"""Core async chat completion with iterative tool calling, plus adapters."""

from __future__ import annotations

import asyncio
import json
import logging
from collections.abc import Awaitable, Callable
from typing import TYPE_CHECKING, Any, cast

import openai

if TYPE_CHECKING:
    from openai.types.chat import ChatCompletion, ChatCompletionMessageParam

logger = logging.getLogger(__name__)

ToolExecutor = Callable[[str, dict[str, str]], str]
ToolCallNotifier = Callable[[str, dict[str, str]], None | Awaitable[None]]

_chat_client: openai.AsyncOpenAI | None = None


def get_chat_client() -> openai.AsyncOpenAI:
    """Return the shared async chat client, building it once."""
    global _chat_client
    if _chat_client is None:
        from vibe_bot.config import CHAT_ENDPOINT, CHAT_ENDPOINT_KEY

        _chat_client = openai.AsyncOpenAI(
            base_url=CHAT_ENDPOINT, api_key=CHAT_ENDPOINT_KEY
        )
    return _chat_client


async def chat_complete(
    messages: list[ChatCompletionMessageParam],
    *,
    model: str,
    max_tokens: int,
    seed: int | None = None,
    tools: list[dict[str, object]] | None = None,
    tool_executor: ToolExecutor | None = None,
    tool_call_notifier: ToolCallNotifier | None = None,
    max_tool_rounds: int = 5,
    timeout: float = 60.0,
) -> str:
    """Send a chat completion, optionally with iterative tool calling.

    Args:
        messages: The conversation messages (system/user/assistant/tool).
        model: The model to use for completion.
        max_tokens: Maximum number of tokens to generate.
        seed: Optional sampling seed.
        tools: Optional list of tool definitions in OpenAI format.
        tool_executor: Sync callable (tool_name, tool_args) -> result string.
        tool_call_notifier: Optional sync-or-async callback invoked before each
            tool call with (tool_name, tool_args).
        max_tool_rounds: Maximum tool call rounds before giving up.
        timeout: Per-request timeout in seconds.

    Returns:
        The model's final response text, stripped of whitespace ("" on failure).

    """
    client = get_chat_client()
    messages = list(messages)

    for _round in range(max_tool_rounds):
        kwargs: dict[str, Any] = {
            "model": model,
            "messages": messages,
            "max_tokens": max_tokens,
            "timeout": timeout,
        }
        if seed is not None:
            kwargs["seed"] = seed
        if tools:
            kwargs["tools"] = cast("list[Any]", tools)

        response = cast(
            "ChatCompletion", await client.chat.completions.create(**kwargs)
        )
        if not response.choices:
            return ""

        message = response.choices[0].message
        tool_calls = message.tool_calls
        if tool_calls and tool_executor is not None:
            assistant_msg: dict[str, object] = {
                "role": "assistant",
                "content": message.content or "",
            }
            tool_call_dicts: list[dict[str, object]] = []
            for tool_call in tool_calls:
                if tool_call.type != "function":
                    continue
                tool_call_dicts.append(
                    {
                        "id": tool_call.id,
                        "type": "function",
                        "function": {
                            "name": tool_call.function.name,
                            "arguments": tool_call.function.arguments,
                        },
                    },
                )
            assistant_msg["tool_calls"] = tool_call_dicts
            messages.append(cast("ChatCompletionMessageParam", assistant_msg))

            for tool_call in tool_calls:
                if tool_call.type != "function":
                    continue
                tool_name = tool_call.function.name
                tool_args = json.loads(tool_call.function.arguments)

                if tool_call_notifier is not None:
                    result = tool_call_notifier(tool_name, tool_args)
                    if result is not None:
                        await result

                tool_result = await asyncio.to_thread(
                    tool_executor, tool_name, tool_args
                )
                messages.append(
                    cast(
                        "ChatCompletionMessageParam",
                        {
                            "role": "tool",
                            "tool_call_id": tool_call.id,
                            "content": tool_result,
                        },
                    ),
                )
            continue

        content = message.content
        if content:
            return content.strip()
        return ""

    return ""


async def chat_completion_instruct(
    system_prompt: str,
    user_prompt: str,
    *,
    model: str,
    max_tokens: int = 1000,
) -> str:
    """Instruction-based completion over :func:`chat_complete`."""
    messages: list[ChatCompletionMessageParam] = [
        {"role": "system", "content": system_prompt},
        {"role": "user", "content": user_prompt},
    ]
    return await chat_complete(messages, model=model, max_tokens=max_tokens, seed=-1)


async def chat_completion_with_history(
    system_prompt: str,
    prompts: list[dict[str, str]],
    *,
    model: str,
    max_tokens: int = 1000,
) -> str:
    """Completion with conversation history over :func:`chat_complete`."""
    messages: list[ChatCompletionMessageParam] = [
        cast(
            "ChatCompletionMessageParam",
            {"role": "system", "content": system_prompt},
        ),
    ]
    messages.extend(cast("list[ChatCompletionMessageParam]", prompts))
    return await chat_complete(messages, model=model, max_tokens=max_tokens, seed=-1)


async def chat_completion_with_tools(
    system_prompt: str,
    prompts: list[dict[str, str]],
    tools: list[dict[str, object]],
    tool_executor: ToolExecutor,
    *,
    model: str,
    max_tokens: int = 1000,
    max_tool_rounds: int = 5,
    tool_call_notifier: ToolCallNotifier | None = None,
) -> str:
    """Tool-capable completion over :func:`chat_complete`."""
    messages: list[ChatCompletionMessageParam] = [
        cast(
            "ChatCompletionMessageParam",
            {"role": "system", "content": system_prompt},
        ),
    ]
    messages.extend(cast("list[ChatCompletionMessageParam]", prompts))
    return await chat_complete(
        messages,
        model=model,
        max_tokens=max_tokens,
        seed=-1,
        tools=tools,
        tool_executor=tool_executor,
        tool_call_notifier=tool_call_notifier,
        max_tool_rounds=max_tool_rounds,
    )