#!/usr/bin/env python3
"""Fail unless a local OpenAI-compatible server emits a structured bash call."""

from __future__ import annotations

import argparse
import json
import urllib.request
from pathlib import Path


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("--base-url", default="http://127.0.0.1:8200/v1")
    parser.add_argument("--model")
    parser.add_argument(
        "--system-prompt",
        type=Path,
        default=Path(__file__).resolve().parents[1] / "harness/system-prompt.md",
    )
    args = parser.parse_args()

    model = args.model
    if model is None:
        with urllib.request.urlopen(f"{args.base_url}/models", timeout=30) as response:
            model = json.load(response)["data"][0]["id"]

    completion_limit = 512
    body = {
        "model": model,
        "messages": [
            {"role": "system", "content": args.system_prompt.read_text().strip()},
            {
                "role": "user",
                "content": (
                    "Inspect the current working directory before making any changes. "
                    "Use the bash tool now."
                ),
            },
        ],
        "tools": [
            {
                "type": "function",
                "function": {
                    "name": "bash",
                    "description": "Execute a bash command in the current working directory.",
                    "parameters": {
                        "type": "object",
                        "properties": {"command": {"type": "string"}},
                        "required": ["command"],
                    },
                },
            }
        ],
        "tool_choice": "auto",
        "temperature": 0.2,
        "top_p": 0.95,
        "max_tokens": completion_limit,
    }
    request = urllib.request.Request(
        f"{args.base_url}/chat/completions",
        data=json.dumps(body).encode(),
        headers={"Authorization": "Bearer local", "Content-Type": "application/json"},
    )
    with urllib.request.urlopen(request, timeout=180) as response:
        result = json.load(response)
    message = result["choices"][0]["message"]
    calls = message.get("tool_calls") or []
    if not calls or calls[0].get("function", {}).get("name") != "bash":
        raise SystemExit(f"expected a structured bash call, got: {message!r}")
    arguments = json.loads(calls[0]["function"]["arguments"])
    command = arguments.get("command")
    if not isinstance(command, str) or not command.strip():
        raise SystemExit(f"bash call has invalid arguments: {arguments!r}")
    usage = result.get("usage") or {}
    completion_tokens = usage.get("completion_tokens")
    if not isinstance(completion_tokens, int) or completion_tokens >= completion_limit:
        raise SystemExit(
            "structured call did not stop before the generation ceiling: "
            f"completion_tokens={completion_tokens!r}, ceiling={completion_limit}"
        )
    print(
        json.dumps(
            {
                "model": model,
                "finish_reason": result["choices"][0].get("finish_reason"),
                "function": "bash",
                "command": command,
                "completion_tokens": completion_tokens,
            },
            indent=2,
        )
    )


if __name__ == "__main__":
    main()