// Package mangawork implements the MangaWork manga base.
// HTML scraping for browse/details; multipart POST to wp-admin/admin-ajax.php for chapter list; CF-protected.
package mangawork

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"net/url"
	"regexp"
	"strings"
	"time"

	"github.com/PuerkitoBio/goquery"

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

type Config struct {
	Name            string
	BaseURL         string
	Lang            string
	SeriesPath      string // default: "series"
	MangaPath       string // default: "manga"
	ChapterDateFmt  string // default: "02/01/2006"
	AuthorLabel     string // default: "Autor(es)"
	PopularOrder    string // default: "popular"
	LatestOrder     string // default: "update"
}

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

func New(cfg Config) *Source {
	if cfg.SeriesPath == "" {
		cfg.SeriesPath = "series"
	}
	if cfg.MangaPath == "" {
		cfg.MangaPath = "manga"
	}
	if cfg.ChapterDateFmt == "" {
		cfg.ChapterDateFmt = "02/01/2006"
	}
	if cfg.AuthorLabel == "" {
		cfg.AuthorLabel = "Autor(es)"
	}
	if cfg.PopularOrder == "" {
		cfg.PopularOrder = "popular"
	}
	if cfg.LatestOrder == "" {
		cfg.LatestOrder = "update"
	}
	c := httpclient.NewClient(httpclient.WithRateLimit(2, 3))
	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("mangawork: HTTP %d", resp.StatusCode)
	}
	return goquery.NewDocumentFromReader(resp.Body)
}

func (s *Source) buildSeriesURL(page int, query, order, status, typ string) string {
	u, _ := url.Parse(s.base() + "/" + s.cfg.SeriesPath + "/")
	q := u.Query()
	q.Set("title", query)
	q.Set("order", order)
	if status != "" {
		q.Set("status", status)
	}
	if typ != "" {
		q.Set("type", typ)
	}
	q.Set("page", fmt.Sprint(page))
	u.RawQuery = q.Encode()
	return u.String()
}

func (s *Source) parseMangaList(doc *goquery.Document) source.MangasPage {
	mangaSelector := fmt.Sprintf("div.w-full.h-full:has(a[href*='/%s/'])", s.cfg.MangaPath)
	anchorSelector := fmt.Sprintf("a[href*='/%s/']", s.cfg.MangaPath)
	var mangas []source.SManga
	doc.Find(mangaSelector).Each(func(_ int, el *goquery.Selection) {
		anchor := el.Find(anchorSelector).First()
		u := anchor.AttrOr("href", "")
		if u == "" {
			return
		}
		m := source.SManga{URL: u}
		m.Title = strings.TrimSpace(anchor.Find("h1").Text())
		if m.Title == "" {
			m.Title = strings.TrimSpace(anchor.AttrOr("title", ""))
		}
		if thumb := anchor.Find("img").First().AttrOr("src", ""); thumb != "" {
			m.ThumbnailURL = util.AbsURL(s.cfg.BaseURL, thumb)
		}
		if m.URL != "" && m.Title != "" {
			mangas = append(mangas, m)
		}
	})
	hasNext := doc.Find(".pagination .page-numbers.current + a[href]").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.buildSeriesURL(page, "", s.cfg.PopularOrder, "", ""))
	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.buildSeriesURL(page, "", s.cfg.LatestOrder, "", ""))
	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.buildSeriesURL(page, query, "title", "", ""))
	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}
	result.Title = strings.TrimSpace(doc.Find("h1.text-4xl.font-bold.mb-2").Text())
	if result.Title == "" {
		result.Title = manga.Title
	}
	if thumb := doc.Find("img[itemprop=image], [itemprop=image] img").First().AttrOr("src", ""); thumb != "" {
		result.ThumbnailURL = util.AbsURL(s.cfg.BaseURL, thumb)
	}
	result.Description = strings.TrimSpace(doc.Find("div.text-base.leading-relaxed.mb-6.text-muted-foreground").Text())

	genres := doc.Find("[itemprop=genre]")
	var genreNames []string
	genres.Each(func(_ int, el *goquery.Selection) {
		if t := strings.TrimSpace(el.Text()); t != "" {
			genreNames = append(genreNames, t)
		}
	})
	result.Genre = strings.Join(genreNames, ", ")

	// Status from the element before the first genre
	if first := genres.First(); first.Length() > 0 {
		statusLabel := strings.TrimSpace(first.Prev().Text())
		result.Status = parseStatus(statusLabel)
	}

	// Author via info item search
	result.Author = findInfoValue(doc, s.cfg.AuthorLabel)
	return result, nil
}

// findInfoValue finds the value of an info item with the given label.
// Info items: "div.grid.grid-cols-2.gap-4.text-sm.text-gray-600.mb-6 > div"
// Each item has a <strong> label and <p> value.
func findInfoValue(doc *goquery.Document, label string) string {
	const infoItemSelector = "div.grid.grid-cols-2.gap-4.text-sm.text-gray-600.mb-6 > div"
	var result string
	doc.Find(infoItemSelector).Each(func(_ int, el *goquery.Selection) {
		if result != "" {
			return
		}
		if strings.TrimSpace(el.Find("strong").Text()) == label {
			result = strings.TrimSpace(el.Find("p").Text())
		}
	})
	return result
}

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
	}

	container := doc.Find("#chapter_list.chapter_list_container").First()
	var chapters []source.SChapter

