#################################################################################
# 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.
#################################################################################
"""
This provides standard valve models for adiabatic control valves.  Beyond the
most common valve models, and adiabatic valve model can be added by supplying
custom callbacks for the pressure-flow relation or valve function.
"""
# Changing existing config block attributes
# pylint: disable=protected-access

__Author__ = "John Eslick"

from enum import Enum

import pyomo.environ as pyo
from pyomo.common.config import ConfigValue, In

from idaes.core import declare_process_block_class
from idaes.models.unit_models.pressure_changer import (
    PressureChangerData,
    ThermodynamicAssumption,
    MaterialBalanceType,
)
from idaes.core.util.exceptions import ConfigurationError
import idaes.logger as idaeslog
import idaes.core.util.scaling as iscale

_log = idaeslog.getLogger(__name__)


class ValveFunctionType(Enum):
    """
    Enum of supported valve types.
    """

    linear = 1
    quick_opening = 2
    equal_percentage = 3


def linear_cb(valve):
    """
    Linear opening valve function callback.
    """

    @valve.Expression(valve.flowsheet().time)
    def valve_function(b, t):
        return b.valve_opening[t]


def quick_cb(valve):
    """
    Quick opening valve function callback.
    """

    @valve.Expression(valve.flowsheet().time)
    def valve_function(b, t):
        return pyo.sqrt(b.valve_opening[t])


def equal_percentage_cb(valve):
    """
    Equal percentage valve function callback.
    """
    valve.alpha = pyo.Var(initialize=100, doc="Valve function parameter")
    valve.alpha.fix()

    @valve.Expression(valve.flowsheet().time)
    def valve_function(b, t):
        return b.alpha ** (b.valve_opening[t] - 1)


def pressure_flow_default_callback(valve):
    """
    Add the default pressure flow relation constraint.  This will be used in the
    valve model, a custom callback is provided.
    """
    umeta = valve.config.property_package.get_metadata().get_derived_units

    valve.Cv = pyo.Var(
        initialize=0.1,
        doc="Valve flow coefficient",
        units=umeta("amount") / umeta("time") / umeta("pressure") ** 0.5,
    )
    valve.Cv.fix()

    valve.flow_var = pyo.Reference(valve.control_volume.properties_in[:].flow_mol)
    valve.pressure_flow_equation_scale = lambda x: x**2

    @valve.Constraint(valve.flowsheet().time)
    def pressure_flow_equation(b, t):
        Po = b.control_volume.properties_out[t].pressure
        Pi = b.control_volume.properties_in[t].pressure
        F = b.control_volume.properties_in[t].flow_mol
        Cv = b.Cv
        fun = b.valve_function[t]
        return F**2 == Cv**2 * (Pi - Po) * fun**2


@declare_process_block_class("Valve", doc="Adiabatic valves")
class ValveData(PressureChangerData):
    """
    Basic valve model class.
    """

    # Same settings as the default pressure changer, but force to expander with
    # isentropic efficiency
    CONFIG = PressureChangerData.CONFIG()
    CONFIG.compressor = False
    CONFIG.get("compressor")._default = False
    CONFIG.get("compressor")._domain = In([False])
    CONFIG.material_balance_type = MaterialBalanceType.componentTotal
    CONFIG.get("material_balance_type")._default = MaterialBalanceType.componentTotal
    CONFIG.thermodynamic_assumption = ThermodynamicAssumption.adiabatic
    CONFIG.get("thermodynamic_assumption")._default = ThermodynamicAssumption.adiabatic
    CONFIG.get("thermodynamic_assumption")._domain = In(
        [ThermodynamicAssumption.adiabatic]
    )
    CONFIG.declare(
        "valve_function_callback",
        ConfigValue(
            default=ValveFunctionType.linear,
            description="Valve function type or callback for custom",
            doc="""This takes either an enumerated valve function type in: {
ValveFunctionType.linear, ValveFunctionType.quick_opening,
ValveFunctionType.equal_percentage, ValveFunctionType.custom} or a callback
function that takes a valve model object as an argument and adds a time-indexed
valve_function expression to it. Any additional required variables, expressions,
or constraints required can also be added by the callback.""",
        ),
    )
    CONFIG.declare(
        "pressure_flow_callback",
        ConfigValue(
            default=pressure_flow_default_callback,
            description="Callback function providing the valve_function expression",
            doc="""This callback function takes a valve model object as an argument
and adds a time-indexed valve_function expression to it.  Any additional required
variables, expressions, or constraints required can also be added by the callback.""",
        ),
    )

    def build(self):
        super().build()

