book.go

package goodreads

import (
	"errors"
	"regexp"
	"strconv"
	"strings"

	"github.com/ketabchi/goodreads/api"
	"github.com/ketabchi/util"

	"github.com/PuerkitoBio/goquery"
)

type Book struct {
	url string
	doc *goquery.Document
	api.Book
}

func NewBookByISBN(isbn string) (*Book, error) {
	gb, err := api.GetBookByISBN(isbn)
	if err != nil {
		return nil, err
	}

	book, err := newBook(gb.URL)
	if err != nil {
		return nil, err
	}
	book.Book = *gb

	return book, nil
}

func NewBookByTitle(title string) (*Book, error) {
	gb, err := api.GetBookByTitle(title)
	if err != nil {
		return nil, err
	}

	book, err := newBook(gb.URL)
	if err != nil {
		return nil, err
	}
	book.Book = *gb

	return book, nil
}

func NewBook(url string) (*Book, error) {
	id := bookID(url)
	if len(id) == 0 {
		return nil, errors.New("can't get book id from url")
	}

	gb, err := api.GetBookByID(id)
	if err != nil {
		return nil, err
	}

	book, err := newBook(gb.URL)
	if err != nil {
		return nil, err
	}
	book.Book = *gb

	return book, nil
}

func newBook(url string) (*Book, error) {
	doc, err := api.GetDoc(url)
	if err != nil {
		return nil, err
	}

	return &Book{url: url, doc: doc}, nil
}

var bookIDRe = regexp.MustCompile(`goodreads\.com\/book\/show\/([0-9]+)`)

func bookID(url string) string {
	ss := bookIDRe.FindStringSubmatch(url)
	if len(ss) < 2 {
		return ""
	}
	return ss[1]
}

func (b *Book) Genres() []string {
	genres := make([]string, 0)

	b.doc.Find(".left .bookPageGenreLink").Each(func(i int, sel *goquery.Selection) {
		g := sel.Text()
		if util.SliceContains(genres, g) {
			return
		}

		s := sel.ParentsUntil(".elementList").Parent().Find(".right .bookPageGenreLink").Text()
		s = strings.Trim(s, "\n ")
		s = strings.ReplaceAll(s, " users", "")
		s = strings.ReplaceAll(s, ",", "")

		count, _ := strconv.Atoi(s)

		if count > 80 {
			genres = append(genres, g)
		}
	})

	return genres
}

func (b *Book) HasAuthor(name string) bool {
	authors := b.Authors
	for _, author := range authors {
		if author.Name == name {
			return true
		}
	}
	return false
}

func (b *Book) Link() string {
	return b.url
}

var serieNumRe = regexp.MustCompile(" #([0-9]+)$")

func (b *Book) Serie() string {
	s := b.doc.Find("#bookSeries a").Text()
	s = strings.Trim(s, "()\n ")
	return serieNumRe.ReplaceAllString(s, "")
}