Adding http handler for lookup subjects stream response

internal/server/http.go

@@ -5,6 +5,12 @@ import (
 	v0 "ciam-rebac/api/relations/v0"
 	"ciam-rebac/internal/conf"
 	"ciam-rebac/internal/service"
+	"context"
+	"encoding/json"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	"io"
+	nethttp "net/http"
 
 	"github.com/go-kratos/kratos/v2/log"
 	"github.com/go-kratos/kratos/v2/middleware/recovery"
@@ -35,5 +41,51 @@ func NewHTTPServer(c *conf.Server, relationships *service.RelationshipsService,
 	v0.RegisterKesselTupleServiceHTTPServer(srv, relationships)
 	v0.RegisterKesselCheckServiceHTTPServer(srv, check)
 	h.RegisterKesselHealthHTTPServer(srv, health)
+
+	srv.HandleFunc("/v0/subjects", func(writer nethttp.ResponseWriter, request *nethttp.Request) {
+		conn, err := grpc.NewClient(c.Grpc.Addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
+		if err != nil {
+			log.Fatalf("could not connect to grpc server: %v", err)
+		}
+		defer conn.Close()
+
+		lookupServiceClient := v0.NewKesselLookupServiceClient(conn)
+
+		body, err := io.ReadAll(request.Body)
+		if err != nil {
+			nethttp.Error(writer, "Failed to read lookup subject body: "+err.Error(), nethttp.StatusInternalServerError)
+			return
+		}
+
+		lookupSubjectsRequest := v0.LookupSubjectsRequest{}
+		if err := json.Unmarshal(body, &lookupSubjectsRequest); err != nil {
+			nethttp.Error(writer, "Failed to unmarshal lookup request body: "+err.Error(), nethttp.StatusBadRequest)
+			return
+		}
+		stream, err := lookupServiceClient.LookupSubjects(context.Background(), &lookupSubjectsRequest)
+		if err != nil {
+			nethttp.Error(writer, "error grpc stream", nethttp.StatusInternalServerError)
+			return
+		}
+		var responses []*v0.LookupSubjectsResponse
+		for {
+			response, err := stream.Recv()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				nethttp.Error(writer, "Failed to receive data from lookup subject stream: "+err.Error(), nethttp.StatusInternalServerError)
+				return
+			}
+			writer.Header().Set("Content-Type", "application/json")
+			writer.Header().Set("Transfer-Encoding", "chunked")
+
+			responses = append(responses, response)
+		}
+		if err := json.NewEncoder(writer).Encode(responses); err != nil {
+			nethttp.Error(writer, "Failed to encode lookup subject response: "+err.Error(), nethttp.StatusInternalServerError)
+			return
+		}
+	})
 	return srv
 }