#!/usr/bin/env python3
# -*- coding: utf-8 -*-
from __future__ import annotations

import math
from typing import TypeVar, Generic, Sequence, Dict, Union

from fastapi import Query
from fastapi_pagination.bases import AbstractPage, AbstractParams, RawParams
from fastapi_pagination.links.bases import create_links
from pydantic import BaseModel

T = TypeVar('T')

"""
重写分页库：fastapi-pagination 
使用方法：example link: https://github.com/uriyyo/fastapi-pagination/tree/main/examples
"""


class Params(BaseModel, AbstractParams):
    page: int = Query(1, ge=1, description='Page number')
    size: int = Query(20, gt=0, le=100, description='Page size')  # 默认 20 条记录

    def to_raw_params(self) -> RawParams:
        return RawParams(
            limit=self.size,
            offset=self.size * (self.page - 1),
        )


class Page(AbstractPage[T], Generic[T]):
    data: Sequence[T]  # 数据
    total: int  # 总数据数
    page: int  # 第n页
    size: int  # 每页数量
    total_pages: int  # 总页数
    links: Dict[str, Union[str, None]]  # 跳转链接

    __params_type__ = Params  # 使用自定义的Params

    @classmethod
    def create(
        cls,
        data: Sequence[T],
        total: int,
        params: Params,
    ) -> Page[T]:
        page = params.page
        size = params.size
        total_pages = math.ceil(total / params.size)
        links = create_links(
            **{
                'first': {'page': 1, 'size': f'{size}'},
                'last': {'page': f'{math.ceil(total / params.size)}', 'size': f'{size}'} if total > 0 else None,
                'next': {'page': f'{page + 1}', 'size': f'{size}'} if (page + 1) <= total_pages else None,
                'prev': {'page': f'{page - 1}', 'size': f'{size}'} if (page - 1) >= 1 else None,
            }
        ).dict()

        return cls(data=data, total=total, page=params.page, size=params.size, total_pages=total_pages, links=links)