from __future__ import annotations

import math
from typing import Any, Generic, TypeVar

from pydantic import BaseModel, ConfigDict

from iti.schemas import to_camel

T = TypeVar("T")


class Envelope(BaseModel, Generic[T]):
    model_config = ConfigDict(alias_generator=to_camel, populate_by_name=True)

    data: T | None = None
    code: int = 200
    message: str = "成功"


def ok(data: Any = None, message: str = "成功", code: int = 200) -> dict[str, Any]:
    return {"data": data, "code": code, "message": message}


def fail(
    message: str = "操作失败", code: int = 500, data: Any = None
) -> dict[str, Any]:
    return {"data": data, "code": code, "message": message}


def pagination(
    *,
    page: int = 1,
    size: int = 10,
    total: int = 0,
    pages: int | None = None,
) -> dict[str, Any]:
    pages = pages if pages is not None else math.ceil(total / size) if size > 0 else 0
    return {
        "page": page,
        "size": size,
        "pages": pages,
        "total": total,
    }


def page(
    items: list[Any],
    page_info: dict[str, Any] | None = None,
    message: str = "成功",
    code: int = 200,
) -> dict[str, Any]:
    return ok({"items": items, "page": page_info or pagination()}, message, code)