"""
Unified API response wrapper.

Provides consistent response format across all API endpoints:
{
    "success": bool,
    "data": {...} | [...] | null,
    "errors": [...] | null,
    "meta": {
        "request_id": "uuid",
        "pagination": {...}  // optional
    }
}
"""

from typing import Any

from rest_framework import status
from rest_framework.response import Response


def api_response(
    data: Any = None,
    *,
    status_code: int = status.HTTP_200_OK,
    request_id: str | None = None,
    pagination: dict[str, Any] | None = None,
    headers: dict[str, str] | None = None,
) -> Response:
    """
    Create a successful API response.

    Args:
        data: Response data (dict, list, or None)
        status_code: HTTP status code (default 200)
        request_id: Request tracking ID
        pagination: Pagination metadata
        headers: Additional response headers

    Returns:
        DRF Response with unified format
    """
    meta = {}
    if request_id:
        meta["request_id"] = request_id
    if pagination:
        meta["pagination"] = pagination

    response_data = {
        "success": True,
        "data": data,
        "errors": None,
        "meta": meta if meta else None,
    }

    return Response(response_data, status=status_code, headers=headers)


def api_error_response(
    errors: list[dict[str, Any]],
    *,
    status_code: int = status.HTTP_400_BAD_REQUEST,
    request_id: str | None = None,
    headers: dict[str, str] | None = None,
) -> Response:
    """
    Create an error API response.

    Args:
        errors: List of error dictionaries, each with 'code' and 'message'
        status_code: HTTP status code (default 400)
        request_id: Request tracking ID
        headers: Additional response headers

    Returns:
        DRF Response with unified error format
    """
    meta = {}
    if request_id:
        meta["request_id"] = request_id

    response_data = {
        "success": False,
        "data": None,
        "errors": errors,
        "meta": meta if meta else None,
    }

    return Response(response_data, status=status_code, headers=headers)


def api_created_response(
    data: Any = None,
    *,
    request_id: str | None = None,
    headers: dict[str, str] | None = None,
) -> Response:
    """Shortcut for 201 Created response."""
    return api_response(
        data,
        status_code=status.HTTP_201_CREATED,
        request_id=request_id,
        headers=headers,
    )


def api_no_content_response(
    *,
    request_id: str | None = None,
    headers: dict[str, str] | None = None,
) -> Response:
    """Shortcut for 204 No Content response."""
    meta = {}
    if request_id:
        meta["request_id"] = request_id

    return Response(
        {"success": True, "data": None, "errors": None, "meta": meta if meta else None},
        status=status.HTTP_204_NO_CONTENT,
        headers=headers,
    )


def api_paginated_response(
    data: list[Any],
    *,
    page: int,
    page_size: int,
    total_count: int,
    request_id: str | None = None,
    headers: dict[str, str] | None = None,
) -> Response:
    """
    Create a paginated API response.

    Args:
        data: List of items for current page
        page: Current page number
        page_size: Number of items per page
        total_count: Total number of items
        request_id: Request tracking ID
        headers: Additional response headers
    """
    total_pages = (total_count + page_size - 1) // page_size if page_size > 0 else 0

    pagination = {
        "page": page,
        "page_size": page_size,
        "total_count": total_count,
        "total_pages": total_pages,
        "has_next": page < total_pages,
        "has_previous": page > 1,
    }

    return api_response(
        data,
        request_id=request_id,
        pagination=pagination,
        headers=headers,
    )