package core

import (
	"context"
	"errors"
	"io/fs"

	"github.com/jmoiron/sqlx"
)

// ServiceNameDatabase is a name for database service.
const ServiceNameDatabase = "core/database"

var (
	// ErrDatabase indicates that error appeared somewhere in database service.
	ErrDatabase = errors.New("database service")
	// ErrDatabaseIsInvalid indicates that database service implementation is invalid.
	ErrDatabaseIsInvalid = errors.New("database service implementation is invalid")
)

// Database is an interface for database service.
type Database interface {
	// Exec is a proxy for ExecContext from sqlx.
	Exec(ctx context.Context, query string, params ...interface{}) error
	// Get is a proxy for GetContext from sqlx.
	Get(ctx context.Context, target interface{}, query string, params ...interface{}) error
	// NamedExec is a proxy for NamedExecContext from sqlx.
	NamedExec(ctx context.Context, query string, param interface{}) error
	// RegisterMigrations registers migrations for applying from other services. Migrations should reside
	// in "migrations" directory in passed filesystem.
	RegisterMigrations(moduleName string, fs fs.FS) error
	// Select is a proxy for SelectContext from sqlx.
	Select(ctx context.Context, target interface{}, query string, params ...interface{}) error
	// Transaction is a wrapper for transactions processing which wraps sqlx's transactions.
	Transaction(ctx context.Context) (DatabaseTransaction, error)
}

// DatabaseTransaction is an interface for database transactions controllers implementations.
type DatabaseTransaction interface {
	Apply(steps ...TransactionFunc) error
}

// TransactionFunc is a function that is used in transactions to mangle with data.
type TransactionFunc func(*sqlx.Tx) error