from typing import Any, Dict, List, Union, Protocol
from dataclasses import dataclass
from sqlalchemy.orm import Query

from Services.PostgresDb.Models.response import PostgresResponse


class DataValidator(Protocol):
    """Protocol for data validation methods."""

    @staticmethod
    def validate_data(data: Any, cls_object: Any) -> None:
        """Validate data and raise HTTPExceptionApi if invalid."""
        ...


@dataclass
class PaginationConfig:
    """
    Configuration for pagination settings.

    Attributes:
        page: Current page number (default: 1)
        size: Items per page (default: 10)
        order_field: Field to order by (default: "id")
        order_type: Order direction (default: "asc")
    """

    page: int = 1
    size: int = 10
    order_field: str = "id"
    order_type: str = "asc"


class Pagination:
    """
    Handles pagination logic for query results.

    Manages page size, current page, ordering, and calculates total pages
    and items based on the data source.

    Attributes:
        DEFAULT_SIZE: Default number of items per page (10)
        MIN_SIZE: Minimum allowed page size (10)
        MAX_SIZE: Maximum allowed page size (40)
    """

    DEFAULT_SIZE = 10
    MIN_SIZE = 10
    MAX_SIZE = 40

    def __init__(self):
        self.size: int = self.DEFAULT_SIZE
        self.page: int = 1
        self.order_field: str = "id"
        self.order_type: str = "asc"
        self.page_count: int = 1
        self.total_count: int = 0
        self.total_pages: int = 1

    def change(self, config: PaginationConfig) -> None:
        """Update pagination settings from config."""
        self.size = (
            config.size
            if self.MIN_SIZE <= config.size <= self.MAX_SIZE
            else self.DEFAULT_SIZE
        )
        self.page = config.page
        self.order_field = config.order_field
        self.order_type = config.order_type
        self._update_page_counts()

    def feed(self, data: Union[List[Any], PostgresResponse, Query]) -> None:
        """Calculate pagination based on data source."""
        self.total_count = (
            len(data)
            if isinstance(data, list)
            else data.count if isinstance(data, PostgresResponse) else data.count()
        )
        self._update_page_counts()

    def _update_page_counts(self) -> None:
        """Update page counts and validate current page."""
        self.total_pages = max(1, (self.total_count + self.size - 1) // self.size)
        self.page = max(1, min(self.page, self.total_pages))
        self.page_count = (
            self.total_count % self.size
            if self.page == self.total_pages and self.total_count % self.size
            else self.size
        )

    def as_dict(self) -> Dict[str, Any]:
        """Convert pagination state to dictionary format."""
        return {
            "size": self.size,
            "page": self.page,
            "totalCount": self.total_count,
            "totalPages": self.total_pages,
            "pageCount": self.page_count,
            "orderField": self.order_field,
            "orderType": self.order_type,
        }