feat: Add base project structure with API and web components

api/app/core/upload_policies.py

@@ -0,0 +1,80 @@
+from dataclasses import dataclass
+from typing import List, Optional
+from app.core.upload_enums import UploadContext
+
+
+@dataclass
+class UploadPolicy:
+    """上传策略，定义文件大小限制、允许的文件类型等规则"""
+    max_file_size: int  # 最大文件大小（字节）
+    allowed_extensions: List[str]  # 允许的文件扩展名列表
+    allowed_mime_types: List[str]  # 允许的 MIME 类型列表
+    require_authentication: bool = True  # 是否需要认证
+    enable_virus_scan: bool = False  # 是否启用病毒扫描
+    enable_compression: bool = False  # 是否启用压缩
+    auto_delete_after_days: Optional[int] = None  # 自动删除天数（None 表示不自动删除）
+
+
+# 各上下文的上传策略配置
+UPLOAD_POLICIES = {
+    UploadContext.AVATAR: UploadPolicy(
+        max_file_size=5 * 1024 * 1024,  # 5MB
+        allowed_extensions=[".jpg", ".jpeg", ".png", ".gif", ".webp"],
+        allowed_mime_types=["image/jpeg", "image/png", "image/gif", "image/webp"],
+        require_authentication=True,
+        enable_compression=True,
+    ),
+    UploadContext.APP_ICON: UploadPolicy(
+        max_file_size=2 * 1024 * 1024,  # 2MB
+        allowed_extensions=[".jpg", ".jpeg", ".png", ".svg"],
+        allowed_mime_types=["image/jpeg", "image/png", "image/svg+xml"],
+        require_authentication=True,
+        enable_compression=True,
+    ),
+    UploadContext.KNOWLEDGE_BASE: UploadPolicy(
+        max_file_size=50 * 1024 * 1024,  # 50MB
+        allowed_extensions=[".pdf", ".doc", ".docx", ".txt", ".md", ".xlsx", ".csv"],
+        allowed_mime_types=[
+            "application/pdf",
+            "application/msword",
+            "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+            "text/plain",
+            "text/markdown",
+            "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+            "text/csv",
+        ],
+        require_authentication=True,
+        enable_virus_scan=True,
+    ),
+    UploadContext.TEMP: UploadPolicy(
+        max_file_size=10 * 1024 * 1024,  # 10MB
+        allowed_extensions=[],  # 允许所有类型
+        allowed_mime_types=[],  # 允许所有类型
+        require_authentication=True,
+        auto_delete_after_days=7,
+    ),
+    UploadContext.ATTACHMENT: UploadPolicy(
+        max_file_size=20 * 1024 * 1024,  # 20MB
+        allowed_extensions=[],  # 允许所有类型
+        allowed_mime_types=[],  # 允许所有类型
+        require_authentication=True,
+    ),
+}
+
+
+def get_upload_policy(context: UploadContext) -> UploadPolicy:
+    """
+    根据上传上下文获取对应的上传策略
+    
+    Args:
+        context: 上传上下文
+        
+    Returns:
+        对应的上传策略
+        
+    Raises:
+        ValueError: 如果上下文不存在对应的策略
+    """
+    if context not in UPLOAD_POLICIES:
+        raise ValueError(f"未定义上传上下文 '{context}' 的策略")
+    return UPLOAD_POLICIES[context]