diff --git a/.gitignore b/.gitignore
index c41509d..abf027c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 settings.py
+tests.py
 
 # Byte-compiled / optimized / DLL files
 __pycache__/
diff --git a/bot.py b/bot.py
index 385509a..668e26e 100644
--- a/bot.py
+++ b/bot.py
@@ -1,7 +1,17 @@
 import logging
-from telegram.ext import Updater
+from telegram.ext import (CommandHandler, MessageHandler, Filters, Updater,
+                          ConversationHandler)
 import settings
 
+from calorie_calculation import (calorie_calculation_start, target_selection, target_weight,
+                                 сalculate_сalorie_сount)
+
+from questionnaire import (questionnaire_start, questionnaire_gender, questionnaire_age,
+                           questionnaire_height, questionnaire_current_weight, level_of_physical_activity,
+                           data_validation, questionnaire_dontknow)
+
+from handlers import greet_user, unknown_command
+
 logging.basicConfig(filename="bot.log", format='%(asctime)s - %(message)s',
                     datefmt='%d-%b-%y %H:%M:%S', level=logging.INFO)
 
@@ -11,6 +21,46 @@ def main():
 
     dp = bot.dispatcher
 
+    questionnaire = ConversationHandler(
+        entry_points=[
+            MessageHandler(Filters.regex('^(Заполнить данные)|^(Да, заполнить данные снова)'), questionnaire_start)
+            ],
+        states={
+            "gender": [MessageHandler(Filters.text, questionnaire_gender)],
+            "age": [MessageHandler(Filters.text, questionnaire_age)],
+            "height": [MessageHandler(Filters.text, questionnaire_height)],
+            "current_weight": [MessageHandler(Filters.text, questionnaire_current_weight)],
+            "level_of_physical_activity": [MessageHandler(Filters.text, level_of_physical_activity)],
+            "data_validation": [MessageHandler(Filters.text, data_validation)]
+        },
+        fallbacks=[
+            MessageHandler(Filters.video | Filters.photo | Filters.document | Filters.location,
+                           questionnaire_dontknow)
+        ]
+    )
+
+    calorie_calculation = ConversationHandler(
+        entry_points=[
+            MessageHandler(Filters.regex('^(Расчёт калорий)'), calorie_calculation_start)
+            ],
+        states={
+            "target_selection": [MessageHandler(Filters.text, target_selection)],
+            "target_weight": [MessageHandler(Filters.text, target_weight)],
+            "сalculate_сalorie_сount": [MessageHandler(Filters.text, сalculate_сalorie_сount)]
+            },
+        fallbacks=[
+            MessageHandler(Filters.video | Filters.photo | Filters.document | Filters.location,
+                           questionnaire_dontknow)
+        ]
+    )
+
+    dp.add_handler(questionnaire)
+    dp.add_handler(calorie_calculation)
+    dp.add_handler(CommandHandler("start", greet_user))
+    dp.add_handler(MessageHandler(
+        Filters.text | Filters.video | Filters.photo | Filters.document | Filters.location,
+        unknown_command))
+
     logging.info("bot started")
     bot.start_polling()
     bot.idle()
diff --git a/calorie_calculation.py b/calorie_calculation.py
new file mode 100644
index 0000000..53c9da4
--- /dev/null
+++ b/calorie_calculation.py
@@ -0,0 +1,87 @@
+from untils import (emoji_to_the_number_of, initial_keyboard, calorie_сalculation,
+                    activity_level_multiplier, keypad_with_weight_selection, keypad_with_target_selection,
+                    main_keyboard)
+from telegram.ext import ConversationHandler
+from db import db, get_or_create_user, add_or_replace_something
+
+
+def calorie_calculation_start(update, context):
+    user = get_or_create_user(db, update.effective_user, update.message.chat.id)
+    if 'questionnaire' not in user:
