package patterns_test

import (
	"testing"

	"gitty.informatik.hs-mannheim.de/steger/pr3-code/go/04-design-pattern/patterns"
)

type valueCalc float64

func (v valueCalc) Calc() float64 {
	return float64(v)
}

func TestCompositeCalculator_Empty(t *testing.T) {
	empty := patterns.NewCompositeCalculator(5.0, func(a, b float64) float64 { return a + b })
	got := empty.Calc()
	want := 5.0
	if got != want {
		t.Errorf("Empty: got %v, want %v", got, want)
	}
}

func TestCompositeCalculator_Addition(t *testing.T) {
	add := patterns.NewCompositeCalculatorFromOperator("+")
	add.Add(valueCalc(5))
	add.Add(valueCalc(3))
	add.Add(valueCalc(2))
	got := add.Calc()
	want := 10.0
	if got != want {
		t.Errorf("Addition: got %v, want %v", got, want)
	}
}

func TestCompositeCalculator_Multiplication(t *testing.T) {
	mul := patterns.NewCompositeCalculatorFromOperator("*")
	mul.Add(valueCalc(2))
	mul.Add(valueCalc(3))
	mul.Add(valueCalc(4))
	got := mul.Calc()
	want := 24.0
	if got != want {
		t.Errorf("Multiplication: got %v, want %v", got, want)
	}
}

func TestCompositeCalculator_Nested(t *testing.T) {
	// + 5 3 2 * 2 3 + 4 4 = 5 + 3 + 2 + (2 * 3 * (4+4)) = 5+3+2+48 = 58
	add := patterns.NewCompositeCalculatorFromOperator("+")
	add.Add(valueCalc(5))
	add.Add(valueCalc(3))
	add.Add(valueCalc(2))

	mul := patterns.NewCompositeCalculatorFromOperator("*")
	mul.Add(valueCalc(2))
	mul.Add(valueCalc(3))

	add2 := patterns.NewCompositeCalculatorFromOperator("+")
	add2.Add(valueCalc(4))
	add2.Add(valueCalc(4))

	mul.Add(add2)
	add.Add(mul)

	got := add.Calc()
	want := 58.0
	if got != want {
		t.Errorf("Nested: got %v, want %v", got, want)
	}
}