dify/api/controllers/files/image_preview.py

from flask import Response, request
from flask_restful import Resource
from werkzeug.exceptions import NotFound

import services
from controllers.files import api
from libs.exception import BaseHTTPException
from services.account_service import TenantService
from services.file_service import FileService


class ImagePreviewApi(Resource):
    def get(self, file_id):
        file_id = str(file_id)

        timestamp = request.args.get("timestamp")
        nonce = request.args.get("nonce")
        sign = request.args.get("sign")

        if not timestamp or not nonce or not sign:
            return {"content": "Invalid request."}, 400

        try:
            generator, mimetype = FileService.get_image_preview(file_id, timestamp, nonce, sign)
        except services.errors.file.UnsupportedFileTypeError:
            raise UnsupportedFileTypeError()

        return Response(generator, mimetype=mimetype)


class WorkspaceWebappLogoApi(Resource):
    def get(self, workspace_id):
        workspace_id = str(workspace_id)

        custom_config = TenantService.get_custom_config(workspace_id)
        webapp_logo_file_id = custom_config.get("replace_webapp_logo") if custom_config is not None else None

        if not webapp_logo_file_id:
            raise NotFound("webapp logo is not found")

        try:
            generator, mimetype = FileService.get_public_image_preview(
                webapp_logo_file_id,
            )
        except services.errors.file.UnsupportedFileTypeError:
            raise UnsupportedFileTypeError()

        return Response(generator, mimetype=mimetype)


api.add_resource(ImagePreviewApi, "/files/<uuid:file_id>/image-preview")
api.add_resource(WorkspaceWebappLogoApi, "/files/workspaces/<uuid:workspace_id>/webapp-logo")


class UnsupportedFileTypeError(BaseHTTPException):
    error_code = "unsupported_file_type"
    description = "File type not allowed."
    code = 415