diff --git a/backend/internal/latest/sites.go b/backend/internal/latest/sites.go
index 52ebfa1..489109c 100644
--- a/backend/internal/latest/sites.go
+++ b/backend/internal/latest/sites.go
@@ -1,6 +1,8 @@
package latest
import (
+ "encoding/json"
+ "html"
"net/url"
"regexp"
"strconv"
@@ -34,6 +36,18 @@ var demonicChapterRe = regexp.MustCompile(`chaptered\.php\?manga=\d+&(?:amp;)?ch
// Only the id prefix is stable; the slug tail follows the title.
var comixSlugRe = regexp.MustCompile(`/title/([^/?#]+)`)
+func comixSeriesID(seriesURL string) (string, bool) {
+ m := comixSlugRe.FindStringSubmatch(seriesURL)
+ if m == nil {
+ return "", false
+ }
+ id := m[1]
+ if i := strings.Index(id, "-"); i != -1 {
+ id = id[:i]
+ }
+ return id, true
+}
+
// kaganeChapterRe matches the chapter numbers in a kagane API response. This
// branch is fed by the browser fetcher, so the body is JSON rather than HTML —
// there are no anchors to scan.
@@ -87,18 +101,14 @@ func latestChapterFrom(site, seriesURL, body string) (latestChapter, bool) {
case "demonic":
re = demonicChapterRe
case "comix":
- m := comixSlugRe.FindStringSubmatch(seriesURL)
- if m == nil {
+ id, ok := comixSeriesID(seriesURL)
+ if !ok {
return latestChapter{}, false
}
// comix ships an SPA: the served HTML carries a JSON state blob instead
// of chapter anchors, and latestChapterUrl is the only place the newest
// chapter appears. Scoping to this series' id prefix keeps a
// "recommended" strip's entries from winning the maximum.
- id := m[1]
- if i := strings.Index(id, "-"); i != -1 {
- id = id[:i]
- }
re = regexp.MustCompile(`"latestChapterUrl":"/title/` + regexp.QuoteMeta(id) + `-[^"]*-chapter-([0-9.]+)"`)
case "kagane":
re = kaganeChapterRe
@@ -146,3 +156,102 @@ func latestChapterFrom(site, seriesURL, body string) (latestChapter, bool) {
}
return best, found
}
+
+var metaTagRe = regexp.MustCompile(`(?is)]*>`)
+var doubleQuotedMetaAttrRe = regexp.MustCompile(`(?is)([a-z][a-z0-9:_-]*)\s*=\s*"([^"]*)"`)
+var singleQuotedMetaAttrRe = regexp.MustCompile(`(?is)([a-z][a-z0-9:_-]*)\s*=\s*'([^']*)'`)
+
+// comix's server-rendered page embeds query data in this JSON script; parsing
+// the target detail entry avoids matching posters from recommended results.
+var comixInitialDataRe = regexp.MustCompile(`(?is)`)
+
+// kagane's browser-fetched series response publishes cover image IDs under
+// series_covers. The API's canonical compressed image route is the only URL
+// form accepted by the store and browser fetcher; no rendition is guessed.
