feat: [backend] vision support (#1510)

Co-authored-by: Garfield Dai <dai.hai@foxmail.com>

api/core/file/file_obj.py

@@ -0,0 +1,79 @@
+import enum
+from typing import Optional
+
+from pydantic import BaseModel
+
+from core.file.upload_file_parser import UploadFileParser
+from core.model_providers.models.entity.message import PromptMessageFile, ImagePromptMessageFile
+from extensions.ext_database import db
+from models.model import UploadFile
+
+
+class FileType(enum.Enum):
+    IMAGE = 'image'
+
+    @staticmethod
+    def value_of(value):
+        for member in FileType:
+            if member.value == value:
+                return member
+        raise ValueError(f"No matching enum found for value '{value}'")
+
+
+class FileTransferMethod(enum.Enum):
+    REMOTE_URL = 'remote_url'
+    LOCAL_FILE = 'local_file'
+
+    @staticmethod
+    def value_of(value):
+        for member in FileTransferMethod:
+            if member.value == value:
+                return member
+        raise ValueError(f"No matching enum found for value '{value}'")
+
+
+class FileObj(BaseModel):
+    id: Optional[str]
+    tenant_id: str
+    type: FileType
+    transfer_method: FileTransferMethod
+    url: Optional[str]
+    upload_file_id: Optional[str]
+    file_config: dict
+
+    @property
+    def data(self) -> Optional[str]:
+        return self._get_data()
+
+    @property
+    def preview_url(self) -> Optional[str]:
+        return self._get_data(force_url=True)
+
+    @property
+    def prompt_message_file(self) -> PromptMessageFile:
+        if self.type == FileType.IMAGE:
+            image_config = self.file_config.get('image')
+
+            return ImagePromptMessageFile(
+                data=self.data,
+                detail=ImagePromptMessageFile.DETAIL.HIGH
+                if image_config.get("detail") == "high" else ImagePromptMessageFile.DETAIL.LOW
+            )
+
+    def _get_data(self, force_url: bool = False) -> Optional[str]:
+        if self.type == FileType.IMAGE:
+            if self.transfer_method == FileTransferMethod.REMOTE_URL:
+                return self.url
+            elif self.transfer_method == FileTransferMethod.LOCAL_FILE:
+                upload_file = (db.session.query(UploadFile)
+                               .filter(
+                    UploadFile.id == self.upload_file_id,
+                    UploadFile.tenant_id == self.tenant_id
+                ).first())
+
+                return UploadFileParser.get_image_data(
+                    upload_file=upload_file,
+                    force_url=force_url
+                )
+
+        return None