require 'rails_helper'

module CitizenBudgetModel
  RSpec.describe Simulator, type: :model do
    let(:valid_attributes) do
      {
        organization_id: 1,
        name: 'Simulator',
      }
    end

    [:organization_id, :name].each do |attribute|
      it { should validate_presence_of attribute }
    end
    it { should validate_numericality_of(:total_revenue).only_integer.is_greater_than(0) }

    it 'should validate the equation' do
      expect(Simulator.new(valid_attributes.merge(equation: 'INVALID'))).to_not be_valid
    end

    describe '#activate!' do
      before(:each) do
        3.times do
          Simulator.create!(valid_attributes).activate!
        end
      end

      it 'should deactivate all active simulators and activate the given simulator' do
        simulator = Simulator.create!(valid_attributes)
        simulator.activate!
        expect(Simulator.where(active: true).count).to eq(1)
        expect(simulator.active).to eq(true)
      end
    end

    describe '#working_equation' do
      let(:simulator) do
        Simulator.new
      end

      it 'should return the equation if set' do
        simulator.equation = '1 + 1'
        expect(simulator.working_equation).to eq('1 + 1')
      end

      it 'should return a default equation it not set' do
        simulator.sections.build.questions.build(machine_name: 'var', default_value: 1, unit_value_down: 1, unit_value_up: 2)
        expect(simulator.working_equation).to eq('(var - 1.0) * (var < 1.0 ? 1.0 : 2.0)')
      end
    end

    describe '#default_equation' do
      it 'should return the empty string if no variables' do
        simulator = Simulator.new
        expect(simulator.default_equation).to eq('')
      end

      it 'should return a default equation if variables' do
        simulator = Simulator.new
        1.upto(3) do |number|
          simulator.sections.build.questions.build({
            machine_name: "variable_#{number}",
            default_value: -number,
            unit_value_down: number * 1.5,
            unit_value_up: number * 2,
          })
        end
        simulator.sections.build.questions.build({
          machine_name: "incomplete",
        })
        expect(simulator.default_equation).to eq('(variable_1 - -1.0) * (variable_1 < -1.0 ? 1.5 : 2.0) + (variable_2 - -2.0) * (variable_2 < -2.0 ? 3.0 : 4.0) + (variable_3 - -3.0) * (variable_3 < -3.0 ? 4.5 : 6.0)')
      end
    end

    describe '#solve' do
      let(:simulator) do
        simulator = Simulator.new(id: 1, equation: 'a + b * id')
      end

      it 'should solve the equation with strings as keys' do
        expect(simulator.solve('a' => 2, 'b' => 3, 'id' => 4)).to eq(14)
      end

      it 'should solve the equation with symbols as keys' do
        expect(simulator.solve(a: 2, b: 3, id: 4)).to eq(14)
      end

      it 'should coerce variable values' do
        expect(simulator.solve(a: '2', b: '3', id: '4')).to eq(14)
      end

      it 'should error if not all variables provided' do
        expect{simulator.solve(a: 2, b: 3)}.to raise_error(NameError, %(undefined local variable or method `id' for #<struct a=2.0, b=3.0>))
      end
    end
  end
end