package shard

import (
	"sync"

	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor"
	meta "github.com/nspcc-dev/neofs-node/pkg/local_object_storage/metabase"
	"github.com/nspcc-dev/neofs-node/pkg/util/logger"
)

// Shard represents single shard of NeoFS Local Storage Engine.
type Shard struct {
	*cfg

	mtx *sync.RWMutex

	weight WeightValues

	blobStor *blobstor.BlobStor

	metaBase *meta.DB
}

// Option represents Shard's constructor option.
type Option func(*cfg)

type cfg struct {
	id *ID

	blobOpts []blobstor.Option

	metaOpts []meta.Option

	log *logger.Logger
}

func defaultCfg() *cfg {
	return new(cfg)
}

// New creates, initializes and returns new Shard instance.
func New(opts ...Option) *Shard {
	c := defaultCfg()

	for i := range opts {
		opts[i](c)
	}

	return &Shard{
		cfg:      c,
		mtx:      new(sync.RWMutex),
		blobStor: blobstor.New(c.blobOpts...),
		metaBase: meta.NewDB(c.metaOpts...),
	}
}

// WithID returns option to set shard identifier.
func WithID(id *ID) Option {
	return func(c *cfg) {
		c.id = id
	}
}

// WithBlobStorOptions returns option to set internal BlobStor options.
func WithBlobStorOptions(opts []blobstor.Option) Option {
	return func(c *cfg) {
		c.blobOpts = opts
	}
}

// WithMetaBaseOptions returns option to set internal metabase options.
func WithMetaBaseOptions(opts []meta.Option) Option {
	return func(c *cfg) {
		c.metaOpts = opts
	}
}

// WithLogger returns option to set Shard's logger.
func WithLogger(l *logger.Logger) Option {
	return func(c *cfg) {
		c.log = l
	}
}