package stalkercms

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"

	"github.com/PuerkitoBio/goquery"

	"goyomi/internal/httpclient/flare"
	"goyomi/internal/source"
)

type Config struct {
	Name                      string
	BaseURL                   string
	Lang                      string
	PopularMangaPath           string
	LatestUpdatesLoadMorePath string
}

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

func New(cfg Config) *Source {
	if cfg.PopularMangaPath == "" {
		cfg.PopularMangaPath = "/manga/todos/"
	}
	if cfg.Lang == "" {
		cfg.Lang = "pt-BR"
	}
	c := flare.NewClient(flare.WithRateLimit(2, 1))
	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 }

type LoadMoreReleasesDTO struct {
	HTML     string `json:"html"`
	HasNext  bool   `json:"hasNext"`
	NextPage int    `json:"nextPage"`
}

type SearchResult struct {
	Title       string `json:"title"`
	URL         string `json:"url"`
	Image       string `json:"image"`
	Description string `json:"description"`
}

type SearchDTO struct {
	Results []SearchResult `json:"results"`
}

func (s *Source) parseStatus(status string) int {
	switch strings.TrimSpace(strings.ToLower(status)) {
	case "em andamento":
		return 1
	case "concluído":
		return 2
	case "hiato":
		return 5
	case "cancelado":
		return 6
	}
	return 0
}

func (s *Source) GetPopularManga(page int) (source.MangasPage, error) {
	doc, err := s.fetchDoc(fmt.Sprintf("%s%s?page=%d", s.cfg.BaseURL, cfg.PopularMangaPath, page))
	if err != nil {
		return source.MangasPage{}, err
	}

	mangas := s.mangaListFromDoc(doc)
	hasNext := doc.Find(".page-link[aria-label=Próxima]:not(disabled)").Length() > 0

	return source.MangasPage{Mangas: mangas, HasNextPage: hasNext}, nil
}

func (s *Source) GetLatestUpdates(page int) (source.MangasPage, error) {
	if page > 1 && s.cfg.LatestUpdatesLoadMorePath != "" {
		url := fmt.Sprintf("%s%s?page=%d", s.cfg.BaseURL, s.cfg.LatestUpdatesLoadMorePath, page)
		req, err := http.NewRequestWithContext(context.Background(), http.MethodGet, url, nil)
		if err != nil {
			return source.MangasPage{}, err
		}
		resp, err := s.client.Do(req)
		if err != nil {
			return source.MangasPage{}, err
		}
		defer resp.Body.Close()

		var dto LoadMoreReleasesDTO
		if err := json.NewDecoder(resp.Body).Decode(&dto); err != nil {
			return source.MangasPage{}, err
		}

		doc, err := goquery.NewDocumentFromReader(strings.NewReader(dto.HTML))
		if err != nil {
			return source.MangasPage{}, err
		}

		mangas := s.mangaListFromDoc(doc)
		return source.MangasPage{Mangas: mangas, HasNextPage: dto.HasNext}, nil
	}

	doc, err := s.fetchDoc(s.cfg.BaseURL)
	if err != nil {
		return source.MangasPage{}, err
	}

	mangas := s.mangaListFromDoc(doc)

	hasNext := true
	if s.cfg.LatestUpdatesLoadMorePath != "" {
		hasNext = doc.Find("#load-more-btn").Length() > 0
	} else {
		hasNext = doc.Find(".page-link[aria-label=Próxima]:not(disabled)").Length() > 0
	}

	return source.MangasPage{Mangas: mangas, HasNextPage: hasNext}, nil
}

func (s *Source) mangaListFromDoc(doc *goquery.Document) []source.SManga {
	mangas := make([]source.SManga, 0)
	doc.Find(".comics-grid a.comic-card-link, div.manga-card-simple").Each(func(_ int, sel *goquery.Selection) {
		title := sel.Find("h3").Text()
		img := sel.Find("img")
		thumb := img.AttrOr("abs:src", "")
		if thumb == "" {
			href := sel.AttrOr("abs:href", "")
			if a := sel.Find("a"); a.Length() > 0 {
				href = a.AttrOr("abs:href", "")
			}
			mangas = append(mangas, source.SManga{
				URL:          href,
				Title:        strings.TrimSpace(title),
				ThumbnailURL: thumb,
			})
		} else {
			href := sel.AttrOr("abs:href", "")
			if a := sel.Find("a"); a.Length() > 0 {
				href = a.AttrOr("abs:href", "")
			}
			mangas = append(mangas, source.SManga{
				URL:          href,
				Title:        strings.TrimSpace(title),
				ThumbnailURL: thumb,
			})
		}
	})
	return mangas
}

