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

from app.models.permission_group import PermissionGroup
from app.models.permission_group_member import PermissionGroupMember
from app.models.permission_group_permission import PermissionGroupPermission


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

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

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

    def list(self, limit: int = 100, offset: int = 0) -> tuple[list[PermissionGroup], int]:
        stmt = select(PermissionGroup).order_by(PermissionGroup.created_at.desc()).limit(limit).offset(offset)
        count_stmt = select(func.count()).select_from(PermissionGroup)
        return list(self.db.scalars(stmt).all()), int(self.db.scalar(count_stmt) or 0)

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

    def update(self, item: PermissionGroup, *, name: str | None = None, status: str | None = None) -> PermissionGroup:
        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 add_member_if_not_exists(self, group_id: str, authentik_sub: str) -> PermissionGroupMember:
        existing = self.db.scalar(
            select(PermissionGroupMember).where(
                PermissionGroupMember.group_id == group_id, PermissionGroupMember.authentik_sub == authentik_sub
            )
        )
        if existing:
            return existing
        row = PermissionGroupMember(group_id=group_id, authentik_sub=authentik_sub)
        self.db.add(row)
        self.db.commit()
        self.db.refresh(row)
        return row

    def remove_member(self, group_id: str, authentik_sub: str) -> int:
        result = self.db.execute(
            delete(PermissionGroupMember).where(
                PermissionGroupMember.group_id == group_id, PermissionGroupMember.authentik_sub == authentik_sub
            )
        )
        self.db.commit()
        return int(result.rowcount or 0)

    def grant_group_permission(
        self,
        group_id: str,
        system: str,
        module: str,
        action: str,
        scope_type: str,
        scope_id: str,
    ) -> PermissionGroupPermission:
        where = [
            PermissionGroupPermission.group_id == group_id,
            PermissionGroupPermission.system == system,
            PermissionGroupPermission.module == module,
            PermissionGroupPermission.action == action,
            PermissionGroupPermission.scope_type == scope_type,
            PermissionGroupPermission.scope_id == scope_id,
        ]
        existing = self.db.scalar(select(PermissionGroupPermission).where(*where))
        if existing:
            return existing
        row = PermissionGroupPermission(
            group_id=group_id,
            system=system,
            module=module,
            action=action,
            scope_type=scope_type,
            scope_id=scope_id,
        )
        self.db.add(row)
        self.db.commit()
        self.db.refresh(row)
        return row

    def revoke_group_permission(
        self,
        group_id: str,
        system: str,
        module: str,
        action: str,
        scope_type: str,
        scope_id: str,
    ) -> int:
        stmt = delete(PermissionGroupPermission).where(
            PermissionGroupPermission.group_id == group_id,
            PermissionGroupPermission.system == system,
            PermissionGroupPermission.module == module,
            PermissionGroupPermission.action == action,
            PermissionGroupPermission.scope_type == scope_type,
            PermissionGroupPermission.scope_id == scope_id,
        )
        result = self.db.execute(stmt)
        self.db.commit()
        return int(result.rowcount or 0)