implement incremental search results

TODO: ensure late search results do not show up for future searches

4 files changed, 75 insertions, 37 deletions

diff --git a/TODO b/TODO
index ed29307..1568877 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,6 @@
 ## Fronted
-- [ ] support incremental search results
+- [X] support incremental search results
+  - [ ] distinguish different search queries
 
 ## Web Backend
 
@@ -8,7 +9,8 @@
 ## Backends
 
 - [X] paralyze search
-  - [ ] report results incrementally
+  - [X] report results incrementally
+  - [ ] distinguish different search queries
 - [X] Implement local storage backend
   - [X] Implement upload
     - [ ] Remove uploaded songs after were played
diff --git a/main.go b/main.go
index 94e11b9..69808bf 100644
--- a/main.go
+++ b/main.go
@@ -32,38 +32,49 @@ func landingPage(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func getConnId(w http.ResponseWriter, r *http.Request) string {
+	uuidCookie, err := r.Cookie("UUID")
+	if err != nil {
+		http.Error(w, "No connection ID cookie set", http.StatusUnauthorized)
+		return ""
+	}
+	return uuidCookie.Value
+}
+
 func searchHandler(w http.ResponseWriter, r *http.Request) {
+	connId := getConnId(w, r)
+	if connId == "" {
+		return
+	}
+
+	conn := wrms.GetConn(connId)
+
 	pattern := r.URL.Query().Get("pattern")
 
 	llog.Debug("Searching for %s", pattern)
 
 	start := time.Now()
 	resultsChan := wrms.Player.Search(pattern)
-	results := []Song{}
 
-	for result := range resultsChan {
-		results = append(results, result...)
-	}
-
-	llog.Debug("searching for %s took %v", pattern, time.Since(start))
+	go func() {
+		for result := range resultsChan {
+			if len(result) > 0 {
+				conn.Send(Event{"search", result})
+			}
+		}
 
-	data, err := json.Marshal(Event{"search", results})
-	if err != nil {
-		llog.Error("Encoding the search result failed with %s", err)
-		return
-	}
+		conn.Send(newNotification("finish-search"))
+		llog.Debug("searching for %s took %v", pattern, time.Since(start))
+	}()
 
-	llog.Info("Search returned: %s", string(data))
-	w.Write(data)
+	fmt.Fprintf(w, "Starting search for %s", pattern)
 }
 
 func genericVoteHandler(w http.ResponseWriter, r *http.Request, vote string) {
-	uuidCookie, err := r.Cookie("UUID")
-	if err != nil {
-		http.Error(w, "No connection ID cookie set", http.StatusUnauthorized)
+	connId := getConnId(w, r)
+	if connId == "" {
 		return
 	}
-	connId := uuidCookie.Value
 
 	songUri := r.URL.Query().Get("song")
 	llog.Info("%s song %s via url %s", vote, songUri, r.URL)
@@ -131,8 +142,8 @@ func wsEndpoint(w http.ResponseWriter, r *http.Request) {
 		cancel()
 	}()
 
-	conn := Connection{id, make(chan Event), c}
-	wrms.Connections = append(wrms.Connections, conn)
+	conn := &Connection{id, make(chan Event), c}
+	wrms.Connections[id] = conn
 
 	llog.Info("New websocket connection with id %d", id)
 
diff --git a/web/client.html b/web/client.html
index f0ec6ed..878bd48 100644
--- a/web/client.html
+++ b/web/client.html
@@ -224,6 +224,12 @@
           case "downvoted":
             handleVotes("down", cmd.songs)
             break;
+          case "search":
+            handleSearch(cmd.songs)
+            break;
+          case "finish-search":
+            handleFinishSearch()
+            break;
         }
       };
 
@@ -232,6 +238,10 @@
       };
 
       function submitSearch() {
+        // Clear search Results
+        let searchResults = document.getElementById("searchResults");
+        searchResults.innerHTML = "";
+
         let searchingIndicator = document.getElementById("searching");
         searchingIndicator.style.display = "block";
         let searchResultsOverlay = document.getElementById("searchResultsOverlay");
@@ -239,7 +249,7 @@
 
         const form = new FormData(document.getElementById("searchForm"));
         const pattern = new URLSearchParams(form).toString();
-        new HttpClient().get("/search?" + pattern, showSearchResults);
+        new HttpClient().get("/search?" + pattern, console.log);
         return false;
       }
 
