// Package mangareader implements the MangaReader base.
// All list types via GET {base}/?page={n}&sort={val}; pages via AJAX; FlareSolverr required.
package mangareader

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
	TypeParam      string // "comic", "manga", "manhwa", etc.
	ChapterListID  string // ID of chapter list container, default "en-chapters"
}

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

func New(cfg Config) *Source {
	if cfg.ChapterListID == "" {
		cfg.ChapterListID = "en-chapters"
	}
	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("mangareader: HTTP %d", resp.StatusCode)
	}
	return goquery.NewDocumentFromReader(resp.Body)
}

func (s *Source) searchURL(page int, sort, query string) string {
	u := fmt.Sprintf("%s/?page=%d", s.base(), page)
	if sort != "" {
		u += "&sort=" + sort
	}
	if s.cfg.TypeParam != "" {
		u += "&type=" + s.cfg.TypeParam
	}
	if query != "" {
		u += "&keyword=" + query
	}
	return u
}

func (s *Source) parseMangaList(doc *goquery.Document) source.MangasPage {
	var mangas []source.SManga
	doc.Find(".manga_list-sbs .manga-poster, .manga_list .manga-poster").Each(func(_ int, el *goquery.Selection) {
		m := source.SManga{}
		el.Find("a").First().Each(func(_ int, a *goquery.Selection) {
			m.URL, _ = a.Attr("href")
		})
		el.Find("img").First().Each(func(_ int, img *goquery.Selection) {
			m.Title = img.AttrOr("alt", "")
			m.ThumbnailURL = imgAttr(img, s.cfg.BaseURL)
		})
		if m.URL != "" {
			mangas = append(mangas, m)
		}
	})
	hasNext := doc.Find("ul.pagination > li.active + li").Length() > 0
	return source.MangasPage{Mangas: mangas, HasNextPage: hasNext}
}

func (s *Source) GetPopularManga(page int) (source.MangasPage, error) {
	doc, err := s.get(context.Background(), s.searchURL(page, "most-viewed", ""))
	if err != nil {
		return source.MangasPage{}, err
	}
	return s.parseMangaList(doc), nil
}

func (s *Source) GetLatestUpdates(page int) (source.MangasPage, error) {
	doc, err := s.get(context.Background(), s.searchURL(page, "latest-updated", ""))
	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(), s.searchURL(page, "", query))
	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}
	detail := doc.Find("#ani_detail")
	result.Title = strings.TrimSpace(detail.Find(".manga-name").First().Text())
	result.ThumbnailURL = imgAttr(detail.Find("img").First(), s.cfg.BaseURL)
	var genres []string
	detail.Find(".genres > a").Each(func(_ int, el *goquery.Selection) {
		if t := strings.TrimSpace(el.Text()); t != "" {
			genres = append(genres, t)
		}
	})
	result.Genre = strings.Join(genres, ", ")
	detail.Find(".anisc-info > .item").Each(func(_ int, el *goquery.Selection) {
		head := strings.TrimSpace(el.Find(".item-head").Text())
		val := strings.TrimSpace(el.Find("a, span:not(.item-head)").First().Text())
		switch {
		case strings.Contains(head, "Author"):
			result.Author = val
		case strings.Contains(head, "Status"):
			result.Status = util.StatusFromString(val)
		}
	})
	var desc strings.Builder
	detail.Find(".description").Each(func(_ int, el *goquery.Selection) {
		desc.WriteString(strings.TrimSpace(el.Text()))
	})
	result.Description = desc.String()
	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("#"+s.cfg.ChapterListID+" > li.chapter-item").Each(func(_ int, el *goquery.Selection) {
		ch := source.SChapter{}
		el.Find("a").First().Each(func(_ int, a *goquery.Selection) {
			ch.URL, _ = a.Attr("href")
			ch.Name = strings.TrimSpace(a.Find(".name").Text())
			if ch.Name == "" {
				ch.Name = strings.TrimSpace(a.Text())
			}
		})
		el.Find(".date").First().Each(func(_ int, e *goquery.Selection) {
			ch.DateUpload = util.ParseRelativeDate(e.Text())
		})
		if ch.URL != "" {
			chapters = append(chapters, ch)
		}
	})
	return chapters, nil
}

func (s *Source) GetPageList(chapter source.SChapter) ([]source.Page, error) {
	chapterURL := util.AbsURL(s.cfg.BaseURL, chapter.URL)
	doc, err := s.get(context.Background(), chapterURL)
	if err != nil {
		return nil, err
	}
	// extract reading ID from the page
	readingID, _ := doc.Find("div[data-reading-id]").First().Attr("data-reading-id")
	if readingID == "" {
		readingID, _ = doc.Find("div[data-id]").First().Attr("data-id")
	}
	if readingID == "" {
		return nil, fmt.Errorf("mangareader: could not find reading ID")
	}
	// double-slash is intentional — matches Kotlin source
	ajaxURL := fmt.Sprintf("%s//ajax/image/list/%s?mode=vertical", s.base(), readingID)
	ajaxDoc, err := s.get(context.Background(), ajaxURL)
	if err != nil {
		return nil, err
	}
	var pages []source.Page
	ajaxDoc.Find(".container-reader-chapter > div > img, .container-reader-chapter img").Each(func(i int, img *goquery.Selection) {
		if u := imgAttr(img, s.cfg.BaseURL); u != "" {
			pages = append(pages, source.Page{Index: i, ImageURL: 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 }

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 ""
}