@@ -1,2 +1,3 @@
 .env
 __debug_bin*
+*.sqlite

@@ -18,6 +18,7 @@
 var templatesDirectory = "templates/"
 var indexTemplate = template.Must(template.ParseFiles(templatesDirectory + "index.html"))
 var videoTemplate = template.Must(template.ParseFiles(templatesDirectory + "video.html"))
+var blacklist = []string{"favicon.ico", "robots.txt"}
 
 func indexHandler(w http.ResponseWriter, r *http.Request) {
 	buf := &bytes.Buffer{}
@@ -30,7 +31,13 @@
 	buf.WriteTo(w)
 }
 
-func watchHandler(newsapi *invidious.Client) http.HandlerFunc {
+func clearHandler(w http.ResponseWriter, r *http.Request) {
+	//TODO: check with some secret API key before clearing cache.
+	invidious.ClearDB()
+	//TODO: return a message
+}
+
+func watchHandler(invidiousClient *invidious.Client) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		u, err := url.Parse(r.URL.String())
 		if err != nil {
@@ -41,7 +48,7 @@
 		params := u.Query()
 		videoId := params.Get("v")
 
-		video, err := newsapi.FetchEverything(videoId)
+		video, err := invidiousClient.GetVideo(videoId)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
@@ -58,9 +65,7 @@ buf.WriteTo(w)
 	}
 }
 
-var blacklist = []string{"favicon.ico", "robots.txt"}
-
-func shortHandler(newsapi *invidious.Client) http.HandlerFunc {
+func shortHandler(invidiousClient *invidious.Client) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		videoId := mux.Vars(r)["videoId"]
 
@@ -69,7 +74,7 @@ http.Error(w, "Not a valid ID.", http.StatusBadRequest)
 			return
 		}
 
-		video, err := newsapi.FetchEverything(videoId)
+		video, err := invidiousClient.GetVideo(videoId)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
@@ -98,13 +103,14 @@ port = "3000"
 	}
 
 	myClient := &http.Client{Timeout: 10 * time.Second}
-	videoapi := invidious.NewClient(myClient, "y.birabittoh.duckdns.org")
+	videoapi := invidious.NewClient(myClient)
 
 	r := mux.NewRouter()
 	r.HandleFunc("/", indexHandler)
+	r.HandleFunc("/clear", clearHandler)
 	r.HandleFunc("/watch", watchHandler(videoapi))
 	r.HandleFunc("/{videoId}", shortHandler(videoapi))
-	//r.HandleFunc("/proxy/{videoId}", proxyHandler)
+	//TODO: r.HandleFunc("/proxy/{videoId}", proxyHandler)
 
 	/*
 		// native go implementation (useless until february 2024)

@@ -5,3 +5,5 @@
 require github.com/joho/godotenv v1.5.1
 
 require github.com/gorilla/mux v1.8.1
+
+require github.com/mattn/go-sqlite3 v1.14.19 

@@ -2,3 +2,5 @@ github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY=
 github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ=
 github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+github.com/mattn/go-sqlite3 v1.14.19 h1:fhGleo2h1p8tVChob4I9HpmVFIAkKGpiukdrgQbWfGI=
+github.com/mattn/go-sqlite3 v1.14.19/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=

@@ -0,0 +1,98 @@
+package invidious
+
+import (
+	"database/sql"
+	"log"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+var dbConnectionString = "file:cache.sqlite?cache=shared&mode="
+var createQuery = `
+CREATE TABLE IF NOT EXISTS videos (
+    videoId TEXT PRIMARY KEY,
+    title TEXT NOT NULL,
+    description TEXT NOT NULL,
+    uploader TEXT NOT NULL,
+    duration int NOT NULL,
+    height TEXT NOT NULL,
+    width TEXT NOT NULL,
+    url TEXT,
+    timestamp DATETIME DEFAULT (datetime('now'))
+);`
+var getVideoQuery = "SELECT * FROM videos WHERE videoId = (?);"
+var cacheVideoQuery = "INSERT OR REPLACE INTO videos (videoId, title, description, uploader, duration, height, width, url) VALUES (?, ?, ?, ?, ?, ?, ?, ?);"
+var clearQuery = "DELETE FROM videos;"
+
+func getDb(mode string) *sql.DB {
+	db, err := sql.Open("sqlite3", dbConnectionString+mode)
+	if err != nil {
+		log.Fatal("Error opening database")
+	}
+	db.SetMaxOpenConns(1)
+	return db
+}
+
+func InitDB() {
+	db := getDb("rwc")
+	defer db.Close()
+
+	_, err := db.Exec(createQuery)
+	if err != nil {
+		log.Printf("%q: %s\n", err, createQuery)
+		return
+	}
+}
+
+func CacheVideoDB(v Video) {
+	db := getDb("rw")
+	defer db.Close()
+
+	stmt, err := db.Prepare(cacheVideoQuery)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer stmt.Close()
+
+	_, err = stmt.Exec(v.VideoId, v.Title, v.Description, v.Uploader, v.Duration, v.Height, v.Width, v.Url)
+	if err != nil {
+		log.Printf("%q: %s\n", err, cacheVideoQuery)
+		return
+	}
+}
+
+func GetVideoDB(videoId string) (*Video, error) {
+	db := getDb("ro")
+	defer db.Close()
+
+	stmt, err := db.Prepare(getVideoQuery)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer stmt.Close()
+
+	t := &Video{}
+	err = stmt.QueryRow(videoId).Scan(&t.VideoId, &t.Title, &t.Description, &t.Uploader, &t.Duration, &t.Height, &t.Width, &t.Url, &t.Timestamp)
+	if err != nil {
+		//log.Printf("%q: %s\n", err, getVideoQuery)
+		return &Video{}, err
+	}
+	return t, nil
+}
+
+func ClearDB() {
+	db := getDb("rw")
+	defer db.Close()
+
+	stmt, err := db.Prepare(clearQuery)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer stmt.Close()
+
+	_, err = stmt.Exec()
+	if err != nil {
+		log.Printf("%q: %s\n", err, cacheVideoQuery)
+		return
+	}
+}

