synapsecns/sanguine

package slackertrace

import (
    "fmt"
    "github.com/slack-io/slacker"
    "github.com/synapsecns/sanguine/core/metrics"
    "go.opentelemetry.io/otel/attribute"
    "go.opentelemetry.io/otel/trace"
)

// TracingMiddleware is a middleware that creates a new span for each command.
func TracingMiddleware(handler metrics.Handler) slacker.CommandMiddlewareHandler {
    return func(next slacker.CommandHandler) slacker.CommandHandler {
        return func(cmdCtx *slacker.CommandContext) {
            ctx, span := handler.Tracer().Start(cmdCtx.Context(), fmt.Sprintf("command.%s", cmdCtx.Definition().Command), trace.WithAttributes(
                attribute.String("user_id", cmdCtx.Event().UserID),
                attribute.String("channel_id", retrieveChannelIfExists(cmdCtx.Event())),
            ))

            cmdCtx.WithContext(ctx)

            defer func() {
                metrics.EndSpan(span)
            }()

            next(cmdCtx)
        }
    }
}

const unknownChannel = "unknown"

func retrieveChannelIfExists(event *slacker.MessageEvent) string {
    if event != nil && event.Channel != nil {
        return event.Channel.ID
    }
    return unknownChannel
}