From e19e022e12f7b70e6c2cbc5ee6d9b94edcbbfb3f Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Mon, 18 May 2020 18:33:40 +0200
Subject: [PATCH 1/9] Track input via message of algebraic expressions as well
 as input via buttons.

---
 davtelepot/__init__.py     |  2 +-
 davtelepot/useful_tools.py | 46 +++++++++++++++++++++++++++++++-------
 2 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/davtelepot/__init__.py b/davtelepot/__init__.py
index 2a58146..ba0bbf1 100644
--- a/davtelepot/__init__.py
+++ b/davtelepot/__init__.py
@@ -11,7 +11,7 @@ __author__ = "Davide Testa"
 __email__ = "davide@davte.it"
 __credits__ = ["Marco Origlia", "Nick Lee @Nickoala"]
 __license__ = "GNU General Public License v3.0"
-__version__ = "2.5.15"
+__version__ = "2.5.16"
 __maintainer__ = "Davide Testa"
 __contact__ = "t.me/davte"
 
diff --git a/davtelepot/useful_tools.py b/davtelepot/useful_tools.py
index 29fdc79..b0299e0 100644
--- a/davtelepot/useful_tools.py
+++ b/davtelepot/useful_tools.py
@@ -238,7 +238,7 @@ async def _calculate_button(bot: Bot,
         if command == 'parser':
             reply_markup = None
             bot.set_individual_text_message_handler(
-                handler=_calculate_command,
+                handler=wrap_calculate_command(record_id=record_id),
                 user_id=user_record['telegram_id']
             )
         elif command == 'info':
@@ -398,11 +398,26 @@ async def calculate_session(bot: Bot,
     )
 
 
+def wrap_calculate_command(record_id: int = None, command_name: str = 'calc'):
+    async def wrapped_calculate_command(bot: Bot,
+                                        update: dict,
+                                        user_record: OrderedDict,
+                                        language: str,):
+        return await _calculate_command(bot=bot,
+                                        update=update,
+                                        user_record=user_record,
+                                        language=language,
+                                        command_name=command_name,
+                                        record_id=record_id)
+    return wrapped_calculate_command
+
+
 async def _calculate_command(bot: Bot,
                              update: dict,
                              user_record: OrderedDict,
                              language: str,
-                             command_name: str = 'calc'):
+                             command_name: str = 'calc',
+                             record_id: int = None):
     if 'reply_to_message' in update:
         update = update['reply_to_message']
     command_aliases = [command_name]
@@ -420,18 +435,33 @@ async def _calculate_command(bot: Bot,
         )
         reply_markup = get_calculator_keyboard()
     else:
-        record_id = bot.db['calculations'].insert(
-            dict(
-                user_id=user_record['id'],
-                created=datetime.datetime.now(),
-                expression=text
+        if record_id is None:
+            record_id = bot.db['calculations'].insert(
+                dict(
+                    user_id=user_record['id'],
+                    created=datetime.datetime.now(),
+                    expression=text
+                )
             )
+            expression = text
+        else:
+            record = bot.db['calculations'].find_one(
+                id=record_id
+            )
+            expression = f"{record['expression'] or ''}\n{text}"
+        bot.db['calculations'].update(
+            dict(
+                id=record_id,
+                modified=datetime.datetime.now(),
+                expression=expression
+            ),
+            ['id']
         )
         text = bot.get_message(
             'useful_tools', 'calculate_command', 'result',
             language=language,
             expressions=evaluate_expressions(bot=bot,
-                                             expressions=text,
+                                             expressions=expression,
                                              language=language)
         )
         reply_markup = get_calculator_keyboard(additional_data=[record_id])

From 10188762275362cb78c419211bf489dfd9e904ac Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Mon, 18 May 2020 18:50:21 +0200
Subject: [PATCH 2/9] Remove whitespace at the end of the expression after del
 button is pressed

