// Package grouple implements the Grouple reader base.
// GET {base}/list?sortType=rate&offset={50*(n-1)}
package grouple

import (
	"context"
	"fmt"
	"net/http"
	"strings"

	"github.com/PuerkitoBio/goquery"

	"goyomi/internal/httpclient"
	"goyomi/internal/source"
	"goyomi/sources/base/util"
)

type Config struct {
	Name    string
	BaseURL string
	Lang    string
}

type Source struct {
	cfg    Config
	client *httpclient.Client
	id     int64
}

func New(cfg Config) *Source {
	c := httpclient.NewClient(httpclient.WithRateLimit(1, 2))
	return &Source{cfg: cfg, client: c, id: source.GenerateSourceID(cfg.Name, cfg.Lang)}
}

func (s *Source) ID() int64           { return s.id }
func (s *Source) Name() string        { return s.cfg.Name }
func (s *Source) Lang() string        { return s.cfg.Lang }
func (s *Source) SupportsLatest() bool { return true }

func (s *Source) get(ctx context.Context, rawURL string) (*goquery.Document, error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
	if err != nil {
		return nil, err
	}
	resp, err := s.client.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("grouple: HTTP %d", resp.StatusCode)
	}
	return goquery.NewDocumentFromReader(resp.Body)
}

func (s *Source) base() string { return strings.TrimRight(s.cfg.BaseURL, "/") }

func (s *Source) parseMangaList(doc *goquery.Document) source.MangasPage {
	var mangas []source.SManga
	doc.Find("div.tile.hovertr").Each(func(_ int, el *goquery.Selection) {
		m := source.SManga{}
		el.Find("a.non-existent, h3 a").First().Each(func(_ int, a *goquery.Selection) {
			if href, ok := a.Attr("href"); ok {
				m.URL = href
			}
			m.Title = strings.TrimSpace(a.Text())
		})
		el.Find("img.lazy").First().Each(func(_ int, img *goquery.Selection) {
			m.ThumbnailURL = util.AbsURL(s.cfg.BaseURL, img.AttrOr("data-original", img.AttrOr("src", "")))
		})
		if m.URL != "" {
			mangas = append(mangas, m)
		}
	})
	hasNext := doc.Find(".pagination .next, li.next a").Length() > 0
	return source.MangasPage{Mangas: mangas, HasNextPage: hasNext}
}

func (s *Source) GetPopularManga(page int) (source.MangasPage, error) {
	offset := 50 * (page - 1)
	doc, err := s.get(context.Background(), fmt.Sprintf("%s/list?sortType=rate&offset=%d", s.base(), offset))
	if err != nil {
		return source.MangasPage{}, err
	}
	return s.parseMangaList(doc), nil
}

func (s *Source) GetLatestUpdates(page int) (source.MangasPage, error) {
	offset := 50 * (page - 1)
	doc, err := s.get(context.Background(), fmt.Sprintf("%s/list?sortType=update&offset=%d", s.base(), offset))
	if err != nil {
		return source.MangasPage{}, err
	}
	return s.parseMangaList(doc), nil
}

func (s *Source) GetSearchManga(page int, query string, filters []source.Filter) (source.MangasPage, error) {
	doc, err := s.get(context.Background(), fmt.Sprintf("%s/search?q=%s&page=%d", s.base(), query, page))
	if err != nil {
		return source.MangasPage{}, err
	}
	return s.parseMangaList(doc), nil
}

func (s *Source) GetMangaDetails(manga source.SManga) (source.SManga, error) {
	doc, err := s.get(context.Background(), util.AbsURL(s.cfg.BaseURL, manga.URL))
	if err != nil {
		return manga, err
	}
	result := source.SManga{URL: manga.URL}
	doc.Find("h1.names span.name").First().Each(func(_ int, el *goquery.Selection) { result.Title = strings.TrimSpace(el.Text()) })
	doc.Find("div.elementList div.subject-meta").First().Each(func(_ int, el *goquery.Selection) { result.Description = strings.TrimSpace(el.Text()) })
	doc.Find("img.hidden-xs").First().Each(func(_ int, img *goquery.Selection) {
		result.ThumbnailURL = util.AbsURL(s.cfg.BaseURL, img.AttrOr("src", ""))
	})
	return result, nil
}

func (s *Source) GetChapterList(manga source.SManga) ([]source.SChapter, error) {
	doc, err := s.get(context.Background(), util.AbsURL(s.cfg.BaseURL, manga.URL))
	if err != nil {
		return nil, err
	}
	var chapters []source.SChapter
	doc.Find("div.chapters-link a, ul.chapters li a").Each(func(_ int, a *goquery.Selection) {
		ch := source.SChapter{}
		if href, ok := a.Attr("href"); ok {
			ch.URL = href
		}
		ch.Name = strings.TrimSpace(a.Text())
		if ch.URL != "" {
			chapters = append(chapters, ch)
		}
	})
	return chapters, nil
}

func (s *Source) GetPageList(chapter source.SChapter) ([]source.Page, error) {
	doc, err := s.get(context.Background(), util.AbsURL(s.cfg.BaseURL, chapter.URL))
	if err != nil {
		return nil, err
	}
	rawURL := util.AbsURL(s.cfg.BaseURL, chapter.URL)
	var pages []source.Page
	doc.Find("img.reader-images, div#sps img").Each(func(i int, img *goquery.Selection) {
		imgURL := util.AbsURL(s.cfg.BaseURL, img.AttrOr("data-src", img.AttrOr("src", "")))
		if imgURL != "" {
			pages = append(pages, source.Page{Index: i, URL: rawURL, ImageURL: imgURL})
		}
	})
	return pages, nil
}

func (s *Source) GetImageURL(page source.Page) (string, error) { return page.ImageURL, nil }
func (s *Source) GetFilterList() []source.Filter               { return nil }