package layer

import (
	"context"
	"encoding/hex"
	"fmt"
	"io"

	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
)

type PatchObjectParams struct {
	Object            *data.ObjectInfo
	BktInfo           *data.BucketInfo
	NewBytes          io.Reader
	Range             *RangeParams
	VersioningEnabled bool
}

func (n *Layer) PatchObject(ctx context.Context, p *PatchObjectParams) (*data.ExtendedObjectInfo, error) {
	if p.Object.Headers[AttributeDecryptedSize] != "" {
		return nil, fmt.Errorf("patch encrypted object")
	}

	if p.Object.Headers[MultipartObjectSize] != "" {
		// TODO: support multipart object patch
		return nil, fmt.Errorf("patch multipart object")
	}

	prmPatch := PrmObjectPatch{
		Container:  p.BktInfo.CID,
		Object:     p.Object.ID,
		Payload:    p.NewBytes,
		Range:      p.Range,
		ObjectSize: p.Object.Size,
	}
	n.prepareAuthParameters(ctx, &prmPatch.PrmAuth, p.BktInfo.Owner)

	objID, err := n.frostFS.PatchObject(ctx, prmPatch)
	if err != nil {
		return nil, fmt.Errorf("patch object: %w", err)
	}

	obj, err := n.objectHead(ctx, p.BktInfo, objID)
	if err != nil {
		return nil, fmt.Errorf("head object: %w", err)
	}

	payloadChecksum, _ := obj.PayloadChecksum()
	hashSum := hex.EncodeToString(payloadChecksum.Value())
	newVersion := &data.NodeVersion{
		BaseNodeVersion: data.BaseNodeVersion{
			OID:      objID,
			ETag:     hashSum,
			FilePath: p.Object.Name,
			Size:     obj.PayloadSize(),
			Created:  &p.Object.Created,
			Owner:    &n.gateOwner,
			// TODO: Add creation epoch
		},
		IsUnversioned: !p.VersioningEnabled,
		IsCombined:    p.Object.Headers[MultipartObjectSize] != "",
	}

	if newVersion.ID, err = n.treeService.AddVersion(ctx, p.BktInfo, newVersion); err != nil {
		return nil, fmt.Errorf("couldn't add new verion to tree service: %w", err)
	}

	p.Object.ID = objID
	p.Object.Size = obj.PayloadSize()
	p.Object.MD5Sum = ""
	p.Object.HashSum = hashSum

	return &data.ExtendedObjectInfo{
		ObjectInfo:  p.Object,
		NodeVersion: newVersion,
	}, nil
}