From c63b20551f470d0f06c7c7767a802d1e3f4045a7 Mon Sep 17 00:00:00 2001 From: Evan Buss Date: Sat, 6 Jul 2024 16:06:08 -0400 Subject: [PATCH] refactor: home page / url passing We now allow multiple OPDS feeds to be pre-defined and displayed on the homepage. As a result we need to pass the feed navigation URLs via query parameter rather than a subpath which would only support proxying to a single OPDS feed. The feed is passed via the q= query parameter and any relative links from the OPDS XML are resolved to a complete URL with domain / scheme. We also check the "Content-Type" header in the response received from the OPDS feed to determine whether to parse an OPDS catalog or just proxy the raw response back (images / files). --- .vscode/launch.json | 16 ++++++++ html/feed.html | 9 +++-- html/home.html | 9 +++++ html/html.go | 47 +++++++++++++++++++----- main.go | 89 +++++++++++++++++++++++++++------------------ opds/opds.go | 4 +- 6 files changed, 123 insertions(+), 51 deletions(-) create mode 100644 .vscode/launch.json create mode 100644 html/home.html diff --git a/.vscode/launch.json b/.vscode/launch.json new file mode 100644 index 0000000..fc7fb6d --- /dev/null +++ b/.vscode/launch.json @@ -0,0 +1,16 @@ +{ + // Use IntelliSense to learn about possible attributes. + // Hover to view descriptions of existing attributes. + // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387 + "version": "0.2.0", + "configurations": [ + { + "name": "Launch Package", + "type": "go", + "request": "launch", + "mode": "auto", + "program": "${workspaceFolder}" + } + + ] +} \ No newline at end of file diff --git a/html/feed.html b/html/feed.html index 3d55daf..1aaedcb 100644 --- a/html/feed.html +++ b/html/feed.html @@ -25,8 +25,9 @@ {{end}}
+ Home {{range .Navigation}} - {{.Label}} + {{.Label}} {{end}}
@@ -35,14 +36,14 @@ {{range .Links}}
  • {{if .ImageURL}} - {{.Title}} + {{.Title}} {{end}}
    {{if .IsDownload}} - {{.Title}} + {{.Title}} {{else}} - {{.Title}} + {{.Title}} {{end}}

    {{.Author}}

    diff --git a/html/home.html b/html/home.html new file mode 100644 index 0000000..cc691eb --- /dev/null +++ b/html/home.html @@ -0,0 +1,9 @@ +{{define "content"}} + +{{end}} diff --git a/html/html.go b/html/html.go index 0d2b53c..d46fad7 100644 --- a/html/html.go +++ b/html/html.go @@ -2,8 +2,11 @@ package html import ( "embed" + "fmt" "html/template" "io" + "log" + "net/url" "strings" "github.com/evan-buss/kobo-opds-proxy/opds" @@ -13,6 +16,7 @@ import ( var files embed.FS var ( + home = parse("home.html") feed = parse("feed.html") ) @@ -21,6 +25,7 @@ func parse(file string) *template.Template { } type FeedParams struct { + URL string Feed *opds.Feed } @@ -44,7 +49,7 @@ type LinkViewModel struct { IsDownload bool } -func convertFeed(feed *opds.Feed) FeedViewModel { +func convertFeed(url string, feed *opds.Feed) FeedViewModel { vm := FeedViewModel{ Title: feed.Title, Search: "", @@ -54,25 +59,25 @@ func convertFeed(feed *opds.Feed) FeedViewModel { for _, link := range feed.Links { if link.Rel == "search" { - vm.Search = link.Href + vm.Search = resolveHref(url, link.Href) } if link.TypeLink == "application/atom+xml;type=feed;profile=opds-catalog" { vm.Navigation = append(vm.Navigation, NavigationViewModel{ - Href: link.Href, + Href: resolveHref(url, link.Href), Label: strings.ToUpper(link.Rel[:1]) + link.Rel[1:], }) } } for _, entry := range feed.Entries { - vm.Links = append(vm.Links, constructLink(entry)) + vm.Links = append(vm.Links, constructLink(url, entry)) } return vm } -func constructLink(entry opds.Entry) LinkViewModel { +func constructLink(url string, entry opds.Entry) LinkViewModel { vm := LinkViewModel{ Title: entry.Title, Content: entry.Content.Content, @@ -87,13 +92,12 @@ func constructLink(entry opds.Entry) LinkViewModel { for _, link := range entry.Links { vm.IsDownload = link.IsDownload() if link.IsNavigation() || link.IsDownload() { - vm.Href = link.Href - + vm.Href = resolveHref(url, link.Href) } // Prefer the first "thumbnail" image we find if vm.ImageURL == "" && link.IsImage("thumbnail") { - vm.ImageURL = link.Href + vm.ImageURL = resolveHref(url, link.Href) } } @@ -101,7 +105,7 @@ func constructLink(entry opds.Entry) LinkViewModel { if vm.ImageURL == "" { for _, link := range entry.Links { if link.IsImage("") { - vm.ImageURL = link.Href + vm.ImageURL = resolveHref(url, link.Href) break } } @@ -109,17 +113,40 @@ func constructLink(entry opds.Entry) LinkViewModel { return vm } +func resolveHref(feedUrl string, relativePath string) string { + baseUrl, err := url.Parse(feedUrl) + if err != nil { + log.Fatal(err) + } + relativeUrl, err := url.Parse(relativePath) + if err != nil { + log.Fatal(err) + } + + resolved := baseUrl.ResolveReference(relativeUrl).String() + fmt.Println("Resolved