+        update.message.reply_text("Чтобы расчитать калорий нужно заполнить данные!",
+                                  reply_markup=initial_keyboard())
+        return ConversationHandler.END
+    update.message.reply_text("Укажите вашу цель",
+                              reply_markup=keypad_with_target_selection())
+    return "target_selection"
+
+
+def target_selection(update, context):
+    user_response = update.message.text
+    if "Сбросить вес" in user_response:
+        update.message.reply_text("Сколько кг вы хотите сбросить? Нажмите на кнопку или введите число с клавиатуры",
+                                  reply_markup=keypad_with_weight_selection())
+        context.user_data["calorie_calculation"] = {"change_multiplier": -1}
+        return "target_weight"
+    elif "Набрать вес" in user_response:
+        update.message.reply_text("Сколько кг вы хотите набрать? Нажмите на кнопку или введите число с клавиатуры",
+                                  reply_markup=keypad_with_weight_selection())
+        context.user_data["calorie_calculation"] = {"change_multiplier": 1}
+        return "target_weight"
+    elif "Сохранить вес" in user_response:
+        user = get_or_create_user(db, update.effective_user, update.message.chat.id)
+        current_weight = user["questionnaire"][-1]["current_weight"]
+        context.user_data["calorie_calculation"] = {"target_weight": current_weight}
+        сalculate_сalorie_сount(update, context)
+        return ConversationHandler.END
+    else:
+        update.message.reply_text("Выберите один из вариантов",
+                                  reply_markup=keypad_with_target_selection())
+        return "target_selection"
+
+
+def target_weight(update, context):
+    user = get_or_create_user(db, update.effective_user, update.message.chat.id)
+    current_weight = user["questionnaire"][-1]["current_weight"]
+    change_multiplier = context.user_data["calorie_calculation"]["change_multiplier"]
+    user_response = update.message.text
+
+    if user_response.isdigit():
+        delta_weight = int(user_response)
+        target_weight = current_weight + change_multiplier*delta_weight
+    elif emoji_to_the_number_of(user_response).isdigit():
+        delta_weight = int(emoji_to_the_number_of(user_response))
+        target_weight = current_weight + change_multiplier*delta_weight
+    else:
+        update.message.reply_text("Введите целое число кг", reply_markup=keypad_with_weight_selection())
+        return "target_weight"
+
+    if target_weight < 0:
+        update.message.reply_text("Желаемый вес меньше нуля", reply_markup=keypad_with_weight_selection())
+        return "target_weight"
+    else:
+        context.user_data["calorie_calculation"]["target_weight"] = target_weight
+        сalculate_сalorie_сount(update, context)
+        return ConversationHandler.END
+
+
+def сalculate_сalorie_сount(update, context):
+    user = get_or_create_user(db, update.effective_user, update.message.chat.id)
+    user_data = user["questionnaire"][-1]
+
+    gender = user_data["gender"]
+    age = user_data["age"]
+    height = user_data["height"]
+    weight = context.user_data["calorie_calculation"]["target_weight"]
+    level_of_physical_activity = user_data["level_of_physical_activity"]
+    multiplier_activity_level = activity_level_multiplier(level_of_physical_activity)
+
+    calorie_count = calorie_сalculation(
+        gender, age, height, weight, multiplier_activity_level
+    )
+
+    add_or_replace_something(db, user['user_id'], "calorie_count", calorie_count)
+    add_or_replace_something(db, user['user_id'], "target_weight", weight)
+
+    update.message.reply_text(f"Вам нужно потреблять {calorie_count} калорий ежедневно", reply_markup=main_keyboard())
+    
