package bolt

import (
	"context"
	"github.com/gisle/stufflog/database/repositories"
	"github.com/gisle/stufflog/models"
	"github.com/gisle/stufflog/slerrors"
	"github.com/vmihailenco/msgpack/v4"
	"go.etcd.io/bbolt"
)

var bnUsers = []byte("User")

type userRepository struct {
	db *bbolt.DB
}

func (r *userRepository) FindID(ctx context.Context, id string) (*models.User, error) {
	user := new(models.User)
	err := r.db.View(func(tx *bbolt.Tx) error {
		value := tx.Bucket(bnUsers).Get(unsafeStringToBytes(id))
		if value == nil {
			return slerrors.NotFound("User")
		}
		err := msgpack.Unmarshal(value, user)
		if err != nil {
			return err
		}
		return nil
	})
	if err != nil {
		return nil, err
	}

	return user, nil
}

func (r *userRepository) List(ctx context.Context) ([]*models.User, error) {
	users := make([]*models.User, 0, 16)
	err := r.db.View(func(tx *bbolt.Tx) error {
		cursor := tx.Bucket(bnUsers).Cursor()

		for key, value := cursor.First(); key != nil; key, value = cursor.Next() {
			user := new(models.User)
			err := msgpack.Unmarshal(value, user)
			if err != nil {
				return err
			}

			users = append(users, user)
		}

		return nil
	})
	if err != nil {
		return nil, err
	}

	return users, nil
}

func (r *userRepository) Save(ctx context.Context, user models.User) error {
	value, err := msgpack.Marshal(&user)
	if err != nil {
		return err
	}

	return r.db.Update(func(tx *bbolt.Tx) error {
		return tx.Bucket(bnUsers).Put(unsafeStringToBytes(user.ID), value)
	})
}

func (r *userRepository) Remove(ctx context.Context, user models.User) error {
	return r.db.Update(func(tx *bbolt.Tx) error {
		return tx.Bucket(bnUsers).Delete(unsafeStringToBytes(user.ID))
	})
}

func newUserRepository(db *bbolt.DB) (repositories.UserRepository, error) {
	err := db.Update(func(tx *bbolt.Tx) error {
		_, err := tx.CreateBucketIfNotExists(bnUsers)
		return err
	})
	if err != nil {
		return nil, err
	}

	return &userRepository{
		db: db,
	}, nil
}