package fa

import (
	"fmt"
	"strings"

	"github.com/PuerkitoBio/goquery"

	"git.anthrove.art/public/go-fa-api/internal/urls"
)

// parseJournal lifts a [Journal] from a /journal/{id}/ document. FA renders
// the journal view inside the author's profile shell, so the author is
// derived from the userpage nav rather than from any byline in the journal
// body itself.
func parseJournal(id JournalID, doc *goquery.Document) (*Journal, error) {
	j := &Journal{ID: id}

	// Title.
	j.Title = trimText(doc.Find("#c-journalTitleTop__subject h3").First())
	if j.Title == "" {
		j.Title = firstNonEmpty(
			trimText(doc.Find("h2.journal-title").First()),
			trimText(doc.Find("h3.journal-title").First()),
		)
	}
	if j.Title == "" {
		return nil, fmt.Errorf("%w: journal %d: missing title", ErrParse, id)
	}

	// Author from the userpage nav at the top of the rendered page.
	authorLink := doc.Find("a.c-usernameBlock__displayName[href^='/user/']").First()
	if authorLink.Length() > 0 {
		href, _ := authorLink.Attr("href")
		j.Author = UserRef{
			DisplayName: trimText(authorLink.Find("span.js-displayName").First()),
			AvatarURL:   urls.AbsoluteCDN(trimAttr(doc.Find("img.user-nav-avatar").First(), "src")),
		}
		if j.Author.DisplayName == "" {
			j.Author.DisplayName = trimText(authorLink)
		}
		if parts := strings.Split(strings.Trim(href, "/"), "/"); len(parts) >= 2 {
			j.Author.Name = strings.ToLower(parts[1])
		}
	}

	// Date from the journal title block.
	j.PostedAt = parsePopupDate(doc.Find("#c-journalTitleTop__date span.popup_date").First())
	if j.PostedAt.IsZero() {
		j.PostedAt = parsePopupDate(doc.Find("span.popup_date").First())
	}

	// Body.
	body := firstNonEmptySel(doc,
		"div.section-body.journal-body-theme div.journal-content",
		"div.journal-content",
		"div.journal-body",
		"section.journal-body",
	)
	if body != nil {
		j.BodyHTML = htmlOf(body)
		j.BodyText = strings.TrimSpace(body.Text())
	}

	return j, nil
}

// parseUserJournalsPage parses a /journals/{user}/[page]/ listing page,
// returning the journal entries it contains and whether a next page exists.
//
// FA renders each entry inside the listing differently from the standalone
// journal page; selectors here target the listing's tile structure.
func parseUserJournalsPage(doc *goquery.Document) (entries []*Journal, hasNext bool) {
	doc.Find("section.journal, section[id^=jid], div.journal[id^=jid]").Each(func(_ int, sel *goquery.Selection) {
		j := &Journal{}
		idAttr, _ := sel.Attr("id")
		idAttr = strings.TrimPrefix(idAttr, "jid:")
		idAttr = strings.TrimPrefix(idAttr, "journal-")
		if n, err := parseID[JournalID](strings.TrimSpace(idAttr)); err == nil {
			j.ID = n
		}
		j.Title = firstNonEmpty(
			trimText(sel.Find("h2 a, h3 a").First()),
			trimText(sel.Find("h2, h3").First()),
		)
		j.PostedAt = parsePopupDate(sel.Find("span.popup_date").First())
		body := sel.Find("div.journal-body, div.journal-content").First()
		j.BodyHTML = htmlOf(body)
		j.BodyText = strings.TrimSpace(body.Text())
		if j.ID != 0 || j.Title != "" {
			entries = append(entries, j)
		}
	})
	hasNext = detectNextPage(doc)
	return entries, hasNext
}