\ No newline at end of file
diff --git a/db.py b/db.py
new file mode 100644
index 0000000..efcab24
--- /dev/null
+++ b/db.py
@@ -0,0 +1,44 @@
+from datetime import datetime
+from pymongo import MongoClient
+import settings
+
+client = MongoClient(settings.MONGO_LINK)
+
+db = client[settings.MONGO_DB]
+
+
+def get_or_create_user(db, effective_user, chat_id):
+    user = db.users.find_one({"user_id": effective_user.id})
+    if not user:
+        user = {
+            "user_id": effective_user.id,
+            "first_name": effective_user.first_name,
+            "last_name": effective_user.last_name,
+            "username": effective_user.username,
+            "chat_id": chat_id
+        }
+        db.users.insert_one(user)
+    return user
+
+
+def save_questionnaire(db, user_id, questionnaire_data):
+    user = db.users.find_one({"user_id": user_id})
+    questionnaire_data['created'] = datetime.now()
+    if 'questionnaire' not in user:
+        db.users.update_one(
+            {'_id': user['_id']},
+            {'$set': {'questionnaire': [questionnaire_data]}}
+        )
+    else:
+        db.users.update_one(
+            {'_id': user['_id']},
+            {'$push': {'questionnaire': questionnaire_data}}
+        )
+
+
+def add_or_replace_something(db, user_id, name, value):
+    user = db.users.find_one({"user_id": user_id})
+    db.users.update_one(
+        {'_id': user['_id']},
+        {'$set': {name: value}}
+        )
diff --git a/handlers.py b/handlers.py
index e69de29..c829ae3 100644
--- a/handlers.py
+++ b/handlers.py
@@ -0,0 +1,19 @@
+from untils import initial_keyboard, main_keyboard, get_emoji
+
+from db import db, get_or_create_user
+
+
+def greet_user(update, context):
+    user = get_or_create_user(db, update.effective_user, update.message.chat.id)
+    if 'questionnaire' not in user:
+        keyboard = initial_keyboard()
+    else:
+        keyboard = main_keyboard()
+    update.message.reply_text(
+        f"Здравствуй {user['first_name']}! {get_emoji('waving_hand')}",
+        reply_markup=keyboard,
+    )
+
+
+def unknown_command(update, context):
+    update.message.reply_text(f"Неизвестная команда {get_emoji('red_question_mark')}", reply_markup=main_keyboard())
diff --git a/questionnaire.py b/questionnaire.py
new file mode 100644
index 0000000..2c28793
--- /dev/null
+++ b/questionnaire.py
@@ -0,0 +1,105 @@
+from telegram import ParseMode, ReplyKeyboardMarkup
+from telegram.ext import ConversationHandler
+from untils import (data_output, gender_selection_button, main_keyboard,
+                    get_emoji, activity_level_selection_button,
+                    list_of_activity_levels)
+from db import db, get_or_create_user, save_questionnaire
+
+
+def questionnaire_start(update, context):
+    update.message.reply_text(
+        "Выберете пол",
+        reply_markup=gender_selection_button()
+    )
+    return "gender"
+
+
+def questionnaire_gender(update, context):
+    user_gender = update.message.text
+    if not ("Мужской" in user_gender or "Женский" in user_gender):
+        update.message.reply_text("Выберете пол")
+        return "gender"
+    else:
+        update.message.reply_text("Введите возраст")
+        context.user_data["questionnaire"] = {"gender": user_gender}
+    return "age"
+
+
+def questionnaire_age(update, context):
+    user_age = update.message.text
+    if user_age.isdigit() is False or user_age == '0':
+        update.message.reply_text("Укажите корректный возраст")
+        return "age"
+    else:
+        update.message.reply_text("Введите рост")
+        context.user_data["questionnaire"]["age"] = int(user_age)
+    return "height"
+
+
+def questionnaire_height(update, context):
+    user_height = update.message.text
+    if user_height.isdigit() is False or user_height == '0':