+func kaganeCoverURL(body string) string {
+ var response struct {
+ SeriesCovers []struct {
+ ImageID string `json:"image_id"`
+ } `json:"series_covers"`
+ }
+ if err := json.Unmarshal([]byte(body), &response); err != nil {
+ return ""
+ }
+ for _, cover := range response.SeriesCovers {
+ if kaganeImageIDRe.MatchString(cover.ImageID) {
+ return "https://kagane.to/api/v2/image/" + cover.ImageID + "/compressed"
+ }
+ }
+ return ""
+}
+
+func comixCoverURL(seriesURL, body string) string {
+ id, ok := comixSeriesID(seriesURL)
+ if !ok {
+ return ""
+ }
+ data := comixInitialDataRe.FindStringSubmatch(body)
+ if data == nil {
+ return ""
+ }
+ var state struct {
+ Queries map[string]json.RawMessage `json:"queries"`
+ }
+ if err := json.Unmarshal([]byte(data[1]), &state); err != nil {
+ return ""
+ }
+ raw := state.Queries[`["manga","detail","`+id+`"]`]
+ if len(raw) == 0 {
+ return ""
+ }
+ var detail struct {
+ Poster struct {
+ Medium string `json:"medium"`
+ } `json:"poster"`
+ }
+ if err := json.Unmarshal(raw, &detail); err != nil {
+ return ""
+ }
+ return publishedCoverURL(detail.Poster.Medium)
+}
+
+// coverFrom reports false for unknown sites, challenge bodies, and pages with
+// no usable cover. Metadata extraction keeps scanning after an empty match so
+// a later published cover is not hidden by an empty tag.
+func coverFrom(site, seriesURL, body string) (string, bool) {
+ var cover string
+ switch site {
+ case "asura", "demonic", "lightnovelworld":
+ cover = metaContent(body, "property", "og:image")
+ case "novelfull":
+ cover = metaContent(body, "name", "image")
+ case "comix":
+ cover = comixCoverURL(seriesURL, body)
+ case "kagane":
+ cover = kaganeCoverURL(body)
+ }
+ return cover, cover != ""
+}
+
+func metaContent(body, attrName, attrValue string) string {
+ for _, tag := range metaTagRe.FindAllString(body, -1) {
+ attrs := make(map[string]string)
+ for _, m := range doubleQuotedMetaAttrRe.FindAllStringSubmatch(tag, -1) {
+ attrs[strings.ToLower(m[1])] = m[2]
+ }
+ for _, m := range singleQuotedMetaAttrRe.FindAllStringSubmatch(tag, -1) {
+ attrs[strings.ToLower(m[1])] = m[2]
+ }
+ if strings.EqualFold(attrs[strings.ToLower(attrName)], attrValue) {
+ if cover := publishedCoverURL(attrs["content"]); cover != "" {
+ return cover
+ }
+ }
+ }
+ return ""
+}
+
+func publishedCoverURL(value string) string {
+ value = strings.TrimSpace(html.UnescapeString(value))
+ return strings.ReplaceAll(value, " ", "%20")
+}
diff --git a/backend/internal/latest/sites_test.go b/backend/internal/latest/sites_test.go
index 49423ad..16cbab0 100644
--- a/backend/internal/latest/sites_test.go
+++ b/backend/internal/latest/sites_test.go
@@ -79,6 +79,119 @@ const lnwSeriesFixture = `
Chapter 9999
`
+// Trimmed from https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af
+// (redirected to ...-00dcbf97) on 2026-08-10.
+const asuraCoverFixture = ``
+
+// Trimmed from https://demonicscans.org/manga/Catastrophic-Necromancer on 2026-08-10.
+// The source publishes the raw space in this URL.
+const demonicCoverFixture = ``
+
+// Trimmed from https://comix.to/title/n8we-dungeons-and-crayons on 2026-08-10.
+// The state includes a recommended poster before the target detail object and
+// nested IDs inside that object; no og:image is present.
+const comixCoverFixture = ``
+
+// Trimmed from GET https://kagane.to/api/v2/series/019fe11a-8670-7cf3-8343-0b02057d3787 on 2026-08-10.
+const kaganeCoverFixture = `{"series_covers":[{"cover_id":"019fe11a-84d1-714b-9cf4-2827f277f3c0","language":"en","volume_number":"1","chapter_number":null,"note":null,"image_id":"019fe11a-84c3-7fc3-a84b-88787374b617"}]}`
+
+// Trimmed from https://novelfull.com/reverend-insanity.html on 2026-08-10.
+const novelfullCoverFixture = ``
+
+// Trimmed from https://lightnovelworld.net/novel/a-will-eternal/ on 2026-08-10.
