// Package constants define constant variable
package constants

// Internal context keys for trace values set by StartTrace middleware.
// These are gin/stdlib context keys only — actual W3C header propagation
// (traceparent / tracestate) is handled automatically by the OTel propagator.
const (
	HeaderTraceID      = "trace-id"
	HeaderSpanID       = "span-id"
	HeaderParentSpanID = "parent-span-id"
)

// traceCtxKey is an unexported type for context keys to avoid collisions with other packages.
type traceCtxKey string

// Typed context keys for trace values — use these with context.WithValue / ctx.Value.
var (
	CtxKeyTraceID      = traceCtxKey(HeaderTraceID)
	CtxKeySpanID       = traceCtxKey(HeaderSpanID)
	CtxKeyParentSpanID = traceCtxKey(HeaderParentSpanID)
)