---
 davtelepot/__init__.py     | 2 +-
 davtelepot/useful_tools.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/davtelepot/__init__.py b/davtelepot/__init__.py
index ba0bbf1..35c0ff9 100644
--- a/davtelepot/__init__.py
+++ b/davtelepot/__init__.py
@@ -11,7 +11,7 @@ __author__ = "Davide Testa"
 __email__ = "davide@davte.it"
 __credits__ = ["Marco Origlia", "Nick Lee @Nickoala"]
 __license__ = "GNU General Public License v3.0"
-__version__ = "2.5.16"
+__version__ = "2.5.17"
 __maintainer__ = "Davide Testa"
 __contact__ = "t.me/davte"
 
diff --git a/davtelepot/useful_tools.py b/davtelepot/useful_tools.py
index b0299e0..1e4c032 100644
--- a/davtelepot/useful_tools.py
+++ b/davtelepot/useful_tools.py
@@ -360,7 +360,7 @@ async def calculate_session(bot: Bot,
             return
         input_value = data[1]
         if input_value == 'del':
-            expression = expression[:-1]
+            expression = expression[:-1].strip()
         elif input_value == 'back':
             pass
         elif input_value in calc_buttons:

From a7fd05410642a1566b9e03a4346de1cf2c7fdca4 Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Mon, 18 May 2020 18:58:14 +0200
Subject: [PATCH 3/9] Multilanguage message in version command

---
 davtelepot/__init__.py             |  2 +-
 davtelepot/administration_tools.py | 18 +++++++++++++-----
 davtelepot/messages.py             | 16 ++++++++++++----
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/davtelepot/__init__.py b/davtelepot/__init__.py
index 35c0ff9..84cf5f0 100644
--- a/davtelepot/__init__.py
+++ b/davtelepot/__init__.py
@@ -11,7 +11,7 @@ __author__ = "Davide Testa"
 __email__ = "davide@davte.it"
 __credits__ = ["Marco Origlia", "Nick Lee @Nickoala"]
 __license__ = "GNU General Public License v3.0"
-__version__ = "2.5.17"
+__version__ = "2.5.18"
 __maintainer__ = "Davide Testa"
 __contact__ = "t.me/davte"
 
diff --git a/davtelepot/administration_tools.py b/davtelepot/administration_tools.py
index 2b8fa5b..7801be5 100644
--- a/davtelepot/administration_tools.py
+++ b/davtelepot/administration_tools.py
@@ -870,7 +870,8 @@ async def get_new_versions(bot: Bot,
     return news
 
 
-async def _version_command(bot: Bot, update, user_record):
+async def _version_command(bot: Bot, update: dict,
+                           user_record: OrderedDict, language: str):
     last_commit = await get_last_commit()
     text = bot.get_message(
         'admin', 'version_command', 'header',
@@ -883,13 +884,19 @@ async def _version_command(bot: Bot, update, user_record):
         for package in bot.packages
     )
     temporary_message = await bot.send_message(
-        text=text + '\n\n⏳ Checking for updates... ☑️',
+        text=text + '\n\n' + bot.get_message(
+            'admin', 'version_command', 'checking_for_updates',
+            language=language
+        ),
         update=update,
         send_default_keyboard=False
     )
     news = await get_new_versions(bot=bot)
     if not news:
-        text += '\n\n⌛️ All packages are updated! ✅'
+        text += '\n\n' + bot.get_message(
+            'admin', 'version_command', 'all_packages_updated',
+            language=language
+        )
     else:
         text += '\n\n' + bot.get_message(
             'admin', 'updates_available', 'header',
@@ -1997,7 +2004,8 @@ def init(telegram_bot: Bot,
                              },
                           show_in_keyboard=False,
                           authorization_level='admin')
-    async def version_command(bot, update, user_record):
+    async def version_command(bot, update, user_record, language):
         return await _version_command(bot=bot,
                                       update=update,
-                                      user_record=user_record)
+                                      user_record=user_record,
+                                      language=language)
diff --git a/davtelepot/messages.py b/davtelepot/messages.py
index b7b16cf..a7247be 100644
--- a/davtelepot/messages.py
+++ b/davtelepot/messages.py
@@ -617,21 +617,29 @@ default_admin_messages = {
         },
     },
     'version_command': {
-        'reply_keyboard_button': {
-            'en': "Version #️⃣",
-            'it': "Versione #️⃣",
+        'all_packages_updated': {
+            'en': "⌛️ All packages are updated! ✅",
+            'it': "⌛️ Tutti i pacchetti sono aggiornati! ✅",
+        },
+        'checking_for_updates': {
+            'en': "⏳ Checking for updates... ☑️",
+            'it': "⏳ Sto cercando aggiornamenti... ☑️",
         },
         'description': {
             'en': "Get packages version and source code last commit",
             'it': "Chiedi la versione dei pacchetti e del codice sorgente",
         },
-        'help_section': None,
         'header': {
             'en': "ℹ️ Version information #️⃣\n\n"
                   "Last commit: <code>{last_commit}</code>",
             'it': "ℹ️ Informazioni sulle versioni dei pacchetti #️⃣\n\n"
                   "Ultimo commit: <code>{last_commit}</code>"
         },
+        'help_section': None,
+        'reply_keyboard_button': {
+            'en': "Version #️⃣",
+            'it': "Versione #️⃣",
+        },
     },
 }
 

