package schema

import (
	"reflect"
	"sync"
)

// sync pools
var (
	normalPool      sync.Map
	poolInitializer = func(reflectType reflect.Type) FieldNewValuePool {
		v, _ := normalPool.LoadOrStore(reflectType, &sync.Pool{
			New: func() interface{} {
				return reflect.New(reflectType).Interface()
			},
		})
		return v.(FieldNewValuePool)
	}

	Build() (sql string, vars []interface{})
}

// GormDataTypeInterface gorm data type interface
type GormDataTypeInterface interface {
	GormDataType() string
}

// FieldNewValuePool field new scan value pool
type FieldNewValuePool interface {
	Get() interface{}
	Put(interface{})
}

// CreateClausesInterface create clauses interface
type CreateClausesInterface interface {
	CreateClauses(*Field) []clause.Interface
}

type Plugin interface {
	Name() string
	Initialize(*DB) error
}

type ParamsFilter interface {
	ParamsFilter(ctx context.Context, sql string, params ...interface{}) (string, []interface{})
}

// ConnPool db conns pool interface
type ConnPool interface {
	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
	ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)

	}
	Scan(rows, tx, ScanInitialized)
	return tx.Error
}

// Connection uses a db connection to execute an arbitrary number of commands in fc. When finished, the connection is
// returned to the connection pool.
func (db *DB) Connection(fc func(tx *DB) error) (err error) {
	if db.Error != nil {
		return db.Error
	}

	tx := db.getInstance()
	sqlDB, err := tx.DB()
	if err != nil {
		return
	}

}

// PrimaryKey returns the index is primary key or not.
func (idx Index) PrimaryKey() (isPrimaryKey bool, ok bool) {
	return idx.PrimaryKeyValue.Bool, idx.PrimaryKeyValue.Valid
}

// Unique returns whether the index is unique or not.
func (idx Index) Unique() (unique bool, ok bool) {
	return idx.UniqueValue.Bool, idx.UniqueValue.Valid
}

// Option return the optional attribute of the index
func (idx Index) Option() string {

		}
	} else {
		onConflict.DoNothing = true
	}

	return
}

func saveAssociations(db *gorm.DB, rel *schema.Relationship, rValues reflect.Value, selectColumns map[string]bool, restricted bool, defaultUpdatingColumns []string) error {
	// stop save association loop
	if checkAssociationsSaved(db, rValues) {
		return nil
	}

	var (
		selects, omits []string

}

// Expr raw expression
type Expr struct {
	SQL                string
	Vars               []interface{}
	WithoutParentheses bool
}

// Build build raw expression
func (expr Expr) Build(builder Builder) {
	var (
		afterParenthesis bool
		idx              int
	)

	for _, v := range []byte(expr.SQL) {
		if v == '?' && len(expr.Vars) > idx {
			if afterParenthesis || expr.WithoutParentheses {

		}
	}

	return ""
}

func IsValidDBNameChar(c rune) bool {
	return !unicode.IsLetter(c) && !unicode.IsNumber(c) && c != '.' && c != '*' && c != '_' && c != '$' && c != '@'
}

// CheckTruth check string true or not
func CheckTruth(vals ...string) bool {
	for _, val := range vals {
		if val != "" && !strings.EqualFold(val, "false") {
			return true
		}
	}

func (m Migrator) ReorderModels(values []interface{}, autoAdd bool) (results []interface{}) {
	type Dependency struct {
		*gorm.Statement
		Depends []*schema.Schema
	}

	var (
		modelNames, orderedModelNames []string
		orderedModelNamesMap          = map[string]bool{}
		parsedSchemas                 = map[*schema.Schema]bool{}
		valuesMap                     = map[string]Dependency{}

	"strings"
	"time"
	"unicode"

	"gorm.io/gorm/utils"
)

const (
	tmFmtWithMS = "2006-01-02 15:04:05.999"
	tmFmtZero   = "0000-00-00 00:00:00"
	nullStr     = "NULL"
)

func isPrintable(s string) bool {
	for _, r := range s {
		if !unicode.IsPrint(r) {
			return false
		}
	}
	return true
}

// A list of Go types that should be converted to SQL primitives