"""Errors with a known execution boundary for MCP calculations."""

from fastapi import HTTPException


class CalculationCapacityExceeded(HTTPException):
    """Raised by admission control before the native function is invoked."""

    code = "CALCULATION_CAPACITY_EXCEEDED"

    def __init__(self) -> None:
        super().__init__(
            503,
            "Calculation capacity is occupied; calculation not started. "
            "Retry the same request after an active calculation finishes.",
        )