        self.valve_opening = pyo.Var(
            self.flowsheet().time,
            initialize=1,
            bounds=(0, 1),
            doc="Fraction open for valve from 0 to 1",
        )
        self.valve_opening.fix()
        # If the valve function callback is set to one of the known enumerated
        # types, set the callback appropriately.  If not callable and not a known
        # type raise ConfigurationError.
        vfcb = self.config.valve_function_callback
        if not callable(vfcb):
            if vfcb == ValveFunctionType.linear:
                self.config.valve_function_callback = linear_cb
            elif vfcb == ValveFunctionType.quick_opening:
                self.config.valve_function_callback = quick_cb
            elif vfcb == ValveFunctionType.equal_percentage:
                self.config.valve_function_callback = equal_percentage_cb
            else:
                raise ConfigurationError("Invalid valve function callback.")
        self.config.valve_function_callback(self)
        self.config.pressure_flow_callback(self)

    def initialize_build(
        self,
        state_args=None,
        outlvl=idaeslog.NOTSET,
        solver=None,
        optarg=None,
    ):
        """
        Initialize the valve based on a deltaP guess.

        Args:
            state_args (dict): Initial state for property initialization
            outlvl : sets output level of initialization routine
            solver (str): Solver to use for initialization
            optarg (dict): Solver arguments dictionary
        """

        for t in self.flowsheet().time:
            if (
                self.deltaP[t].fixed
                or self.ratioP[t].fixed
                or self.outlet.pressure[t].fixed
            ):
                continue
            # Generally for the valve initialization pressure drop won't be
            # fixed, so if there is no good guess on deltaP try to out one in
            Pout = self.outlet.pressure[t]
            Pin = self.inlet.pressure[t]
            if self.deltaP[t].value is not None:
                prdp = pyo.value((self.deltaP[t] - Pin) / Pin)
            else:
                prdp = -100  # crazy number to say don't use deltaP as guess
            if pyo.value(Pout / Pin) > 1 or pyo.value(Pout / Pin) < 0.0:
                if pyo.value(self.ratioP[t]) <= 1 and pyo.value(self.ratioP[t]) >= 0:
                    Pout.value = pyo.value(Pin * self.ratioP[t])
                elif prdp <= 1 and prdp >= 0:
                    Pout.value = pyo.value(prdp * Pin)
                else:
                    Pout.value = pyo.value(Pin * 0.95)
            self.deltaP[t] = pyo.value(Pout - Pin)
            self.ratioP[t] = pyo.value(Pout / Pin)

        # one bad thing about reusing this is that the log messages aren't
        # really compatible with being nested inside another initialization
        super().initialize_build(
            state_args=state_args, outlvl=outlvl, solver=solver, optarg=optarg
        )

    def calculate_scaling_factors(self):
        """
        Calculate pressure flow constraint scaling from flow variable scale.
        """
        # The value of the valve opening and the output of the valve function
        # expression are between 0 and 1, so the only thing that needs to be
        # scaled here is the pressure-flow constraint, which can be scaled by
        # using the flow variable scale.  The flow variable could be defined
        # in different ways, so the flow variable is determined here from a
        # "flow_var[t]" reference set in the pressure-flow callback. The flow
        # term could be in various forms, so an optional
        # "pressure_flow_equation_scale" function can be defined in the callback
        # as well.  The pressure-flow function could be flow = f(Pin, Pout), but
        # it could also be flow**2 = f(Pin, Pout), ... The so
        # "pressure_flow_equation_scale" provides the form of the LHS side as
        # a function of the flow variable.

        super().calculate_scaling_factors()

        # Do some error trapping.
        if not hasattr(self, "pressure_flow_equation"):
            raise AttributeError(
                "Pressure-flow callback must define pressure_flow_equation[t]"
            )
        # Check for flow term form if none assume flow = f(Pin, Pout)
        if hasattr(self, "pressure_flow_equation_scale"):
            ff = self.pressure_flow_equation_scale
        else:
            ff = lambda x: x
        # if the "flow_var" is not set raise an exception
        if not hasattr(self, "flow_var"):
            raise AttributeError(
                "Pressure-flow callback must define flow_var[t] reference"
            )

        # Calculate and set the pressure-flow relation scale.
        if hasattr(self, "pressure_flow_equation"):
            for t, c in self.pressure_flow_equation.items():
                iscale.constraint_scaling_transform(
                    c,
                    ff(
                        iscale.get_scaling_factor(
                            self.flow_var[t], default=1, warning=True
                        )
                    ),
                )

    def _get_performance_contents(self, time_point=0):
        pc = super()._get_performance_contents(time_point=time_point)

        pc["vars"]["Opening"] = self.valve_opening[time_point]
        try:
            pc["vars"]["Valve Coefficient"] = self.Cv
        except AttributeError:
            pass
        if self.config.valve_function_callback == ValveFunctionType.equal_percentage:
            pc["vars"]["alpha"] = self.alpha
        return pc
