"""Thin HTTP client for the centralized Oliver AI Cost Tracker."""

import asyncio
from typing import Optional

import httpx

from ..core.config import settings
from ..core.logging import get_logger

logger = get_logger(__name__)


class BudgetExceeded(Exception):
    """Raised by preflight() when the cost tracker rejects a call due to budget limits."""


def preflight(
    *,
    model: str,
    user_external_id: str,
    project_id: Optional[str] = None,
) -> None:
    if not settings.cost_tracker_base_url or not settings.cost_tracker_enabled:
        return
    try:
        payload = {
            "source_app": settings.cost_tracker_source_app,
            "model": model,
            "user_external_id": user_external_id,
        }
        if project_id:
            payload["project_external_id"] = project_id
        resp = httpx.post(
            f"{settings.cost_tracker_base_url}/preflight",
            headers={"X-API-Key": settings.cost_tracker_api_key},
            json=payload,
            timeout=5.0,
        )
        resp.raise_for_status()
        data = resp.json()
        if not data.get("allow", True):
            raise BudgetExceeded(data.get("deny_reason") or "Budget exceeded")
    except BudgetExceeded:
        raise
    except Exception as e:
        logger.warning(f"Cost tracker preflight failed (non-fatal): {e}")


async def aio_preflight(
    *,
    model: str,
    user_external_id: str,
    project_id: Optional[str] = None,
) -> None:
    await asyncio.to_thread(preflight, model=model, user_external_id=user_external_id, project_id=project_id)


def record(
    *,
    model: str,
    provider: str,
    user_external_id: str,
    project_id: Optional[str] = None,
    job_external_id: str = "",
    input_tokens: int = 0,
    output_tokens: int = 0,
    chars: Optional[int] = None,
    latency_ms: int = 0,
    status: str = "success",
) -> None:
    if not settings.cost_tracker_base_url or not settings.cost_tracker_enabled:
        return
    try:
        units: dict = {}
        if chars is not None:
            units["char"] = chars
        else:
            if input_tokens:  units["token_input"] = input_tokens
            if output_tokens: units["token_output"] = output_tokens

        payload: dict = {
            "source_app": settings.cost_tracker_source_app,
            "model": model,
            "provider": provider,
            "user_external_id": user_external_id,
            "units": units,
            "latency_ms": latency_ms,
            "status": status,
        }
        if project_id:    payload["project_external_id"] = project_id
        if job_external_id: payload["job_external_id"] = job_external_id

        httpx.post(
            f"{settings.cost_tracker_base_url}/usage/record",
            headers={"X-API-Key": settings.cost_tracker_api_key},
            json=payload,
            timeout=3.0,
        )
    except Exception as e:
        logger.warning(f"Cost tracker record failed (non-fatal): {e}")


async def aio_record(**kwargs) -> None:
    await asyncio.to_thread(record, **kwargs)