package client

import (
	"context"

	"github.com/nspcc-dev/neofs-api-go/pkg/netmap"
	"github.com/nspcc-dev/neofs-api-go/v2/client"
	v2netmap "github.com/nspcc-dev/neofs-api-go/v2/netmap"
	v2signature "github.com/nspcc-dev/neofs-api-go/v2/signature"
	"github.com/pkg/errors"
)

// Netmap contains methods related to netmap.
type Netmap interface {
	// EndpointInfo returns attributes, address and public key of the node, specified
	// in client constructor via address or open connection. This can be used as a
	// health check to see if node is alive and responses to requests.
	EndpointInfo(context.Context, ...CallOption) (*netmap.NodeInfo, error)
	// Epoch returns the epoch number from the local state of the remote host.
	Epoch(context.Context, ...CallOption) (uint64, error)
	// NetworkInfo returns information about the NeoFS network of which the remote server is a part.
	NetworkInfo(context.Context, ...CallOption) (*netmap.NetworkInfo, error)
}

// EndpointInfo returns attributes, address and public key of the node, specified
// in client constructor via address or open connection. This can be used as a
// health check to see if node is alive and responses to requests.
func (c clientImpl) EndpointInfo(ctx context.Context, opts ...CallOption) (*netmap.NodeInfo, error) {
	switch c.remoteNode.Version.Major() {
	case 2:
		resp, err := c.endpointInfoV2(ctx, opts...)
		if err != nil {
			return nil, err
		}

		return netmap.NewNodeInfoFromV2(resp.GetBody().GetNodeInfo()), nil
	default:
		return nil, errUnsupportedProtocol
	}
}

// Epoch returns the epoch number from the local state of the remote host.
func (c clientImpl) Epoch(ctx context.Context, opts ...CallOption) (uint64, error) {
	switch c.remoteNode.Version.Major() {
	case 2:
		resp, err := c.endpointInfoV2(ctx, opts...)
		if err != nil {
			return 0, err
		}

		return resp.GetMetaHeader().GetEpoch(), nil
	default:
		return 0, errUnsupportedProtocol
	}
}

func (c clientImpl) endpointInfoV2(ctx context.Context, opts ...CallOption) (*v2netmap.LocalNodeInfoResponse, error) {
	// apply all available options
	callOptions := c.defaultCallOptions()

	for i := range opts {
		opts[i].apply(&callOptions)
	}

	reqBody := new(v2netmap.LocalNodeInfoRequestBody)

	req := new(v2netmap.LocalNodeInfoRequest)
	req.SetBody(reqBody)
	req.SetMetaHeader(v2MetaHeaderFromOpts(callOptions))

	err := v2signature.SignServiceMessage(callOptions.key, req)
	if err != nil {
		return nil, err
	}

	switch c.remoteNode.Protocol {
	case GRPC:
		cli, err := v2NetmapClientFromOptions(c.opts)
		if err != nil {
			return nil, errors.Wrap(err, "can't create grpc client")
		}

		resp, err := cli.LocalNodeInfo(ctx, req)
		if err != nil {
			return nil, errors.Wrap(err, "transport error")
		}

		err = v2signature.VerifyServiceMessage(resp)
		if err != nil {
			return nil, errors.Wrap(err, "can't verify response message")
		}

		return resp, nil
	default:
		return nil, errUnsupportedProtocol
	}
}

func v2NetmapClientFromOptions(opts *clientOptions) (cli *v2netmap.Client, err error) {
	switch {
	case opts.grpcOpts.v2NetmapClient != nil:
		// return value from client cache
		return opts.grpcOpts.v2NetmapClient, nil

	case opts.grpcOpts.conn != nil:
		cli, err = v2netmap.NewClient(v2netmap.WithGlobalOpts(
			client.WithGRPCConn(opts.grpcOpts.conn)),
		)

	case opts.addr != "":
		cli, err = v2netmap.NewClient(v2netmap.WithGlobalOpts(
			client.WithNetworkAddress(opts.addr),
			client.WithDialTimeout(opts.dialTimeout),
		))

	default:
		return nil, errOptionsLack("Netmap")
	}

	// check if client correct and save in cache
	if err != nil {
		return nil, err
	}

	opts.grpcOpts.v2NetmapClient = cli

	return cli, nil
}

// NetworkInfo returns information about the NeoFS network of which the remote server is a part.
func (c clientImpl) NetworkInfo(ctx context.Context, opts ...CallOption) (*netmap.NetworkInfo, error) {
	switch c.remoteNode.Version.Major() {
	case 2:
		resp, err := c.networkInfoV2(ctx, opts...)
		if err != nil {
			return nil, err
		}

		return netmap.NewNetworkInfoFromV2(resp.GetBody().GetNetworkInfo()), nil
	default:
		return nil, errUnsupportedProtocol
	}
}

func (c clientImpl) networkInfoV2(ctx context.Context, opts ...CallOption) (*v2netmap.NetworkInfoResponse, error) {
	// apply all available options
	callOptions := c.defaultCallOptions()

	for i := range opts {
		opts[i].apply(&callOptions)
	}

	reqBody := new(v2netmap.NetworkInfoRequestBody)

	req := new(v2netmap.NetworkInfoRequest)
	req.SetBody(reqBody)
	req.SetMetaHeader(v2MetaHeaderFromOpts(callOptions))

	err := v2signature.SignServiceMessage(callOptions.key, req)
	if err != nil {
		return nil, err
	}

	switch c.remoteNode.Protocol {
	case GRPC:
		cli, err := v2NetmapClientFromOptions(c.opts)
		if err != nil {
			return nil, errors.Wrap(err, "could not create grpc client")
		}

		resp, err := cli.NetworkInfo(ctx, req)
		if err != nil {
			return nil, errors.Wrap(err, "v2 NetworkInfo RPC failure")
		}

		err = v2signature.VerifyServiceMessage(resp)
		if err != nil {
			return nil, errors.Wrap(err, "response message verification failed")
		}

		return resp, nil
	default:
		return nil, errUnsupportedProtocol
	}
}