feat(kemono): Add podcast endpoint

README.md

@@ -90,6 +90,7 @@ An Atom feed is generated by default, but a file extension of
 ### Kemono
 
 - `/kemono/{service}/user/{name}`
+- `/kemono/{service}/podcast/{name}`
 
 #### Query Parameters
 | Name    | Description                                                   | Default |

go.mod

@@ -5,6 +5,7 @@ go 1.22.4
 require (
 	github.com/Masterminds/sprig/v3 v3.2.3
 	github.com/bradleyfalzon/ghinstallation/v2 v2.11.0
+	github.com/eduncan911/podcast v1.4.2
 	github.com/go-chi/chi/v5 v5.0.12
 	github.com/google/go-containerregistry v0.19.1
 	github.com/google/go-github/v62 v62.0.0

go.sum

@@ -33,6 +33,8 @@ github.com/docker/docker v26.1.3+incompatible h1:lLCzRbrVZrljpVNobJu1J2FHk8V0s4B
 github.com/docker/docker v26.1.3+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
 github.com/docker/docker-credential-helpers v0.8.2 h1:bX3YxiGzFP5sOXWc3bTPEXdEaZSeVMrFgOr3T+zrFAo=
 github.com/docker/docker-credential-helpers v0.8.2/go.mod h1:P3ci7E3lwkZg6XiHdRKft1KckHiO9a2rNtyFbZ/ry9M=
+github.com/eduncan911/podcast v1.4.2 h1:S+fsUlbR2ULFou2Mc52G/MZI8JVJHedbxLQnoA+MY/w=
+github.com/eduncan911/podcast v1.4.2/go.mod h1:mSxiK1z5KeNO0YFaQ3ElJlUZbbDV9dA7R9c1coeeXkc=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@@ -146,6 +148,7 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=

internal/feed/feed.go

@@ -9,6 +9,7 @@ import (
 	"path"
 	"strings"
 
+	"github.com/eduncan911/podcast"
 	"github.com/go-chi/chi/v5"
 	"github.com/gorilla/feeds"
 )
@@ -56,39 +57,49 @@ func SetType(next http.Handler) http.Handler {
 
 func WriteFeed(w http.ResponseWriter, r *http.Request) error {
 	format := r.Context().Value(TypeKey).(OutputFormat)
-	feed := r.Context().Value(FeedKey).(*feeds.Feed)
+	feed := r.Context().Value(FeedKey)
 
 	var buf bytes.Buffer
 
-	switch format {
-	case OutputAtom, OutputUnknown:
-		atomFeed := (&feeds.Atom{Feed: feed}).AtomFeed()
-		if feed.Image != nil {
-			atomFeed.Icon = feed.Image.Url
-		}
-		if err := feeds.WriteXML(atomFeed, &buf); err != nil {
-			return err
-		}
-		w.Header().Set("Content-Type", "application/rss+xml")
-	case OutputJSON:
-		jsonFeed := (&feeds.JSON{Feed: feed}).JSONFeed()
-		if feed.Image != nil {
-			jsonFeed.Icon = feed.Image.Url
-		}
-		e := json.NewEncoder(&buf)
-		e.SetIndent("", "  ")
-		if err := e.Encode(jsonFeed); err != nil {
-			return err
+	switch feed := feed.(type) {
+	case *feeds.Feed:
+		switch format {
+		case OutputAtom, OutputUnknown:
+			atomFeed := (&feeds.Atom{Feed: feed}).AtomFeed()
+			if feed.Image != nil {
+				atomFeed.Icon = feed.Image.Url
+			}
+			if err := feeds.WriteXML(atomFeed, &buf); err != nil {
+				return err
+			}
+			w.Header().Set("Content-Type", "application/rss+xml")
+		case OutputJSON:
+			jsonFeed := (&feeds.JSON{Feed: feed}).JSONFeed()
+			if feed.Image != nil {
+				jsonFeed.Icon = feed.Image.Url
+			}
+			e := json.NewEncoder(&buf)
+			e.SetIndent("", "  ")
+			if err := e.Encode(jsonFeed); err != nil {
+				return err
+			}
+			w.Header().Set("Content-Type", "application/json")
+		case OutputRSS:
+			if err := feed.WriteRss(&buf); err != nil {
+				return err
+			}
+			w.Header().Set("Content-Type", "application/rss+xml")
+		default:
+			http.Error(w, "400 invalid format", http.StatusBadRequest)
+			return nil
 		}
-		w.Header().Set("Content-Type", "application/json")
-	case OutputRSS:
-		if err := feed.WriteRss(&buf); err != nil {
+	case *podcast.Podcast:
+		if err := feed.Encode(&buf); err != nil {
 			return err
 		}
-		w.Header().Set("Content-Type", "application/rss+xml")
+		w.Header().Set("Content-Type", "application/xml")
 	default:
-		http.Error(w, "400 invalid format", http.StatusBadRequest)
-		return nil
+		panic("invalid feed type")
 	}
 
 	if _, err := io.Copy(w, &buf); err != nil {

internal/kemono/creator.go

@@ -14,6 +14,7 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/eduncan911/podcast"
 	"github.com/gabe565/transsmute/internal/util"
 	"github.com/gorilla/feeds"
 	"github.com/jellydator/ttlcache/v3"
@@ -212,3 +213,55 @@ func (c *Creator) Feed(ctx context.Context, pages uint64, tag, query string) (*f
 