@@ -259,20 +269,17 @@
         new HttpClient().post("/add", JSON.stringify(song), console.log);
       }
 
-      function showSearchResults(responseText) {
-        response = JSON.parse(responseText)
-        if (!response)
-          return
-
+      function handleFinishSearch() {
         let searchingIndicator = document.getElementById("searching");
         searchingIndicator.style.display = "none";
         let searchResultsOverlay = document.getElementById("searchResultsOverlay");
         searchResultsOverlay['aria-busy'] = false;
+      }
 
+      function handleSearch(songs) {
+        let searchResultsOverlay = document.getElementById("searchResultsOverlay");
         let searchResults = document.getElementById("searchResults");
-        // Clear search Results
-        searchResults.innerHTML = "";
-        for (const song of response.songs) {
+        for (const song of songs) {
           let listItem = document.createElement("li");
           listItem.addEventListener("click", function() {
             addSong(song);
diff --git a/wrms.go b/wrms.go
index 9cd0ac4..22cd62a 100644
--- a/wrms.go
+++ b/wrms.go
@@ -44,12 +44,20 @@ type Event struct {
 	Songs []Song `json:"songs"`
 }
 
+func newNotification(notification string) Event {
+	return Event{notification, nil}
+}
+
 type Connection struct {
 	Id     uuid.UUID
 	Events chan Event
 	C      *websocket.Conn
 }
 
+func (c *Connection) Send(ev Event) {
+	c.Events <- ev
+}
+
 func (c *Connection) Close() {
 	llog.Info("Closing connection %s", c.Id)
 	close(c.Events)
@@ -57,7 +65,7 @@ func (c *Connection) Close() {
 }
 
 type Wrms struct {
-	Connections []Connection
+	Connections map[uuid.UUID]*Connection
 	Songs       []Song
 	queue       Playlist
 	CurrentSong Song
@@ -69,10 +77,20 @@ type Wrms struct {
 func NewWrms(config Config) *Wrms {
 	wrms := Wrms{}
 	wrms.Config = config
+	wrms.Connections = make(map[uuid.UUID]*Connection)
 	wrms.Player = NewPlayer(&wrms, strings.Split(config.Backends, " "))
 	return &wrms
 }
 
+func (wrms *Wrms) GetConn(connId string) *Connection {
+	id, err := uuid.Parse(connId)
+	if err != nil {
+		llog.Fatal("Failed to parse connId %s: %v", connId, err)
+	}
+
+	return wrms.Connections[id]
+}
+
 func (wrms *Wrms) Close() {
 	llog.Info("Closing WRMS")
 	for _, conn := range wrms.Connections {
@@ -80,10 +98,10 @@ func (wrms *Wrms) Close() {
 	}
 }
 
-func (wrms *Wrms) Broadcast(cmd Event) {
-	llog.Info("Broadcasting %v", cmd)
-	for i := 0; i < len(wrms.Connections); i++ {
-		wrms.Connections[i].Events <- cmd
+func (wrms *Wrms) Broadcast(ev Event) {
+	llog.Info("Broadcasting %v", ev)
+	for _, conn := range wrms.Connections {
+		conn.Send(ev)
 	}
 }
 
@@ -122,14 +140,14 @@ func (wrms *Wrms) PlayPause() {
 			wrms.Next()
 			if wrms.CurrentSong.Uri == "" {
 				llog.Info("No song left to play")
-				wrms.Broadcast(Event{"stop", []Song{}})
+				wrms.Broadcast(newNotification("stop"))
 				return
 			}
 		}
 		ev = Event{"play", []Song{wrms.CurrentSong}}
 		wrms.Player.Play(&wrms.CurrentSong)
 	} else {
-		ev = Event{"pause", []Song{}}
+		ev = newNotification("pause")
 		wrms.Player.Pause()
 	}