package serverinterceptors

import (
	"context"

	"github.com/tal-tech/go-zero/core/opentelemetry"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/baggage"
	"go.opentelemetry.io/otel/codes"
	"go.opentelemetry.io/otel/trace"
	"google.golang.org/grpc"
	gcodes "google.golang.org/grpc/codes"
	"google.golang.org/grpc/metadata"
	"google.golang.org/grpc/status"
)

// UnaryOpenTracingInterceptor returns a grpc.UnaryServerInterceptor for opentelemetry.
func UnaryOpenTracingInterceptor() grpc.UnaryServerInterceptor {
	propagator := otel.GetTextMapPropagator()
	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo,
		handler grpc.UnaryHandler) (interface{}, error) {
		if !opentelemetry.Enabled() {
			return handler(ctx, req)
		}

		requestMetadata, _ := metadata.FromIncomingContext(ctx)
		metadataCopy := requestMetadata.Copy()
		bags, spanCtx := opentelemetry.Extract(ctx, propagator, &metadataCopy)
		ctx = baggage.ContextWithBaggage(ctx, bags)
		tr := otel.Tracer(opentelemetry.TraceName)
		name, attr := opentelemetry.SpanInfo(info.FullMethod, opentelemetry.PeerFromCtx(ctx))
		ctx, span := tr.Start(trace.ContextWithRemoteSpanContext(ctx, spanCtx), name,
			trace.WithSpanKind(trace.SpanKindServer), trace.WithAttributes(attr...))
		defer span.End()

		opentelemetry.MessageReceived.Event(ctx, 1, req)
		resp, err := handler(ctx, req)
		if err != nil {
			s, _ := status.FromError(err)
			span.SetStatus(codes.Error, s.Message())
			span.SetAttributes(opentelemetry.StatusCodeAttr(s.Code()))
			opentelemetry.MessageSent.Event(ctx, 1, s.Proto())
			return nil, err
		}

		span.SetAttributes(opentelemetry.StatusCodeAttr(gcodes.OK))
		opentelemetry.MessageSent.Event(ctx, 1, resp)

		return resp, nil
	}
}

// StreamOpenTracingInterceptor returns a grpc.StreamServerInterceptor for opentelemetry.
func StreamOpenTracingInterceptor() grpc.StreamServerInterceptor {
	propagator := otel.GetTextMapPropagator()
	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
		ctx := ss.Context()
		if !opentelemetry.Enabled() {
			return handler(srv, opentelemetry.WrapServerStream(ctx, ss))
		}

		requestMetadata, _ := metadata.FromIncomingContext(ctx)
		metadataCopy := requestMetadata.Copy()
		bags, spanCtx := opentelemetry.Extract(ctx, propagator, &metadataCopy)
		ctx = baggage.ContextWithBaggage(ctx, bags)
		tr := otel.Tracer(opentelemetry.TraceName)
		name, attr := opentelemetry.SpanInfo(info.FullMethod, opentelemetry.PeerFromCtx(ctx))
		ctx, span := tr.Start(trace.ContextWithRemoteSpanContext(ctx, spanCtx), name,
			trace.WithSpanKind(trace.SpanKindServer), trace.WithAttributes(attr...))
		defer span.End()

		if err := handler(srv, opentelemetry.WrapServerStream(ctx, ss)); err != nil {
			s, _ := status.FromError(err)
			span.SetStatus(codes.Error, s.Message())
			span.SetAttributes(opentelemetry.StatusCodeAttr(s.Code()))
			return err
		}

		span.SetAttributes(opentelemetry.StatusCodeAttr(gcodes.OK))
		return nil
	}
}