package importer

import (
	"encoding/csv"
	"io"
	"strings"

	"git.yetaga.in/alazyreader/library/book"
)

func CSVToBooks(r io.Reader) ([]book.Book, error) {
	reader := csv.NewReader(r)
	header, err := reader.Read()
	if err != nil {
		return nil, err
	}
	hmap := parseHeader(header)
	books := []book.Book{}

	for {
		row, err := reader.Read()
		if err == io.EOF {
			break
		}
		if err != nil {
			return books, err
		}
		b := book.Book{
			Title:       row[hmap["title"]],
			Authors:     parseAuthors(row[hmap["author"]]),
			SortAuthor:  row[hmap["authorlast"]],
			ISBN10:      row[hmap["isbn-10"]],
			ISBN13:      row[hmap["isbn-13"]],
			Format:      row[hmap["format"]],
			Genre:       row[hmap["genre"]],
			Publisher:   row[hmap["publisher"]],
			Series:      row[hmap["series"]],
			Volume:      row[hmap["volume"]],
			Year:        row[hmap["year"]],
			Signed:      row[hmap["signed"]] == "yes", // convert from known string to bool
			Description: row[hmap["description"]],
			Notes:       row[hmap["notes"]],
			OnLoan:      row[hmap["onloan"]],
			CoverURL:    row[hmap["coverurl"]],
		}
		books = append(books, b)
	}
	return books, nil
}

func parseHeader(header []string) map[string]int {
	m := make(map[string]int, len(header)-1)
	for i := range header {
		m[strings.TrimSpace(strings.ToLower(header[i]))] = i
	}
	return m
}

func parseAuthors(a string) []string {
	as := strings.Split(a, ";")
	for i := range as {
		as[i] = strings.TrimSpace(as[i])
	}
	return as
}