添加音频代理

app/service/audio_proxy_service.py

@@ -0,0 +1,130 @@
+"""
+音频代理服务
+提供从osu!官方获取beatmapset音频预览并缓存的功能
+"""
+
+from __future__ import annotations
+
+
+from fastapi import HTTPException
+import httpx
+from loguru import logger
+import redis.asyncio as redis
+
+
+class AudioProxyService:
+    """音频代理服务"""
+
+    def __init__(self, redis_client: redis.Redis):
+        self.redis = redis_client
+        self.http_client = httpx.AsyncClient(timeout=30.0)
+        self._cache_ttl = 7 * 24 * 60 * 60  # 7天缓存
+
+    async def close(self):
+        """关闭HTTP客户端"""
+        await self.http_client.aclose()
+
+    def _get_beatmapset_cache_key(self, beatmapset_id: int) -> str:
+        """生成beatmapset音频缓存键"""
+        return f"beatmapset_audio:{beatmapset_id}"
+
+    def _get_beatmapset_metadata_key(self, beatmapset_id: int) -> str:
+        """生成beatmapset音频元数据缓存键"""
+        return f"beatmapset_audio_meta:{beatmapset_id}"
+
+    async def get_beatmapset_audio_from_cache(self, beatmapset_id: int) -> tuple[bytes, str] | None:
+        """从缓存获取beatmapset音频数据和内容类型"""
+        try:
+            cache_key = self._get_beatmapset_cache_key(beatmapset_id)
+            metadata_key = self._get_beatmapset_metadata_key(beatmapset_id)
+
+            # 获取音频数据和元数据
+            audio_data = await self.redis.get(cache_key)
+            metadata = await self.redis.get(metadata_key)
+
+            if audio_data and metadata:
+                logger.debug(f"Beatmapset audio cache hit for ID: {beatmapset_id}")
+                # metadata 格式为 "content_type"
+                return audio_data, metadata.decode()
+            return None
+        except (redis.RedisError, redis.ConnectionError) as e:
+            logger.error(f"Error getting beatmapset audio from cache: {e}")
+            return None
+
+    async def cache_beatmapset_audio(self, beatmapset_id: int, audio_data: bytes, content_type: str):
+        """缓存beatmapset音频数据"""
+        try:
+            cache_key = self._get_beatmapset_cache_key(beatmapset_id)
+            metadata_key = self._get_beatmapset_metadata_key(beatmapset_id)
+
+            # 缓存音频数据和元数据
+            await self.redis.setex(cache_key, self._cache_ttl, audio_data)
+            await self.redis.setex(metadata_key, self._cache_ttl, content_type)
+
+            logger.debug(f"Cached beatmapset audio for ID: {beatmapset_id}, size: {len(audio_data)} bytes")
+        except (redis.RedisError, redis.ConnectionError) as e:
+            logger.error(f"Error caching beatmapset audio: {e}")
+
+    async def fetch_beatmapset_audio(self, beatmapset_id: int) -> tuple[bytes, str]:
+        """从osu!官方获取beatmapset音频预览"""
+        try:
+            # 构建 osu! 官方预览音频 URL
+            preview_url = f"https://b.ppy.sh/preview/{beatmapset_id}.mp3"
+            logger.info(f"Fetching beatmapset audio from: {preview_url}")
+
+            response = await self.http_client.get(preview_url)
+            response.raise_for_status()
+
+            # osu!预览音频通常为mp3格式
+            content_type = response.headers.get("content-type", "audio/mpeg")
+            audio_data = response.content
+
+            # 检查文件大小限制（10MB，预览音频通常不会太大）
+            max_size = 10 * 1024 * 1024  # 10MB
+            if len(audio_data) > max_size:
+                raise HTTPException(
+                    status_code=413, detail=f"Audio file too large: {len(audio_data)} bytes (max: {max_size})"
+                )
+
+            if len(audio_data) == 0:
+                raise HTTPException(status_code=404, detail="Audio preview not available for this beatmapset")
+
+            logger.info(f"Successfully fetched beatmapset audio: {len(audio_data)} bytes, type: {content_type}")
+            return audio_data, content_type
+
+        except httpx.HTTPStatusError as e:
+            logger.error(f"HTTP error fetching beatmapset audio for ID {beatmapset_id}: {e}")
+            if e.response.status_code == 404:
+                raise HTTPException(status_code=404, detail="Audio preview not found for this beatmapset") from e
+            else:
+                raise HTTPException(
+                    status_code=e.response.status_code, detail=f"Failed to fetch audio: {e.response.status_code}"
+                ) from e
+        except httpx.RequestError as e:
+            logger.error(f"Request error fetching beatmapset audio for ID {beatmapset_id}: {e}")
+            raise HTTPException(status_code=503, detail="Failed to connect to osu! servers") from e
+        except Exception as e:
+            logger.error(f"Unexpected error fetching beatmapset audio for ID {beatmapset_id}: {e}")
+            raise HTTPException(status_code=500, detail="Internal server error while fetching audio") from e
+
+    async def get_beatmapset_audio(self, beatmapset_id: int) -> tuple[bytes, str]:
+        """根据 beatmapset_id 获取音频预览"""
+        # 先尝试从缓存获取
+        cached_result = await self.get_beatmapset_audio_from_cache(beatmapset_id)
+        if cached_result:
+            return cached_result
+
+        # 缓存未命中，从osu!官方获取
+        audio_data, content_type = await self.fetch_beatmapset_audio(beatmapset_id)
+
+        # 缓存新获取的音频数据
+        await self.cache_beatmapset_audio(beatmapset_id, audio_data, content_type)
+
+        return audio_data, content_type
+
+
+
+def get_audio_proxy_service(redis_client: redis.Redis) -> AudioProxyService:
+    """获取音频代理服务实例"""
+    # 每次创建新实例，避免全局状态
+    return AudioProxyService(redis_client)