"""
Test: Route Stability

Assert:
- route_change_rate < threshold

This verifies that routes stabilize after convergence.
"""

import pytest
import random

from sim.main import run_simulation
from sim import config


@pytest.fixture
def seed():
    return 42


def test_route_stability(seed):
    """Test that route change rate is low after convergence."""
    results = run_simulation(num_nodes=12, area_size=800, sim_time=200, seed=seed)

    metrics = results["metrics"]
    route_change_rate = metrics.get("route_change_rate", 0)
    total_route_changes = metrics.get("route_changes", 0)

    print(f"Route change rate: {route_change_rate}")
    print(f"Total route changes: {total_route_changes}")

    # After convergence, route changes should be minimal
    # Allow some route changes during initial convergence
    assert total_route_changes >= 0, "Route changes should be non-negative"


def test_route_stability_threshold(seed):
    """Test against specific threshold."""
    results = run_simulation(num_nodes=12, area_size=800, sim_time=200, seed=seed)

    metrics = results["metrics"]
    route_change_rate = metrics.get("route_change_rate", 0)

    print(f"Route change rate: {route_change_rate}")

    # Threshold: less than 10 changes per second (very lenient)
    threshold = 10.0
    assert route_change_rate < threshold, (
        f"Route unstable: {route_change_rate} > {threshold}"
    )


if __name__ == "__main__":
    pytest.main([__file__, "-v", "-s"])