// Package excel -----------------------------
// @file      : templateInter.go
// @author    : JJXu
// @contact   : wavingbear@163.com
// @time      : 2022/7/23 15:34
// -------------------------------------------
package excel

import (
	"errors"
	"fmt"
	"github.com/xuri/excelize/v2"
	"io"
	"log"
	"path/filepath"
	"reflect"
	"sync"
)

var (
	ErrSheetNotExist    = errors.New("sheet does not exist")
	ErrSheetDataFrormat = errors.New("sheet data format must be slice or struct")
	//ErrSheetNameNotInTemplate = errors.New("sheet name not in emailTemplate")
)

//======================================================================================================================
// 												Sheet define

// 抽象工作簿
type Sheet interface {
	GetData() any
	SheetName() string
}

// 实例化工作簿
func NewSheet(sheetName string, datas any) Sheet {
	return &newSheetDefine{
		Datas: datas,
		Name:  sheetName,
	}
}

// 定义一个能够通用的工作簿结构，此结构必须遵循Sheet接口规范
type newSheetDefine struct {
	Datas any
	Name  string
}

func (s *newSheetDefine) GetData() any {
	return s.Datas
}
func (s *newSheetDefine) SheetName() string {
	return s.Name
}

//======================================================================================================================
// 												Sheet define

// WriteToExcel 通过模板文件写入数据并另存为
// param fileName : 文件名
// param filesSuffix : 文件后缀名生成函数
// param fileRoot : 导出目录
// param templatePath : 模板文件路径
// param sheets : Sheet类型的数据，类型为[]Sheet
// return path : 文件路径
// return exfileName : 导出后的文件名
// return err
func WriteToExcel(fileName string, fileRoot string, templatePath string, sheets ...Sheet) (path string, exFileName string, err error) {
	var exc *Excel
	exc, err = NewExcelTemplate(fileName, fileRoot, templatePath, sheets...)
	if err != nil {
		return
	}
	return exc.WriteToFile()
}

// ReadDataFromExcel 从excel文件读取数据
func ReadDataFromExcel(filepath string, sheetName string, handler func(rowIndex int, rows []string)) error {
	ex := Excel{OriginFilePath: filepath}
	return ex.ReadSheetData(sheetName, handler)
}

// ReadDataFromBytes 从io口读取数据，用户http上传的附件
func ReadDataFromBytes(file io.Reader, sheetName string, handler func(rowIndex int, rows []string)) error {
	exce, err := excelize.OpenReader(file)
	if err != nil {
		return err
	}
	var ex = Excel{ex: exce}
	return ex.ReadSheetData(sheetName, handler)
}

// 新建工作表实例
func NewExcelTemplate(fileName string, fileRoot string, templatePath string, sheets ...Sheet) (exc *Excel, err error) {
	exc = &Excel{
		SaveRoot:       fileRoot,
		SaveName:       fileName,
		OriginFilePath: templatePath,
		rwLock:         sync.RWMutex{},
	}
	if sheets != nil {
		err = exc.AddSheets(sheets...)
		if err != nil {
			return
		}
	}
	return exc, nil
}

type Excel struct {
	ex             *excelize.File
	SaveRoot       string
	SaveName       string
	OriginFilePath string
	Sheets         map[string]Sheet
	rwLock         sync.RWMutex
	Opts           []Option
}

// UseOption 使用可选项
func (s *Excel) UseOption(opts ...Option) {
	if opts != nil {
		s.Opts = append(s.Opts, opts...)
	}
}

// 添加工作簿
// 注意如果添加相同的工作簿，之前的会被覆盖
func (s *Excel) AddSheets(sheets ...Sheet) (err error) {
	if s.Sheets == nil {
		s.Sheets = make(map[string]Sheet, 0)
	}
	for _, sheet := range sheets {
		var sheetName = sheet.SheetName()
		s.Sheets[sheetName] = sheet
	}
	return
}

// 删除工作簿
func (s *Excel) DeleteSheets(sheetName string) error {
	if s.Sheets == nil {
		return nil
	} else if s.Sheets[sheetName] != nil {
		delete(s.Sheets, sheetName)
	} else {
		return ErrSheetNotExist
	}
	return nil
}

// 读取工作簿
func (s *Excel) ReadSheetData(sheetName string, handler func(rowIndex int, rows []string)) (err error) {
	if s.ex == nil {
		s.ex, err = excelize.OpenFile(s.OriginFilePath)
		if err != nil {
			return
		}
	}
	datas, err := s.ex.GetRows(sheetName)
	for i, rows := range datas {
		handler(i, rows)
	}
	return nil
}

// 写入到文件
func (s *Excel) WriteToFile() (path string, fileName string, err error) {
	if s.ex == nil {
		s.ex, err = excelize.OpenFile(s.OriginFilePath)
		if err != nil {
			return
		}
	}
	if s.Opts != nil {
		for _, opt := range s.Opts {
			opt(s)
		}
	}
	//插入数据
	var cellNameList []string
	for sheetName, st := range s.Sheets {
		var firstRow = s.getFirstEmptyRowIndex(s.ex, sheetName)
		var SheetData = reflect.ValueOf(st.GetData())
		var SheetType = reflect.TypeOf(st.GetData())
		switch SheetData.Kind() {
		case reflect.Slice:
			cellNameList = s.getJsonFieldList(SheetType)
			var rowLen = SheetData.Len()
			for i := 0; i < rowLen; i++ {
				var dataMap = s.dataToMap(SheetData.Index(i), SheetType)
				for column, v := range cellNameList {
					var axis = GetCellIndex(i+firstRow+1, column+1)
					err = s.ex.SetCellValue(sheetName, axis, dataMap[v])
					if err != nil {
						fmt.Println(err.Error())
					}
				}
			}
		case reflect.Struct:
			cellNameList = s.getJsonFieldList(SheetType)
			var dataMap = s.dataToMap(SheetData, SheetType)
			for column, v := range cellNameList {
				var axis = GetCellIndex(firstRow+1, column+1)
				err = s.ex.SetCellValue(sheetName, axis, dataMap[v])
				if err != nil {
					fmt.Println(err.Error())
				}
			}
		default:
			return "", "", ErrSheetDataFrormat
		}

	}
	//保存
	path = filepath.ToSlash(filepath.Join(s.SaveRoot, s.SaveName))
	s.rwLock.Lock()
	if err = s.ex.SaveAs(path); err != nil {
		log.Println(fmt.Sprintf("save file error :%v", err))
		s.rwLock.Unlock()
		return
	}
	s.rwLock.Unlock()
	return
}

// getJsonFieldList 获取json字段列表
func (s *Excel) getJsonFieldList(sheetType reflect.Type) (tagList []string) {
	t := sheetType.Elem()
	for i := 0; i < t.NumField(); i++ {
		tagList = append(tagList, t.Field(i).Tag.Get("json"))
	}
	return
}

// dataToMap 数据转字典
func (s *Excel) dataToMap(sheet reflect.Value, sheetType reflect.Type) (dataMap map[string]any) {
	dataMap = make(map[string]any)
	t := sheetType.Elem()
	for i := 0; i < t.NumField(); i++ {
		dataMap[t.Field(i).Tag.Get("json")] = sheet.Field(i).Interface()
	}
	return dataMap
}

// getFirstEmptyRowIndex 获取首个空行的索引位置
func (s *Excel) getFirstEmptyRowIndex(ex *excelize.File, sheetName string) (index int) {
	rows, err := ex.GetRows(sheetName)
	if err != nil {
		return 1
	}
	return len(rows)
}