From 7f140371b61be62e192d8fa9af0366e96db2be2e Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Mon, 18 May 2020 19:31:26 +0200
Subject: [PATCH 4/9] Prettify expressions

---
 davtelepot/__init__.py     |  2 +-
 davtelepot/useful_tools.py | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/davtelepot/__init__.py b/davtelepot/__init__.py
index 84cf5f0..c75d6c4 100644
--- a/davtelepot/__init__.py
+++ b/davtelepot/__init__.py
@@ -11,7 +11,7 @@ __author__ = "Davide Testa"
 __email__ = "davide@davte.it"
 __credits__ = ["Marco Origlia", "Nick Lee @Nickoala"]
 __license__ = "GNU General Public License v3.0"
-__version__ = "2.5.18"
+__version__ = "2.5.19"
 __maintainer__ = "Davide Testa"
 __contact__ = "t.me/davte"
 
diff --git a/davtelepot/useful_tools.py b/davtelepot/useful_tools.py
index 1e4c032..80fdf7c 100644
--- a/davtelepot/useful_tools.py
+++ b/davtelepot/useful_tools.py
@@ -7,6 +7,7 @@ import datetime
 import json
 import logging
 import operator
+import re
 
 from collections import OrderedDict
 from typing import List, Union
@@ -182,6 +183,16 @@ def get_operators() -> dict:
 
 calc_buttons = get_calc_buttons()
 operators = get_operators()
+operators_spacer = re.compile(r"(\d)\s*([+\-*%]|/{1,2})\s*(\d)")
+spaced_operators = r"\1 \2 \3"
+operators_space_remover = re.compile(r"(\d)\s*(\*\*)\s*(\d)")
+un_spaced_operators = r"\1\2\3"
+
+
+def prettify_expression(expression):
+    expression = operators_spacer.sub(spaced_operators, expression)
+    expression = operators_space_remover.sub(un_spaced_operators, expression)
+    return expression
 
 
 def get_calculator_keyboard(additional_data: list = None):
@@ -367,6 +378,7 @@ async def calculate_session(bot: Bot,
             expression += calc_buttons[input_value]['value']
         else:
             logging.error(f"Invalid input from calculator button: {input_value}")
+    expression = prettify_expression(expression)
     if record:
         bot.db['calculations'].update(
             dict(
@@ -449,6 +461,7 @@ async def _calculate_command(bot: Bot,
                 id=record_id
             )
             expression = f"{record['expression'] or ''}\n{text}"
+        expression = prettify_expression(expression)
         bot.db['calculations'].update(
             dict(
                 id=record_id,

From 2131c6acf9103c06e50bccd6ebe781450d06447d Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Mon, 18 May 2020 22:08:10 +0200
Subject: [PATCH 5/9] Prevent `message is not modified` exceptions

