package fit

import (
	"testing"
)

type selectTest struct {
	item testItem
	bin  int
	pos  int
}

type testItem int64

func (t *testItem) Size() int64 {
	return int64(*t)
}

var firstTests = []selectTest{
	{
		item: testItem(8),
		bin:  0,
		pos:  0,
	},
	{
		item: testItem(1),
		bin:  0,
		pos:  1,
	},
	{
		item: testItem(3),
		bin:  1,
		pos:  0,
	},
	{
		item: testItem(1),
		bin:  0,
		pos:  2,
	},
	{
		item: testItem(4),
		bin:  1,
		pos:  1,
	},
}

// one must swap the bins in head, as they are sorted in place. this isn't nice.
var bestTests = []selectTest{
	{
		item: testItem(6),
		bin:  0,
		pos:  0,
	},
	{
		item: testItem(8),
		bin:  1,
		pos:  0,
	},
	{
		item: testItem(1),
		bin:  0,
		pos:  1,
	},
	{
		item: testItem(2),
		bin:  1,
		pos:  1,
	},
	{
		item: testItem(1),
		bin:  0,
		pos:  2,
	},
}

var worstTests = []selectTest{
	{
		item: testItem(6),
		bin:  0,
		pos:  0,
	},
	{
		item: testItem(8),
		bin:  1,
		pos:  0,
	},
	{
		item: testItem(1),
		bin:  0,
		pos:  1,
	},
	{
		item: testItem(2),
		bin:  0,
		pos:  2,
	},
	{
		item: testItem(1),
		bin:  0,
		pos:  1,
	},
}

func testSelect(t *testing.T, binSelect BinSelectFunc, tests []selectTest) {
	bins := []Bin{}

	for _, test := range tests {
		var err error
		bins, err = binSelect(bins, 10, &test.item)
		if err != nil {
			t.FailNow()
		}
		t.Logf("%#v", bins)

		binItem := bins[test.bin].Items()[test.pos]
		if binItem.Size() != test.item.Size() {
			t.Logf("items differ: %+v %+v", binItem, test.item)
			t.Fail()
		}
	}
}

func TestFirst(t *testing.T) {
	testSelect(t, First, firstTests)
}

func TestBest(t *testing.T) {
	testSelect(t, Best, bestTests)
}

func TestWorst(t *testing.T) {
	testSelect(t, Worst, worstTests)
}