package Mysql

import (
	"errors"
	"fmt"
	gorm2 "github.com/jinzhu/gorm"
	"math"
	"reflect"
	"regexp"
)

type BaseModel struct{}

func (b *BaseModel) GetDb() (*gorm2.DB, error) {
	//return GetDb(Buder)
	return nil, errors.New("单数据不在支持 请切换到BaseManyModel")
}

/**
获取字段下的gorm
@param structs BaseFieldInterface  字段结构体
@param key string 结构体属性字段
@param hasTable bool 返回时是否需字段前带表名
@param aliasTable string 别名
*/
func (b *BaseModel) getFieldTag(structs BaseFieldInterface, key string, hasTable bool, aliasTable string) []string {
	object := reflect.ValueOf(structs)
	myref := object
	typeOfType := myref.Type()
	var dbField []string
	for i := 0; i < myref.NumField(); i++ {
		itemField := typeOfType.Field(i)
		if key != "" && itemField.Name == key {
			tagColumn, err := getColumn(itemField.Tag.Get("gorm"))
			if err == nil {
				if hasTable {
					if aliasTable != "" {
						dbField = []string{aliasTable + ".`" + tagColumn + "`"}
					} else {
						dbField = []string{"`" + structs.TableName() + "`.`" + tagColumn + "`"}
					}

				} else {
					dbField = []string{tagColumn}
				}
			}
			break
		} else {
			tagColumn, err := getColumn(itemField.Tag.Get("gorm"))
			if err == nil {
				if tagColumn != "" && tagColumn != "-" {
					if hasTable {
						if aliasTable != "" {
							dbField = []string{aliasTable + ".`" + tagColumn + "`"}
						} else {
							dbField = append(dbField, "`"+structs.TableName()+"`.`"+tagColumn+"`")
						}

					} else {
						dbField = append(dbField, tagColumn)
					}
				}
			}
		}

	}
	return dbField
}

//查找gorm column
func getColumn(Tag string) (string, error) {
	columnREG := `column:(.*);?`
	regx := regexp.MustCompile(columnREG)
	s := regx.FindAllStringSubmatch(Tag, -1)
	if len(s) == 0 {
		return "", errors.New(fmt.Sprintf("column match error %s", columnREG))
	}
	column := s[0][1]
	return column, nil
}

/**
获取所有 tag
*/
func (b *BaseModel) GetAllFieldTag(structs BaseFieldInterface) []string {
	return b.getFieldTag(structs, "", true, "")
}

/**
获取指定tag
*/
func (b *BaseModel) GetItemTag(structs BaseFieldInterface, key string) string {
	item := b.getFieldTag(structs, key, true, "")
	return item[0]
}

/**
获取指定标签 并转为别名
*/
func (b *BaseModel) GetItemTagAliasTable(structs BaseFieldInterface, key string, AliasTable string) string {
	item := b.getFieldTag(structs, key, true, AliasTable)
	return item[0]
}

func (b *BaseModel) GetItemTagNotTable(structs BaseFieldInterface, key string) string {
	item := b.getFieldTag(structs, key, false, "")
	return item[0]
}

/**
@title 总页数计算
@param page int 当前页
@param pageSize int 每页显示
@param totalNum int 总记录数
*/
func (b *BaseModel) Paginator(page int, pageSize int, totalNum int) int {
	totalPages := int(math.Ceil(float64(totalNum) / float64(pageSize))) //page总数
	return totalPages
}