import math
import sys
import os
# Ensure the src/ directory is in the import path so tests can import the package
ROOT = os.path.dirname(os.path.dirname(__file__))
SRC = os.path.join(ROOT, 'src')
if SRC not in sys.path:
    sys.path.insert(0, SRC)
from catopt_graph.admm_lite import AdmmLite


def test_admm_lite_two_agent_convergence():
    solver = AdmmLite(mu=1.0, max_iter=500, tol=1e-6)
    solver.add_agent("agent_A")
    solver.add_agent("agent_B")

    x1, x2, converged = solver.run()

    # The toy problem with constraint x1 + x2 = 1 (min of x1^2/2 + x2^2/2) has unique solution x1 = x2 = 0.5
    assert converged or math.isfinite(x1) and math.isfinite(x2)
    assert abs(x1 - 0.5) < 1e-3
    assert abs(x2 - 0.5) < 1e-3