package services

import (
	"context"
	"fmt"
	"strings"

	grpcService "git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/frostfs/services/tree"
	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/tokens"
	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/tree"
	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
	"google.golang.org/grpc"
)

type GetNodeByPathResponseInfoWrapper struct {
	response *grpcService.GetNodeByPathResponse_Info
}

func (n GetNodeByPathResponseInfoWrapper) GetMeta() []tree.Meta {
	res := make([]tree.Meta, len(n.response.Meta))
	for i, value := range n.response.Meta {
		res[i] = value
	}
	return res
}

type GetSubTreeResponseBodyWrapper struct {
	response *grpcService.GetSubTreeResponse_Body
}

func (n GetSubTreeResponseBodyWrapper) GetMeta() []tree.Meta {
	res := make([]tree.Meta, len(n.response.Meta))
	for i, value := range n.response.Meta {
		res[i] = value
	}
	return res
}

type ServiceClientGRPC struct {
	key     *keys.PrivateKey
	conn    *grpc.ClientConn
	service grpcService.TreeServiceClient
}

func NewTreeServiceClientGRPC(ctx context.Context, addr string, key *keys.PrivateKey, grpcOpts ...grpc.DialOption) (*ServiceClientGRPC, error) {
	conn, err := grpc.Dial(addr, grpcOpts...)
	if err != nil {
		return nil, fmt.Errorf("did not connect: %v", err)
	}

	c := grpcService.NewTreeServiceClient(conn)
	if _, err = c.Healthcheck(ctx, &grpcService.HealthcheckRequest{}); err != nil {
		return nil, fmt.Errorf("healthcheck: %w", err)
	}

	return &ServiceClientGRPC{
		key:     key,
		conn:    conn,
		service: c,
	}, nil
}

func (c *ServiceClientGRPC) GetNodes(ctx context.Context, p *tree.GetNodesParams) ([]tree.NodeResponse, error) {
	request := &grpcService.GetNodeByPathRequest{
		Body: &grpcService.GetNodeByPathRequest_Body{
			ContainerId:   p.CnrID[:],
			TreeId:        p.TreeID,
			Path:          p.Path,
			Attributes:    p.Meta,
			PathAttribute: tree.FileNameKey,
			LatestOnly:    p.LatestOnly,
			AllAttributes: p.AllAttrs,
			BearerToken:   getBearer(ctx),
		},
	}

	if err := c.signRequest(request.Body, func(key, sign []byte) {
		request.Signature = &grpcService.Signature{
			Key:  key,
			Sign: sign,
		}
	}); err != nil {
		return nil, err
	}

	resp, err := c.service.GetNodeByPath(ctx, request)
	if err != nil {
		return nil, handleError("failed to get node by path", err)
	}

	res := make([]tree.NodeResponse, len(resp.GetBody().GetNodes()))
	for i, info := range resp.GetBody().GetNodes() {
		res[i] = GetNodeByPathResponseInfoWrapper{info}
	}

	return res, nil
}

func getBearer(ctx context.Context) []byte {
	token, err := tokens.LoadBearerToken(ctx)
	if err != nil {
		return nil
	}
	return token.Marshal()
}

func handleError(msg string, err error) error {
	if strings.Contains(err.Error(), "not found") {
		return fmt.Errorf("%w: %s", tree.ErrNodeNotFound, err.Error())
	} else if strings.Contains(err.Error(), "is denied by") {
		return fmt.Errorf("%w: %s", tree.ErrNodeAccessDenied, err.Error())
	}
	return fmt.Errorf("%s: %w", msg, err)
}