package database

import (
	"bytes"
	"encoding/json"
	"os"
	"path/filepath"

	"go.jolheiser.com/gpm/go-gpm"

	"go.etcd.io/bbolt"
)

var packageBucket = []byte("packages")

type Database struct {
	db *bbolt.DB
}

func Load(dbPath string) (*Database, error) {
	if err := os.MkdirAll(filepath.Dir(dbPath), os.ModePerm); err != nil {
		return nil, err
	}
	db, err := bbolt.Open(dbPath, os.ModePerm, nil)
	if err != nil {
		return nil, err
	}
	return &Database{
			db: db,
		}, db.Update(func(tx *bbolt.Tx) error {
			_, err := tx.CreateBucketIfNotExists(packageBucket)
			return err
		})
}

func (d *Database) Package(name string) (gpm.Package, error) {
	var pkg gpm.Package
	data, err := d.PackageJSON(name)
	if err != nil {
		return pkg, err
	}
	return pkg, json.NewDecoder(bytes.NewReader(data)).Decode(&pkg)
}

func (d *Database) PackageJSON(name string) (pkg []byte, err error) {
	return pkg, d.db.View(func(tx *bbolt.Tx) error {
		pkg = tx.Bucket(packageBucket).Get([]byte(name))
		return nil
	})
}

func (d *Database) Packages() (pkgs []gpm.Package, err error) {
	return pkgs, d.db.View(func(tx *bbolt.Tx) error {
		return tx.Bucket(packageBucket).ForEach(func(key, val []byte) error {
			var pkg gpm.Package
			if err := json.NewDecoder(bytes.NewReader(val)).Decode(&pkg); err != nil {
				return err
			}
			pkgs = append(pkgs, pkg)
			return nil
		})
	})
}

func (d *Database) PutPackage(pkg gpm.Package) error {
	return d.db.Update(func(tx *bbolt.Tx) error {
		data, err := json.Marshal(pkg)
		if err != nil {
			return err
		}
		return tx.Bucket(packageBucket).Put([]byte(pkg.Name), data)
	})
}

func (d *Database) RemovePackage(name string) error {
	return d.db.Update(func(tx *bbolt.Tx) error {
		return tx.Bucket(packageBucket).Delete([]byte(name))
	})
}