feat: add album handler

Serves a page including the album name, artist, track list, and credits.
Each of the tracks have links to the lyrics page, provided there is one
available.

album.go

@@ -0,0 +1,139 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/PuerkitoBio/goquery"
+	"github.com/gorilla/mux"
+)
+
+type album struct {
+	Artist string
+	Name   string
+	Image  string
+	About  [2]string
+
+	Tracks []Track
+}
+
+type Track struct {
+	Title string
+	Url   string
+}
+
+type albumMetadata struct {
+	Album struct {
+		Id          int    `json:"id"`
+		Image       string `json:"cover_art_thumbnail_url"`
+		Name        string `json:"name"`
+		Description string `json:"description_preview"`
+		Artist      `json:"artist"`
+	}
+	AlbumAppearances []AlbumAppearances `json:"album_appearances"`
+}
+
+type AlbumAppearances struct {
+	Id          int `json:"id"`
+	TrackNumber int `json:"track_number"`
+	Song        struct {
+		Title string `json:"title"`
+		Url   string `json:"url"`
+	}
+}
+
+type Artist struct {
+	Name string `json:"name"`
+}
+
+func (a *album) parseAlbumData(doc *goquery.Document) {
+	pageMetadata, exists := doc.Find("meta[itemprop='page_data']").Attr("content")
+	if !exists {
+		return
+	}
+
+	var albumMetadataFromPage albumMetadata
+	json.Unmarshal([]byte(pageMetadata), &albumMetadataFromPage)
+
+	albumData := albumMetadataFromPage.Album
+	a.Artist = albumData.Artist.Name
+	a.Name = albumData.Name
+	a.Image = albumData.Image
+	a.About[0] = albumData.Description
+	a.About[1] = truncateText(albumData.Description)
+
+	for _, track := range albumMetadataFromPage.AlbumAppearances {
+		url := strings.Replace(track.Song.Url, "https://genius.com", "", -1)
+		a.Tracks = append(a.Tracks, Track{Title: track.Song.Title, Url: url})
+	}
+}
+
+func (a *album) parse(doc *goquery.Document) {
+	a.parseAlbumData(doc)
+}
+
+func albumHandler(w http.ResponseWriter, r *http.Request) {
+	artist := mux.Vars(r)["artist"]
+	albumName := mux.Vars(r)["albumName"]
+
+	id := fmt.Sprintf("%s/%s", artist, albumName)
+
+	if data, err := getCache(id); err == nil {
+		render("album", w, data)
+		return
+	}
+
+	url := fmt.Sprintf("https://genius.com/albums/%s/%s", artist, albumName)
+
+	resp, err := sendRequest(url)
+	if err != nil {
+		logger.Errorln(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		render("error", w, map[string]string{
+			"Status": "500",
+			"Error":  "cannot reach genius servers",
+		})
+		return
+	}
+
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusNotFound {
+		w.WriteHeader(http.StatusNotFound)
+		render("error", w, map[string]string{
+			"Status": "404",
+			"Error":  "page not found",
+		})
+		return
+	}
+
+	doc, err := goquery.NewDocumentFromReader(resp.Body)
+	if err != nil {
+		logger.Errorln(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		render("error", w, map[string]string{
+			"Status": "500",
+			"Error":  "something went wrong",
+		})
+		return
+	}
+
+	cf := doc.Find(".cloudflare_content").Length()
+	if cf > 0 {
+		logger.Errorln("cloudflare got in the way")
+		render("error", w, map[string]string{
+			"Status": "500",
+			"Error":  "damn cloudflare, issue #21 on GitHub",
+		})
+		return
+	}
+
+	var a album
+	a.parse(doc)
+
+	render("album", w, a)
+
+	setCache(id, a)
+}

main.go

@@ -31,6 +31,7 @@ func main() {
 	r.HandleFunc("/{id}-lyrics", lyricsHandler)
 	r.HandleFunc("/images/{filename}.{ext}", proxyHandler)
 	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
+	r.HandleFunc("/albums/{artist}/{albumName}", albumHandler)
 	r.NotFoundHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusNotFound)
 		render("error", w, map[string]string{

static/style.css

@@ -105,6 +105,7 @@ a {
 	width: 20rem;
 	border-radius: 3px;
 	box-shadow: 0 1px 1px #ddd;
+	max-width: 200px;
 }
 
 #container {
@@ -130,6 +131,15 @@ a {
 	color: #1e1e1e;
 }
 
+#album-tracklist{
+	display: flex;
+	flex-direction: column;
+	gap: 1rem;
+	flex-basis: 0;
+	flex-shrink: 0;
+	flex-grow: 1;
+}
+
 #credits p {
 	font-size: 1.3rem;
 	padding: 0.5rem;

views/album.tmpl

@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html>
+	<head>
+		<title>{{.Artist}} - {{.Name}}</title>
+		<meta charset="utf-8" />
+		<meta name="viewport" content="width=device-width, initial-scale=1" />
+		<link rel="stylesheet" type="text/css" href="/static/style.css" />
+		<script type="text/javascript" src="/static/script.js" defer></script>
+	</head>
+	<body>	
+		{{template "navbar"}}
+		<div id="container">
+			<div id="metadata">
+				<img src="{{extractURL .Image}}"/>
+				<h2>{{.Artist}}</h2>
+				<h1>{{.Name}}</h1>
+			</div>
+			<div id="album-tracklist">
+				{{range .Tracks}}
+					<a href="{{.Url}}">
+						<p>{{.Title}}</p>
+					</a>
+				{{end}}
+			</div>
+			<div id="info">
+				<div id="about">
+					<h1 id="title">About</h1>
+					<p class="hidden" id="full_about">{{index .About 0}}</p>
+					<p id="summary">{{index .About 1}}</p>
+				</div>
+			</div>
+		</div>
+		{{template "footer"}}
+	</body>
+</html>