---
 davtelepot/__init__.py     |  2 +-
 davtelepot/useful_tools.py | 33 +++++++++++++++++++++++----------
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/davtelepot/__init__.py b/davtelepot/__init__.py
index c75d6c4..aec296a 100644
--- a/davtelepot/__init__.py
+++ b/davtelepot/__init__.py
@@ -11,7 +11,7 @@ __author__ = "Davide Testa"
 __email__ = "davide@davte.it"
 __credits__ = ["Marco Origlia", "Nick Lee @Nickoala"]
 __license__ = "GNU General Public License v3.0"
-__version__ = "2.5.19"
+__version__ = "2.5.20"
 __maintainer__ = "Davide Testa"
 __contact__ = "t.me/davte"
 
diff --git a/davtelepot/useful_tools.py b/davtelepot/useful_tools.py
index 80fdf7c..0ceedda 100644
--- a/davtelepot/useful_tools.py
+++ b/davtelepot/useful_tools.py
@@ -186,12 +186,21 @@ operators = get_operators()
 operators_spacer = re.compile(r"(\d)\s*([+\-*%]|/{1,2})\s*(\d)")
 spaced_operators = r"\1 \2 \3"
 operators_space_remover = re.compile(r"(\d)\s*(\*\*)\s*(\d)")
-un_spaced_operators = r"\1\2\3"
+non_spaced_operators = r"\1\2\3"
+multiple_newlines_regex = re.compile(r"[\n|\r][\n|\s]{2,}")
+multiple_spaces_regex = re.compile(r"\s{2,}")
 
 
 def prettify_expression(expression):
+    """Make expression cleaner to read.
+
+    Place a single space around binary operators `+,-,*,%,/,//`, no space
+        around `**`, single newlines and single spaces.
+    """
     expression = operators_spacer.sub(spaced_operators, expression)
-    expression = operators_space_remover.sub(un_spaced_operators, expression)
+    expression = operators_space_remover.sub(non_spaced_operators, expression)
+    expression = multiple_newlines_regex.sub('\n', expression)
+    expression = multiple_spaces_regex.sub(' ', expression)
     return expression
 
 
@@ -353,6 +362,7 @@ async def calculate_session(bot: Bot,
     record = bot.db['calculations'].find_one(
         id=record_id
     )
+    old_expression = record['expression']
     if record is None:
         logging.error("Invalid record identifier!")
         return
@@ -389,19 +399,22 @@ async def calculate_session(bot: Bot,
             ['id']
         )
     if expression:
-        text = bot.get_message(
-            'useful_tools', 'calculate_command', 'result',
-            language=language,
-            expressions=evaluate_expressions(bot=bot,
-                                             expressions=expression,
-                                             language=language)
-        )
+        if expression.strip(' \n') != old_expression.strip(' \n'):
+            text = bot.get_message(
+                'useful_tools', 'calculate_command', 'result',
+                language=language,
+                expressions=evaluate_expressions(bot=bot,
+                                                 expressions=expression,
+                                                 language=language)
+            )
+        else:
+            text = ''
     else:
         text = bot.get_message(
             'useful_tools', 'calculate_command', 'instructions',
             language=language
         )
-    if last_entry is None:
+    if last_entry is None or not text:
         return
     await bot.edit_message_text(
         text=text,

From 995bfee084342c081038893524711107edeb180c Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Mon, 18 May 2020 22:25:30 +0200
Subject: [PATCH 6/9] TypeError bug fixed

---
 davtelepot/__init__.py     | 2 +-
 davtelepot/useful_tools.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/davtelepot/__init__.py b/davtelepot/__init__.py
index aec296a..4f0d80d 100644
--- a/davtelepot/__init__.py
+++ b/davtelepot/__init__.py
@@ -11,7 +11,7 @@ __author__ = "Davide Testa"
 __email__ = "davide@davte.it"
 __credits__ = ["Marco Origlia", "Nick Lee @Nickoala"]
 __license__ = "GNU General Public License v3.0"
-__version__ = "2.5.20"
+__version__ = "2.5.21"
 __maintainer__ = "Davide Testa"
 __contact__ = "t.me/davte"
 
diff --git a/davtelepot/useful_tools.py b/davtelepot/useful_tools.py
index 0ceedda..235507f 100644
--- a/davtelepot/useful_tools.py
+++ b/davtelepot/useful_tools.py
@@ -362,7 +362,7 @@ async def calculate_session(bot: Bot,
     record = bot.db['calculations'].find_one(
         id=record_id
     )
-    old_expression = record['expression']
+    old_expression = record['expression'] or ''
     if record is None:
         logging.error("Invalid record identifier!")
         return

