// Package gattsu implements the Gattsu Brazilian adult manga base.
// Popular = Latest: GET {base}/page/{n}; no separate popular endpoint.
package gattsu

import (
	"context"
	"fmt"
	"net/http"
	"regexp"
	"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) base() string { return strings.TrimRight(s.cfg.BaseURL, "/") }

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
	}
	req.Header.Set("Referer", s.cfg.BaseURL+"/")
	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("gattsu: HTTP %d", resp.StatusCode)
	}
	return goquery.NewDocumentFromReader(resp.Body)
}

// thumbSizeRe matches WordPress size suffix like "-150x150." and replaces with ".".
var thumbSizeRe = regexp.MustCompile(`-\d+x\d+\.`)

func withoutSize(u string) string {
	return thumbSizeRe.ReplaceAllString(u, ".")
}

func imgAttr(img *goquery.Selection, baseURL string) string {
	for _, attr := range []string{"data-lazy-src", "data-src", "data-cfsrc", "src"} {
		if v, ok := img.Attr(attr); ok && v != "" && !strings.HasPrefix(v, "data:") {
			return util.AbsURL(baseURL, v)
		}
	}
	return ""
}

func (s *Source) mangaFromElement(el *goquery.Selection) source.SManga {
	m := source.SManga{}
	m.URL, _ = el.Attr("href")
	m.Title = strings.TrimSpace(el.Find("span.thumb-titulo").Text())
	el.Find("span.thumb-imagem img.wp-post-image").First().Each(func(_ int, img *goquery.Selection) {
		if src, ok := img.Attr("src"); ok {
			m.ThumbnailURL = withoutSize(util.AbsURL(s.cfg.BaseURL, src))
		}
	})
	return m
}

func (s *Source) parseList(doc *goquery.Document) source.MangasPage {
	var mangas []source.SManga
	prefix := s.base()
	sel := fmt.Sprintf("div.meio div.lista ul li a[href^=%s]", prefix)
	doc.Find(sel).Each(func(_ int, el *goquery.Selection) {
		m := s.mangaFromElement(el)
		if m.URL != "" {
			mangas = append(mangas, m)
		}
	})
	hasNext := doc.Find(".next.page-numbers, a.next").Length() > 0
	return source.MangasPage{Mangas: mangas, HasNextPage: hasNext}
}

func (s *Source) fetchPage(page int) (source.MangasPage, error) {
	var u string
	if page == 1 {
		u = s.base() + "/"
	} else {
		u = fmt.Sprintf("%s/page/%d", s.base(), page)
	}
	doc, err := s.get(context.Background(), u)
	if err != nil {
		return source.MangasPage{}, err
	}
	return s.parseList(doc), nil
}

func (s *Source) GetPopularManga(page int) (source.MangasPage, error) { return s.fetchPage(page) }
func (s *Source) GetLatestUpdates(page int) (source.MangasPage, error) { return s.fetchPage(page) }

func (s *Source) GetSearchManga(page int, query string, filters []source.Filter) (source.MangasPage, error) {
	u := fmt.Sprintf("%s/?s=%s&post_type=post", s.base(), query)
	if page > 1 {
		u = fmt.Sprintf("%s/page/%d/?s=%s&post_type=post", s.base(), page, query)
	}
	doc, err := s.get(context.Background(), u)
	if err != nil {
		return source.MangasPage{}, err
	}
	return s.parseList(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, Status: source.StatusCompleted}
	postBox := doc.Find("div.meio div.post-box").First()
	result.Title = strings.TrimSpace(postBox.Find("h1.post-titulo").Text())
	if result.Title == "" {
		result.Title = manga.Title
	}
	result.Author = strings.TrimSpace(postBox.Find("ul.post-itens li:contains(Artista) a").First().Text())
	var genres []string
	postBox.Find("ul.post-itens li:contains(Tags) a").Each(func(_ int, a *goquery.Selection) {
		if t := strings.TrimSpace(a.Text()); t != "" {
			genres = append(genres, t)
		}
	})
	result.Genre = strings.Join(genres, ", ")
	var descParts []string
	postBox.Find("div.post-texto p").Each(func(_ int, p *goquery.Selection) {
		t := strings.TrimSpace(p.Text())
		t = strings.TrimPrefix(t, "Sinopse :")
		if t = strings.TrimSpace(t); t != "" {
			descParts = append(descParts, t)
		}
	})
	result.Description = strings.Join(descParts, "\n\n")
	postBox.Find("div.post-capa > img.wp-post-image").First().Each(func(_ int, img *goquery.Selection) {
		if src, ok := img.Attr("src"); ok {
			result.ThumbnailURL = withoutSize(util.AbsURL(s.cfg.BaseURL, src))
		}
	})
	return result, nil
}

func (s *Source) GetChapterList(manga source.SManga) ([]source.SChapter, error) {
	// Gattsu pages are single-chapter galleries; the manga page is the chapter.
	return []source.SChapter{{
		URL:  manga.URL,
		Name: manga.Title,
	}}, 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
	}
	sel := "div.meio div.post-box ul.post-fotos li a > img, " +
		"div.meio div.post-box.listaImagens div.galeriaHtml img"
	var pages []source.Page
	doc.Find(sel).Each(func(i int, img *goquery.Selection) {
		if u := imgAttr(img, s.cfg.BaseURL); u != "" {
			pages = append(pages, source.Page{Index: i, ImageURL: withoutSize(u)})
		}
	})
	return pages, nil
}

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