# Source code for openff.evaluator.protocols.miscellaneous

    """
    A collection of miscellaneous protocols, mostly aimed at performing simple
    math operations.
    """
    import typing

    import numpy as np
    import pint

    from openff.evaluator.attributes import UNDEFINED
    from openff.evaluator.forcefield import ParameterGradient
    from openff.evaluator.substances import Component, MoleFraction, Substance
    from openff.evaluator.workflow import Protocol, workflow_protocol
    from openff.evaluator.workflow.attributes import InputAttribute, OutputAttribute

    @workflow_protocol()
    class AddValues(Protocol):
        """A protocol to add together a list of values.

        Notes
        -----
        The `values` input must either be a list of pint.Quantity, a ProtocolPath to a list
        of pint.Quantity, or a list of ProtocolPath which each point to a pint.Quantity.
        """

        values = InputAttribute(
            docstring="The values to add together.", type_hint=list, default_value=UNDEFINED
        )

        result = OutputAttribute(
            docstring="The sum of the values.",
            type_hint=typing.Union[
                int, float, pint.Measurement, pint.Quantity, ParameterGradient
            ],
        )

        def _execute(self, directory, available_resources):

            if len(self.values) < 1:
                raise ValueError("There were no values to add together")

            self.result = self.values[0]

            for value in self.values[1:]:
                self.result += value

    @workflow_protocol()
    class SubtractValues(Protocol):
        """A protocol to subtract one value from another such that:

        `result = value_b - value_a`
        """

        value_a = InputAttribute(
            docstring="`value_a` in the formula `result` = `value_b` - `value_a`.",
            type_hint=typing.Union[
                int, float, pint.Quantity, pint.Measurement, ParameterGradient
            ],
            default_value=UNDEFINED,
        )
        value_b = InputAttribute(
            docstring="`value_b` in the formula `result` = `value_b` - `value_a`.",
            type_hint=typing.Union[
                int, float, pint.Quantity, pint.Measurement, ParameterGradient
            ],
            default_value=UNDEFINED,
        )

        result = OutputAttribute(
            docstring="The results of `value_b` - `value_a`.",
            type_hint=typing.Union[
                int, float, pint.Measurement, pint.Quantity, ParameterGradient
            ],
        )

        def _execute(self, directory, available_resources):
            self.result = self.value_b - self.value_a

    @workflow_protocol()
    class MultiplyValue(Protocol):
        """A protocol which multiplies a value by a specified scalar
        """

        value = InputAttribute(
            docstring="The value to multiply.",
            type_hint=typing.Union[
                int, float, pint.Quantity, pint.Measurement, ParameterGradient
            ],
            default_value=UNDEFINED,
        )
        multiplier = InputAttribute(
            docstring="The scalar to multiply by.",
            type_hint=typing.Union[int, float, pint.Quantity],
            default_value=UNDEFINED,
        )

        result = OutputAttribute(
            docstring="The result of the multiplication.",
            type_hint=typing.Union[
                int, float, pint.Measurement, pint.Quantity, ParameterGradient
            ],
        )

        def _execute(self, directory, available_resources):
            self.result = self.value * self.multiplier

    @workflow_protocol()
    class DivideValue(Protocol):
        """A protocol which divides a value by a specified scalar
        """

        value = InputAttribute(
            docstring="The value to divide.",
            type_hint=typing.Union[
                int, float, pint.Quantity, pint.Measurement, ParameterGradient
            ],
            default_value=UNDEFINED,
        )
        divisor = InputAttribute(
            docstring="The scalar to divide by.",
            type_hint=typing.Union[int, float, pint.Quantity],
            default_value=UNDEFINED,
        )

        result = OutputAttribute(
            docstring="The result of the division.",
            type_hint=typing.Union[
                int, float, pint.Measurement, pint.Quantity, ParameterGradient
            ],
        )

        def _execute(self, directory, available_resources):
            self.result = self.value / self.divisor