	// Collect chapters already present on the page
	container.Find("li").Each(func(_ int, el *goquery.Selection) {
		if ch, ok := s.chapterFromElement(el); ok {
			chapters = append(chapters, ch)
		}
	})

	postID := strings.TrimSpace(container.AttrOr("data-post-id", ""))
	if postID == "" {
		return chapters, nil
	}
	count := strings.TrimSpace(container.AttrOr("data-count", "1000"))

	// Paginate via admin-ajax if there are more chapters
	currentPage := 1
	for {
		nextBtn := doc.Find("button.load-chapters[data-paged]").First()
		if nextBtn.Length() == 0 {
			break
		}
		nextPage := strings.TrimSpace(nextBtn.AttrOr("data-paged", ""))
		if nextPage == "" || nextPage == fmt.Sprint(currentPage) {
			break
		}
		order := strings.TrimSpace(nextBtn.AttrOr("data-order", "DESC"))

		ajaxDoc, err := s.postChapterListPage(manga.URL, postID, count, nextPage, order)
		if err != nil {
			break
		}
		doc = ajaxDoc
		ajaxDoc.Find("li").Each(func(_ int, el *goquery.Selection) {
			if ch, ok := s.chapterFromElement(el); ok {
				chapters = append(chapters, ch)
			}
		})
		if p, _ := fmt.Sscan(nextPage, &currentPage); p == 0 {
			break
		}
	}

	// Deduplicate
	seen := map[string]bool{}
	unique := chapters[:0]
	for _, ch := range chapters {
		if !seen[ch.URL] {
			seen[ch.URL] = true
			unique = append(unique, ch)
		}
	}
	return unique, nil
}

var chapterNumRe = regexp.MustCompile(`(\d+(?:[.,]\d+)?)`)

func (s *Source) chapterFromElement(el *goquery.Selection) (source.SChapter, bool) {
	anchor := el.Find("a[href]").First()
	if anchor.Length() == 0 {
		return source.SChapter{}, false
	}
	u := anchor.AttrOr("href", "")
	if u == "" {
		return source.SChapter{}, false
	}

	nameEl := el.Find("span.m-0, span.line-clamp-1").First()
	name := strings.TrimSpace(nameEl.Text())
	if name == "" {
		name = strings.TrimSpace(anchor.Text())
	}

	// Date from last span
	var dateStr string
	el.Find("span").Each(func(_ int, sp *goquery.Selection) {
		t := strings.TrimSpace(sp.Text())
		if t != "" && t != name {
			dateStr = t
		}
	})

	return source.SChapter{
		URL:        u,
		Name:       name,
		DateUpload: parseChapterDate(dateStr, s.cfg.ChapterDateFmt),
	}, true
}

func (s *Source) postChapterListPage(referer, postID, count, page, order string) (*goquery.Document, error) {
	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	_ = w.WriteField("action", "load_chapters")
	_ = w.WriteField("post_id", postID)
	_ = w.WriteField("count", count)
	_ = w.WriteField("paged", page)
	_ = w.WriteField("order", order)
	w.Close()

	ajaxURL := s.base() + "/wp-admin/admin-ajax.php"
	req, err := http.NewRequestWithContext(context.Background(), http.MethodPost, ajaxURL, &buf)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Content-Type", w.FormDataContentType())
	req.Header.Set("Referer", util.AbsURL(s.cfg.BaseURL, referer))
	req.Header.Set("Origin", s.cfg.BaseURL)
	req.Header.Set("Accept", "*/*")

	resp, err := s.client.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	return goquery.NewDocumentFromReader(bytes.NewReader(body))
}

var pageImageRe = regexp.MustCompile(`"image"\s*:\s*"([^"]+)"`)

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
	}

	// Primary: div.reader-area img
	var pages []source.Page
	doc.Find("div.reader-area img#imagech, div.reader-area img[src*='/manga_auto_capitulos/']").Each(func(i int, img *goquery.Selection) {
		u := imgAttr(img)
		if u != "" {
			pages = append(pages, source.Page{Index: i, ImageURL: util.AbsURL(s.cfg.BaseURL, u)})
		}
	})
	if len(pages) > 0 {
		return pages, nil
	}

	// Fallback: extract "image": "url" from inline script
	var scriptData string
	doc.Find("script").Each(func(_ int, el *goquery.Selection) {
		html, _ := el.Html()
		if strings.Contains(html, `"image"`) {
			scriptData += html
		}
	})
	for i, m := range pageImageRe.FindAllStringSubmatch(scriptData, -1) {
		imgURL := strings.ReplaceAll(m[1], `\/`, "/")
		pages = append(pages, source.Page{Index: i, ImageURL: imgURL})
	}
	return pages, nil
}

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

func parseChapterDate(s, format string) int64 {
	if s == "" {
		return 0
	}
	t, err := time.Parse(format, s)
	if err != nil {
		return 0
	}
	return t.UnixMilli()
}

func parseStatus(s string) int {
	switch strings.ToLower(s) {
	case "publishing", "ongoing", "em andamento":
		return source.StatusOngoing
	case "finished", "completed", "concluído", "concluido", "finalizado":
		return source.StatusCompleted
	case "on hold", "on-hold", "hiatus", "em hiato":
		return source.StatusHiatus
	case "cancelled", "canceled", "cancelado":
		return source.StatusCancelled
	}
	return source.StatusUnknown
}

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