"""VK API клиент — вызов wall.post с format_data."""

from __future__ import annotations

import json
from typing import Optional

import httpx

from app.config import settings
from app.converters.markdown_to_vk import FormatItem, format_data_json


class VkApiError(Exception):
    """Ошибка VK API. Содержит код ошибки и описание."""
    def __init__(self, error_code: int, error_msg: str):
        self.error_code = error_code
        self.error_msg = error_msg
        super().__init__(f"VK API error #{error_code}: {error_msg}")


class VkClient:
    """HTTP-клиент для VK API."""

    BASE_URL = "https://api.vk.com/method"

    def __init__(self, access_token: str):
        self.access_token = access_token
        self._client = httpx.AsyncClient(timeout=30.0)

    async def close(self):
        await self._client.aclose()

    async def wall_post(
        self,
        message: str,
        owner_id: Optional[int] = None,
        from_group: bool = False,
        friends_only: bool = False,
        publish_date: Optional[int] = None,
        attachments: Optional[str] = None,
        signed: Optional[bool] = None,
        format_data: Optional[list[FormatItem]] = None,
    ) -> dict:
        """Публикует запись на стене через wall.post.
        
        Возвращает ответ VK API с полями post_id, owner_id.
        """
        params = {
            "access_token": self.access_token,
            "v": settings.vk_api_version,
            "message": message,
        }

        if owner_id is not None:
            params["owner_id"] = owner_id
        if from_group:
            params["from_group"] = 1
        if friends_only:
            params["friends_only"] = 1
        if publish_date is not None:
            params["publish_date"] = publish_date
        if attachments is not None:
            params["attachments"] = attachments
        if signed is not None:
            params["signed"] = 1 if signed else 0
        if format_data:
            params["format_data"] = format_data_json(format_data)

        response = await self._client.post(f"{self.BASE_URL}/wall.post", data=params)
        data = response.json()

        if "error" in data:
            err = data["error"]
            raise VkApiError(
                error_code=err.get("error_code", 0),
                error_msg=err.get("error_msg", "Unknown error"),
            )

        return data.get("response", {})

    async def users_get(self, user_ids: str) -> list[dict]:
        """Получает информацию о пользователе (для проверки токена/имени)."""
        params = {
            "access_token": self.access_token,
            "v": settings.vk_api_version,
            "user_ids": user_ids,
        }
        response = await self._client.post(f"{self.BASE_URL}/users.get", data=params)
        data = response.json()
        if "error" in data:
            err = data["error"]
            raise VkApiError(
                error_code=err.get("error_code", 0),
                error_msg=err.get("error_msg", "Unknown error"),
            )
        return data.get("response", [])

    async def check_token(self) -> tuple[bool, str]:
        """Проверяет валидность токена. Возвращает (is_valid, display_name)."""
        try:
            users = await self.users_get("")
            if users:
                name = f"{users[0].get('first_name', '')} {users[0].get('last_name', '')}".strip()
                return True, name or "Unknown"
            return False, "Token invalid"
        except VkApiError:
            return False, "Token invalid or expired"