fallback_solver.py•1.83 kB
"""Fallback solver for when OR-Tools is not available."""
import logging
import platform
from typing import Any
logger = logging.getLogger(__name__)
class FallbackSolver:
"""Fallback solver that returns error messages when OR-Tools is not available."""
def __init__(self) -> None:
"""Initialize fallback solver."""
self.solver_name = "Fallback"
def _get_installation_message(self) -> str:
"""Get platform-specific installation instructions."""
system = platform.system()
if system == "Darwin": # macOS
return (
"OR-Tools is not available. For full functionality on macOS:\n"
"1. Install via Homebrew: 'brew install or-tools && pip install ortools'\n"
"2. Or use regular venv: 'python -m venv venv && source venv/bin/activate && pip install ortools'\n"
"Note: OR-Tools may not work in isolated environments (uvx) due to native library paths."
)
else:
return "OR-Tools is not available. Please install it with 'pip install ortools'"
def solve_assignment_problem(self, *args: Any, **kwargs: Any) -> dict[str, Any]:
"""Return error message for assignment problem."""
return {
"status": "error",
"error_message": self._get_installation_message(),
"total_cost": None,
"assignments": [],
"execution_time": 0.0,
}
def solve_transportation_problem(self, *args: Any, **kwargs: Any) -> dict[str, Any]:
"""Return error message for transportation problem."""
return {
"status": "error",
"error_message": self._get_installation_message(),
"total_cost": None,
"flows": [],
"execution_time": 0.0,
}