package logic

import (
	"context"
	"encoding/json"
	"fusen-gateway/proto/goutils/basic"
	"net/http"

	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
	"google.golang.org/protobuf/encoding/protojson"
	"google.golang.org/protobuf/proto"
)

type EmptyMarshaler struct {
	runtime.JSONPb
}

func (m *EmptyMarshaler) Marshal(v interface{}) ([]byte, error) {
	return nil, nil
}

var fsProtoJSON = &runtime.JSONPb{
	MarshalOptions: protojson.MarshalOptions{
		EmitUnpopulated: true,
	},
	UnmarshalOptions: protojson.UnmarshalOptions{
		DiscardUnknown: true,
	},
}

func ResponseHeaderMatcher(ctx context.Context, w http.ResponseWriter, resp proto.Message) error {
	headers := w.Header()
	key := http.CanonicalHeaderKey("Grpc-Metadata-" + string(basic.M_FusenResponse))
	w.WriteHeader(200)

	if location, ok := headers[key]; ok {
		// w.Header().Set("Location", location[0])
		// w.WriteHeader(http.StatusFound)
		jbuf := []byte(location[0])
		gresp := &basic.GatewayResponse{}
		err := json.Unmarshal(jbuf, gresp)
		if err != nil {
			return err
		}
		gresp.Data = resp
		rdata, err := fsProtoJSON.Marshal(resp)
		if err != nil {
			return err
		}

		w.Write(rdata)
	}
	// w.WriteHeader(200)
	// w.Write([]byte("error"))
	return nil
}