@@ -4,12 +4,19 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log"
 	"net/http"
 	"net/url"
+	"os"
 	"strconv"
 	"strings"
+	"time"
 )
 
+var instancesEndpoint = "https://api.invidious.io/instances.json?sort_by=api,type"
+var videosEndpoint = "https://%s/api/v1/videos/%s?fields=videoId,title,description,author,lengthSeconds,size,formatStreams"
+var timeToLive, _ = time.ParseDuration("6h")
+
 type Client struct {
 	http     *http.Client
 	Instance string
@@ -31,6 +38,7 @@ FormatStreams []Format `json:"formatStreams"`
 	Url           string
 	Height        int
 	Width         int
+	Timestamp     time.Time
 }
 
 func filter[T any](ss []T, test func(T) bool) (ret []T) {
@@ -50,13 +58,19 @@ }
 	return res
 }
 
-func (c *Client) FetchEverything(videoId string) (*Video, error) {
-	endpoint := fmt.Sprintf("https://%s/api/v1/videos/%s?fields=videoId,title,description,author,lengthSeconds,size,formatStreams", c.Instance, url.QueryEscape(videoId))
+func (c *Client) FetchVideo(videoId string) (*Video, error) {
+	if c.Instance == "" {
+		err := c.NewInstance()
+		if err != nil {
+			log.Fatal(err, "Could not get a new instance.")
+			os.Exit(1)
+		}
+	}
+	endpoint := fmt.Sprintf(videosEndpoint, c.Instance, url.QueryEscape(videoId))
 	resp, err := c.http.Get(endpoint)
 	if err != nil {
 		return nil, err
 	}
-
 	defer resp.Body.Close()
 
 	body, err := io.ReadAll(resp.Body)
@@ -86,6 +100,63 @@
 	return res, err
 }
 
-func NewClient(httpClient *http.Client, instance string) *Client {
-	return &Client{httpClient, instance}
+func (c *Client) GetVideo(videoId string) (*Video, error) {
+	log.Println("Video", videoId, "was requested.")
+
+	video, err := GetVideoDB(videoId)
+	if err == nil {
+		now := time.Now()
+		delta := now.Sub(video.Timestamp)
+		if delta < timeToLive {
+			log.Println("Found a valid cache entry from", delta, "ago.")
+			return video, nil
+		}
+	}
+
+	video, err = c.FetchVideo(videoId)
+	if err != nil {
+		log.Println(err)
+		err = c.NewInstance()
+		if err != nil {
+			log.Fatal("Could not get a new instance: ", err)
+			time.Sleep(10)
+		}
+		return c.GetVideo(videoId)
+	}
+	log.Println("Retrieved by API.")
+
+	CacheVideoDB(*video)
+	return video, nil
+}
+
+func (c *Client) NewInstance() error {
+	resp, err := c.http.Get(instancesEndpoint)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf(string(body))
+	}
+
+	var jsonArray [][]interface{}
+	err = json.Unmarshal(body, &jsonArray)
+	if err != nil {
+		return err
+	}
+
+	c.Instance = jsonArray[0][0].(string)
+	log.Println("Using new instance:", c.Instance)
+	return nil
+}
+
+func NewClient(httpClient *http.Client) *Client {
+	InitDB()
+	return &Client{httpClient, ""}
 }

@@ -15,7 +15,7 @@ <meta property="twitter:card" content="player" />
     <meta property="twitter:site" content="{{ .Uploader }}" />
     <meta property="twitter:creator" content="{{ .Uploader }}" />
     <meta property="twitter:title" content="{{ .Title }}" />
-    <!--<meta http-equiv="refresh" content="0;url=https://www.youtube.com/watch?v={{ .VideoId }}" />-->
+    <meta http-equiv="refresh" content="0;url=https://www.youtube.com/watch?v={{ .VideoId }}" />
     <meta property="og:url" content="https://www.youtube.com/watch?v={{ .VideoId }}" />
     <meta property="og:title" content="{{ .Title }}" />
     <meta property="og:description" content="{{ .Description }}" />