package shard

import (
	"context"
	"errors"

	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/pkg/tracing"
	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/trace"
	"go.uber.org/zap"
)

// DeletePrm groups the parameters of Delete operation.
type DeletePrm struct {
	addr []oid.Address
}

// DeleteRes groups the resulting values of Delete operation.
type DeleteRes struct {
	deleted uint64
}

// SetAddresses is a Delete option to set the addresses of the objects to delete.
//
// Option is required.
func (p *DeletePrm) SetAddresses(addr ...oid.Address) {
	p.addr = append(p.addr, addr...)
}

// Delete removes data from the shard's writeCache, metaBase and
// blobStor.
func (s *Shard) Delete(ctx context.Context, prm DeletePrm) (DeleteRes, error) {
	ctx, span := tracing.StartSpanFromContext(ctx, "Shard.Delete",
		trace.WithAttributes(
			attribute.String("shard_id", s.ID().String()),
			attribute.Int("addr_count", len(prm.addr)),
		))
	defer span.End()

	s.m.RLock()
	defer s.m.RUnlock()

	return s.delete(ctx, prm)
}

func (s *Shard) delete(ctx context.Context, prm DeletePrm) (DeleteRes, error) {
	if s.info.Mode.ReadOnly() {
		return DeleteRes{}, ErrReadOnlyMode
	} else if s.info.Mode.NoMetabase() {
		return DeleteRes{}, ErrDegradedMode
	}

	result := DeleteRes{}
	for _, addr := range prm.addr {
		select {
		case <-ctx.Done():
			return result, ctx.Err()
		default:
		}

		s.deleteObjectFromWriteCacheSafe(ctx, addr)

		s.deleteFromBlobstorSafe(ctx, addr)

		if err := s.deleteFromMetabase(ctx, addr); err != nil {
			return result, err // stop on metabase error ?
		}
		result.deleted++
	}

	return result, nil
}

func (s *Shard) deleteObjectFromWriteCacheSafe(ctx context.Context, addr oid.Address) {
	if s.hasWriteCache() {
		err := s.writeCache.Delete(ctx, addr)
		if err != nil && !IsErrNotFound(err) && !errors.Is(err, writecache.ErrReadOnly) {
			s.log.Warn(logs.ShardCantDeleteObjectFromWriteCache, zap.Error(err))
		}
	}
}

func (s *Shard) deleteFromBlobstorSafe(ctx context.Context, addr oid.Address) {
	var sPrm meta.StorageIDPrm
	sPrm.SetAddress(addr)

	res, err := s.metaBase.StorageID(ctx, sPrm)
	if err != nil {
		s.log.Debug("can't get storage ID from metabase",
			zap.Stringer("object", addr),
			zap.String("error", err.Error()))
	}
	storageID := res.StorageID()

	var delPrm common.DeletePrm
	delPrm.Address = addr
	delPrm.StorageID = storageID

	_, err = s.blobStor.Delete(ctx, delPrm)
	if err != nil {
		s.log.Debug("can't remove object from blobStor",
			zap.Stringer("object_address", addr),
			zap.String("error", err.Error()))
	}
}

func (s *Shard) deleteFromMetabase(ctx context.Context, addr oid.Address) error {
	var delPrm meta.DeletePrm
	delPrm.SetAddresses(addr)

	res, err := s.metaBase.Delete(ctx, delPrm)
	if err != nil {
		return err
	}
	s.decObjectCounterBy(physical, res.RawObjectsRemoved())
	s.decObjectCounterBy(logical, res.AvailableObjectsRemoved())
	removedPayload := res.RemovedPhysicalObjectSizes()[0]
	logicalRemovedPayload := res.RemovedLogicalObjectSizes()[0]
	if logicalRemovedPayload > 0 {
		s.addToContainerSize(addr.Container().EncodeToString(), -int64(logicalRemovedPayload))
	}
	s.addToPayloadSize(-int64(removedPayload))

	return nil
}