from __future__ import annotations

import unittest

from app.simulation.components.amesim.flow.pipes import AmesimPnl00r
from app.simulation.core.medium import IdealGasMedium
from app.simulation.registry import COMPONENT_MODEL_REGISTRY


class AmesimPnl00rComponentTests(unittest.TestCase):
    def setUp(self) -> None:
        self.medium = IdealGasMedium()

    def test_default_create_preserves_amesim_parameter_contract(self) -> None:
        pipe = COMPONENT_MODEL_REGISTRY["amesim_pnl00r"].create(
            "pnl_1",
            self.medium,
            {},
        )

        self.assertIsInstance(pipe, AmesimPnl00r)
        self.assertEqual(set(pipe.ports), {"port_1", "port_2"})
        self.assertEqual(set(pipe.parameter_values), {"diam", "le", "rr", "gi"})
        self.assertEqual(pipe.parameter_values["diam"], 0.01)
        self.assertEqual(pipe.gi, 0)

    def test_rejects_fractional_gas_index(self) -> None:
        with self.assertRaisesRegex(ValueError, "gi must be an integer"):
            COMPONENT_MODEL_REGISTRY["amesim_pnl00r"].create(
                "pnl_1",
                self.medium,
                {"gi": 1.5},
            )

    def test_zero_pressure_drop_has_zero_flow_and_finite_results(self) -> None:
        pipe = AmesimPnl00r("pnl_1", self.medium)
        pipe.port_1.p = 100000.0
        pipe.port_2.p = 100000.0
        pipe.port_1.m_flow = 0.0
        pipe.port_2.m_flow = 0.0

        residuals = {
            residual.id.rsplit(":", 1)[1]: residual
            for residual in pipe.pressure_flow_equation_residuals()
        }

        self.assertEqual(pipe.mass_flow(100000.0, 100000.0), 0.0)
        self.assertEqual(residuals["mass_flow_balance"].value, 0.0)
        self.assertEqual(residuals["pressure_flow_relation"].value, 0.0)
        self.assertEqual(set(pipe.component_result_values()), {"re", "cm", "v", "ff"})

    def test_mass_flow_is_bidirectional_by_pressure_order(self) -> None:
        pipe = AmesimPnl00r("pnl_1", self.medium, diam=0.014, le=1.0, rr=0.045 / 14.0)

        forward = pipe.mass_flow(501000.0, 500000.0)
        reverse = pipe.mass_flow(500000.0, 501000.0)

        self.assertGreater(forward, 0.0)
        self.assertLess(reverse, 0.0)
        self.assertAlmostEqual(forward, -reverse, delta=abs(forward) * 0.02)

    def test_friction_factor_transitions_from_laminar_to_turbulent(self) -> None:
        pipe = AmesimPnl00r("pnl_1", self.medium, rr=1e-5)

        self.assertAlmostEqual(pipe.friction_factor(100.0), 64.0 / 100.0)
        self.assertGreater(pipe.friction_factor(100000.0), 0.0)
        self.assertLess(pipe.friction_factor(100000.0), 0.1)

    def test_darcy_pressure_drop_uses_flow_sign(self) -> None:
        pipe = AmesimPnl00r("pnl_1", self.medium)
        density = self.medium.density(500000.0, 300.0)

        forward = pipe.darcy_pressure_drop(0.01, density=density, temperature=300.0)
        reverse = pipe.darcy_pressure_drop(-0.01, density=density, temperature=300.0)

        self.assertGreater(forward, 0.0)
        self.assertLess(reverse, 0.0)
        self.assertAlmostEqual(forward, -reverse)


if __name__ == "__main__":
    unittest.main()