package gorm

import (
	"database/sql"

	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
)

// Migrator returns migrator
func (db *DB) Migrator() Migrator {
	return db.Dialector.Migrator(db)
}

// AutoMigrate run auto migration for given models
func (db *DB) AutoMigrate(dst ...interface{}) error {
	return db.Migrator().AutoMigrate(dst...)
}

// ViewOption view option
type ViewOption struct {
	Replace     bool
	CheckOption string
	Query       *DB
}

type Migrator interface {
	// AutoMigrate
	AutoMigrate(dst ...interface{}) error

	// Database
	CurrentDatabase() string
	FullDataTypeOf(*schema.Field) clause.Expr

	// Tables
	CreateTable(dst ...interface{}) error
	DropTable(dst ...interface{}) error
	HasTable(dst interface{}) bool
	RenameTable(oldName, newName interface{}) error

	// Columns
	AddColumn(dst interface{}, field string) error
	DropColumn(dst interface{}, field string) error
	AlterColumn(dst interface{}, field string) error
	MigrateColumn(dst interface{}, field *schema.Field, columnType *sql.ColumnType) error
	HasColumn(dst interface{}, field string) bool
	RenameColumn(dst interface{}, oldName, field string) error
	ColumnTypes(dst interface{}) ([]*sql.ColumnType, error)

	// Views
	CreateView(name string, option ViewOption) error
	DropView(name string) error

	// Constraints
	CreateConstraint(dst interface{}, name string) error
	DropConstraint(dst interface{}, name string) error
	HasConstraint(dst interface{}, name string) bool

	// Indexes
	CreateIndex(dst interface{}, name string) error
	DropIndex(dst interface{}, name string) error
	HasIndex(dst interface{}, name string) bool
	RenameIndex(dst interface{}, oldName, newName string) error
}