package database

import (
	"fmt"
	"os"
	"path/filepath"
	"time"

	bolt "go.etcd.io/bbolt"
)

const (
	usersBucket string = "users"
)

func New(path string) (*bolt.DB, error) {
	dir := filepath.Dir(path)

	if err := os.MkdirAll(dir, 0o700); err != nil {
		return nil, fmt.Errorf("unable to create directory %q: %w", dir, err)
	}

	opts := bolt.Options{
		Timeout: 1 * time.Second,
	}

	boltdb, err := bolt.Open(path, 0o600, &opts)
	if err != nil {
		return nil, fmt.Errorf(
			"unable to open the database at %q: %w",
			path,
			err,
		)
	}

	if err := ensureBuckets(boltdb); err != nil {
		return nil, fmt.Errorf(
			"unable to ensure that the required buckets are present in the database: %w",
			err,
		)
	}

	return boltdb, nil
}

func ensureBuckets(boltdb *bolt.DB) error {
	err := boltdb.Update(func(tx *bolt.Tx) error {
		for _, bucket := range getBuckets() {
			if _, err := tx.CreateBucketIfNotExists(bucket); err != nil {
				return fmt.Errorf(
					"unable to ensure the existence of the %q bucket: %w",
					string(bucket),
					err,
				)
			}
		}

		return nil
	})
	if err != nil {
		return fmt.Errorf(
			"error ensuring the existence of the buckets in the database: %w",
			err,
		)
	}

	return nil
}

func getBuckets() [][]byte {
	return [][]byte{[]byte(usersBucket)}
}