 	return f, nil
 }
+
+func (c *Creator) Podcast(ctx context.Context, pages uint64, tag string) (*podcast.Podcast, error) {
+	var pubdate *time.Time
+	if c.Indexed != 0 {
+		d := time.Unix(int64(c.Updated), 0)
+		pubdate = &d
+	}
+	f := podcast.New(c.Name, c.PublicURL().String(), "", pubdate, nil)
+	f.IBlock = "Yes"
+
+	for page := range pages {
+		posts, err := c.FetchPostPage(ctx, page, "")
+		if err != nil {
+			return nil, err
+		}
+		f.Items = slices.Grow(f.Items, len(posts))
+
+		for _, post := range posts {
+			if tag != "" {
+				tags, err := post.Tags()
+				if err != nil {
+					return nil, err
+				}
+				if !slices.Contains(tags, tag) {
+					continue
+				}
+			}
+
+			item, image, err := post.PodcastItem(ctx)
+			if err != nil {
+				if errors.Is(err, ErrNoAudio) {
+					continue
+				}
+				return nil, err
+			}
+			f.Items = append(f.Items, item)
+			if image != nil && f.Image == nil {
+				f.AddImage(image.ThumbURL().String())
+			}
+		}
+
+		if len(posts) < 50 {
+			break
+		}
+	}
+
+	if f.Image == nil {
+		f.AddImage(c.ImageURL().String())
+	}
+
+	return &f, nil
+}

internal/kemono/podcast_handler.go

@@ -0,0 +1,55 @@
+package kemono
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"strconv"
+
+	"github.com/gabe565/transsmute/internal/feed"
+	"github.com/gabe565/transsmute/internal/util"
+	"github.com/go-chi/chi/v5"
+)
+
+func podcastHandler(host string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		creator, err := GetCreatorInfo(r.Context(), host, chi.URLParam(r, "service"), chi.URLParam(r, "creator"))
+		if err != nil {
+			if errors.Is(err, ErrCreatorNotFound) {
+				http.Error(w, err.Error(), http.StatusNotFound)
+				return
+			} else if errors.Is(err, util.ErrUpstreamRequest) {
+				http.Error(w, err.Error(), http.StatusServiceUnavailable)
+				return
+			}
+			panic(err)
+		}
+
+		pagesRaw := r.URL.Query().Get("pages")
+		pages := uint64(1)
+		if pagesRaw != "" {
+			var err error
+			if pages, err = strconv.ParseUint(pagesRaw, 10, 64); err != nil || pages == 0 {
+				http.Error(w, "pages must be a positive integer", http.StatusBadRequest)
+				return
+			}
+		}
+
+		tag := r.URL.Query().Get("tag")
+
+		f, err := creator.Podcast(r.Context(), pages, tag)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusServiceUnavailable)
+			panic(err)
+		}
+
+		if val := r.URL.Query().Get("title"); val != "" {
+			f.Title = val
+		}
+
+		r = r.WithContext(context.WithValue(r.Context(), feed.FeedKey, f))
+		if err := feed.WriteFeed(w, r); err != nil {
+			panic(err)
+		}
+	}
+}

internal/kemono/post.go

@@ -4,14 +4,17 @@ import (
 	"context"
 	"encoding/csv"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
 	"net/url"
 	"path"
+	"strconv"
 	"strings"
 	"time"
 
+	"github.com/eduncan911/podcast"
 	"github.com/gabe565/transsmute/internal/util"
 	"github.com/gorilla/feeds"
 )
@@ -63,6 +66,47 @@ func (p *Post) FeedItem() *feeds.Item {
 	return item
 }
 
+var ErrNoAudio = errors.New("no audio file")
+
+func (p *Post) PodcastItem(ctx context.Context) (*podcast.Item, *Attachment, error) {
+	var audio, image *Attachment
+	for _, attachment := range p.Attachments {
+		switch {
+		case attachment.IsAudio() && audio == nil:
+			audio = attachment
+		case attachment.IsImage() && image == nil:
+			image = attachment
+		}
+	}
+	if audio == nil {
+		return nil, nil, ErrNoAudio
+	}
+
+	audioInfo, err := audio.Info(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	item := &podcast.Item{
+		Title:       p.Title,
+		Link:        p.creator.PostURL(p).String(),
+		Description: p.Content,
+		GUID:        p.ID,
+		Enclosure: &podcast.Enclosure{
+			URL:             audio.URL().String(),
+			LengthFormatted: strconv.Itoa(audioInfo.Size),
+			TypeFormatted:   audioInfo.MIMEType,
+		},
+	}
+	if image != nil {
+		item.AddImage(image.ThumbURL().String())
+	}
+	if parsed, err := time.Parse("2006-01-02T15:04:05", p.Published); err == nil {
+		item.AddPubDate(&parsed)
+	}
+	return item, image, nil
+}
+
 type Embed struct {
 	URL         string `json:"url"`
 	Subject     string `json:"subject"`
@@ -85,6 +129,11 @@ func (a *Attachment) IsVideo() bool {
 	return ext == ".mp4" || ext == ".webm"
 }
 
+func (a *Attachment) IsAudio() bool {
+	ext := path.Ext(a.Path)
+	return ext == ".mp3" || ext == ".m4a"
+}
+
 func (a *Attachment) ThumbURL() *url.URL {
 	u := &url.URL{
 		Scheme: "https",

internal/kemono/routes.go

@@ -19,6 +19,7 @@ func Routes(r chi.Router, conf config.Kemono) error {
 
 		for name, host := range conf.Hosts {
 			r.Get("/"+name+"/{service}/user/{creator}", postHandler(host))
+			r.Get("/"+name+"/{service}/podcast/{creator}", podcastHandler(host))
 		}
 	}
 	return nil