package grpc

import (
	"fmt"
	"strings"

	"github.com/golang/protobuf/jsonpb"
	"github.com/golang/protobuf/proto"
	"github.com/jhump/protoreflect/desc"
	"google.golang.org/grpc/metadata"
	"google.golang.org/grpc/status"

	"github.com/felangga/chiko/internal/entity"
)

type handler struct {
	grpc GRPC

	method            *desc.MethodDescriptor
	methodCount       int
	reqHeaders        metadata.MD
	reqHeadersCount   int
	respHeaders       metadata.MD
	respHeadersCount  int
	respMessages      []string
	respTrailers      metadata.MD
	respStatus        *status.Status
	respTrailersCount int
}

func (h *handler) OnReceiveResponse(msg proto.Message) {
	// Print headers to log window
	headerResp := "  Headers:"
	for key, values := range h.respHeaders {
		headerResp += fmt.Sprintf("\n    ► %s: %s", key, strings.Join(values, ","))
	}

	statusCode := fmt.Sprintf("  Status Code: %d %s", h.respStatus.Code(), h.respStatus.Message())

	// Print the gRPC response
	jsm := jsonpb.Marshaler{Indent: "  "}
	respStr, err := jsm.MarshalToString(msg)
	if err != nil {
		h.grpc.Logger.Error(fmt.Sprintf("failed to generate JSON form of response message: %v", err))
		return
	}

	h.respMessages = append(h.respMessages, respStr)
	output := fmt.Sprintf("\n%s\n\n%s\n\n%s", statusCode, headerResp, respStr)
	out := entity.Output{
		Content:    output,
		WithHeader: true,
	}

	h.grpc.Logger.PrintOutput(out)
}

func (h *handler) OnResolveMethod(md *desc.MethodDescriptor) {
	h.methodCount++
	h.method = md
}

func (h *handler) OnSendHeaders(md metadata.MD) {
	h.reqHeadersCount++
	h.reqHeaders = md
}

func (h *handler) OnReceiveHeaders(md metadata.MD) {
	h.respHeadersCount++
	h.respHeaders = md
}

func (h *handler) OnReceiveTrailers(stat *status.Status, md metadata.MD) {
	h.respTrailersCount++
	h.respTrailers = md
	h.respStatus = stat
}