package tracer

import "context"

type Tracer interface {
	Start(ctx context.Context, spanName string, opts ...interface{}) (context.Context, Span)
}

type Span interface {
	RecordError(err error)
	End()
}

var tracer Tracer = &NoOpTracer{}

// Can be used for your own tracing (for example, with Lightstep)
func SetTracer(t Tracer) {
	tracer = t
}

func Start(ctx context.Context, spanName string, opts ...interface{}) (context.Context, Span) {
	return tracer.Start(ctx, spanName, opts...)
}

type NoOpTracer struct{}

func (t *NoOpTracer) Start(ctx context.Context, _ string, _ ...interface{}) (context.Context, Span) {
	return ctx, &NoOpSpan{}
}

type NoOpSpan struct{}

func (s *NoOpSpan) RecordError(_ error) {}

func (s *NoOpSpan) End() {}