package control

import (
	"bytes"
	"context"
	"fmt"

	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/refs"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/client/container"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/client/netmap"
	control "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/control/ir"
	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

// HealthCheck returns health status of the local IR node.
//
// If request is not signed with a key from white list, permission error returns.
func (s *Server) HealthCheck(_ context.Context, req *control.HealthCheckRequest) (*control.HealthCheckResponse, error) {
	if err := s.isValidRequest(req); err != nil {
		return nil, status.Error(codes.PermissionDenied, err.Error())
	}

	resp := new(control.HealthCheckResponse)

	body := new(control.HealthCheckResponse_Body)
	resp.SetBody(body)

	body.SetHealthStatus(s.prm.healthChecker.HealthStatus())

	if err := SignMessage(&s.prm.key.PrivateKey, resp); err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	return resp, nil
}

// TickEpoch forces a new epoch.
//
// If request is not signed with a key from white list, permission error returns.
func (s *Server) TickEpoch(_ context.Context, req *control.TickEpochRequest) (*control.TickEpochResponse, error) {
	if err := s.isValidRequest(req); err != nil {
		return nil, status.Error(codes.PermissionDenied, err.Error())
	}

	resp := new(control.TickEpochResponse)
	resp.SetBody(new(control.TickEpochResponse_Body))

	epoch, err := s.netmapClient.Epoch()
	if err != nil {
		return nil, fmt.Errorf("getting current epoch: %w", err)
	}

	vub, err := s.netmapClient.NewEpochControl(epoch+1, req.GetBody().GetVub())
	if err != nil {
		return nil, fmt.Errorf("forcing new epoch: %w", err)
	}
	resp.Body.Vub = vub

	if err := SignMessage(&s.prm.key.PrivateKey, resp); err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	return resp, nil
}

// RemoveNode forces a node removal.
//
// If request is not signed with a key from white list, permission error returns.
func (s *Server) RemoveNode(_ context.Context, req *control.RemoveNodeRequest) (*control.RemoveNodeResponse, error) {
	if err := s.isValidRequest(req); err != nil {
		return nil, status.Error(codes.PermissionDenied, err.Error())
	}

	resp := new(control.RemoveNodeResponse)
	resp.SetBody(new(control.RemoveNodeResponse_Body))

	nm, err := s.netmapClient.NetMap()
	if err != nil {
		return nil, fmt.Errorf("getting netmap: %w", err)
	}
	var nodeInfo netmap.NodeInfo
	for _, info := range nm.Nodes() {
		if bytes.Equal(info.PublicKey(), req.GetBody().GetKey()) {
			nodeInfo = info
			break
		}
	}
	if len(nodeInfo.PublicKey()) == 0 {
		return nil, status.Error(codes.NotFound, "no such node")
	}
	if nodeInfo.Status().IsOffline() {
		return nil, status.Error(codes.FailedPrecondition, "node is already offline")
	}

	vub, err := s.netmapClient.ForceRemovePeer(nodeInfo, req.GetBody().GetVub())
	if err != nil {
		return nil, fmt.Errorf("forcing node removal: %w", err)
	}
	resp.Body.Vub = vub

	if err := SignMessage(&s.prm.key.PrivateKey, resp); err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	return resp, nil
}

// RemoveContainer forces a container removal.
func (s *Server) RemoveContainer(_ context.Context, req *control.RemoveContainerRequest) (*control.RemoveContainerResponse, error) {
	if err := s.isValidRequest(req); err != nil {
		return nil, status.Error(codes.PermissionDenied, err.Error())
	}

	if len(req.GetBody().GetContainerId()) > 0 && len(req.GetBody().GetOwner()) > 0 {
		return nil, status.Error(codes.InvalidArgument, "specify the owner and container at the same time is not allowed")
	}
	var vub uint32
	if len(req.GetBody().GetContainerId()) > 0 {
		var containerID cid.ID
		if err := containerID.Decode(req.GetBody().GetContainerId()); err != nil {
			return nil, status.Error(codes.InvalidArgument, "failed to parse container ID: "+err.Error())
		}
		var err error
		vub, err = s.removeContainer(containerID, req.GetBody().GetVub())
		if err != nil {
			return nil, err
		}
	} else {
		var ownerID refs.OwnerID
		if err := ownerID.Unmarshal(req.GetBody().GetOwner()); err != nil {
			return nil, status.Error(codes.InvalidArgument, "failed to parse ownerID: %s"+err.Error())
		}
		var owner user.ID
		if err := owner.ReadFromV2(ownerID); err != nil {
			return nil, status.Error(codes.InvalidArgument, "failed to read owner: "+err.Error())
		}

		cids, err := s.containerClient.ContainersOf(&owner)
		if err != nil {
			return nil, fmt.Errorf("failed to get owner's containers: %w", err)
		}

		for _, containerID := range cids {
			vub, err = s.removeContainer(containerID, req.GetBody().GetVub())
			if err != nil {
				return nil, err
			}
		}
	}

	resp := &control.RemoveContainerResponse{
		Body: &control.RemoveContainerResponse_Body{
			Vub: vub,
		},
	}
	if err := SignMessage(&s.prm.key.PrivateKey, resp); err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}
	return resp, nil
}

func (s *Server) removeContainer(containerID cid.ID, vub uint32) (uint32, error) {
	var prm container.DeletePrm
	prm.SetCID(containerID[:])
	prm.SetControlTX(true)
	prm.SetVUB(vub)

	vub, err := s.containerClient.Delete(prm)
	if err != nil {
		return 0, fmt.Errorf("forcing container removal: %w", err)
	}
	return vub, nil
}