"""Regression tests for Python-facing solver validation."""

import pathlib

import numpy as np

import pytest

import shutil

import subprocess

import sys

import pycddp

def _make_solver(horizon=6, dt=0.1):

x0 = np.array([0.0, 0.0])

xref = np.array([0.0, 0.0])

opts = pycddp.CDDPOptions()

opts.verbose = False

opts.print_solver_header = False

return pycddp.CDDP(x0, xref, horizon, dt, opts)

def test_solve_by_name_raises_for_unknown_solver():

solver = _make_solver()

with pytest.raises(ValueError, match="Unknown solver 'NONEXISTENT'"):

solver.solve_by_name("NONEXISTENT")

@pytest.mark.parametrize(

("solver_name", "expected_solver_name"),

[

("CLDDP", "CLDDP"),

("CLCDDP", "CLDDP"),

("LOGDDP", "LogDDP"),

],

)

def test_solve_by_name_accepts_core_aliases(solver_name, expected_solver_name):

dt = 0.05

horizon = 20

x0 = np.array([np.pi, 0.0])

xref = np.array([0.0, 0.0])

opts = pycddp.CDDPOptions()

opts.max_iterations = 20

opts.verbose = False

opts.print_solver_header = False

solver = pycddp.CDDP(x0, xref, horizon, dt, opts)

solver.set_dynamical_system(

pycddp.Pendulum(dt, length=0.5, mass=1.0, damping=0.01)

)

solver.set_objective(

pycddp.QuadraticObjective(

np.zeros((2, 2)), 0.1 * np.eye(1), 100.0 * np.eye(2), xref, [], dt

)

)

solver.add_constraint(

"ctrl", pycddp.ControlConstraint(np.array([-50.0]), np.array([50.0]))

)

solution = solver.solve_by_name(solver_name)

assert solution.solver_name == expected_solver_name

assert solution.status_message

assert len(solution.state_trajectory) == horizon + 1

def test_set_initial_trajectory_requires_dynamical_system():

solver = _make_solver()

X = [np.zeros(2) for _ in range(solver.horizon + 1)]

U = [np.zeros(1) for _ in range(solver.horizon)]

with pytest.raises(ValueError, match="is a dynamical system set"):

solver.set_initial_trajectory(X, U)

def test_set_dynamical_system_rejects_abstract_base():

solver = _make_solver()

with pytest.raises(TypeError, match="DynamicalSystem is an abstract base class"):

solver.set_dynamical_system(pycddp.DynamicalSystem(2, 1, 0.1))

def test_set_objective_rejects_abstract_base():

with pytest.raises(TypeError, match="No constructor defined"):

pycddp.Objective()

def test_set_initial_trajectory_rejects_bad_lengths():

solver = _make_solver()

solver.set_dynamical_system(pycddp.Pendulum(0.1))

X = [np.zeros(2) for _ in range(solver.horizon)]

U = [np.zeros(1) for _ in range(solver.horizon)]

with pytest.raises(ValueError, match="expected X length"):

solver.set_initial_trajectory(X, U)

def test_set_initial_trajectory_rejects_bad_state_dimension():

solver = _make_solver()

solver.set_dynamical_system(pycddp.Pendulum(0.1))

X = [np.zeros(2) for _ in range(solver.horizon + 1)]

X[2] = np.zeros(3)

U = [np.zeros(1) for _ in range(solver.horizon)]

with pytest.raises(ValueError, match="state vector 2"):

solver.set_initial_trajectory(X, U)

def test_set_initial_trajectory_rejects_bad_control_dimension():

solver = _make_solver()

solver.set_dynamical_system(pycddp.Pendulum(0.1))

X = [np.zeros(2) for _ in range(solver.horizon + 1)]

U = [np.zeros(1) for _ in range(solver.horizon)]

U[1] = np.zeros(2)

with pytest.raises(ValueError, match="control vector 1"):

solver.set_initial_trajectory(X, U)

def test_import_error_message_is_actionable(tmp_path):

package_dir = tmp_path / "pycddp"

package_dir.mkdir()

source_dir = pathlib.Path(__file__).resolve().parents[1] / "pycddp"

shutil.copy(source_dir / "__init__.py", package_dir / "__init__.py")

shutil.copy(source_dir / "_version.py", package_dir / "_version.py")

proc = subprocess.run(

[

sys.executable,

"-I",

"-S",

"-c",

(

"import sys; "

f"sys.path.insert(0, {str(tmp_path)!r}); "

"import pycddp"

),

],

capture_output=True,

text=True,

check=False,

)

assert proc.returncode != 0

assert "Failed to import the native pycddp extension" in proc.stderr