from sqlalchemy import func, or_, select
from sqlalchemy.orm import Session

from app.models.system import System


class SystemsRepository:
    def __init__(self, db: Session) -> None:
        self.db = db

    def get_by_key(self, system_key: str) -> System | None:
        return self.db.scalar(select(System).where(System.system_key == system_key))

    def get_by_id(self, system_id: str) -> System | None:
        return self.db.scalar(select(System).where(System.id == system_id))

    def list(self, *, keyword: str | None = None, status: str | None = None, limit: int = 100, offset: int = 0) -> tuple[list[System], int]:
        stmt = select(System)
        count_stmt = select(func.count()).select_from(System)
        if keyword:
            pattern = f"%{keyword}%"
            cond = or_(System.system_key.ilike(pattern), System.name.ilike(pattern))
            stmt = stmt.where(cond)
            count_stmt = count_stmt.where(cond)
        if status:
            stmt = stmt.where(System.status == status)
            count_stmt = count_stmt.where(System.status == status)

        stmt = stmt.order_by(System.created_at.desc()).limit(limit).offset(offset)
        return list(self.db.scalars(stmt).all()), int(self.db.scalar(count_stmt) or 0)

    def create(self, *, system_key: str, name: str, status: str = "active") -> System:
        item = System(system_key=system_key, name=name, status=status)
        self.db.add(item)
        self.db.commit()
        self.db.refresh(item)
        return item

    def update(
        self,
        item: System,
        *,
        name: str | None = None,
        status: str | None = None,
    ) -> System:
        if name is not None:
            item.name = name
        if status is not None:
            item.status = status
        self.db.commit()
        self.db.refresh(item)
        return item

    def delete(self, item: System) -> None:
        self.db.delete(item)
        self.db.commit()