From cd7392c2fd18a0c75fe68cf3e18380d9da9d6403 Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Tue, 19 May 2020 12:53:20 +0200
Subject: [PATCH 7/9] Prettify expressions removing whitespace around newlines
 and adjusting whitespace around parentheses

---
 davtelepot/__init__.py     |  2 +-
 davtelepot/useful_tools.py | 19 ++++++++++++++++---
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/davtelepot/__init__.py b/davtelepot/__init__.py
index 4f0d80d..fd511fd 100644
--- a/davtelepot/__init__.py
+++ b/davtelepot/__init__.py
@@ -11,7 +11,7 @@ __author__ = "Davide Testa"
 __email__ = "davide@davte.it"
 __credits__ = ["Marco Origlia", "Nick Lee @Nickoala"]
 __license__ = "GNU General Public License v3.0"
-__version__ = "2.5.21"
+__version__ = "2.5.22"
 __maintainer__ = "Davide Testa"
 __contact__ = "t.me/davte"
 
diff --git a/davtelepot/useful_tools.py b/davtelepot/useful_tools.py
index 235507f..9b7d0f5 100644
--- a/davtelepot/useful_tools.py
+++ b/davtelepot/useful_tools.py
@@ -183,12 +183,19 @@ def get_operators() -> dict:
 
 calc_buttons = get_calc_buttons()
 operators = get_operators()
-operators_spacer = re.compile(r"(\d)\s*([+\-*%]|/{1,2})\s*(\d)")
+
+operators_spacer = re.compile(r"([\d\(\)])\s*([+\-*%]|/{1,2})\s*([\d\(\)])")
 spaced_operators = r"\1 \2 \3"
-operators_space_remover = re.compile(r"(\d)\s*(\*\*)\s*(\d)")
+operators_space_remover = re.compile(r"([\d\(\)])\s*(\*\*)\s*([\d\(\)])")
 non_spaced_operators = r"\1\2\3"
 multiple_newlines_regex = re.compile(r"[\n|\r][\n|\s]{2,}")
-multiple_spaces_regex = re.compile(r"\s{2,}")
+multiple_spaces_regex = re.compile(r"[^\S\n\r]{2,}")
+parentheses_regex_list = [
+    {'pattern': re.compile(r"[^\S\n\r]*(\()[^\S\n\r]*(\d)"),
+     'replace': r" \1\2"},
+    {'pattern': re.compile(r"(\d)[^\S\n\r]*(\))"),
+     'replace': r"\1\2"}
+]
 
 
 def prettify_expression(expression):
@@ -196,11 +203,17 @@ def prettify_expression(expression):
 
     Place a single space around binary operators `+,-,*,%,/,//`, no space
         around `**`, single newlines and single spaces.
+        No space after `(` or before `)`.
+        No space at the beginning or ending of a line.
     """
     expression = operators_spacer.sub(spaced_operators, expression)
     expression = operators_space_remover.sub(non_spaced_operators, expression)
+    for regex in parentheses_regex_list:
+        expression = regex['pattern'].sub(regex['replace'], expression)
     expression = multiple_newlines_regex.sub('\n', expression)
     expression = multiple_spaces_regex.sub(' ', expression)
+    expression = expression.replace('\n ', '\n')
+    expression = expression.replace(' \n', '\n')
     return expression
 
 

From e3cde032badcc5e69d725c2fdf47a6579be83c70 Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Tue, 19 May 2020 15:20:23 +0200
Subject: [PATCH 8/9] Small fixes in calculation command

