Add base64 conversion, keyboard layout correcting; remove the shrugging

¯\_(ツ)_/¯ was removed in favor of recently discovered specialized
@shrugbot.

Implement #4.

Author: kozalosev

app/bot.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+import string
 import logging
 from aiohttp import web
 from aiotg import Bot, Chat, InlineQuery
@@ -51,26 +52,27 @@ def empty_suggest(chat: Chat, _) -> None:
 
 
 @bot.inline
-def shrug_shoulders(request: InlineQuery) -> None:
-    str_from_bin = bin_to_str(request.query)
-    str_from_hex = hex_to_str(request.query)
-
+def inline_request_handler(request: InlineQuery) -> None:
     results = InlineQueryResultsBuilder()
     add_article = get_articles_generator_for(results)
 
-    if str_from_bin:
-        add_article("Притвориться человеком", str_from_bin)
-    elif str_from_hex:
-        add_article("Просто текст", str_from_hex)
-    else:
-        lentach_logo = "{} ¯\_(ツ)_/¯".format(request.query).lstrip()
-        add_article("Пожать плечами", lentach_logo)
-
-        if request.query:
-            binary = str_to_bin(request.query)
-            hex_str = str_to_hex(request.query)
-            add_article("Говорить, как робот", binary)
-            add_article("Типа программист", hex_str)
+    if all(map(lambda char: char in (0, 1), request.query)):
+        str_from_bin = bin_to_str(request.query)
+        if str_from_bin:
+            add_article("Притвориться человеком", str_from_bin)
+    elif all(map(lambda char: char in string.hexdigits, request.query)):
+        str_from_hex = hex_to_str(request.query)
+        if str_from_hex:
+            add_article("Просто текст", str_from_hex)
+    elif all(map(lambda char: char in string.ascii_letters + string.digits + '+/=', request.query)):
+        str_from_base64 = base64_to_str(request.query)
+        if str_from_base64:
+            add_article("Дешифровка", str_from_base64)
+    elif request.query:
+        add_article("Проблемы с раскладкой?", switch_keyboard_layout(request.query))
+        add_article("Говорить, как робот", str_to_bin(request.query))
+        add_article("Типа программист", str_to_hex(request.query))
+        add_article("Шифровка", str_to_base64(request.query))
 
     request.answer(results.build_list())
 

app/strconv.py

@@ -1,10 +1,14 @@
 """Utility functions for string conversions."""
 
 import re
+import string
+import base64
+import binascii
 from typing import Optional
 
 
-__all__ = ['escape_html', 'str_to_bin', 'str_to_hex', 'bin_to_str', 'hex_to_str']
+__all__ = ['escape_html', 'str_to_bin', 'str_to_hex', 'str_to_base64', 'bin_to_str', 'hex_to_str', 'base64_to_str',
+           'switch_keyboard_layout']
 
 
 def escape_html(text: str) -> str:
@@ -40,6 +44,10 @@ def str_to_hex(s: str) -> str:
     return " ".join(bl)
 
 
+def str_to_base64(s: str) -> str:
+    return base64.encodebytes(bytes(s, 'UTF-8')).decode('UTF-8').rstrip()
+
+
 def bin_to_str(b: str) -> Optional[str]:
     """
     '01001000 01100101 01101100 01101100 01101111' => 'Hello'
@@ -66,3 +74,27 @@ def hex_to_str(s: str) -> Optional[str]:
         return bytearray.fromhex(s).decode()
     except ValueError:
         return None
+
+
+def base64_to_str(b: str) -> Optional[str]:
+    try:
+        return base64.decodebytes(bytes(b, 'UTF-8')).decode('UTF-8')
+    except binascii.Error or UnicodeDecodeError:
+        return None
+
+
+def switch_keyboard_layout(s: str) -> str:
+    en_weight = sum(c in string.ascii_letters for c in s)
+    ru_weight = sum(c in _russian_letters for c in s)
+    if ru_weight > en_weight:
+        return s.translate(_layouts_correspondings_table_ru_en)
+    else:
+        return s.translate(_layouts_correspondings_table_en_ru)
+
+
+_russian_letters = "абвгдеёжзийклмонпрстуфхцчшщъыьэюяАБВГДЕЁЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯ"
+_latin_layout = "qwertyuiop[]asdfghjkl;'\zxcvbnm,./QWERTYUIOP{}ASDFGHJKL:\"|ZXCVBNM<>?@#$^&"
+_cyrillic_layout = "йцукенгшщзхъфывапролджэ\ячсмитьбю.ЙЦУКЕНГШЩЗХЪФЫВАПРОЛДЖЭ/ЯЧСМИТЬБЮ,\"№;:?"
+
+_layouts_correspondings_table_en_ru = str.maketrans(_latin_layout, _cyrillic_layout)
+_layouts_correspondings_table_ru_en = str.maketrans(_cyrillic_layout, _latin_layout)

tests/test_strconv.py

@@ -55,3 +55,35 @@ def test_to_str(self):
     def test_fails(self):
         assert hex_to_str(self.f1) is None
         assert hex_to_str(self.f2) is None
+
+
+class TestBase64:
+    s = "Hello World"
+    b = "SGVsbG8gV29ybGQ="
+    sr = "Привет, мир!"
+    br = "0J/RgNC40LLQtdGCLCDQvNC40YAh"
+    f = "Не base64-строка"
+
+    def test_from_str(self):
+        assert str_to_base64(self.s) == self.b
+
+    def test_to_str(self):
+        assert base64_to_str(self.b) == self.s
+
+    def test_russian(self):
+        assert str_to_base64(self.sr) == self.br
+        assert base64_to_str(self.br) == self.sr
+
+    def test_fails(self):
+        assert base64_to_str(self.f) is None
+
+
+class TestLayoutSwitcher:
+    en = "J,kf;fkcz c hfcrkflrjq"
+    ru = "Облажался с раскладкой"
+
+    def test_en_ru(self):
+        assert switch_keyboard_layout(self.en) == self.ru
+
+    def test_ru_en(self):
+        assert switch_keyboard_layout(self.ru) == self.en