Initial commit: party-mix-app with prefetch cache, audio preload optimizations

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/backend/internal/handlers/remote.go

@@ -0,0 +1,162 @@
+package handlers
+
+import (
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+)
+
+type RemoteQueueItem struct {
+	Title     string `json:"title"`
+	Owner     string `json:"owner"`
+	ColorBg   string `json:"color_bg"`
+	ColorText string `json:"color_text"`
+	Img       string `json:"img,omitempty"`
+}
+
+type RemoteVersion struct {
+	Title    string `json:"title"`
+	Artist   string `json:"artist"`
+	Duration string `json:"duration"`
+	Img      string `json:"img,omitempty"`
+}
+
+type RemoteState struct {
+	Title         string            `json:"title"`
+	Artist        string            `json:"artist"`
+	Cover         string            `json:"cover"`
+	IsPlaying     bool              `json:"is_playing"`
+	Volume        float64           `json:"volume"`
+	Progress      float64           `json:"progress"`
+	Duration      float64           `json:"duration"`
+	QueueLen      int               `json:"queue_len"`
+	CurIdx        int               `json:"cur_idx"`
+	Queue         []RemoteQueueItem `json:"queue,omitempty"`
+	Versions      []RemoteVersion   `json:"versions,omitempty"`
+	ActiveVersion int               `json:"active_version"`
+}
+
+type RemoteCommand struct {
+	ID    string  `json:"id"`
+	Cmd   string  `json:"cmd"`
+	Value float64 `json:"value,omitempty"`
+	Text  string  `json:"text,omitempty"`
+}
+
+type remoteRoom struct {
+	state    RemoteState
+	commands []RemoteCommand
+	lastSeen time.Time
+	mu       sync.Mutex
+}
+
+var (
+	remoteMu    sync.RWMutex
+	remoteRooms = map[string]*remoteRoom{}
+)
+
+func init() {
+	go func() {
+		for {
+			time.Sleep(30 * time.Minute)
+			remoteMu.Lock()
+			for id, r := range remoteRooms {
+				if time.Since(r.lastSeen) > 4*time.Hour {
+					delete(remoteRooms, id)
+				}
+			}
+			remoteMu.Unlock()
+		}
+	}()
+}
+
+func CreateRemoteRoom(c *gin.Context) {
+	id := uuid.NewString()[:8]
+	remoteMu.Lock()
+	remoteRooms[id] = &remoteRoom{lastSeen: time.Now()}
+	remoteMu.Unlock()
+	c.JSON(http.StatusOK, gin.H{"id": id})
+}
+
+func PushRemoteState(c *gin.Context) {
+	id := c.Param("id")
+	remoteMu.RLock()
+	room, ok := remoteRooms[id]
+	remoteMu.RUnlock()
+	if !ok {
+		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
+		return
+	}
+	var s RemoteState
+	if err := c.ShouldBindJSON(&s); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	room.mu.Lock()
+	room.state = s
+	room.lastSeen = time.Now()
+	room.mu.Unlock()
+	c.Status(http.StatusNoContent)
+}
+
+func GetRemoteState(c *gin.Context) {
+	id := c.Param("id")
+	remoteMu.RLock()
+	room, ok := remoteRooms[id]
+	remoteMu.RUnlock()
+	if !ok {
+		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
+		return
+	}
+	room.mu.Lock()
+	s := room.state
+	room.mu.Unlock()
+	c.JSON(http.StatusOK, s)
+}
+
+func SendRemoteCommand(c *gin.Context) {
+	id := c.Param("id")
+	remoteMu.RLock()
+	room, ok := remoteRooms[id]
+	remoteMu.RUnlock()
+	if !ok {
+		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
+		return
+	}
+	var cmd RemoteCommand
+	if err := c.ShouldBindJSON(&cmd); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	cmd.ID = uuid.NewString()
+	room.mu.Lock()
+	room.commands = append(room.commands, cmd)
+	if len(room.commands) > 50 {
+		room.commands = room.commands[len(room.commands)-50:]
+	}
+	room.mu.Unlock()
+	c.JSON(http.StatusOK, gin.H{"ok": true})
+}
+
+func PollRemoteCommands(c *gin.Context) {
+	id := c.Param("id")
+	remoteMu.RLock()
+	room, ok := remoteRooms[id]
+	remoteMu.RUnlock()
+	if !ok {
+		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
+		return
+	}
+	room.mu.Lock()
+	cmds := room.commands
+	room.commands = nil
+	room.lastSeen = time.Now()
+	room.mu.Unlock()
+	if cmds == nil {
+		cmds = []RemoteCommand{}
+	}
+	c.JSON(http.StatusOK, cmds)
+}