- Consider `_` as a digit when prettifying expressions
- Shorten buffer time for calculation sessions
- Redundant escape
---
 davtelepot/useful_tools.py | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/davtelepot/useful_tools.py b/davtelepot/useful_tools.py
index 9b7d0f5..28cf048 100644
--- a/davtelepot/useful_tools.py
+++ b/davtelepot/useful_tools.py
@@ -184,16 +184,16 @@ def get_operators() -> dict:
 calc_buttons = get_calc_buttons()
 operators = get_operators()
 
-operators_spacer = re.compile(r"([\d\(\)])\s*([+\-*%]|/{1,2})\s*([\d\(\)])")
+operators_spacer = re.compile(r"([\d()_])\s*([+\-*%]|/{1,2})\s*([\d()_])")
 spaced_operators = r"\1 \2 \3"
-operators_space_remover = re.compile(r"([\d\(\)])\s*(\*\*)\s*([\d\(\)])")
+operators_space_remover = re.compile(r"([\d()_])\s*(\*\*)\s*([\d()_])")
 non_spaced_operators = r"\1\2\3"
 multiple_newlines_regex = re.compile(r"[\n|\r][\n|\s]{2,}")
 multiple_spaces_regex = re.compile(r"[^\S\n\r]{2,}")
 parentheses_regex_list = [
-    {'pattern': re.compile(r"[^\S\n\r]*(\()[^\S\n\r]*(\d)"),
+    {'pattern': re.compile(r"[^\S\n\r]*(\()[^\S\n\r]*([\d_])"),
      'replace': r" \1\2"},
-    {'pattern': re.compile(r"(\d)[^\S\n\r]*(\))"),
+    {'pattern': re.compile(r"([\d_])[^\S\n\r]*(\))"),
      'replace': r"\1\2"}
 ]
 
@@ -214,7 +214,7 @@ def prettify_expression(expression):
     expression = multiple_spaces_regex.sub(' ', expression)
     expression = expression.replace('\n ', '\n')
     expression = expression.replace(' \n', '\n')
-    return expression
+    return expression.strip(' ')
 
 
 def get_calculator_keyboard(additional_data: list = None):
@@ -360,7 +360,7 @@ def evaluate_expressions(bot: Bot,
 async def calculate_session(bot: Bot,
                             record_id: int,
                             language: str,
-                            buffer_seconds: Union[int, float] = 1):
+                            buffer_seconds: Union[int, float] = .5):
     # Wait until input ends
     queue = bot.shared_data['calc'][record_id]
     queue_len = None

From 7ad4f48de18644488b81949fcf7b06c720e1ee8e Mon Sep 17 00:00:00 2001
From: Davte <davte@libero.it>
Date: Tue, 19 May 2020 15:12:38 +0200
Subject: [PATCH 9/9] Send long text messages as files

---
 davtelepot/__init__.py |  2 +-
 davtelepot/bot.py      | 37 +++++++++++++++++++++++++++++++++++--
 davtelepot/messages.py | 17 +++++++++++++++++
 3 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/davtelepot/__init__.py b/davtelepot/__init__.py
index fd511fd..4565090 100644
--- a/davtelepot/__init__.py
+++ b/davtelepot/__init__.py
@@ -11,7 +11,7 @@ __author__ = "Davide Testa"
 __email__ = "davide@davte.it"
 __credits__ = ["Marco Origlia", "Nick Lee @Nickoala"]
 __license__ = "GNU General Public License v3.0"
-__version__ = "2.5.22"
+__version__ = "2.6.0"
 __maintainer__ = "Davide Testa"
 __contact__ = "t.me/davte"
 
