package middleware

import (
	"reflect"
	"testing"
)

func TestOrderedIDsAdd(t *testing.T) {
	o := newOrderedIDs()

	noError(t, o.Add(&mockIder{"first"}, After))
	noError(t, o.Add(&mockIder{"second"}, After))
	noError(t, o.Add(&mockIder{"third"}, After))
	noError(t, o.Add(&mockIder{"real-first"}, Before))

	if err := o.Add(&mockIder{""}, After); err == nil {
		t.Errorf("expect error adding empty ID, got none")
	}
	if err := o.Add(&mockIder{"second"}, After); err == nil {
		t.Errorf("expect error adding duplicate, got none")
	}
	if err := o.Add(&mockIder{"unique"}, 123); err == nil {
		t.Errorf("expect error add unknown relative position, got none")
	}

	expectIDs := []string{"real-first", "first", "second", "third"}

	if e, a := expectIDs, o.List(); !reflect.DeepEqual(e, a) {
		t.Errorf("expect %v order, got %v", e, a)
	}
}

func TestOrderedIDsInsert(t *testing.T) {
	o := newOrderedIDs()

	noError(t, o.Add(&mockIder{"first"}, After))
	noError(t, o.Insert(&mockIder{"third"}, "first", After))
	noError(t, o.Insert(&mockIder{"second"}, "third", Before))
	noError(t, o.Insert(&mockIder{"real-first"}, "first", Before))
	noError(t, o.Insert(&mockIder{"not-yet-last"}, "second", After))
	noError(t, o.Insert(&mockIder{"last"}, "third", After))

	if err := o.Insert(&mockIder{""}, "first", After); err == nil {
		t.Errorf("expect error insert empty ID, got none")
	}
	if err := o.Insert(&mockIder{"second"}, "", After); err == nil {
		t.Errorf("expect error insert with empty relative ID, got none")
	}
	if err := o.Insert(&mockIder{"second"}, "third", After); err == nil {
		t.Errorf("expect error insert duplicate, got none")
	}
	if err := o.Insert(&mockIder{"unique"}, "not-found", After); err == nil {
		t.Errorf("expect error insert not found relative ID, got none")
	}
	if err := o.Insert(&mockIder{"unique"}, "first", 123); err == nil {
		t.Errorf("expect error insert unknown relative position, got none")
	}

	expectIDs := []string{"real-first", "first", "second", "not-yet-last", "third", "last"}
	if e, a := expectIDs, o.List(); !reflect.DeepEqual(e, a) {
		t.Errorf("expect %v order, got %v", e, a)
	}
}

func TestOrderedIDsGet(t *testing.T) {
	o := newOrderedIDs()

	noError(t, o.Add(&mockIder{"first"}, After))
	noError(t, o.Add(&mockIder{"second"}, After))

	f, ok := o.Get("not-found")
	if ok || f != nil {
		t.Fatalf("expect id not to be found, but was")
	}

	f, ok = o.Get("first")
	if !ok {
		t.Fatalf("expect id to be found, was not")
	}
	if e, a := "first", f.ID(); e != a {
		t.Errorf("expect %v id, got %v", e, a)
	}
}

func TestOrderedIDsSwap(t *testing.T) {
	o := newOrderedIDs()

	noError(t, o.Add(&mockIder{"first"}, After))
	noError(t, o.Add(&mockIder{"second"}, After))
	noError(t, o.Add(&mockIder{"third"}, After))

	if _, err := o.Swap("first", &mockIder{""}); err == nil {
		t.Errorf("expect error swap empty ID, got none")
	}
	if _, err := o.Swap("", &mockIder{"second"}); err == nil {
		t.Errorf("expect error swap with empty relative ID, got none")
	}

	if _, err := o.Swap("not-exists", &mockIder{"last"}); err == nil {
		t.Errorf("expect error swap not-exists ID, got none")
	}
	if _, err := o.Swap("second", &mockIder{"first"}); err == nil {
		t.Errorf("expect error swap to existing ID, got none")
	}

	r, err := o.Swap("second", &mockIder{"otherSecond"})
	noError(t, err)
	if r == nil {
		t.Fatalf("expect removed item to be returned")
	}
	if e, a := "second", r.ID(); e != a {
		t.Errorf("expect %v removed ider, got %v", e, a)
	}

