"""One OpenAI-compatible provider call, and the model listing beside it.

Chat completions with function tools is the dialect every hosted provider and
every local server speaks — OpenAI, Anthropic's compatibility endpoint,
OpenRouter, Ollama, vLLM — so one client covers them without a provider SDK.
The admin types the URL; the model never chooses where a request goes.
"""

from __future__ import annotations

from typing import Any
from urllib.parse import urlparse

import httpx


class ProviderError(Exception):
    """The provider answered, and the answer was a refusal."""


def check_base(api_base: str) -> None:
    parsed = urlparse(api_base)
    if parsed.scheme not in ("http", "https") or not parsed.hostname:
        raise ValueError("The provider URL must be an http(s) URL")


def _headers(api_key: str) -> dict[str, str]:
    return {"Authorization": f"Bearer {api_key}"}


def _detail(response: httpx.Response) -> str:
    try:
        error = response.json().get("error")
    except ValueError:
        error = None
    if isinstance(error, dict):
        error = error.get("message")
    text = str(error or response.text or response.reason_phrase)
    return f"{response.status_code}: {text[:300]}"


async def chat_completion(
    *,
    api_base: str,
    api_key: str,
    model: str,
    messages: list[dict[str, Any]],
    tools: list[dict[str, Any]],
    timeout: float = 120.0,
) -> dict[str, Any]:
    """``POST {api_base}/chat/completions``, the whole answer at once."""
    body: dict[str, Any] = {"model": model, "messages": messages}
    if tools:
        body["tools"] = tools
    async with httpx.AsyncClient(timeout=timeout) as http:
        response = await http.post(
            api_base.rstrip("/") + "/chat/completions",
            json=body,
            headers=_headers(api_key),
        )
    if response.is_error:
        raise ProviderError(_detail(response))
    result: dict[str, Any] = response.json()
    return result


async def list_models(api_base: str, api_key: str, timeout: float = 15.0) -> list[str]:
    """The ids ``GET {api_base}/models`` offers, for the settings screen."""
    async with httpx.AsyncClient(timeout=timeout) as http:
        response = await http.get(
            api_base.rstrip("/") + "/models", headers=_headers(api_key)
        )
    if response.is_error:
        raise ProviderError(_detail(response))
    data = response.json().get("data") or []
    return sorted(str(m["id"]) for m in data if isinstance(m, dict) and "id" in m)