new api service and logic implemented

Services/pagination.py

@@ -0,0 +1,102 @@
+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,
+        }