"""资源代理辅助方法与路由装饰器。"""

from __future__ import annotations

from collections.abc import Awaitable, Callable
from functools import wraps
import re
from typing import Any

from app.config import settings

from fastapi import Response
from pydantic import BaseModel

Handler = Callable[..., Awaitable[Any]]


def _replace_asset_urls_in_string(value: str) -> str:
    result = value
    custom_domain = settings.custom_asset_domain
    asset_prefix = settings.asset_proxy_prefix
    avatar_prefix = settings.avatar_proxy_prefix
    beatmap_prefix = settings.beatmap_proxy_prefix
    audio_proxy_base_url = f"{settings.server_url}api/private/audio/beatmapset"

    result = re.sub(
        r"^https://assets\.ppy\.sh/",
        f"https://{asset_prefix}.{custom_domain}/",
        result,
    )

    result = re.sub(
        r"^https://b\.ppy\.sh/preview/(\d+)\\.mp3",
        rf"{audio_proxy_base_url}/\1",
        result,
    )

    result = re.sub(
        r"^//b\.ppy\.sh/preview/(\d+)\\.mp3",
        rf"{audio_proxy_base_url}/\1",
        result,
    )

    result = re.sub(
        r"^https://a\.ppy\.sh/",
        f"https://{avatar_prefix}.{custom_domain}/",
        result,
    )

    result = re.sub(
        r"https://b\.ppy\.sh/",
        f"https://{beatmap_prefix}.{custom_domain}/",
        result,
    )
    return result


def _replace_asset_urls_in_data(data: Any) -> Any:
    if isinstance(data, str):
        return _replace_asset_urls_in_string(data)
    if isinstance(data, list):
        return [_replace_asset_urls_in_data(item) for item in data]
    if isinstance(data, tuple):
        return tuple(_replace_asset_urls_in_data(item) for item in data)
    if isinstance(data, dict):
        return {key: _replace_asset_urls_in_data(value) for key, value in data.items()}
    return data


async def replace_asset_urls(data: Any) -> Any:
    """替换数据中的 osu! 资源 URL。"""

    if not settings.enable_asset_proxy:
        return data

    if hasattr(data, "model_dump"):
        raw = data.model_dump()
        processed = _replace_asset_urls_in_data(raw)
        try:
            return data.__class__(**processed)
        except Exception:
            return processed

    if isinstance(data, (dict, list, tuple, str)):
        return _replace_asset_urls_in_data(data)

    return data


def asset_proxy_response(func: Handler) -> Handler:
    """装饰器：在返回响应前替换资源 URL。"""

    @wraps(func)
    async def wrapper(*args, **kwargs):
        result = await func(*args, **kwargs)

        if not settings.enable_asset_proxy:
            return result

        if isinstance(result, Response):
            return result

        if isinstance(result, BaseModel):
            result = result.model_dump()

        return _replace_asset_urls_in_data(result)

    return wrapper  # type: ignore[return-value]