package pool

import (
	"github.com/stretchr/testify/assert"
	"testing"
)

func TestPool_Add(t *testing.T) {
	p := &Pool{
		Max:   10,
		Value: 3,
	}
	p.Add(4)
}

func TestPool_Add_Overflows(t *testing.T) {
	shad := &Pool{
		Max:   5,
		Value: 0,
	}
	dist := &Pool{
		OverflowsTo: shad,
		Max:         5,
		Value:       0,
	}
	dist.Add(8)
	assert.Equal(t, shad.Value, 3)
}

func TestPool_Subtract(t *testing.T) {
	p := &Pool{
		Max:   10,
		Value: 8,
	}
	p.Subtract(6)
	assert.Equal(t, 2, p.Value)
}

func TestPool_Subtract_Empties(t *testing.T) {
	p := &Pool{
		Max:   10,
		Value: 4,
	}
	p.Subtract(8)
	assert.Equal(t, 0, p.Value)
}

func TestPool_Subtract_Flows(t *testing.T) {
	dest := &Pool{
		Value: 0,
		Max:   Infinite,
	}
	p := &Pool{
		SubtractsTo: dest,
		Max:         Infinite,
		Value:       10,
	}
	p.Subtract(8)
	assert.Equal(t, 8, dest.Value)
	assert.Equal(t, 2, p.Value)
}

func TestPool_Subtract_Flows_Empties(t *testing.T) {
	dest := &Pool{
		Value: 0,
		Max:   Infinite,
	}
	p := &Pool{
		SubtractsTo: dest,
		Max:         Infinite,
		Value:       5,
	}
	p.Subtract(8)
	assert.Equal(t, 5, dest.Value)
	assert.Equal(t, 0, p.Value)
}