Add guild model (#50)

# Description

### Context
In order to improve the system we'll go back to using a database that can be accessed easily from different places. The previous Sqlite3 database will be used just as "cache" on the bot, while MongoDB will be set up to be used widely.
### This diff
* Add handler to interact with the database
* Add Guild Model again on MongoDB

# Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [ ] Documentation update

# How Has This Been Tested?

Locally tested and added unit tests

# Checklist:

- [x] I have commented my code, particularly in hard-to-understand areas
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my feature works

otter_welcome_buddy/cogs/events.py

@@ -5,8 +5,11 @@
 from discord.ext.commands import Bot
 
 from otter_welcome_buddy.common.constants import OTTER_ROLE
+from otter_welcome_buddy.database.handlers.db_guild_handler import DbGuildHandler
+from otter_welcome_buddy.database.models.external.guild_model import GuildModel
 from otter_welcome_buddy.formatters import debug
 from otter_welcome_buddy.settings import WELCOME_MESSAGES
+from otter_welcome_buddy.startup.database import init_guild_table
 
 
 logger = logging.getLogger(__name__)
@@ -26,8 +29,22 @@ def __init__(
     @commands.Cog.listener()
     async def on_ready(self) -> None:
         """Ready Event"""
+        init_guild_table(self.bot)
+
         logger.info(self.debug_formatter.bot_is_ready())
 
+    @commands.Cog.listener()
+    async def on_guild_join(self, guild: discord.Guild) -> None:
+        """Event fired when a guild is either created or the bot join into"""
+        if DbGuildHandler.get_guild(guild_id=guild.id) is None:
+            guild_model: GuildModel = GuildModel(guild_id=guild.id)
+            DbGuildHandler.insert_guild(guild_model=guild_model)
+
+    @commands.Cog.listener()
+    async def on_guild_remove(self, guild: discord.Guild) -> None:
+        """Event fired when a guild is deleted or the bot is removed from it"""
+        DbGuildHandler.delete_guild(guild_id=guild.id)
+
     @commands.Cog.listener()
     async def on_raw_reaction_add(self, payload: discord.RawReactionActionEvent) -> None:
         """Event fired when a user react to the welcome message, giving the entry role to him"""

otter_welcome_buddy/database/handlers/db_guild_handler.py

@@ -0,0 +1,29 @@
+from mongoengine import DoesNotExist
+
+from otter_welcome_buddy.database.models.external.guild_model import GuildModel
+
+
+class DbGuildHandler:
+    """Class to interact with the table guild via static methods"""
+
+    @staticmethod
+    def get_guild(guild_id: int) -> GuildModel | None:
+        """Static method to get a guild by its id"""
+        try:
+            guild_model: GuildModel = GuildModel.objects(guild_id=guild_id).get()
+            return guild_model
+        except DoesNotExist:
+            return None
+
+    @staticmethod
+    def insert_guild(guild_model: GuildModel) -> GuildModel:
+        """Static method to insert a guild record"""
+        guild_model = guild_model.save()
+        return guild_model
+
+    @staticmethod
+    def delete_guild(guild_id: int) -> None:
+        """Static method to delete an interview match record by a guild_id"""
+        guild_model: GuildModel | None = GuildModel.objects(guild_id=guild_id).first()
+        if guild_model:
+            guild_model.delete()

otter_welcome_buddy/database/models/external/guild_model.py

@@ -0,0 +1,14 @@
+from mongoengine import Document
+from mongoengine import IntField
+
+
+class GuildModel(Document):
+    """
+    A model that represents a guild (server) in the database.
+
+    Attributes:
+        guild_id (int): The identifier for the guild, is taken from discord records and is
+                        the primary key of the object
+    """
+
+    guild_id = IntField(primary_key=True, required=True)

otter_welcome_buddy/startup/database.py

@@ -1,15 +1,26 @@
 import os
 
+from discord.ext.commands import Bot
 from dotenv import load_dotenv
 from mongoengine import connect as mongo_connect
 from pymongo import monitoring
 
 from otter_welcome_buddy.common.constants import DATA_FILE_PATH
 from otter_welcome_buddy.common.utils.database import get_cache_engine
 from otter_welcome_buddy.database.dbconn import BaseModel
+from otter_welcome_buddy.database.handlers.db_guild_handler import DbGuildHandler
+from otter_welcome_buddy.database.models.external.guild_model import GuildModel
 from otter_welcome_buddy.log.dblogger import DbCommandLogger
 
 
+def init_guild_table(bot: Bot) -> None:
+    """Verify that all the guilds that the bot is part of are in the database"""
+    for guild in bot.guilds:
+        if DbGuildHandler.get_guild(guild_id=guild.id) is None:
+            guild_model: GuildModel = GuildModel(guild_id=guild.id)
+            DbGuildHandler.insert_guild(guild_model=guild_model)
+
+
 async def init_database() -> None:
     """Initialize the database from the existing models"""
     load_dotenv()

tests/cogs/test_events.py

@@ -12,6 +12,8 @@
 from pytest_mock import MockFixture
 
 from otter_welcome_buddy.cogs import events
+from otter_welcome_buddy.database.handlers.db_guild_handler import DbGuildHandler
+from otter_welcome_buddy.database.models.external.guild_model import GuildModel
 
