package store

import (
	"github.com/boltdb/bolt"
)

type BoltClient struct {
	db *bolt.DB
}

func NewBolt(path string) (*BoltClient, error) {
	db, err := bolt.Open(path, 0600, nil)
	if err != nil {
		return nil, err
	}
	return &BoltClient{
		db: db,
	}, nil
}

func (bc *BoltClient) Close() error {
	return bc.db.Close()
}

func (bc *BoltClient) Set(namespace, key string, value []byte) error {
	return bc.db.Update(func(tx *bolt.Tx) error {
		bucket, err := tx.CreateBucketIfNotExists([]byte(namespace))
		if err != nil {
			return err
		}
		return bucket.Put([]byte(key), value)
	})
}

func (bc *BoltClient) List(namespace, key string, asc bool, limit int) ([]string, error) {
	if limit < 1 {
		limit = 10000
	}
	found := []string{}
	err := bc.db.View(func(tx *bolt.Tx) error {
		bucket := tx.Bucket([]byte(namespace))
		if bucket == nil {
			return nil
		}
		c := bucket.Cursor()
		if asc {
			for k, _ := c.Seek([]byte(key)); k != nil && len(found) < limit; k, _ = c.Next() {
				found = append(found, string(k))
			}
		} else {
			for k, _ := c.Seek([]byte(key)); k != nil && len(found) < limit; k, _ = c.Next() {
				found = append(found, string(k))
			}
		}
		return nil
	})
	return found, err
}

func (bc *BoltClient) Get(namespace, key string) ([]byte, error) {
	var result []byte
	err := bc.db.View(func(tx *bolt.Tx) error {
		bucket := tx.Bucket([]byte(namespace))
		if bucket == nil {
			return nil
		}
		result = bucket.Get([]byte(key))
		return nil
	})
	return result, err
}