package object

import (
	"context"
	"errors"
	"fmt"

	clientcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/client"
	netmapCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/netmap"
	internalclient "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/internal/client"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/util"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
)

type ClientConstructor interface {
	Get(clientcore.NodeInfo) (clientcore.MultiAddressClient, error)
}

// RemoteReader represents utility for getting
// the object from a remote host.
type RemoteReader struct {
	keyStorage *util.KeyStorage

	clientCache ClientConstructor
}

// RemoteRequestPrm groups remote operation parameters.
type RemoteRequestPrm struct {
	addr oid.Address
	raw  bool
	node netmap.NodeInfo
}

const remoteOpTTL = 1

var ErrNotFound = errors.New("object header not found")

// NewRemoteReader creates, initializes and returns new RemoteHeader instance.
func NewRemoteReader(keyStorage *util.KeyStorage, cache ClientConstructor) *RemoteReader {
	return &RemoteReader{
		keyStorage:  keyStorage,
		clientCache: cache,
	}
}

// WithNodeInfo sets information about the remote node.
func (p *RemoteRequestPrm) WithNodeInfo(v netmap.NodeInfo) *RemoteRequestPrm {
	if p != nil {
		p.node = v
	}

	return p
}

// WithObjectAddress sets object address.
func (p *RemoteRequestPrm) WithObjectAddress(v oid.Address) *RemoteRequestPrm {
	if p != nil {
		p.addr = v
	}

	return p
}

func (p *RemoteRequestPrm) WithRaw(v bool) *RemoteRequestPrm {
	if p != nil {
		p.raw = v
	}
	return p
}

// Head requests object header from the remote node.
func (h *RemoteReader) Head(ctx context.Context, prm *RemoteRequestPrm) (*objectSDK.Object, error) {
	key, err := h.keyStorage.GetKey(nil)
	if err != nil {
		return nil, fmt.Errorf("(%T) could not receive private key: %w", h, err)
	}

	var info clientcore.NodeInfo

	err = clientcore.NodeInfoFromRawNetmapElement(&info, netmapCore.Node(prm.node))
	if err != nil {
		return nil, fmt.Errorf("parse client node info: %w", err)
	}

	c, err := h.clientCache.Get(info)
	if err != nil {
		return nil, fmt.Errorf("(%T) could not create SDK client %s: %w", h, info.AddressGroup(), err)
	}

	var headPrm internalclient.HeadObjectPrm

	headPrm.SetClient(c)
	headPrm.SetPrivateKey(key)
	headPrm.SetAddress(prm.addr)
	headPrm.SetTTL(remoteOpTTL)
	if prm.raw {
		headPrm.SetRawFlag()
	}

	res, err := internalclient.HeadObject(ctx, headPrm)
	if err != nil {
		return nil, fmt.Errorf("(%T) could not head object in %s: %w", h, info.AddressGroup(), err)
	}

	return res.Header(), nil
}

func (h *RemoteReader) Get(ctx context.Context, prm *RemoteRequestPrm) (*objectSDK.Object, error) {
	key, err := h.keyStorage.GetKey(nil)
	if err != nil {
		return nil, fmt.Errorf("(%T) could not receive private key: %w", h, err)
	}

	var info clientcore.NodeInfo

	err = clientcore.NodeInfoFromRawNetmapElement(&info, netmapCore.Node(prm.node))
	if err != nil {
		return nil, fmt.Errorf("parse client node info: %w", err)
	}

	c, err := h.clientCache.Get(info)
	if err != nil {
		return nil, fmt.Errorf("(%T) could not create SDK client %s: %w", h, info.AddressGroup(), err)
	}

	var getPrm internalclient.GetObjectPrm

	getPrm.SetClient(c)
	getPrm.SetPrivateKey(key)
	getPrm.SetAddress(prm.addr)
	getPrm.SetTTL(remoteOpTTL)
	if prm.raw {
		getPrm.SetRawFlag()
	}

	res, err := internalclient.GetObject(ctx, getPrm)
	if err != nil {
		return nil, fmt.Errorf("(%T) could not head object in %s: %w", h, info.AddressGroup(), err)
	}

	return res.Object(), nil
}