    @workflow_protocol()
    class WeightByMoleFraction(Protocol):
        """Multiplies a value by the mole fraction of a component
        in a `Substance`.
        """

        value = InputAttribute(
            docstring="The value to be weighted.",
            type_hint=typing.Union[
                float, int, pint.Measurement, pint.Quantity, ParameterGradient
            ],
            default_value=UNDEFINED,
        )

        component = InputAttribute(
            docstring="The component whose mole fraction to weight by.",
            type_hint=Substance,
            default_value=UNDEFINED,
        )
        full_substance = InputAttribute(
            docstring="The full substance which describes the mole fraction of the component.",
            type_hint=Substance,
            default_value=UNDEFINED,
        )

        weighted_value = OutputAttribute(
            "The value weighted by the `component`s mole fraction as determined from the "
            "`full_substance`.",
            type_hint=typing.Union[
                float, int, pint.Measurement, pint.Quantity, ParameterGradient
            ],
        )

        def _weight_values(self, mole_fraction):
            """Weights a value by a components mole fraction.

            Parameters
            ----------
            mole_fraction: float
                The mole fraction to weight by.

            Returns
            -------
            float, int, pint.Measurement, pint.Quantity, ParameterGradient
                The weighted value.
            """
            return self.value * mole_fraction

        def _execute(self, directory, available_resources):

            assert len(self.component.components) == 1

            main_component = self.component.components[0]
            amounts = self.full_substance.get_amounts(main_component)

            if len(amounts) != 1:

                raise ValueError(
                    f"More than one type of amount was defined for component "
                    f"{main_component}. Only a single mole fraction must be defined.",
                )

            amount = next(iter(amounts))

            if not isinstance(amount, MoleFraction):

                raise ValueError(
                    f"The component {main_component} was given as an exact amount, and "
                    f"not a mole fraction"
                )

            self.weighted_value = self._weight_values(amount.value)

    @workflow_protocol()
    class FilterSubstanceByRole(Protocol):
        """A protocol which takes a substance as input, and returns a substance which only
        contains components whose role match a given criteria.
        """

        input_substance = InputAttribute(
            docstring="The substance to filter.",
            type_hint=Substance,
            default_value=UNDEFINED,
        )

        component_roles = InputAttribute(
            docstring="The roles to filter substance components against.",
            type_hint=list,
            default_value=UNDEFINED,
        )

        expected_components = InputAttribute(
            docstring="The number of components expected to remain after filtering. "
            "An exception is raised if this number is not matched.",
            type_hint=int,
            default_value=UNDEFINED,
            optional=True,
        )

        filtered_substance = OutputAttribute(
            docstring="The filtered substance.", type_hint=Substance
        )

        def _execute(self, directory, available_resources):

            filtered_components = []
            total_mole_fraction = 0.0

            for component in self.input_substance.components:

                if component.role not in self.component_roles:
                    continue

                filtered_components.append(component)

                amounts = self.input_substance.get_amounts(component)

                for amount in amounts:

                    if not isinstance(amount, MoleFraction):
                        continue

                    total_mole_fraction += amount.value

            if self.expected_components != UNDEFINED and self.expected_components != len(
                filtered_components
            ):

                raise ValueError(
                    f"The filtered substance does not contain the expected number of "
                    f"components ({self.expected_components}) - {filtered_components}",
                )

            inverse_mole_fraction = (
                1.0 if np.isclose(total_mole_fraction, 0.0) else 1.0 / total_mole_fraction
            )

            self.filtered_substance = Substance()

            for component in filtered_components:

                amounts = self.input_substance.get_amounts(component)

                for amount in amounts:

                    if isinstance(amount, MoleFraction):
                        amount = MoleFraction(amount.value * inverse_mole_fraction)

                    self.filtered_substance.add_component(component, amount)

        def validate(self, attribute_type=None):

            super(FilterSubstanceByRole, self).validate(attribute_type)
            assert all(isinstance(x, Component.Role) for x in self.component_roles)