URL: ", resolved) + return resolved +} func Feed(w io.Writer, p FeedParams, partial string) error { if partial == "" { partial = "layout.html" } - vm := convertFeed(p.Feed) + vm := convertFeed(p.URL, p.Feed) return feed.ExecuteTemplate(w, partial, vm) } +type FeedInfo struct { + Title string + URL string +} + +func Home(w io.Writer, p []FeedInfo) error { + return home.ExecuteTemplate(w, "layout.html", p) +} + func StaticFiles() embed.FS { return files } diff --git a/main.go b/main.go index 373eb00..39f79bd 100644 --- a/main.go +++ b/main.go @@ -4,6 +4,7 @@ import ( "io" "log" "log/slog" + "mime" "net/http" "time" @@ -11,55 +12,78 @@ import ( "github.com/evan-buss/kobo-opds-proxy/opds" ) -const baseUrl = "http://calibre.terminus" - func main() { router := http.NewServeMux() - router.HandleFunc("GET /", handleFeed()) - router.HandleFunc("GET /acquisition/{path...}", handleAcquisition()) + router.HandleFunc("GET /{$}", handleHome()) + router.HandleFunc("GET /feed", handleFeed()) router.Handle("GET /static/", http.FileServer(http.FS(html.StaticFiles()))) slog.Info("Starting server", slog.String("port", "8080")) log.Fatal(http.ListenAndServe(":8080", router)) } -func handleFeed() http.HandlerFunc { +func handleHome() http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { - opdsUrl := baseUrl + r.URL.RequestURI() - - slog.Info("Fetching feed", slog.String("path", opdsUrl)) - - feed, err := fetchFeed(opdsUrl) - if err != nil { - slog.Error("Failed to parse feed", slog.String("path", r.URL.RawPath), slog.Any("error", err)) - http.Error(w, "An unexpected error occurred", http.StatusInternalServerError) - return - } - - err = html.Feed(w, html.FeedParams{Feed: feed}, "") - if err != nil { - slog.Error("Failed to render feed", slog.String("path", r.URL.RawPath), slog.Any("error", err)) - http.Error(w, "An unexpected error occurred", http.StatusInternalServerError) - return + slog.Info("Rendering home page") + feeds := []html.FeedInfo{ + { + Title: "Evan's Library", + URL: "http://calibre.terminus/opds", + }, + { + Title: "Project Gutenberg", + URL: "https://m.gutenberg.org/ebooks.opds/", + }, } + html.Home(w, feeds) } } -func handleAcquisition() http.HandlerFunc { +func handleFeed() http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { - opdsUrl := baseUrl + "/" + r.PathValue("path") - resp, err := fetchFromUrl(opdsUrl) - if err != nil { - slog.Error("Failed to fetch acquisition", slog.String("path", opdsUrl), slog.Any("error", err)) - http.Error(w, "An unexpected error occurred", http.StatusInternalServerError) + queryURL := r.URL.Query().Get("q") + if queryURL == "" { + http.Error(w, "No feed specified", http.StatusBadRequest) return } + slog.Info("Fetching feed", slog.String("path", queryURL)) + + resp, err := fetchFromUrl(queryURL) + if err != nil { + handleError(r, w, "Failed to fetch feed", err) + return + } + + defer resp.Body.Close() + + contentType := resp.Header.Get("Content-Type") + mimeType, _, err := mime.ParseMediaType(contentType) + if err != nil { + handleError(r, w, "Failed to parse content type", err) + } + + if mimeType == "application/atom+xml" { + feed, err := opds.ParseFeed(resp.Body) + + if err != nil { + handleError(r, w, "Failed to parse feed", err) + return + } + + err = html.Feed(w, html.FeedParams{URL: queryURL, Feed: feed}, "") + if err != nil { + handleError(r, w, "Failed to render feed", err) + return + } + } + for k, v := range resp.Header { w.Header()[k] = v } io.Copy(w, resp.Body) + } } @@ -77,12 +101,7 @@ func fetchFromUrl(url string) (*http.Response, error) { return client.Do(req) } -func fetchFeed(url string) (*opds.Feed, error) { - r, err := fetchFromUrl(url) - if err != nil { - return nil, err - } - defer r.Body.Close() - - return opds.ParseFeed(r.Body) +func handleError(r *http.Request, w http.ResponseWriter, message string, err error) { + slog.Error(message, slog.String("path", r.URL.RawPath), slog.Any("error", err)) + http.Error(w, "An unexpected error occurred", http.StatusInternalServerError) } diff --git a/opds/opds.go b/opds/opds.go index c2c98fc..9c3b9d2 100644 --- a/opds/opds.go +++ b/opds/opds.go @@ -22,7 +22,7 @@ func (link Link) IsDownload() bool { } func (link Link) IsImage(category string) bool { - if strings.HasPrefix(link.TypeLink, "image") { + if strings.HasPrefix(link.TypeLink, "image") && !strings.HasPrefix(link.Href, "data") { return strings.Contains(link.Rel, category) } @@ -30,5 +30,5 @@ func (link Link) IsImage(category string) bool { } func (link Link) IsNavigation() bool { - return link.TypeLink == "application/atom+xml;type=feed;profile=opds-catalog" + return link.TypeLink == "application/atom+xml;type=feed;profile=opds-catalog" || link.Rel == "subsection" }