+        update.message.reply_text("Укажите корректный рост")
+        return "height"
+    else:
+        update.message.reply_text("Введите текущий вес")
+        context.user_data["questionnaire"]["height"] = int(user_height)
+    return "current_weight"
+
+
+def questionnaire_current_weight(update, context):
+    user_weight = update.message.text
+    if user_weight.isdigit() is False or user_weight == '0':
+        update.message.reply_text("Укажите корректный вес")
+        return "current_weight"
+    else:
+        update.message.reply_text(
+            "Выберете уровень физической активности",
+            reply_markup=activity_level_selection_button()
+            )
+        context.user_data["questionnaire"]["current_weight"] = int(user_weight)
+    return "level_of_physical_activity"
+
+
+def level_of_physical_activity(update, context):
+    user_response = update.message.text
+    level_of_physical_activity = [level[0] for level in list_of_activity_levels()]
+    if user_response not in level_of_physical_activity:
+        update.message.reply_text("Выберете уровень физической активности")
+        return "level_of_physical_activity"
+    else:
+        context.user_data["questionnaire"]["level_of_physical_activity"] = user_response
+        user_text = data_output(context)
+        keyboard = [
+            [f"Данные верны {get_emoji('check_mark')}",
+             f"Данные неверны. {get_emoji('cross_mark')}"]
+            ]
+        update.message.reply_text(user_text, parse_mode=ParseMode.HTML,
+                                  reply_markup=ReplyKeyboardMarkup(keyboard, one_time_keyboard=True,
+                                                                   resize_keyboard=True)
+                                  )
+        return "data_validation"
+
+
+def data_validation(update, context):
+    user = get_or_create_user(db, update.effective_user, update.message.chat.id)
+    user_response = update.message.text
+    if "Данные верны" in user_response:
+        save_questionnaire(db, user['user_id'], context.user_data['questionnaire'])
+        update.message.reply_text(f"Ваши данные сохранены {get_emoji('memo')}")
+        update.message.reply_text(f"Изменить данные можно в Профиле {get_emoji('bust_in_silhouette')}",
+                                  reply_markup=main_keyboard())
+        return ConversationHandler.END
+    else:
+        keyboard = [
+            [f"Да, заполнить данные снова {get_emoji('counterclockwise_arrows_button')}"],
+            [f"Нет. Вернутсья на главную {get_emoji('BACK_arrow')}"]
+            ]
+        update.message.reply_text("Ваши данные не сохранены. Заполнить данные снова?",
+                                  reply_markup=ReplyKeyboardMarkup(keyboard, one_time_keyboard=True,
+                                                                   resize_keyboard=True))
+        return ConversationHandler.END
+
+
+def questionnaire_dontknow(update, context):
+    update.message.reply_text("Некорректные данные(")
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..d1fde19
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,16 @@
+APScheduler==3.6.3
+cachetools==4.2.2
+certifi==2022.12.7
+dnspython==2.3.0
+emoji==0.5.4
+mypy==1.1.1
+mypy-extensions==1.0.0
+pymongo==4.3.3
+python-telegram-bot==13.14
+pytz==2022.7.1
+pytz-deprecation-shim==0.1.0.post0
+six==1.16.0
+tornado==6.1
+typing_extensions==4.5.0
+tzdata==2022.7
+tzlocal==4.2
\ No newline at end of file
diff --git a/untils.py b/untils.py
index e69de29..f4d72b2 100644
--- a/untils.py
+++ b/untils.py
@@ -0,0 +1,98 @@
+from telegram import ReplyKeyboardMarkup
+from emoji import emojize
+
+
+def list_of_activity_levels():
+    return [
+            [f"Минимальный {get_emoji('yawning_face')}"],
