#################################################################################
# The Institute for the Design of Advanced Energy Systems Integrated Platform
# Framework (IDAES IP) was produced under the DOE Institute for the
# Design of Advanced Energy Systems (IDAES).
#
# Copyright (c) 2018-2023 by the software owners: The Regents of the
# University of California, through Lawrence Berkeley National Laboratory,
# National Technology & Engineering Solutions of Sandia, LLC, Carnegie Mellon
# University, West Virginia University Research Corporation, et al.
# All rights reserved.  Please see the files COPYRIGHT.md and LICENSE.md
# for full copyright and license information.
#################################################################################

import pytest
import pyomo.environ as pyo
from pyomo.util.check_units import assert_units_consistent

from idaes.core import FlowsheetBlock
from idaes.models.properties import iapws95
from idaes.models_extra.power_generation.unit_models import FWH0D
from idaes.core.util.model_statistics import degrees_of_freedom
from idaes.core.solvers import get_solver
from idaes.models.properties.general_helmholtz import helmholtz_available

# Set up solver
solver = get_solver()


@pytest.mark.skipif(not helmholtz_available(), reason="General Helmholtz not available")
@pytest.mark.unit
def test_fwh_model():
    model = pyo.ConcreteModel()
    model.fs = FlowsheetBlock(
        dynamic=False, default_property_package=iapws95.Iapws95ParameterBlock()
    )
    model.fs.properties = model.fs.config.default_property_package
    model.fs.fwh = FWH0D(
        has_desuperheat=True,
        has_drain_cooling=True,
        has_drain_mixer=True,
        property_package=model.fs.properties,
    )

    model.fs.fwh.desuperheat.hot_side_inlet.flow_mol[:].set_value(100)
    model.fs.fwh.desuperheat.hot_side_inlet.pressure.fix(201325)
    model.fs.fwh.desuperheat.hot_side_inlet.enth_mol.fix(60000)
    model.fs.fwh.drain_mix.drain.flow_mol.fix(1)
    model.fs.fwh.drain_mix.drain.pressure.fix(201325)
    model.fs.fwh.drain_mix.drain.enth_mol.fix(20000)
    model.fs.fwh.cooling.cold_side_inlet.flow_mol.fix(400)
    model.fs.fwh.cooling.cold_side_inlet.pressure.fix(101325)
    model.fs.fwh.cooling.cold_side_inlet.enth_mol.fix(3000)
    model.fs.fwh.condense.area.fix(1000)
    model.fs.fwh.condense.overall_heat_transfer_coefficient.fix(100)
    model.fs.fwh.desuperheat.area.fix(1000)
    model.fs.fwh.desuperheat.overall_heat_transfer_coefficient.fix(10)
    model.fs.fwh.cooling.area.fix(1000)
    model.fs.fwh.cooling.overall_heat_transfer_coefficient.fix(10)
    model.fs.fwh.initialize(optarg={"max_iter": 50})

    assert degrees_of_freedom(model) == 0
    assert (
        abs(pyo.value(model.fs.fwh.desuperheat.hot_side_inlet.flow_mol[0]) - 98.335)
        < 0.01
    )


@pytest.mark.skipif(not helmholtz_available(), reason="General Helmholtz not available")
@pytest.mark.integration
def test_fwh_units():
    model = pyo.ConcreteModel()
    model.fs = FlowsheetBlock(
        dynamic=False, default_property_package=iapws95.Iapws95ParameterBlock()
    )
    model.fs.properties = model.fs.config.default_property_package
    model.fs.fwh = FWH0D(
        has_desuperheat=True,
        has_drain_cooling=True,
        has_drain_mixer=True,
        property_package=model.fs.properties,
    )

    assert_units_consistent(model)
