// Package econetgrpc implements the EconetService gRPC API over a shared
// econetclient.Client, exposing read-only device state.
package econetgrpc

import (
	"context"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
	"go.opentelemetry.io/otel/trace"
	grpccodes "google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"

	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/otel"

	pb "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1"
	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/config"
	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetclient"
)

type EconetGRPCServer struct {
	tracer trace.Tracer
	ctx    context.Context
	cfg    *config.ServiceConfig
	client *econetclient.Client
	pb.UnimplementedEconetServiceServer
}

func NewEconetGRPCServer(ctx context.Context, cfg *config.ServiceConfig, client *econetclient.Client) *EconetGRPCServer {
	return &EconetGRPCServer{
		ctx:    ctx,
		cfg:    cfg,
		client: client,
		tracer: otel.GetTracer(ctx, "econetGRPCServer"),
	}
}

func (s *EconetGRPCServer) ListDevices(ctx context.Context, _ *pb.ListDevicesRequest) (
	*pb.ListDevicesResponse, error,
) {
	_, span := s.tracer.Start(ctx, "listDevices")
	defer span.End()

	devices := s.client.Devices()
	resp := &pb.ListDevicesResponse{Devices: make([]*pb.Device, 0, len(devices))}
	for _, d := range devices {
		resp.Devices = append(resp.Devices, deviceToProto(d))
	}

	span.SetAttributes(attribute.Int("devices", len(resp.Devices)))
	span.SetStatus(codes.Ok, "")
	return resp, nil
}

func (s *EconetGRPCServer) GetDevice(ctx context.Context, req *pb.GetDeviceRequest) (
	*pb.GetDeviceResponse, error,
) {
	_, span := s.tracer.Start(ctx, "getDevice", trace.WithAttributes(
		attribute.String("serialNumber", req.GetSerialNumber()),
	))
	defer span.End()

	d := s.client.Device(req.GetSerialNumber())
	if d == nil {
		err := status.Errorf(grpccodes.NotFound, "no device with serial %q", req.GetSerialNumber())
		span.SetStatus(codes.Error, err.Error())
		return nil, err
	}

	span.SetStatus(codes.Ok, "")
	return &pb.GetDeviceResponse{Device: deviceToProto(d)}, nil
}