diff --git a/davtelepot/bot.py b/davtelepot/bot.py
index 62f268c..fa4ca7e 100644
--- a/davtelepot/bot.py
+++ b/davtelepot/bot.py
@@ -52,6 +52,7 @@ from aiohttp import web
 from .api import TelegramBot, TelegramError
 from .database import ObjectWithDatabase
 from .languages import MultiLanguageObject
+from .messages import davtelepot_messages
 from .utilities import (
     async_get, escape_html_chars, extract, get_secure_key,
     make_inline_query_answer, make_lines_of_buttons, remove_html_tags
@@ -82,6 +83,7 @@ class Bot(TelegramBot, ObjectWithDatabase, MultiLanguageObject):
     _authorization_denied_message = None
     _unknown_command_message = None
     TELEGRAM_MESSAGES_MAX_LEN = 4096
+    _max_message_length = 3 * (TELEGRAM_MESSAGES_MAX_LEN - 100)
     _default_inline_query_answer = [
         dict(
             type='article',
@@ -120,6 +122,7 @@ class Bot(TelegramBot, ObjectWithDatabase, MultiLanguageObject):
         TelegramBot.__init__(self, token)
         ObjectWithDatabase.__init__(self, database_url=database_url)
         MultiLanguageObject.__init__(self)
+        self.messages['davtelepot'] = davtelepot_messages
         self._path = None
         self.preliminary_tasks = []
         self.final_tasks = []
@@ -128,6 +131,7 @@ class Bot(TelegramBot, ObjectWithDatabase, MultiLanguageObject):
         self._certificate = certificate
         self._max_connections = max_connections
         self._allowed_updates = allowed_updates
+        self._max_message_length = None
         self._session_token = get_secure_key(length=10)
         self._name = None
         self._telegram_id = None
@@ -399,6 +403,17 @@ class Bot(TelegramBot, ObjectWithDatabase, MultiLanguageObject):
         """
         return self._allowed_updates or []
 
+    @property
+    def max_message_length(self) -> int:
+        return self._max_message_length or self.__class__._max_message_length
+
+    @classmethod
+    def set_class_max_message_length(cls, max_message_length: int):
+        cls._max_message_length = max_message_length
+
+    def set_max_message_length(self, max_message_length: int):
+        self._max_message_length = max_message_length
+
     @property
     def name(self):
         """Bot name."""
@@ -1178,6 +1193,8 @@ class Bot(TelegramBot, ObjectWithDatabase, MultiLanguageObject):
             update = update['message']
         if chat_id is None and 'chat' in update:
             chat_id = self.get_chat_id(update)
+        if user_record is None:
+            user_record = self.db['users'].find_one(telegram_id=chat_id)
         if reply_to_update and 'message_id' in update:
             reply_to_message_id = update['message_id']
         if (
@@ -1195,13 +1212,29 @@ class Bot(TelegramBot, ObjectWithDatabase, MultiLanguageObject):
             return
         parse_mode = str(parse_mode)
         if isinstance(text, dict):
-            if user_record is None:
-                user_record = self.db['users'].find_one(telegram_id=chat_id)
             text = self.get_message(
                 update=update,
                 user_record=user_record,
                 messages=text
             )
+        if len(text) > self.max_message_length:
+            message_file = io.StringIO(text)
+            message_file.name = self.get_message(
+                'davtelepot', 'long_message', 'file_name',
+                update=update,
+                user_record=user_record,
+            )
+            return await self.send_document(
+                chat_id=chat_id,
+                document=message_file,
+                caption=self.get_message(
+                    'davtelepot', 'long_message', 'caption',
+                    update=update,
+                    user_record=user_record,
+                ),
+                use_stored_file_id=False,
+                parse_mode='HTML'
+            )
         text_chunks = self.split_message_text(
             text=text,
             limit=self.__class__.TELEGRAM_MESSAGES_MAX_LEN - 100,
diff --git a/davtelepot/messages.py b/davtelepot/messages.py
index a7247be..c54b016 100644
--- a/davtelepot/messages.py
+++ b/davtelepot/messages.py
@@ -1,5 +1,22 @@
 """Default messages for bot functions."""
 
+davtelepot_messages = {
+    'long_message': {
+        'file_name': {
+            'en': "Long message.html",
+            'it': "Messaggio lungo.html",
+        },
+        'caption': {
+            'en': "<b>Long message</b>\n\n"
+                  "This message is too long to be sent as individual "
+                  "messages.",
+            'it': "<b>Messaggio lungo</b>\n\n"
+                  "Questo messaggio è troppo lungo per essere inviato come "
+                  "messaggi separati.",
+        }
+    }
+}
+
 default_admin_messages = {
     'cancel': {
         'button': {