"""The two HTTP contracts exposed by the supplied n8n workflows."""

from __future__ import annotations

import httpx

from config import Settings, require_webhook_url


class WebhookError(RuntimeError):
    """An n8n request failed or returned an unusable response."""


class N8NClient:
    def __init__(
        self,
        settings: Settings,
        transport: httpx.AsyncBaseTransport | None = None,
    ) -> None:
        self.settings = settings
        self._transport = transport

    async def ask(self, message: str, collection_name: str, session_id: str) -> str:
        message = message.strip()
        collection_name = collection_name.strip()
        if not message or not collection_name or not session_id:
            raise ValueError("Укажите вопрос и коллекцию.")

        url = require_webhook_url(self.settings.chat_webhook_url, "вопросов")
        try:
            async with httpx.AsyncClient(
                transport=self._transport,
                timeout=self.settings.chat_timeout_seconds,
            ) as client:
                response = await client.post(
                    url,
                    json={
                        "message": message,
                        "collection_name": collection_name,
                        "session_id": session_id,
                    },
                )
                response.raise_for_status()
        except httpx.TimeoutException as exc:
            raise WebhookError("Время ожидания ответа истекло. Попробуйте ещё раз.") from exc
        except httpx.HTTPStatusError as exc:
            raise WebhookError(
                f"Webhook вопросов вернул HTTP {exc.response.status_code}."
            ) from exc
        except httpx.RequestError as exc:
            raise WebhookError("Не удалось связаться с webhook вопросов.") from exc

        answer = response.text.strip()
        if not answer:
            raise WebhookError("Webhook вопросов вернул пустой ответ.")
        return answer

    async def upload(self, filename: str, contents: bytes, collection_name: str) -> None:
        collection_name = collection_name.strip()
        if not collection_name:
            raise ValueError("Укажите коллекцию.")
        if not filename.lower().endswith(".md"):
            raise ValueError("Можно загружать только файлы .md.")
        if not contents:
            raise ValueError("Выбранный файл пуст.")
        if len(contents) > self.settings.max_file_bytes:
            raise ValueError("Размер файла превышает допустимый предел.")

        url = require_webhook_url(self.settings.upload_webhook_url, "загрузки")
        try:
            async with httpx.AsyncClient(
                transport=self._transport,
                timeout=self.settings.upload_timeout_seconds,
            ) as client:
                response = await client.post(
                    url,
                    data={"collection_name": collection_name},
                    files={"file": (filename, contents, "text/markdown")},
                )
                response.raise_for_status()
        except httpx.TimeoutException as exc:
            raise WebhookError("Время ожидания загрузки истекло. Проверьте n8n перед повтором.") from exc
        except httpx.HTTPStatusError as exc:
            raise WebhookError(
                f"Webhook загрузки вернул HTTP {exc.response.status_code}."
            ) from exc
        except httpx.RequestError as exc:
            raise WebhookError("Не удалось связаться с webhook загрузки.") from exc