Feature/agent isolation chat

backend/app/api/attachment_api.py

@@ -0,0 +1,183 @@
+import base64
+import logging
+from fastapi import APIRouter, UploadFile, File
+from fastapi.responses import JSONResponse
+
+from app.core.config import settings
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/upload", tags=["upload"])
+
+
+def _extract_pdf_text(file_bytes: bytes) -> tuple[str | None, str]:
+    """尝试提取 PDF 文本内容
+
+    Returns:
+        tuple: (提取的文本或None, 错误信息)
+    """
+    try:
+        import fitz
+        import io
+    except ImportError:
+        return None, "PyMuPDF库未安装，无法解析PDF文件"
+
+    try:
+        doc = fitz.open(stream=io.BytesIO(file_bytes), filetype="pdf")
+        if doc.is_closed:
+            return None, "PDF文件格式错误，无法打开"
+        text = ""
+        for page_num, page in enumerate(doc):
+            try:
+                page_text = page.get_text()
+                text += page_text
+            except Exception as e:
+                logger.warning(f"[PDF] 第{page_num + 1}页提取失败: {e}")
+                continue
+        doc.close()
+
+        if not text.strip():
+            return None, "PDF文件中没有可提取的文本内容（可能是扫描件或图片型PDF）"
+        return text.strip(), ""
+    except Exception as e:
+        error_msg = f"PDF文件解析失败: {str(e)}"
+        logger.warning(f"[UploadForward] {error_msg}")
+        return None, error_msg
+
+
+def _extract_docx_text(file_bytes: bytes) -> tuple[str | None, str]:
+    """尝试提取 Word 文档文本内容
+
+    Returns:
+        tuple: (提取的文本或None, 错误信息)
+    """
+    try:
+        import docx
+        import io
+    except ImportError:
+        return None, "python-docx库未安装，无法解析Word文档"
+
+    try:
+        doc = docx.Document(io.BytesIO(file_bytes))
+        paragraphs = []
+        for para in doc.paragraphs:
+            if para.text.strip():
+                paragraphs.append(para.text.strip())
+
+        for table in doc.tables:
+            for row in table.rows:
+                row_text = " | ".join(cell.text.strip() for cell in row.cells if cell.text.strip())
+                if row_text:
+                    paragraphs.append(row_text)
+
+        text = "\n".join(paragraphs)
+        if not text:
+            return None, "Word文档中没有可提取的文本内容"
+        return text, ""
+    except Exception as e:
+        error_msg = f"Word文档解析失败: {str(e)}"
+        logger.warning(f"[UploadForward] {error_msg}")
+        return None, error_msg
+
+
+@router.post("/forward")
+async def forward_file(file: UploadFile = File(...)):
+    try:
+        file_bytes = await file.read()
+    except Exception as e:
+        logger.warning(f"[UploadForward] 文件读取失败: {e}")
+        return JSONResponse(
+            status_code=400,
+            content={"status": "error", "message": "文件读取失败，请重新上传"},
+        )
+
+    if len(file_bytes) > settings.FILE_MAX_SIZE:
+        return JSONResponse(
+            status_code=400,
+            content={"status": "error", "message": f"文件大小超过限制 ({settings.FILE_MAX_SIZE // 1024 // 1024}MB)"},
+        )
+
+    try:
+        filename = file.filename or "unknown"
+        content_type = file.content_type or ""
+        ext = filename.split('.')[-1].lower() if '.' in filename else ''
+
+        if not ext and content_type:
+            ext_map = {
+                "image/jpeg": "jpg",
+                "image/png": "png",
+                "image/gif": "gif",
+                "image/bmp": "bmp",
+                "image/webp": "webp",
+                "application/pdf": "pdf",
+                "application/vnd.openxmlformats-officedocument.wordprocessingml.document": "docx",
+            }
+            ext = ext_map.get(content_type, "")
+
+        image_extensions = {'jpg', 'jpeg', 'png', 'gif', 'bmp', 'webp'}
+        if ext in image_extensions:
+            b64 = base64.b64encode(file_bytes).decode('utf-8')
+            mime = f"image/{ext if ext != 'jpg' else 'jpeg'}"
+            content = f"data:{mime};base64,{b64}"
+            return {
+                "status": "success",
+                "content": content,
+                "type": "image",
+                "filename": filename,
+            }
+
+        if ext == 'pdf':
+            text, error = _extract_pdf_text(file_bytes)
+            if text:
+                return {
+                    "status": "success",
+                    "content": text,
+                    "type": "text",
+                    "filename": filename,
+                }
+            return JSONResponse(
+                status_code=400,
+                content={"status": "error", "message": error or "无法提取PDF文本内容"},
+            )
+
+        if ext in ('docx', 'doc'):
+            text, error = _extract_docx_text(file_bytes)
+            if text:
+                return {
+                    "status": "success",
+                    "content": text,
+                    "type": "text",
+                    "filename": filename,
+                }
+            return JSONResponse(
+                status_code=400,
+                content={"status": "error", "message": error or "无法提取Word文档文本内容"},
+            )
+
+        text_extensions = {'txt', 'md', 'csv', 'json', 'xml', 'html', 'css', 'js', 'py', 'java', 'cpp', 'c', 'h', 'go', 'rs', 'ts', 'sql', 'yaml', 'yml'}
+        if ext in text_extensions:
+            try:
+                text = file_bytes.decode('utf-8')
+            except UnicodeDecodeError:
+                try:
+                    text = file_bytes.decode('gbk')
+                except UnicodeDecodeError:
+                    text = file_bytes.decode('utf-8', errors='ignore')
+            return {
+                "status": "success",
+                "content": text,
+                "type": "text",
+                "filename": filename,
+            }
+
+        return JSONResponse(
+            status_code=400,
+            content={"status": "error", "message": f"不支持的文件类型: .{ext}"},
+        )
+
+    except Exception as e:
+        logger.warning(f"[UploadForward] 文件处理失败: {e}")
+        return JSONResponse(
+            status_code=500,
+            content={"status": "error", "message": "文件上传处理失败，请稍后重试"},
+        )