package main

import (
	"archive/zip"
	"encoding/csv"
	"fmt"
	"os"
	"path/filepath"
	"time"
)

// Экспорт в CSV, сжатый в ZIP-архив
type CsvExporter struct {
	Encoding Encoding
}

func (c *CsvExporter) FileExt() string {
	return ".zip"
}

func (c *CsvExporter) Convert(filePath string, rows chan []any) error {
	f, err := os.Create(filePath + c.FileExt())
	if err != nil {
		return err
	}

	z := zip.NewWriter(f)

	zw, err := z.Create(filepath.Base(filePath) + ".csv")
	if err != nil {
		f.Close()
		return err
	}

	/*var enc io.Writer
	if c.Encoding == EncodingWndows1251 {
		enc = charmap.Windows1251.NewEncoder().Writer(zw)
	} else {
		enc = zw
	}*/

	enc, err := c.Encoding.Encoder()
	if err != nil {
		return err
	}

	w := csv.NewWriter(enc.Writer(zw))
	w.Comma = ';'

	for row := range rows {
		rowsStr := make([]string, len(row))
		for i := range row {
			rowsStr[i] = toCsvField(row[i])
		}

		err = w.Write(rowsStr)
		if err != nil {
			f.Close()
			return err
		}
	}

	w.Flush()

	if w.Error() != nil {
		f.Close()
		return w.Error()
	}

	err = z.Close()
	if err != nil {
		f.Close()
		return err
	}

	return f.Close()
}

func toCsvField(a any) string {
	if a == nil {
		return ""
	}

	switch v := a.(type) {
	case time.Time:
		return v.Format("02.01.2006 15:04:05")
	}

	return fmt.Sprint(a)
}