new: add mime types parsing (#431)

aiogram/types/document.py

@@ -2,6 +2,7 @@ from . import base
 from . import fields
 from . import mixins
 from .photo_size import PhotoSize
+from ..utils import helper
 
 
 class Document(base.TelegramObject, mixins.Downloadable):
@@ -16,3 +17,34 @@ class Document(base.TelegramObject, mixins.Downloadable):
     file_name: base.String = fields.Field()
     mime_type: base.String = fields.Field()
     file_size: base.Integer = fields.Field()
+
+    @property
+    def mime_base(self) -> str:
+        base_type, _, _ = self.mime_type.partition('/')
+        return base_type
+
+    @property
+    def mime_subtype(self) -> str:
+        _, _, subtype = self.mime_type.partition('/')
+        return subtype
+
+
+class MimeBase(helper.Helper):
+    """
+    List of mime base types registered in IANA
+
+    https://www.iana.org/assignments/media-types/media-types.xhtml
+    """
+
+    mode = helper.HelperMode.lowercase
+
+    APPLICATION = helper.Item()  # application
+    AUDIO = helper.Item()  # audio
+    EXAMPLE = helper.Item()  # example
+    FONT = helper.Item()  # font
+    IMAGE = helper.Item()  # image
+    MESSAGE = helper.Item()  # message
+    MODEL = helper.Item()  # model
+    MULTIPART = helper.Item()  # multipart
+    TEXT = helper.Item()  # text
+    VIDEO = helper.Item()  # video