from typing import Any, Dict, Optional, Union, TypeVar, Type from sqlalchemy import desc, asc from pydantic import BaseModel from Controllers.Postgres.response import PostgresResponse # Type variable for class methods returning self T = TypeVar("T", bound="BaseModel") class PaginateConfig: """ Configuration for pagination settings. 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 = 1 MAX_SIZE = 100 class ListOptions(BaseModel): """ Query for list option abilities """ page: Optional[int] = 1 size: Optional[int] = 10 order_field: Optional[Union[tuple[str], list[str]]] = ["uu_id"] order_type: Optional[Union[tuple[str], list[str]]] = ["asc"] # include_joins: Optional[list] = None class PaginateOnly(ListOptions): """ Query for list option abilities """ query: Optional[dict] = None class PaginationConfig(BaseModel): """ 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: Optional[Union[tuple[str], list[str]]] = ["uu_id"] order_type: Optional[Union[tuple[str], list[str]]] = ["asc"] def __init__(self, **data): super().__init__(**data) if self.order_field is None: self.order_field = ["uu_id"] if self.order_type is None: self.order_type = ["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 = PaginateConfig.DEFAULT_SIZE MIN_SIZE = PaginateConfig.MIN_SIZE MAX_SIZE = PaginateConfig.MAX_SIZE def __init__(self, data: PostgresResponse): self.data = data self.size: int = self.DEFAULT_SIZE self.page: int = 1 self.orderField: Optional[Union[tuple[str], list[str]]] = ["uu_id"] self.orderType: Optional[Union[tuple[str], list[str]]] = ["asc"] self.page_count: int = 1 self.total_count: int = 0 self.all_count: int = 0 self.total_pages: int = 1 self._update_page_counts() def change(self, **kwargs) -> None: """Update pagination settings from config.""" config = PaginationConfig(**kwargs) self.size = ( config.size if self.MIN_SIZE <= config.size <= self.MAX_SIZE else self.DEFAULT_SIZE ) self.page = config.page self.orderField = config.order_field self.orderType = config.order_type self._update_page_counts() def feed(self, data: PostgresResponse) -> None: """Calculate pagination based on data source.""" self.data = data self._update_page_counts() def _update_page_counts(self) -> None: """Update page counts and validate current page.""" if self.data: self.total_count = self.data.count self.all_count = self.data.total_count self.size = ( self.size if self.MIN_SIZE <= self.size <= self.MAX_SIZE else self.DEFAULT_SIZE ) 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 refresh(self) -> None: """Reset pagination state to defaults.""" self._update_page_counts() def reset(self) -> None: """Reset pagination state to defaults.""" self.size = self.DEFAULT_SIZE self.page = 1 self.orderField = "uu_id" self.orderType = "asc" @property def as_dict(self) -> Dict[str, Any]: """Convert pagination state to dictionary format.""" self.refresh() return { "size": self.size, "page": self.page, "allCount": self.all_count, "totalCount": self.total_count, "totalPages": self.total_pages, "pageCount": self.page_count, "orderField": self.orderField, "orderType": self.orderType, } class PaginationResult: """ Result of a paginated query. Contains the query result and pagination state. data: PostgresResponse of query results pagination: Pagination state Attributes: _query: Original query object pagination: Pagination state """ def __init__( self, data: PostgresResponse, pagination: Pagination, response_model: Type[T] = None, ): self._query = data.query self.pagination = pagination self.response_type = data.is_list self.limit = self.pagination.size self.offset = self.pagination.size * (self.pagination.page - 1) self.order_by = self.pagination.orderField self.response_model = response_model def dynamic_order_by(self): """ Dynamically order a query by multiple fields. Returns: Ordered query object. """ if not len(self.order_by) == len(self.pagination.orderType): raise ValueError( "Order by fields and order types must have the same length." ) order_criteria = zip(self.order_by, self.pagination.orderType) for field, direction in order_criteria: if hasattr(self._query.column_descriptions[0]["entity"], field): if direction.lower().startswith("d"): self._query = self._query.order_by( desc( getattr(self._query.column_descriptions[0]["entity"], field) ) ) else: self._query = self._query.order_by( asc( getattr(self._query.column_descriptions[0]["entity"], field) ) ) return self._query @property def data(self) -> Union[list | dict]: """Get query object.""" query_ordered = self.dynamic_order_by() query_paginated = query_ordered.limit(self.limit).offset(self.offset) queried_data = ( query_paginated.all() if self.response_type else query_paginated.first() ) data = ( [result.get_dict() for result in queried_data] if self.response_type else queried_data.get_dict() ) if self.response_model: return [self.response_model(**item).model_dump() for item in data] return data