"""
SQLite database ORM using SQLAlchemy.
"""

from sqlalchemy import create_engine, Column, String, Integer, Float, DateTime, Text, ForeignKey, Boolean
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, Session
from datetime import datetime
import uuid
from pathlib import Path

from . import config

Base = declarative_base()


class VoiceProfile(Base):
    """Voice profile database model."""
    __tablename__ = "profiles"
    
    id = Column(String, primary_key=True, default=lambda: str(uuid.uuid4()))
    name = Column(String, unique=True, nullable=False)
    description = Column(Text)
    language = Column(String, default="en")
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)


class ProfileSample(Base):
    """Voice profile sample database model."""
    __tablename__ = "profile_samples"
    
    id = Column(String, primary_key=True, default=lambda: str(uuid.uuid4()))
    profile_id = Column(String, ForeignKey("profiles.id"), nullable=False)
    audio_path = Column(String, nullable=False)
    reference_text = Column(Text, nullable=False)


class Generation(Base):
    """Generation history database model."""
    __tablename__ = "generations"

    id = Column(String, primary_key=True, default=lambda: str(uuid.uuid4()))
    profile_id = Column(String, ForeignKey("profiles.id"), nullable=False)
    text = Column(Text, nullable=False)
    language = Column(String, default="en")
    audio_path = Column(String, nullable=False)
    duration = Column(Float, nullable=False)
    seed = Column(Integer)
    instruct = Column(Text)
    created_at = Column(DateTime, default=datetime.utcnow)


class Project(Base):
    """Audio studio project database model."""
    __tablename__ = "projects"
    
    id = Column(String, primary_key=True, default=lambda: str(uuid.uuid4()))
    name = Column(String, nullable=False)
    data = Column(Text)  # JSON string
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)


class AudioChannel(Base):
    """Audio channel (bus) database model."""
    __tablename__ = "audio_channels"
    
    id = Column(String, primary_key=True, default=lambda: str(uuid.uuid4()))
    name = Column(String, nullable=False)
    is_default = Column(Boolean, default=False)
    created_at = Column(DateTime, default=datetime.utcnow)


class ChannelDeviceMapping(Base):
    """Mapping between channels and OS audio devices."""
    __tablename__ = "channel_device_mappings"
    
    id = Column(String, primary_key=True, default=lambda: str(uuid.uuid4()))
    channel_id = Column(String, ForeignKey("audio_channels.id"), nullable=False)
    device_id = Column(String, nullable=False)  # OS device identifier


class ProfileChannelMapping(Base):
    """Mapping between voice profiles and audio channels (many-to-many)."""
    __tablename__ = "profile_channel_mappings"
    
    profile_id = Column(String, ForeignKey("profiles.id"), primary_key=True)
    channel_id = Column(String, ForeignKey("audio_channels.id"), primary_key=True)


# Database setup will be initialized in init_db()
engine = None
SessionLocal = None
_db_path = None


def init_db():
    """Initialize database tables."""
    global engine, SessionLocal, _db_path

    _db_path = config.get_db_path()
    _db_path.parent.mkdir(parents=True, exist_ok=True)

    engine = create_engine(
        f"sqlite:///{_db_path}",
        connect_args={"check_same_thread": False},
    )

    SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
    Base.metadata.create_all(bind=engine)
    
    # Create default channel if it doesn't exist
    db = SessionLocal()
    try:
        default_channel = db.query(AudioChannel).filter(AudioChannel.is_default == True).first()
        if not default_channel:
            default_channel = AudioChannel(
                id=str(uuid.uuid4()),
                name="Default",
                is_default=True
            )
            db.add(default_channel)
            
            # Assign all existing profiles to default channel
            profiles = db.query(VoiceProfile).all()
            for profile in profiles:
                mapping = ProfileChannelMapping(
                    profile_id=profile.id,
                    channel_id=default_channel.id
                )
                db.add(mapping)
            
            db.commit()
    finally:
        db.close()


def get_db():
    """Get database session (generator for dependency injection)."""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()