 if TYPE_CHECKING:
     from discord.types.gateway import MessageReactionAddEvent
@@ -77,3 +79,58 @@ async def test_onRawReactionAdd_addRole(
     # Assert
     mock_get_role.assert_called_once()
     mock_add_roles.assert_called_once()
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("is_new_guild", [True, False])
+async def test_onGuildJoin_insertDb(
+    mocker: MockFixture,
+    mock_bot: Bot,
+    mock_guild: Guild,
+    mock_debug_fmt,
+    mock_guild_model: GuildModel,
+    is_new_guild: bool,
+):
+    # Arrange
+    mock_guild.id = 111
+    mock_bot.guilds = [mock_guild]
+    cog = events.BotEvents(mock_bot, mock_debug_fmt)
+
+    mock_get_guild = mocker.patch.object(
+        DbGuildHandler,
+        "get_guild",
+        return_value=None if is_new_guild else mock_guild_model,
+    )
+    mock_insert_guild = mocker.patch.object(DbGuildHandler, "insert_guild")
+
+    # Act
+    await cog.on_guild_join(mock_guild)
+
+    # Assert
+    mock_get_guild.assert_called_once_with(guild_id=mock_guild.id)
+    if is_new_guild:
+        mock_insert_guild.assert_called_once()
+    else:
+        mock_insert_guild.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_onGuildRemove_deleteDb(
+    mocker: MockFixture,
+    mock_bot: Bot,
+    mock_guild: Guild,
+    mock_debug_fmt,
+    mock_guild_model: GuildModel,
+):
+    # Arrange
+    mock_guild.id = mock_guild_model.id
+    mock_bot.guilds = [mock_guild]
+    cog = events.BotEvents(mock_bot, mock_debug_fmt)
+
+    mock_delete_guild = mocker.patch.object(DbGuildHandler, "delete_guild")
+
+    # Act
+    await cog.on_guild_remove(mock_guild)
+
+    # Assert
+    mock_delete_guild.assert_called_once_with(guild_id=mock_guild.id)

tests/conftest.py

@@ -8,6 +8,11 @@
 from discord import Member
 from discord import Role
 from discord.ext.commands import Bot
+from mongoengine import connect as mongo_connect
+from mongoengine import disconnect as mongo_disconnect
+from mongomock import MongoClient
+
+from otter_welcome_buddy.database.models.external.guild_model import GuildModel
 
 
 @pytest.fixture
@@ -60,3 +65,23 @@ def temporary_cache():
     yield db_path
     if os.path.exists(db_path):
         os.remove(db_path)
+
+
+@pytest.fixture()
+def temporary_mongo_connection():
+    mock_mongo_connection = mongo_connect(
+        "mongoenginetest",
+        host="mongodb://localhost",
+        mongo_client_class=MongoClient,
+    )
+    yield mock_mongo_connection
+    mongo_disconnect()
+
+
+@pytest.fixture()
+def mock_guild_model(temporary_mongo_connection) -> GuildModel:
+    mock_guild_model = GuildModel(
+        guild_id=123,
+    )
+    mock_guild_model.save()
+    return mock_guild_model

tests/database/handlers/test_db_guild_handler.py

@@ -0,0 +1,80 @@
+import pytest
+from mongoengine import DoesNotExist
+from mongoengine import ValidationError
+from mongomock import MongoClient
+
+from otter_welcome_buddy.database.handlers.db_guild_handler import DbGuildHandler
+from otter_welcome_buddy.database.models.external.guild_model import GuildModel
+
+
+def test_get_guild_succeed(temporary_mongo_connection: MongoClient) -> None:
+    # Arrange
+    mocked_guild_id: int = 123
+    mocked_guild_model: GuildModel = GuildModel(
+        guild_id=mocked_guild_id,
+    )
+    mocked_guild_model.save()
+
+    # Act
+    result = DbGuildHandler.get_guild(guild_id=mocked_guild_id)
+
+    # Assert
+    assert result is not None
+    assert result.id == mocked_guild_id
+
+
+def test_get_guild_not_found(temporary_mongo_connection: MongoClient) -> None:
+    # Act
+    result = DbGuildHandler.get_guild(guild_id=123)
+
+    # Assert
+    assert result is None
+
+
+def test_insert_guild_succeed(temporary_mongo_connection: MongoClient) -> None:
+    # Arrange
+    mocked_guild_id: int = 123
+    mocked_guild_model: GuildModel = GuildModel(
+        guild_id=mocked_guild_id,
+    )
+
+    # Act
+    result = DbGuildHandler.insert_guild(guild_model=mocked_guild_model)
+
+    # Assert
+    assert result is not None
+    assert result.id == mocked_guild_id
+
+
+def test_insert_guild_failed(temporary_mongo_connection: MongoClient) -> None:
+    # Arrange
+    mocked_guild_model: GuildModel = GuildModel()
+
+    # Act / Assert
+    with pytest.raises(ValidationError):
+        DbGuildHandler.insert_guild(guild_model=mocked_guild_model)
+
+
+def test_delete_guild_valid_id(temporary_mongo_connection: MongoClient) -> None:
+    # Arrange
+    mocked_guild_id: int = 123
+    mocked_guild_model: GuildModel = GuildModel(
+        guild_id=mocked_guild_id,
+    )
+    mocked_guild_model.save()
+
+    # Act
+    DbGuildHandler.delete_guild(guild_id=mocked_guild_id)
+
+    # Assert
+    with pytest.raises(DoesNotExist):
+        GuildModel.objects(guild_id=mocked_guild_id).get()
+
+
+def test_delete_guild_invalid_id(temporary_mongo_connection: MongoClient) -> None:
+    # Act
+    DbGuildHandler.delete_guild(guild_id=123)
+
+    # Assert
+    with pytest.raises(DoesNotExist):
+        GuildModel.objects(guild_id=123).get()