package server

import (
	"encoding/json"
	"net/http"
	"strconv"
	"context"

	"sync-live/internal/room"
)

// handleRoomPlaylist 处理房间播放列表的 CRUD。
func (s *Server) handleRoomPlaylist(w http.ResponseWriter, r *http.Request) {
	roomName := r.PathValue("room")
	if roomName == "" {
		http.Error(w, "room required", http.StatusBadRequest)
		return
	}
	if s.roomSvc == nil || s.roomSvc.Store().DB() == nil {
		http.Error(w, "room service not configured", http.StatusServiceUnavailable)
		return
	}

	switch r.Method {
	case http.MethodGet:
		items, err := s.roomSvc.Store().ListPlaylistItems(r.Context(), roomName)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		if items == nil {
			items = []*room.PlaylistItem{}
		}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(map[string]interface{}{"items": items})

	case http.MethodPost:
		user := actorName(r)
		if user == "" {
			http.Error(w, "unauthorized", http.StatusUnauthorized)
			return
		}
		if err := s.roomSvc.EnsurePermission(r.Context(), roomName, user, room.PermControlStream); err != nil {
			http.Error(w, err.Error(), http.StatusForbidden)
			return
		}
		var body struct {
			URL   string `json:"url"`
			Title string `json:"title"`
		}
		if err := json.NewDecoder(r.Body).Decode(&body); err != nil || body.URL == "" {
			http.Error(w, "url required", http.StatusBadRequest)
			return
		}
		item := &room.PlaylistItem{
			RoomName: roomName,
			URL:      body.URL,
			Title:    body.Title,
			AddedBy:  user,
		}
		created, err := s.roomSvc.Store().AddPlaylistItem(r.Context(), item)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		// 通过 WebSocket 广播播放列表变更
		s.broadcastPlaylistUpdate(r.Context(), roomName)
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(created)

	case http.MethodDelete:
		user := actorName(r)
		if user == "" {
			http.Error(w, "unauthorized", http.StatusUnauthorized)
			return
		}
		if err := s.roomSvc.EnsurePermission(r.Context(), roomName, user, room.PermControlStream); err != nil {
			http.Error(w, err.Error(), http.StatusForbidden)
			return
		}
		itemIDStr := r.URL.Query().Get("id")
		itemID, err := strconv.ParseInt(itemIDStr, 10, 64)
		if err != nil || itemID <= 0 {
			http.Error(w, "valid item id required", http.StatusBadRequest)
			return
		}
		if err := s.roomSvc.Store().RemovePlaylistItem(r.Context(), roomName, itemID); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		s.broadcastPlaylistUpdate(r.Context(), roomName)
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(map[string]interface{}{"ok": true})

	default:
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
	}
}

// handleRoomPlayback 处理同步播放状态的读取和更新。
func (s *Server) handleRoomPlayback(w http.ResponseWriter, r *http.Request) {
	roomName := r.PathValue("room")
	if roomName == "" {
		http.Error(w, "room required", http.StatusBadRequest)
		return
	}
	if s.roomSvc == nil || s.roomSvc.Store().DB() == nil {
		http.Error(w, "room service not configured", http.StatusServiceUnavailable)
		return
	}

	switch r.Method {
	case http.MethodGet:
		ps, err := s.roomSvc.Store().GetPlaybackState(r.Context(), roomName)
		if err != nil {
			// 无状态时返回默认值
			ps = &room.PlaybackState{Room: roomName, Rate: 1}
		}
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(ps)

	case http.MethodPost, http.MethodPut:
		user := actorName(r)
		if user == "" {
			http.Error(w, "unauthorized", http.StatusUnauthorized)
			return
		}
		if err := s.roomSvc.EnsurePermission(r.Context(), roomName, user, room.PermControlStream); err != nil {
			http.Error(w, err.Error(), http.StatusForbidden)
			return
		}
		var body struct {
			Position    float64 `json:"position"`
			Playing     bool    `json:"playing"`
			Rate        float64 `json:"rate"`
			CurrentItem int64   `json:"current_item_id"`
		}
		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
			http.Error(w, "bad json", http.StatusBadRequest)
			return
		}
		if body.Rate <= 0 {
			body.Rate = 1
		}
		ps := &room.PlaybackState{
			Room:        roomName,
			Position:    body.Position,
			Playing:     body.Playing,
			Rate:        body.Rate,
			CurrentItem: body.CurrentItem,
			UpdatedBy:   user,
		}
		if err := s.roomSvc.Store().SavePlaybackState(r.Context(), ps); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		// 通过 WebSocket 广播播放状态变更
		s.hub.broadcastEvent(roomName, "playback", ps)
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(ps)

	default:
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
	}
}

// broadcastPlaylistUpdate 向房间广播播放列表变更事件。
func (s *Server) broadcastPlaylistUpdate(ctx context.Context, roomName string) {
	items, _ := s.roomSvc.Store().ListPlaylistItems(ctx, roomName)
	s.hub.broadcastEvent(roomName, "playlist_update", items)
}