package meta

import (
	"go.etcd.io/bbolt"
)

type bucketCache struct {
	locked    *bbolt.Bucket
	graveyard *bbolt.Bucket
	garbage   *bbolt.Bucket
}

func newBucketCache() *bucketCache {
	return &bucketCache{}
}

func lockedBucket(bc *bucketCache, tx *bbolt.Tx) *bbolt.Bucket {
	if bc == nil {
		return tx.Bucket(bucketNameLocked)
	}
	return getBucket(&bc.locked, tx, bucketNameLocked)
}

func graveyardBucket(bc *bucketCache, tx *bbolt.Tx) *bbolt.Bucket {
	if bc == nil {
		return tx.Bucket(graveyardBucketName)
	}
	return getBucket(&bc.graveyard, tx, graveyardBucketName)
}

func garbageBucket(bc *bucketCache, tx *bbolt.Tx) *bbolt.Bucket {
	if bc == nil {
		return tx.Bucket(garbageBucketName)
	}
	return getBucket(&bc.garbage, tx, garbageBucketName)
}

func getBucket(cache **bbolt.Bucket, tx *bbolt.Tx, name []byte) *bbolt.Bucket {
	if *cache != nil {
		return *cache
	}

	*cache = tx.Bucket(name)
	return *cache
}