package copilot

import (
	"context"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/propagation"
)

// getTraceContext extracts the current W3C Trace Context (traceparent/tracestate)
// from the Go context using the global OTel propagator.
func getTraceContext(ctx context.Context) (traceparent, tracestate string) {
	carrier := propagation.MapCarrier{}
	otel.GetTextMapPropagator().Inject(ctx, carrier)
	return carrier.Get("traceparent"), carrier.Get("tracestate")
}

// contextWithTraceParent returns a new context with trace context extracted from
// the provided W3C traceparent and tracestate headers.
func contextWithTraceParent(ctx context.Context, traceparent, tracestate string) context.Context {
	if traceparent == "" {
		return ctx
	}
	carrier := propagation.MapCarrier{
		"traceparent": traceparent,
	}
	if tracestate != "" {
		carrier["tracestate"] = tracestate
	}
	return otel.GetTextMapPropagator().Extract(ctx, carrier)
}