from typing import Generic, TypeVar

from fastapi import Query
from pydantic import BaseModel

from .config import get_settings

T = TypeVar("T")


class Page(BaseModel, Generic[T]):
    total: int
    limit: int
    offset: int
    items: list[T]


class PageParams:
    """Reusable dependency for `?limit=&offset=` with env-configured caps."""

    def __init__(
        self,
        limit: int = Query(default=None, ge=1, description="Max rows to return"),
        offset: int = Query(default=0, ge=0, description="Rows to skip"),
    ):
        settings = get_settings()
        if limit is None:
            limit = settings.default_limit
        self.limit = min(limit, settings.max_limit)
        self.offset = offset