From 42e06256955bb244da7e26614a9f209f795bf8a3 Mon Sep 17 00:00:00 2001
From: Solomon Victorino <git@solomonvictorino.com>
Date: Sat, 6 Apr 2024 00:14:51 -0600
Subject: [PATCH] feat: support direct annotation links

---
 handlers/annotations.go |  2 +-
 handlers/handler.go     |  6 ++++--
 handlers/lyrics.go      | 10 ++++++++--
 handlers/lyrics_test.go | 13 ++++++++++++-
 static/script.js        | 13 +++++++++++--
 5 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/handlers/annotations.go b/handlers/annotations.go
index 8033506..43d251a 100644
--- a/handlers/annotations.go
+++ b/handlers/annotations.go
@@ -18,7 +18,7 @@ import (
 
 func annotations(l *logrus.Logger) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		id := mux.Vars(r)["id"]
+		id := mux.Vars(r)["annotation-id"]
 		if a, err := getCache[data.Annotation]("annotation:" + id); err == nil {
 			encoder := json.NewEncoder(w)
 
diff --git a/handlers/handler.go b/handlers/handler.go
index c81d929..137a53c 100644
--- a/handlers/handler.go
+++ b/handlers/handler.go
@@ -16,13 +16,15 @@ func New(logger *logrus.Logger) *mux.Router {
 	r.Use(mustHeaders)
 
 	r.Handle("/", templ.Handler(views.HomePage()))
-	r.HandleFunc("/{id}-lyrics", lyrics(logger)).Methods("GET")
 	r.HandleFunc("/albums/{artist}/{albumName}", album(logger)).Methods("GET")
 	r.HandleFunc("/images/{filename}.{ext}", imageProxy(logger)).Methods("GET")
 	r.HandleFunc("/search", search(logger)).Methods("GET")
-	r.HandleFunc("/{id}/{artist-song}/{verse}/annotations", annotations(logger)).Methods("GET")
+	r.HandleFunc("/{annotation-id}/{artist-song}/{verse}/annotations", annotations(logger)).Methods("GET")
 	r.HandleFunc("/instances.json", instances(logger)).Methods("GET")
 	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
+	r.PathPrefix("/{annotation-id}/{artist-song}-lyrics").HandlerFunc(lyrics(logger)).Methods("GET")
+	r.PathPrefix("/{annotation-id}/{artist-song}").HandlerFunc(lyrics(logger)).Methods("GET")
+	r.PathPrefix("/{annotation-id}").HandlerFunc(lyrics(logger)).Methods("GET")
 	r.NotFoundHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusNotFound)
 		views.ErrorPage(404, "page not found").Render(context.Background(), w)
diff --git a/handlers/lyrics.go b/handlers/lyrics.go
index 966e1fb..bb0c138 100644
--- a/handlers/lyrics.go
+++ b/handlers/lyrics.go
@@ -14,14 +14,20 @@ import (
 
 func lyrics(l *logrus.Logger) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		id := mux.Vars(r)["id"]
+		// prefer artist-song over annotation-id for cache key when available
+		id := mux.Vars(r)["artist-song"]
+		if id == "" {
+			id = mux.Vars(r)["annotation-id"]
+		} else {
+			id = id + "-lyrics"
+		}
 
 		if s, err := getCache[data.Song](id); err == nil {
 			views.LyricsPage(s).Render(context.Background(), w)
 			return
 		}
 
-		url := fmt.Sprintf("https://genius.com/%s-lyrics", id)
+		url := fmt.Sprintf("https://genius.com/%s", id)
 		resp, err := sendRequest(url)
 		if err != nil {
 			l.Errorln(err)
diff --git a/handlers/lyrics_test.go b/handlers/lyrics_test.go
index 7c2445a..006386f 100644
--- a/handlers/lyrics_test.go
+++ b/handlers/lyrics_test.go
@@ -10,7 +10,18 @@ import (
 )
 
 func TestLyrics(t *testing.T) {
-	url := "/The-silver-seas-catch-yer-own-train-lyrics"
+	urls := []string{"/The-silver-seas-catch-yer-own-train-lyrics",
+		"/1784308/The-silver-seas-catch-yer-own-train",
+		"/1784308/The-silver-seas-catch-yer-own-train-lyrics",
+		"/1784308/The-silver-seas-catch-yer-own-train/Baby-you-and-i-are-not-the-same-you-say-you-like-sun-i-like-the-rain",
+		"/1784308/The-silver-seas-catch-yer-own-train-lyrics/Baby-you-and-i-are-not-the-same-you-say-you-like-sun-i-like-the-rain",
+		"/1784308"}
+	for _, url := range urls {
+		t.Run(url, func(t *testing.T) { testLyrics(t, url) })
+	}
+}
+
+func testLyrics(t *testing.T, url string) {
 	title := "The Silver Seas"
 	artist := "Catch Yer Own Train"
 
diff --git a/static/script.js b/static/script.js
index 65bffdd..c8e955a 100644
--- a/static/script.js
+++ b/static/script.js
@@ -8,8 +8,17 @@ function showAbout() {
 
 fullAbout && [fullAbout, summary].forEach(item => item.onclick = showAbout)
 
-document.querySelectorAll("#lyrics a").forEach(item => {
-	item.addEventListener("click", getAnnotation)
+window.addEventListener("load", () => {
+	document.querySelectorAll("#lyrics a").forEach(item => {
+		item.addEventListener("click", getAnnotation)
+	})
+
+	const linkedAnnotationId = window.location.pathname.match(new RegExp("/(\\d+)"))?.[1]
+	if (linkedAnnotationId) {
+		const target = document.querySelector(`a[href^="/${linkedAnnotationId}"][class^="ReferentFragmentdesktop__ClickTarget"] > span`)
+		target?.click()
+		target?.scrollIntoView()
+	}
 })
 
 function getAnnotation(e) {