package gen

import (
	"database/sql"

	"gorm.io/gorm"
	"gorm.io/gorm/schema"

	"gorm.io/gen/field"
)

type (
	// Condition query condition
	// field.Expr and subquery are expect value
	Condition interface {
		BeCond() interface{}
		CondError() error
	}
)

var (
	_ Condition = (field.Expr)(nil)
	_ Condition = (field.Value)(nil)
	_ Condition = (subQuery)(nil)
	_ Condition = (Dao)(nil)
)

type subQuery interface {
	underlyingDB() *gorm.DB
	underlyingDO() *DO

	Condition
}

// Dao CRUD methods
type Dao interface {
	subQuery

	As(alias string) Dao

	Not(conds ...Condition) Dao
	Or(conds ...Condition) Dao

	Select(columns ...field.Expr) Dao
	Where(conds ...Condition) Dao
	Order(columns ...field.Expr) Dao
	Distinct(columns ...field.Expr) Dao
	Omit(columns ...field.Expr) Dao
	Join(table schema.Tabler, conds ...field.Expr) Dao
	LeftJoin(table schema.Tabler, conds ...field.Expr) Dao
	RightJoin(table schema.Tabler, conds ...field.Expr) Dao
	Group(columns ...field.Expr) Dao
	Having(conds ...Condition) Dao
	Limit(limit int) Dao
	Offset(offset int) Dao
	Scopes(funcs ...func(Dao) Dao) Dao
	Unscoped() Dao
	Attrs(attrs ...field.AssignExpr) Dao
	Assign(attrs ...field.AssignExpr) Dao
	Joins(field field.RelationField) Dao
	Preload(field field.RelationField) Dao

	Create(value interface{}) error
	CreateInBatches(value interface{}, batchSize int) error
	Save(value interface{}) error
	First() (result interface{}, err error)
	Take() (result interface{}, err error)
	Last() (result interface{}, err error)
	Find() (results interface{}, err error)
	FindInBatch(batchSize int, fc func(tx Dao, batch int) error) (results interface{}, err error)
	FindInBatches(dest interface{}, batchSize int, fc func(tx Dao, batch int) error) error
	FirstOrInit() (result interface{}, err error)
	FirstOrCreate() (result interface{}, err error)
	Update(column field.Expr, value interface{}) (info resultInfo, err error)
	UpdateSimple(columns ...field.AssignExpr) (info resultInfo, err error)
	Updates(values interface{}) (info resultInfo, err error)
	UpdateColumn(column field.Expr, value interface{}) (info resultInfo, err error)
	UpdateColumns(values interface{}) (info resultInfo, err error)
	UpdateColumnSimple(columns ...field.AssignExpr) (info resultInfo, err error)
	Delete() (info resultInfo, err error)
	Count() (int64, error)
	Row() *sql.Row
	Rows() (*sql.Rows, error)
	Scan(dest interface{}) error
	Pluck(column field.Expr, dest interface{}) error
	ScanRows(rows *sql.Rows, dest interface{}) error
}