Initial MCM project: FastAPI + Textual TUI unified messenger

MultiCustomerMessenger supporting Telegram (python-telegram-bot),
WhatsApp (Green API) and SMS (python-gsmmodem-new). REST API with
Bearer-token auth, SQLAlchemy models for MariaDB, APScheduler for
background polling, and Textual TUI running in same asyncio event-loop.

db/database.py

@@ -0,0 +1,38 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import DeclarativeBase, sessionmaker
+from sqlalchemy.pool import StaticPool
+from config import settings
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+_connect_args = {}
+_pool_class = None
+
+if settings.database_url.startswith("sqlite"):
+    _connect_args = {"check_same_thread": False}
+    _pool_class = StaticPool
+
+engine = create_engine(
+    settings.database_url,
+    connect_args=_connect_args,
+    **({"poolclass": _pool_class} if _pool_class else {}),
+    echo=settings.debug,
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+
+def init_db() -> None:
+    from db import models  # noqa: F401 – Modelle müssen importiert sein
+    Base.metadata.create_all(bind=engine)

db/models.py

@@ -0,0 +1,144 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import (
+    Boolean,
+    Column,
+    DateTime,
+    Enum,
+    ForeignKey,
+    Index,
+    Integer,
+    String,
+    Table,
+    Text,
+)
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from db.database import Base
+
+
+def _uuid() -> str:
+    return str(uuid.uuid4())
+
+
+# ── Many-to-many: Conversation ↔ Contact ──────────────────────────────────────
+conversation_participants = Table(
+    "conversation_participants",
+    Base.metadata,
+    Column("conversation_id", String, ForeignKey("conversations.id", ondelete="CASCADE")),
+    Column("contact_id", String, ForeignKey("contacts.id", ondelete="CASCADE")),
+)
+
+
+# ── Contact ────────────────────────────────────────────────────────────────────
+class Contact(Base):
+    __tablename__ = "contacts"
+
+    id = Column(String, primary_key=True, default=_uuid)
+    name = Column(String(255), nullable=False, index=True)
+    phone = Column(String(32), nullable=True, unique=True)
+    email = Column(String(255), nullable=True)
+    telegram_id = Column(String(64), nullable=True, unique=True)
+    telegram_username = Column(String(255), nullable=True)
+    whatsapp_phone = Column(String(32), nullable=True)
+    notes = Column(Text, nullable=True)
+    created_at = Column(DateTime, default=func.now(), nullable=False)
+    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())
+
+    conversations = relationship(
+        "Conversation",
+        secondary=conversation_participants,
+        back_populates="participants",
+    )
+    messages_sent = relationship(
+        "Message",
+        back_populates="sender",
+        foreign_keys="Message.sender_id",
+    )
+
+
+# ── Conversation ───────────────────────────────────────────────────────────────
+class Conversation(Base):
+    __tablename__ = "conversations"
+
+    id = Column(String, primary_key=True, default=_uuid)
+    channel = Column(
+        Enum("telegram", "whatsapp", "sms", name="channel_type"),
+        nullable=False,
+        index=True,
+    )
+    channel_conversation_id = Column(String(255), nullable=True)
+    title = Column(String(255), nullable=True)
+    is_group = Column(Boolean, default=False, nullable=False)
+    is_archived = Column(Boolean, default=False, nullable=False)
+    last_message_at = Column(DateTime, nullable=True)
+    created_at = Column(DateTime, default=func.now(), nullable=False)
+    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())
+
+    participants = relationship(
+        "Contact",
+        secondary=conversation_participants,
+        back_populates="conversations",
+    )
+    messages = relationship(
+        "Message",
+        back_populates="conversation",
+        cascade="all, delete-orphan",
+        order_by="Message.created_at",
+    )
+
+    __table_args__ = (
+        Index("idx_conv_channel_native", "channel", "channel_conversation_id"),
+    )
+
+
+# ── Message ────────────────────────────────────────────────────────────────────
+class Message(Base):
+    __tablename__ = "messages"
+
+    id = Column(String, primary_key=True, default=_uuid)
+    conversation_id = Column(
+        String, ForeignKey("conversations.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    sender_id = Column(String, ForeignKey("contacts.id"), nullable=True)
+
+    channel = Column(
+        Enum("telegram", "whatsapp", "sms", name="channel_type"),
+        nullable=False,
+        index=True,
+    )
+    channel_message_id = Column(String(255), nullable=True)
+    direction = Column(
+        Enum("inbound", "outbound", name="message_direction"),
+        nullable=False,
+        default="outbound",
+    )
+    text = Column(Text, nullable=False)
+    status = Column(
+        Enum("pending", "sent", "delivered", "read", "failed", name="message_status"),
+        default="pending",
+        nullable=False,
+        index=True,
+    )
+
+    reply_to_id = Column(String, ForeignKey("messages.id"), nullable=True)
+    is_edited = Column(Boolean, default=False, nullable=False)
+    error_message = Column(Text, nullable=True)
+    retry_count = Column(Integer, default=0, nullable=False)
+
+    created_at = Column(DateTime, default=func.now(), nullable=False, index=True)
+    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())
+    sent_at = Column(DateTime, nullable=True)
+    delivered_at = Column(DateTime, nullable=True)
+    read_at = Column(DateTime, nullable=True)
+
+    conversation = relationship("Conversation", back_populates="messages")
+    sender = relationship("Contact", back_populates="messages_sent", foreign_keys=[sender_id])
+    reply_to = relationship("Message", remote_side="Message.id", backref="replies")
+
+    __table_args__ = (
+        Index("idx_msg_channel_native", "channel", "channel_message_id"),
+        Index("idx_msg_conv_created", "conversation_id", "created_at"),
+    )