from sqlalchemy import create_engine, Column, Integer, String, Text, DateTime, Boolean, ForeignKey, UniqueConstraint
from sqlalchemy.orm import DeclarativeBase, sessionmaker
from datetime import datetime
import uuid

DATABASE_URL = "sqlite:///./speechify.db"
engine = create_engine(DATABASE_URL, connect_args={"check_same_thread": False})
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


class Base(DeclarativeBase):
    pass


class User(Base):
    __tablename__ = "users"
    id = Column(Integer, primary_key=True, index=True)
    username = Column(String(50), unique=True, nullable=False, index=True)
    email = Column(String(100), unique=True, nullable=False)
    password_hash = Column(String(255), nullable=False)
    role = Column(String(10), default="user")
    is_active = Column(Boolean, default=True)
    email_verified = Column(Boolean, default=False)
    created_at = Column(DateTime, default=datetime.utcnow)


class VerificationToken(Base):
    __tablename__ = "verification_tokens"
    id = Column(Integer, primary_key=True)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    token = Column(String(64), unique=True, nullable=False, index=True)
    created_at = Column(DateTime, default=datetime.utcnow)


class Document(Base):
    __tablename__ = "documents"
    id = Column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    title = Column(String(500))
    content = Column(Text)
    source_type = Column(String(20))
    created_at = Column(DateTime, default=datetime.utcnow)


class Progress(Base):
    __tablename__ = "progress"
    id = Column(Integer, primary_key=True)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    document_id = Column(String(36), ForeignKey("documents.id"), nullable=False)
    sentence_index = Column(Integer, default=0)
    updated_at = Column(DateTime, default=datetime.utcnow)
    __table_args__ = (UniqueConstraint("user_id", "document_id", name="uq_user_doc"),)


class Setting(Base):
    """Global admin settings (key/value)"""
    __tablename__ = "settings"
    key = Column(String(100), primary_key=True)
    value = Column(Text)


class UserSetting(Base):
    """Per-user settings (key/value)"""
    __tablename__ = "user_settings"
    id = Column(Integer, primary_key=True)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    key = Column(String(100), nullable=False)
    value = Column(Text)
    __table_args__ = (UniqueConstraint("user_id", "key", name="uq_user_setting"),)


def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


def init_db():
    Base.metadata.create_all(bind=engine)