                tool_calls = message.ToolCalls.Any() ? message.ToolCalls.Select(t => new
                {
                    id = t.Id,
                    type = t.Kind,
                    function = new
                    {
                        name = t.FunctionName,
                        arguments = IsContentLoggingEnabled ? t.FunctionArguments : null,
                    }
                }) : null
            }
        };

        var eventBodyString = JsonSerializer.Serialize(eventBody);

        List<KeyValuePair<string, object?>> state =
        [
            new KeyValuePair<string, object?>("event.name", "gen_ai.choice"),
            new KeyValuePair<string, object?>("gen_ai.system", "openai"),
        ];

        _logger.Log(LogLevel.Information, new EventId(1, "gen_ai.choice"), state, null, (s, e) => eventBodyString);
    }
}

// a perfect future
private void LogChoiceFuture(ChatCompletion message)
{
    List<KeyValuePair<string, object?>> attributes =
    [
        new KeyValuePair<string, object?>("gen_ai.system", "openai"),
    ];

    _logger.Log(LogLevel.Information, new EventId(1, "gen_ai.choice"), attributes, eventBody);
}