func (s *Source) GetSearchManga(page int, query string, filters []source.Filter) (source.MangasPage, error) {
	if query == "" {
		return source.MangasPage{}, nil
	}

	u, _ := url.Parse(s.cfg.BaseURL + "/search/live-search/")
	q := u.Query()
	q.Set("q", query)
	u.RawQuery = q.Encode()

	req, err := http.NewRequestWithContext(context.Background(), http.MethodGet, u.String(), nil)
	if err != nil {
		return source.MangasPage{}, err
	}
	resp, err := s.client.Do(req)
	if err != nil {
		return source.MangasPage{}, err
	}
	defer resp.Body.Close()

	var result SearchDTO
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return source.MangasPage{}, err
	}

	mangas := make([]source.SManga, len(result.Results))
	for i, r := range result.Results {
		mangas[i] = source.SManga{
			URL:          r.URL,
			Title:        r.Title,
			ThumbnailURL: r.Image,
			Description:  r.Description,
		}
	}

	return source.MangasPage{Mangas: mangas, HasNextPage: false}, nil
}

func (s *Source) GetMangaDetails(manga source.SManga) (source.SManga, error) {
	doc, err := s.fetchDoc(manga.URL)
	if err != nil {
		return manga, err
	}

	title := doc.Find("h1").Text()
	thumb := doc.Find(".sidebar-cover-image img").AttrOr("abs:src", "")
	desc := doc.Find(".manga-description").Text()
	genre := doc.Find("a.genre-tag").Map(func(_ int, sel *goquery.Selection) string {
		return sel.Text()
	})
	statusText := doc.Find(".status-tag").Text()
	status := s.parseStatus(statusText)

	manga.Title = strings.TrimSpace(title)
	manga.ThumbnailURL = thumb
	manga.Description = strings.TrimSpace(desc)
	manga.Genre = joinStrings(genre, ", ")
	manga.Status = status
	manga.Initialized = true

	return manga, nil
}

func (s *Source) GetChapterList(manga source.SManga) ([]source.SChapter, error) {
	chapters := make([]source.SChapter, 0)
	page := 1

	for {
		mangaURL := manga.URL
		if strings.Contains(mangaURL, "?") {
			mangaURL += "&page=" + fmt.Sprintf("%d", page)
		} else {
			mangaURL += "?page=" + fmt.Sprintf("%d", page)
		}

		doc, err := s.fetchDoc(mangaURL)
		if err != nil {
			break
		}

		doc.Find(".chapter-item-list a.chapter-link").Each(func(_ int, sel *goquery.Selection) {
			name := sel.Find(".chapter-number").Text()
			dateText := sel.Find(".chapter-date").Text()
			href := sel.AttrOr("abs:href", "")

			var dateUpload int64
			dateFormat := "02/01/2006"
			if t, err := time.Parse(dateFormat, strings.TrimSpace(dateText)); err == nil {
				dateUpload = t.UnixMilli()
			}

			chapters = append(chapters, source.SChapter{
				URL:        href,
				Name:       strings.TrimSpace(name),
				DateUpload: dateUpload,
			})
		})

		if doc.Find(".page-link[aria-label=Próxima]:not(disabled)").Length() == 0 {
			break
		}
		page++
	}

	return chapters, nil
}

func (s *Source) GetPageList(chapter source.SChapter) ([]source.Page, error) {
	doc, err := s.fetchDoc(chapter.URL)
	if err != nil {
		return nil, err
	}

	pages := make([]source.Page, 0)
	doc.Find(".chapter-image-canvas").Each(func(i int, sel *goquery.Selection) {
		imgURL := sel.AttrOr("data-src-url", "")
		pages = append(pages, source.Page{Index: i, 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
}

func (s *Source) fetchDoc(rawURL string) (*goquery.Document, error) {
	req, err := http.NewRequestWithContext(context.Background(), 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()

	html, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	return goquery.NewDocumentFromReader(strings.NewReader(string(html)))
}

func joinStrings(ss []string, sep string) string {
	if len(ss) == 0 {
		return ""
	}
	result := ss[0]
	for i := 1; i < len(ss); i++ {
		result += sep + ss[i]
	}
	return result
}

var cfg = struct {
	PopularMangaPath string
}{}

func init() {
	cfg.PopularMangaPath = "/manga/todos/"
}

var _ source.CatalogueSource = (*Source)(nil)