package models

import (
	"gorm.io/gorm"
)

func Paginate(pageNum, pageSize int) func(db *gorm.DB) *gorm.DB {
	return func(db *gorm.DB) *gorm.DB {
		offset := (pageNum - 1) * pageSize
		return db.Offset(offset).Limit(pageSize)
	}
}

func Query(query string, args ...interface{}) func(db *gorm.DB) *gorm.DB {
	implement := false
	for _, arg := range args {
		switch arg.(type) {
		case string:
			if len(arg.(string)) > 0 {
				implement = true
			}
		default:
			implement = true
		}
	}
	if implement {
		return func(db *gorm.DB) *gorm.DB {
			return db.Where(query, args...)
		}
	}
	return func(db *gorm.DB) *gorm.DB {
		return db
	}
}

func String(query string, arg string) func(db *gorm.DB) *gorm.DB {
	if len(arg) > 0 {
		return func(db *gorm.DB) *gorm.DB {
			return db.Where(query, arg)
		}
	}
	return func(db *gorm.DB) *gorm.DB {
		return db
	}
}