package main

import (
	"fmt"
	"net/http"
	"regexp"
	"strconv"
	"strings"
	"time"

	"git.milar.in/nyaanime/model"
	"github.com/PuerkitoBio/goquery"
)

var torrentLinkRegex = regexp.MustCompile(`https:\/\/nyaa\.si\/download\/(\d+?)\.torrent`)

func GetTorrents() ([]model.Torrent, error) {
	resp, err := http.Get("https://nyaa.si/?page=rss&f=0&c=1_0")
	if err != nil {
		return nil, ErrTorrentNotObtainable.Wrap(err, "torrent data acqusition failed")
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		return nil, ErrTorrentNotObtainable.New("invalid status code from nyaa.si: " + strconv.Itoa(resp.StatusCode))
	}

	nyaa, err := goquery.NewDocumentFromReader(resp.Body)
	if err != nil {
		return nil, ErrTorrentNotObtainable.Wrap(err, "nyaa.si response parsing failed")
	}

	torrents := make([]model.Torrent, 0, 75)

	nyaa.Find("item").Each(func(i int, s *goquery.Selection) {
		time, err := time.Parse(time.RFC1123Z, s.Find("pubDate").Text())
		if err != nil {
			fmt.Println("could not parse time:", s.Find("pubDate"))
			return
		}

		seeders, err := strconv.Atoi(s.Find("nyaa\\:seeders").Text())
		if err != nil {
			fmt.Println("could not parse seeders:", s.Find("nyaa\\:seeders").Text())
			return
		}

		leechers, err := strconv.Atoi(s.Find("nyaa\\:leechers").Text())
		if err != nil {
			fmt.Println("could not parse leechers:", s.Find("nyaa\\:leechers").Text())
			return
		}

		downloads, err := strconv.Atoi(s.Find("nyaa\\:downloads").Text())
		if err != nil {
			fmt.Println("could not parse downloads:", s.Find("nyaa\\:downloads").Text())
			return
		}

		// goquery can't parse the link tag for some reason
		// therefore I have to get around this bug by exploiting regex
		matches := torrentLinkRegex.FindStringSubmatch(s.Text())
		link := matches[0]
		id := matches[1]

		torrents = append(torrents, model.Torrent{
			ID:        model.TorrentID(id),
			Title:     s.Find("title").Text(),
			Link:      link,
			Time:      time,
			Seeders:   seeders,
			Leechers:  leechers,
			Downloads: downloads,
			Trusted:   strings.Contains(strings.ToLower(s.Find("nyaa\\:trusted").Text()), "yes"),
		})
	})

	return torrents, nil
}