from collections.abc import Iterator
from contextlib import contextmanager
from datetime import datetime

from sqlalchemy import Boolean, DateTime, Integer, String, Text, create_engine, select
from sqlalchemy.orm import DeclarativeBase, Mapped, Session, mapped_column, sessionmaker

from app.config import get_settings


DEFAULT_SETTINGS = {
    "terminal_mode": "3",
    "search_provider": "brave",
    "ollama_base_url": "http://127.0.0.1:11434",
    "default_model": "qwen3.5:4b",
}

DEFAULT_TOOLS = {
    "brave_search": True,
    "searxng_search": False,
    "web_fetch": True,
    "apple_notes": True,
    "files": True,
    "terminal": True,
}


class Base(DeclarativeBase):
    pass


class SettingORM(Base):
    __tablename__ = "settings"

    key: Mapped[str] = mapped_column(String(100), primary_key=True)
    value: Mapped[str] = mapped_column(Text, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)


class ToolStateORM(Base):
    __tablename__ = "tool_states"

    name: Mapped[str] = mapped_column(String(100), primary_key=True)
    enabled: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
    updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)


class AuthorizedUserORM(Base):
    __tablename__ = "authorized_users"

    telegram_user_id: Mapped[int] = mapped_column(Integer, primary_key=True)
    username: Mapped[str | None] = mapped_column(String(255))
    display_name: Mapped[str | None] = mapped_column(String(255))
    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)


class MemoryItemORM(Base):
    __tablename__ = "memory_items"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    content: Mapped[str] = mapped_column(Text, nullable=False)
    kind: Mapped[str] = mapped_column(String(50), nullable=False, default="message")
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)


class AuditLogORM(Base):
    __tablename__ = "audit_logs"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    category: Mapped[str] = mapped_column(String(50), nullable=False)
    message: Mapped[str] = mapped_column(Text, nullable=False)
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)


class SecretORM(Base):
    __tablename__ = "secrets"

    key: Mapped[str] = mapped_column(String(100), primary_key=True)
    value: Mapped[str] = mapped_column(Text, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)


settings = get_settings()
engine = create_engine(
    settings.db_url,
    connect_args={"check_same_thread": False} if settings.db_url.startswith("sqlite") else {},
)
SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False)


def init_db() -> None:
    Base.metadata.create_all(bind=engine)
    with session_scope() as session:
        _seed_defaults(session)


def _seed_defaults(session: Session) -> None:
    for key, value in DEFAULT_SETTINGS.items():
        if session.get(SettingORM, key) is None:
            session.add(SettingORM(key=key, value=value))

    for name, enabled in DEFAULT_TOOLS.items():
        if session.get(ToolStateORM, name) is None:
            session.add(ToolStateORM(name=name, enabled=enabled))


def get_session() -> Iterator[Session]:
    session = SessionLocal()
    try:
        yield session
    finally:
        session.close()


@contextmanager
def session_scope() -> Iterator[Session]:
    session = SessionLocal()
    try:
        yield session
        session.commit()
    except Exception:
        session.rollback()
        raise
    finally:
        session.close()


def list_recent_logs(session: Session, limit: int = 10) -> list[str]:
    stmt = select(AuditLogORM).order_by(AuditLogORM.created_at.desc(), AuditLogORM.id.desc()).limit(limit)
    return [row.message for row in session.scalars(stmt)]