package export

import (
	"errors"
	"github.com/tealeg/xlsx/v3"
	"reflect"
)

const Sheet_Name = "sheet_1"

type Excel struct {
	f      *File
	count  int //总数
	isNew  bool
	titles []string
	file   *xlsx.File
	sheet  *xlsx.Sheet
}

func NewExcel(fileName string, limit int, param map[string]string) *Excel {
	return &Excel{
		f: NewFile(fileName, limit, param),
	}
}

func (e *Excel) slice() {
	if e.f.slice() {
		e.reset()
	}
}

func (e *Excel) reset() {
	e.save()
	e.f.NextFile()
	e.Open()
	e.WriteTitle(nil)
	e.slice()
}

func (e *Excel) Open() error {
	var err error
	if e.f.IsFileExist() {
		e.file, err = xlsx.OpenFile(e.f.FileName())
		if err != nil {
			return err
		}
	} else {
		e.isNew = true
		e.file = xlsx.NewFile()
	}

	var ok bool
	e.sheet, ok = e.file.Sheet[Sheet_Name]
	if !ok {
		e.sheet, err = e.file.AddSheet(Sheet_Name)
		if err != nil {
			return err
		}
	} else {
		//需要处理偏移数据
		e.f.SetRow(e.sheet.MaxRow)
	}

	return nil
}

func (e *Excel) save() error {
	return e.file.Save(e.f.FileName())
}

func (e *Excel) WriteTitle(titles []string) error {
	if e.file == nil || e.sheet == nil {
		return errors.New("没有执行open方法")
	}

	if titles != nil {
		e.titles = titles
	}

	if e.titles != nil && e.isNew {
		e.Write(e.titles)
		e.isNew = false
	}
	return nil
}

func (e *Excel) Write(data interface{}) error {
	if e.f.slice() {
		e.reset()
	}
	row := e.sheet.AddRow()

	v := reflect.ValueOf(data)
	if v.Kind() == reflect.Ptr {
		v = v.Elem()
	}
	if v.Kind() != reflect.Slice {
		return errors.New("数据无效，不是切片类型")
	}

	switch val := data.(type) {
	case []string:
		row.WriteSlice(val, -1)
	case []interface{}:
		for _, i := range data.([]interface{}) {
			cell := row.AddCell()
			cell.SetValue(i)
		}
	}
	return nil
}

func (e *Excel) Close() error {
	return e.save()
}