"""
Database connection and session management.

PostgreSQL via asyncpg + SQLAlchemy async.
"""

from datetime import datetime

from sqlalchemy import (
    JSON,
    Column,
    DateTime,
    Float,
    Integer,
    String,
    Text,
    func,
)
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
from sqlalchemy.orm import DeclarativeBase

from config import get_settings


class Base(DeclarativeBase):
    """SQLAlchemy declarative base for all ORM models."""

    pass


# ============================================================
# ORM Models
# ============================================================


class CallRecord(Base):
    __tablename__ = "call_records"

    id = Column(String, primary_key=True)
    direction = Column(String, nullable=False)  # inbound / outbound
    remote_number = Column(String, index=True, nullable=False)
    status = Column(String, nullable=False)  # completed / missed / failed / active / on_hold
    mode = Column(String, nullable=False)  # direct / hold_slayer / ai_assisted
    intent = Column(Text)  # What the user wanted (for hold_slayer)
    started_at = Column(DateTime, default=func.now())
    ended_at = Column(DateTime, nullable=True)
    duration = Column(Integer, default=0)  # seconds
    hold_time = Column(Integer, default=0)  # seconds spent on hold
    device_used = Column(String)
    recording_path = Column(String, nullable=True)
    transcript = Column(Text, nullable=True)
    summary = Column(Text, nullable=True)
    action_items = Column(JSON, nullable=True)
    sentiment = Column(String, nullable=True)
    call_flow_id = Column(String, nullable=True)  # which flow was used
    classification_timeline = Column(JSON, nullable=True)  # [{time, type, confidence}, ...]
    metadata_ = Column("metadata", JSON, nullable=True)

    def __repr__(self) -> str:
        return f"<CallRecord {self.id} {self.remote_number} {self.status}>"


class StoredCallFlow(Base):
    __tablename__ = "call_flows"

    id = Column(String, primary_key=True)
    name = Column(String, nullable=False)
    phone_number = Column(String, index=True, nullable=False)
    description = Column(Text)
    steps = Column(JSON, nullable=False)  # Serialized list[CallFlowStep]
    last_verified = Column(DateTime, nullable=True)
    avg_hold_time = Column(Integer, nullable=True)
    success_rate = Column(Float, nullable=True)
    times_used = Column(Integer, default=0)
    last_used = Column(DateTime, nullable=True)
    notes = Column(Text, nullable=True)
    tags = Column(JSON, default=list)
    created_at = Column(DateTime, default=func.now())
    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())

    def __repr__(self) -> str:
        return f"<StoredCallFlow {self.id} {self.phone_number}>"


class Contact(Base):
    __tablename__ = "contacts"

    id = Column(String, primary_key=True)
    name = Column(String, nullable=False)
    phone_numbers = Column(JSON, nullable=False)  # [{number, label, primary}, ...]
    category = Column(String)  # personal / business / service
    routing_preference = Column(String, nullable=True)  # how to handle their calls
    notes = Column(Text, nullable=True)
    call_count = Column(Integer, default=0)
    last_call = Column(DateTime, nullable=True)
    created_at = Column(DateTime, default=func.now())
    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())

    def __repr__(self) -> str:
        return f"<Contact {self.id} {self.name}>"


class Device(Base):
    __tablename__ = "devices"

    id = Column(String, primary_key=True)
    name = Column(String, nullable=False)  # "Office SIP Phone"
    type = Column(String, nullable=False)  # sip_phone / cell / tablet / softphone
    sip_uri = Column(String, nullable=True)  # sip:robert@gateway.helu.ca
    phone_number = Column(String, nullable=True)  # For PSTN devices
    priority = Column(Integer, default=10)  # Routing priority (lower = higher priority)
    is_online = Column(String, default="false")
    capabilities = Column(JSON, default=list)  # ["voice", "video", "sms"]
    last_seen = Column(DateTime, nullable=True)
    created_at = Column(DateTime, default=func.now())
    updated_at = Column(DateTime, default=func.now(), onupdate=func.now())

    def __repr__(self) -> str:
        return f"<Device {self.id} {self.name} ({self.type})>"


# ============================================================
# Engine & Session
# ============================================================

_engine = None
_session_factory = None


def get_engine():
    """Get or create the async engine."""
    global _engine
    if _engine is None:
        settings = get_settings()
        _engine = create_async_engine(
            settings.database_url,
            echo=settings.debug,
            pool_size=10,
            max_overflow=20,
        )
    return _engine


def get_session_factory() -> async_sessionmaker[AsyncSession]:
    """Get or create the session factory."""
    global _session_factory
    if _session_factory is None:
        _session_factory = async_sessionmaker(
            get_engine(),
            class_=AsyncSession,
            expire_on_commit=False,
        )
    return _session_factory


async def get_db() -> AsyncSession:
    """Dependency: yield an async database session."""
    factory = get_session_factory()
    async with factory() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise


async def init_db():
    """Create all tables. For development; use Alembic migrations in production."""
    engine = get_engine()
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)


async def close_db():
    """Close the database engine."""
    global _engine, _session_factory
    if _engine is not None:
        await _engine.dispose()
        _engine = None
        _session_factory = None