# IfcOpenShell - IFC toolkit and geometry engine
# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
#
# This file is part of IfcOpenShell.
#
# IfcOpenShell is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# IfcOpenShell is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.

import ifcopenshell.api


class Usecase:
    def __init__(self, file, cost_item=None, cost_rate=None):
        """Assigns a cost value to a cost item from a schedule of rates

        Instead of assigning cost values from scratch for each cost item in a
        cost schedule, the cost values may instead be assigned from a schedule
        of rates.

        A schedule of rates is just another cost schedule which have cost values
        but no quantities. This API will allow you to "copy" the values from a
        cost item in the schedule of rates into another cost item in your own
        cost schedule. When the schedule of rates value is updated, then your
        cost item values will also be updated. You can think of the schedule of
        rates as a "template" to quickly populate your rates from.

        :param cost_item: The IfcCostItem that you want to copy the values to
        :type cost_item: ifcopenshell.entity_instance.entity_instance
        :param cost_rate: The IfcCostItem that you want to copy the values from
        :type cost_rate: ifcopenshell.entity_instance.entity_instance
        :return: None
        :rtype: None

        Example:

        .. code:: python

            # Let's create a schedule of rates with a single rate in it of 5.0
            rate_tables = ifcopenshell.api.run("cost.add_cost_schedule", model,
                predefined_type="SCHEDULEOFRATES")
            rate = ifcopenshell.api.run("cost.add_cost_item", model, cost_schedule=schedule)
            value = ifcopenshell.api.run("cost.add_cost_value", model, parent=rate)
            ifcopenshell.api.run("cost.edit_cost_value", model, cost_value=value,
                attributes={"AppliedValue": 5.0})

            # And this schedule will be for our actual cost plan / estimate / etc
            schedule = ifcopenshell.api.run("cost.add_cost_schedule", model)
            item = ifcopenshell.api.run("cost.add_cost_item", model, cost_schedule=schedule)

            # Now the cost item has the same rate as the one from the schedule of rate's item
            ifcopenshell.api.run("cost.assign_cost_value", model, cost_item=item, cost_rate=rate)
        """
        self.file = file
        self.settings = {"cost_item": cost_item, "cost_rate": cost_rate}

    def execute(self):
        if self.settings["cost_item"].CostValues:
            [
                ifcopenshell.api.run(
                    "cost.remove_cost_value",
                    self.file,
                    parent=self.settings["cost_item"],
                    cost_value=cost_value,
                )
                for cost_value in self.settings["cost_item"].CostValues
            ]
        # This is an assumption, and not part of the official IFC documentation
        self.settings["cost_item"].CostValues = self.settings["cost_rate"].CostValues