	expectIDs := []string{"first", "otherSecond", "third"}
	if e, a := expectIDs, o.List(); !reflect.DeepEqual(e, a) {
		t.Errorf("expect %v order, got %v", e, a)
	}
}

func TestOrderedIDsRemove(t *testing.T) {
	o := newOrderedIDs()
	firstIder := &mockIder{"first"}
	noError(t, o.Add(firstIder, After))
	noError(t, o.Insert(&mockIder{"third"}, "first", After))
	if removed, err := o.Remove("first"); err != nil {
		t.Errorf("expect no error, got %v", err)
	} else if removed != firstIder {
		t.Error("removed ider did not match expected")
	}
	noError(t, o.Insert(&mockIder{"last"}, "third", After))

	if _, err := o.Remove(""); err == nil {
		t.Errorf("expect error remove empty ID, got none")
	}
	if _, err := o.Remove("not-exists"); err == nil {
		t.Errorf("expect error remove not exists ID, got none")
	}

	expectIDs := []string{"third", "last"}
	if e, a := expectIDs, o.List(); !reflect.DeepEqual(e, a) {
		t.Errorf("expect %v order, got %v", e, a)
	}
}

func TestOrderedIDsClear(t *testing.T) {
	o := newOrderedIDs()

	noError(t, o.Add(&mockIder{"first"}, After))
	noError(t, o.Add(&mockIder{"second"}, After))

	o.Clear()

	noError(t, o.Add(&mockIder{"third"}, After))
	noError(t, o.Add(&mockIder{"fourth"}, After))

	expectIDs := []string{"third", "fourth"}
	if e, a := expectIDs, o.List(); !reflect.DeepEqual(e, a) {
		t.Errorf("expect %v order, got %v", e, a)
	}
}

func TestOrderedIDsGetOrder(t *testing.T) {
	o := newOrderedIDs()

	noError(t, o.Add(&mockIder{"first"}, After))
	noError(t, o.Add(&mockIder{"second"}, After))
	noError(t, o.Add(&mockIder{"third"}, After))
	noError(t, o.Add(&mockIder{"real-first"}, Before))

	expectIDs := []string{"real-first", "first", "second", "third"}
	if e, a := expectIDs, o.List(); !reflect.DeepEqual(e, a) {
		t.Errorf("expect %v order, got %v", e, a)
	}

	actualOrder := o.GetOrder()

	if e, a := len(expectIDs), len(actualOrder); e != a {
		t.Errorf("expect %v IDs, got %v", e, a)
	}

	compareGetOrder(t, expectIDs, actualOrder)
}

func TestRelativeOrder_insert(t *testing.T) {
	var ro relativeOrder

	if err := ro.insert(0, After); err != nil {
		t.Errorf("expect no error, got %v", err)
	}
	if err := ro.insert(0, Before); err != nil {
		t.Errorf("expect no error, got %v", err)
	}

	if len(ro.order) > 0 {
		t.Errorf("expect slice to be empty")
	}

	if err := ro.insert(0, After, "foo"); err != nil {
		t.Errorf("expect no error, got %v", err)
	}
	if err := ro.insert(0, After, "bar"); err != nil {
		t.Errorf("expect no error, got %v", err)
	}
	if err := ro.insert(1, After, "baz"); err != nil {
		t.Errorf("expect no error, got %v", err)
	}
	if err := ro.insert(1, Before, "fob"); err != nil {
		t.Errorf("expect no error, got %v", err)
	}
	if err := ro.insert(3, Before, "bas"); err != nil {
		t.Errorf("expect no error, got %v", err)
	}
	if err := ro.insert(3, After, "bat"); err != nil {
		t.Errorf("expect no error, got %v", err)
	}
	if err := ro.insert(0, 1024, "zzz"); err == nil {
		t.Error("expect error, got nil")
	}

	expect := []string{"foo", "fob", "bar", "bas", "bat", "baz"}
	if !reflect.DeepEqual(expect, ro.order) {
		t.Errorf("%v != %v", expect, ro.order)
	}
}

func compareGetOrder(t *testing.T, expected []string, actual []interface{}) {
	t.Helper()
	for _, eID := range expected {
		var found bool
		for _, aIder := range actual {
			if e, a := eID, aIder.(ider).ID(); e == a {
				if found {
					t.Errorf("expect only one %v, got more", e)
				}
				found = true
			}
		}
		if !found {
			t.Errorf("expect to find %v, did not", eID)
		}
	}
}