// Package gigaviewer implements the GigaViewer (Hatena) base.
// GET {base}/series returns all manga; no pagination.
package gigaviewer

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

	"github.com/PuerkitoBio/goquery"

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

type Config struct {
	Name    string
	BaseURL string
	Lang    string
}

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

func New(cfg Config) *Source {
	c := flare.NewClient(flare.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
	}
	req.Header.Set("Origin", s.cfg.BaseURL)
	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("gigaviewer: HTTP %d", resp.StatusCode)
	}
	return goquery.NewDocumentFromReader(resp.Body)
}

func (s *Source) fetchAllManga() ([]source.SManga, error) {
	doc, err := s.get(context.Background(), strings.TrimRight(s.cfg.BaseURL, "/")+"/series")
	if err != nil {
		return nil, err
	}
	var mangas []source.SManga
	doc.Find("ul.series-list li a").Each(func(_ int, el *goquery.Selection) {
		m := source.SManga{}
		if href, ok := el.Attr("href"); ok {
			m.URL = href
		}
		el.Find("h2.series-list-title").First().Each(func(_ int, e *goquery.Selection) {
			m.Title = strings.TrimSpace(e.Text())
		})
		el.Find("div.series-list-thumb img").First().Each(func(_ int, img *goquery.Selection) {
			if v, ok := img.Attr("data-src"); ok && v != "" {
				m.ThumbnailURL = util.AbsURL(s.cfg.BaseURL, v)
			} else if v, ok := img.Attr("src"); ok && v != "" {
				m.ThumbnailURL = util.AbsURL(s.cfg.BaseURL, v)
			}
		})
		if m.URL != "" {
			mangas = append(mangas, m)
		}
	})
	return mangas, nil
}

func (s *Source) GetPopularManga(page int) (source.MangasPage, error) {
	if page > 1 {
		return source.MangasPage{HasNextPage: false}, nil
	}
	mangas, err := s.fetchAllManga()
	return source.MangasPage{Mangas: mangas, HasNextPage: false}, err
}

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

func (s *Source) GetSearchManga(page int, query string, filters []source.Filter) (source.MangasPage, error) {
	mangas, err := s.fetchAllManga()
	if err != nil {
		return source.MangasPage{}, err
	}
	q := strings.ToLower(query)
	var matched []source.SManga
	for _, m := range mangas {
		if strings.Contains(strings.ToLower(m.Title), q) {
			matched = append(matched, m)
		}
	}
	return source.MangasPage{Mangas: matched, HasNextPage: false}, 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("section.series-information div.series-header").First().Each(func(_ int, el *goquery.Selection) {
		el.Find("h1.series-header-title").First().Each(func(_ int, e *goquery.Selection) { result.Title = strings.TrimSpace(e.Text()) })
		el.Find("h2.series-header-author").First().Each(func(_ int, e *goquery.Selection) { result.Author = strings.TrimSpace(e.Text()) })
		el.Find("p.series-header-description").First().Each(func(_ int, e *goquery.Selection) { result.Description = strings.TrimSpace(e.Text()) })
		el.Find("div.series-header-image img").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("ul.series-episode-list li a, li.episode a").Each(func(_ int, a *goquery.Selection) {
		ch := source.SChapter{}
		if href, ok := a.Attr("href"); ok {
			ch.URL = href
		}
		a.Find(".series-episode-list-title, .episode-title").First().Each(func(_ int, e *goquery.Selection) {
			ch.Name = strings.TrimSpace(e.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("div.js-page-viewer img, .page-image img").Each(func(i int, img *goquery.Selection) {
		imgURL := util.AbsURL(s.cfg.BaseURL, img.AttrOr("src", img.AttrOr("data-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 }