package observability

import (
	"context"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/go-chi/chi/v5"
	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
	"go.opentelemetry.io/otel/sdk/trace/tracetest"
	"go.opentelemetry.io/otel/trace"
)

func TestTraceContextRoundTrip(t *testing.T) {
	want := trace.NewSpanContext(trace.SpanContextConfig{
		TraceID:    trace.TraceID{1},
		SpanID:     trace.SpanID{2},
		TraceFlags: trace.FlagsSampled,
		Remote:     true,
	})
	ctx := trace.ContextWithRemoteSpanContext(context.Background(), want)

	traceparent, tracestate := InjectToTraceparentAndTracestate(ctx)
	if traceparent == "" {
		t.Fatal("traceparent is empty")
	}

	got := trace.SpanContextFromContext(ExtractFromTraceparentAndTracestate(context.Background(), traceparent, tracestate))
	if got.TraceID() != want.TraceID() || got.SpanID() != want.SpanID() || !got.IsSampled() || !got.IsRemote() {
		t.Fatalf("span context = %v, want %v", got, want)
	}
}

func TestOTelRouteMiddlewareUsesRouteTemplate(t *testing.T) {
	oldProvider := otel.GetTracerProvider()
	recorder := tracetest.NewSpanRecorder()
	provider := sdktrace.NewTracerProvider(sdktrace.WithSpanProcessor(recorder))
	otel.SetTracerProvider(provider)
	t.Cleanup(func() {
		_ = provider.Shutdown(context.Background())
		otel.SetTracerProvider(oldProvider)
	})

	router := chi.NewRouter()
	router.Use(OTelRouteMiddleware)
	router.Get("/things/{id}", func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusNoContent)
	})
	handler := otelhttp.NewHandler(router, "HTTP")

	request := httptest.NewRequest(http.MethodGet, "/things/raw-user-id", nil)
	response := httptest.NewRecorder()
	handler.ServeHTTP(response, request)

	spans := recorder.Ended()
	if len(spans) != 1 {
		t.Fatalf("ended spans = %d, want 1", len(spans))
	}
	if got := spans[0].Name(); got != "HTTP /things/{id}" {
		t.Fatalf("span name = %q, want route template", got)
	}
	for _, attr := range spans[0].Attributes() {
		if attr.Key == attribute.Key("http.route") && attr.Value.AsString() == "/things/{id}" {
			return
		}
	}
	t.Fatal("http.route template attribute is missing")
}

func TestTracingConstants(t *testing.T) {
	tests := []struct {
		got  string
		want string
	}{
		{UserDIDKey, "tangled.user.did"},
		{OwnerDIDKey, "tangled.owner.did"},
		{RepoDIDKey, "tangled.repo.did"},
		{TargetRepoDIDKey, "tangled.repo.target.did"},
		{PipelineIDKey, "tangled.pipeline.id"},
		{WorkflowIDKey, "tangled.workflow.id"},
		{WorkflowEngineKey, "tangled.workflow.engine"},
		{LeaseIDKey, "tangled.lease.id"},
		{ExecutorNodeIDKey, "tangled.executor.node_id"},
		{JobIDKey, "tangled.job.id"},
		{RequestIDKey, "tangled.request.id"},
		{CollectionKey, "atproto.collection"},
		{RKeyKey, "atproto.rkey"},
		{StepNameKey, "tangled.step.name"},
		{StepIndexKey, "tangled.step.index"},
	}
	for _, tc := range tests {
		if tc.got != tc.want {
			t.Errorf("got %q, want %q", tc.got, tc.want)
		}
	}
}