+            [f"Низкий {get_emoji('flushed_face')}"],
+            [f"Умеренный {get_emoji('smiling_face_with_sunglasses')}"],
+            [f"Высокий {get_emoji('face_with_steam_from_nose')}"],
+            [f"Экстремальный {get_emoji('smiling_face_with_horns')}"]
+        ]
+
+
+def activity_level_multiplier(level):
+    if level == f"Минимальный {get_emoji('yawning_face')}":
+        return 1.2
+    elif level == f"Низкий {get_emoji('flushed_face')}":
+        return 1.375
+    elif level == f"Умеренный {get_emoji('smiling_face_with_sunglasses')}":
+        return 1.55
+    elif level == f"Высокий {get_emoji('face_with_steam_from_nose')}":
+        return 1.7
+    return 1.9
+
+
+def calorie_сalculation(gender: str, age: int, height: int, weight: int, activity_level_multiplier: float) -> int:
+    if "Женский" in gender:
+        calorie_count = 655.1 + (9.563*weight) + (1.85*height) - (4.676*age)
+        return calorie_count
+    calorie_count = 66.5 + (13.75*weight) + (5.003*height) - (6.775*age)
+    return int(calorie_count)
+
+
+def initial_keyboard():
+    return ReplyKeyboardMarkup([[f"Заполнить данные {get_emoji('pencil')}"], [f"Расчёт калорий {get_emoji('abacus')}"],
+                                [f"Пищевая ценность {get_emoji('fire')}", f"Дейли рацион {get_emoji('receipt')}"],
+                                [f"Рецепт блюда {get_emoji('man_cook')}", f"Профиль {get_emoji('bust_in_silhouette')}"]
+                                ])
+
+
+def main_keyboard():
+    return ReplyKeyboardMarkup([[f"Расчёт калорий {get_emoji('abacus')}"],
+                                [f"Пищевая ценность {get_emoji('fire')}", f"Дейли рацион {get_emoji('receipt')}"],
+                                [f"Рецепт блюда {get_emoji('man_cook')}", f"Профиль {get_emoji('bust_in_silhouette')}"]
+                                ])
+
+
+def gender_selection_button():
+    return ReplyKeyboardMarkup([
+        [f"Мужской {get_emoji('man')}", f"Женский {get_emoji('woman')}"]
+        ], one_time_keyboard=True, resize_keyboard=True)
+
+
+def activity_level_selection_button():
+    buttons = list_of_activity_levels()
+    return ReplyKeyboardMarkup(buttons, one_time_keyboard=True)
+
+
+def get_emoji(emoji_name: str):
+    return emojize(f":{emoji_name}:")
+
+
+def data_output(context):
+    text = f"""<b>Пол</b>: {context.user_data['questionnaire']['gender']}
+<b>Возраст</b>: {context.user_data['questionnaire']['age']}
+<b>Рост</b>: {context.user_data['questionnaire']['height']}
+<b>Текцщий вес</b>: {context.user_data['questionnaire']['current_weight']}
+<b>Уровень физической активности</b>: {context.user_data['questionnaire']['level_of_physical_activity']}
+"""
+    return text
+
+
+def emoji_to_the_number_of(emoji):
+    if f"{get_emoji('keycap_2')}{get_emoji('keycap_0')}" in emoji:
+        return "20"
+    elif f"{get_emoji('keycap_1')}{get_emoji('keycap_5')}" in emoji:
+        return "15"
+    elif f"{get_emoji('keycap_1')}{get_emoji('keycap_0')}" in emoji:
+        return "10"
+    elif f"{get_emoji('keycap_5')}" in emoji:
+        return "5"
+    return "unknown emoji or missing emoji"
+
+
+def keypad_with_weight_selection():
+    return ReplyKeyboardMarkup([
+        [f"{get_emoji('keycap_5')} кг", f"{get_emoji('keycap_1')}{get_emoji('keycap_0')} кг"],
+        [f"{get_emoji('keycap_1')}{get_emoji('keycap_5')} кг", f"{get_emoji('keycap_2')}{get_emoji('keycap_0')} кг"]
+        ], one_time_keyboard=True, resize_keyboard=True)
+
+
+def keypad_with_target_selection():
+    return ReplyKeyboardMarkup([
+            [f"Сбросить вес {get_emoji('down_arrow')}"],
+            [f"Набрать вес {get_emoji('up_arrow')}"],
+            [f"Сохранить вес {get_emoji('left-right arrow')}"]
+        ], one_time_keyboard=True, resize_keyboard=True)