+const lnwCoverFixture = ``
+
+func TestCoverFrom(t *testing.T) {
+ const comixURL = "https://comix.to/title/n8we-dungeons-and-crayons"
+ tests := []struct {
+ name string
+ site string
+ seriesURL string
+ body string
+ wantOK bool
+ wantCover string
+ }{
+ {
+ name: "asura uses published metadata URL",
+ site: "asura", body: asuraCoverFixture, wantOK: true,
+ wantCover: "https://cdn.asurascans.com/asura-images/covers/chronicles-of-the-demon-faction.d4dcb8.webp",
+ },
+ {
+ name: "demonic escapes raw spaces",
+ site: "demonic", body: demonicCoverFixture, wantOK: true,
+ wantCover: "https://readermc.org/images/thumbnails/Catastrophic%20Necromancer.webp",
+ },
+ {
+ name: "comix takes target medium poster",
+ site: "comix", seriesURL: comixURL, body: comixCoverFixture, wantOK: true,
+ wantCover: "https://static.comix.to/039d/i/1/34/6a6742bf15736@280.jpg",
+ },
+ {
+ name: "kagane reads API cover image ID",
+ site: "kagane", body: kaganeCoverFixture, wantOK: true,
+ wantCover: "https://kagane.to/api/v2/image/019fe11a-84c3-7fc3-a84b-88787374b617/compressed",
+ },
+ {
+ name: "novelfull reads image metadata",
+ site: "novelfull", body: novelfullCoverFixture, wantOK: true,
+ wantCover: "https://novelfull.com/uploads/webp/novel/reverend-insanity-82661d911a.webp",
+ },
+ {
+ name: "lightnovelworld reads og image",
+ site: "lightnovelworld", body: lnwCoverFixture, wantOK: true,
+ wantCover: "https://lightnovelworld.net/wp-content/uploads/2026/03/a-will-eternal-1.webp",
+ },
+ {
+ name: "later metadata cover survives empty match",
+ site: "asura",
+ body: `` + asuraCoverFixture,
+ wantOK: true,
+ wantCover: "https://cdn.asurascans.com/asura-images/covers/chronicles-of-the-demon-faction.d4dcb8.webp",
+ },
+ {
+ name: "page without cover is empty",
+ site: "asura", body: ``,
+ },
+ {
+ name: "unknown site is empty",
+ site: "unknown", body: asuraCoverFixture,
+ },
+ }
+
+ for _, tt := range tests {
+ t.Run(tt.name, func(t *testing.T) {
+ got, ok := coverFrom(tt.site, tt.seriesURL, tt.body)
+ if ok != tt.wantOK {
+ t.Fatalf("ok = %v, want %v (got %q)", ok, tt.wantOK, got)
+ }
+ if got != tt.wantCover {
+ t.Errorf("cover = %q, want %q", got, tt.wantCover)
+ }
+ })
+ }
+}
+
+func TestCoverFromChallenge(t *testing.T) {
+ tests := []struct {
+ site string
+ seriesURL string
+ }{
+ {"asura", "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af"},
+ {"demonic", "https://demonicscans.org/manga/Catastrophic-Necromancer"},
+ {"comix", "https://comix.to/title/n8we-dungeons-and-crayons"},
+ {"kagane", "https://kagane.to/series/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"},
+ {"novelfull", "https://novelfull.com/reverend-insanity.html"},
+ {"lightnovelworld", "https://lightnovelworld.net/novel/a-will-eternal/"},
+ }
+ for _, tt := range tests {
+ t.Run(tt.site, func(t *testing.T) {
+ if got, ok := coverFrom(tt.site, tt.seriesURL, challengeFixture); ok || got != "" {
+ t.Fatalf("cover = %q, ok = %v, want empty", got, ok)
+ }
+ })
+ }
+}
+
func TestLatestChapterFrom(t *testing.T) {
const asuraURL = "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af"
const demonicURL = "https://demonicscans.org/manga/Catastrophic-Necromancer"