package app

import "testing"

func TestToastStackPushAndOrder(t *testing.T) {
	var s toastStack
	s.push(toastInfo, "one")
	s.push(toastError, "two")
	s.push(toastAttention, "three")

	snap := s.snapshot()
	if len(snap) != 3 {
		t.Fatalf("snapshot len = %d, want 3", len(snap))
	}
	if snap[0].text != "one" || snap[1].text != "two" || snap[2].text != "three" {
		t.Fatalf("snapshot order wrong: %#v", snap)
	}
	if snap[0].kind != toastInfo || snap[1].kind != toastError || snap[2].kind != toastAttention {
		t.Fatalf("snapshot kinds wrong: %#v", snap)
	}
	// IDs strictly increase.
	if !(snap[0].id < snap[1].id && snap[1].id < snap[2].id) {
		t.Fatalf("ids not increasing: %#v", snap)
	}
}

func TestToastStackCapDropsOldest(t *testing.T) {
	var s toastStack
	for i := 0; i < toastStackCap+3; i++ {
		s.push(toastInfo, "msg")
	}
	snap := s.snapshot()
	if len(snap) != toastStackCap {
		t.Fatalf("len = %d, want %d", len(snap), toastStackCap)
	}
	// The earliest IDs should have been dropped, leaving the highest
	// toastStackCap IDs.
	for i := 1; i < len(snap); i++ {
		if snap[i].id <= snap[i-1].id {
			t.Fatalf("ordering broken after cap: %#v", snap)
		}
	}
	// First retained id should be 4 (1,2,3 dropped; cap=5 leaves 4..8).
	want := uint64(toastStackCap + 3 - toastStackCap + 1)
	if snap[0].id != want {
		t.Fatalf("first retained id = %d, want %d", snap[0].id, want)
	}
}

func TestToastStackDismissTop(t *testing.T) {
	var s toastStack
	if s.dismissTop() {
		t.Fatalf("dismissTop on empty stack returned true")
	}
	s.push(toastInfo, "a")
	s.push(toastError, "b")
	if !s.dismissTop() {
		t.Fatalf("dismissTop returned false with items present")
	}
	snap := s.snapshot()
	if len(snap) != 1 || snap[0].text != "a" {
		t.Fatalf("after dismissTop: %#v", snap)
	}
	if !s.dismissTop() {
		t.Fatalf("dismissTop on last item returned false")
	}
	if s.length() != 0 {
		t.Fatalf("length after final dismiss = %d, want 0", s.length())
	}
}

func TestToastStackClear(t *testing.T) {
	var s toastStack
	if s.clear() {
		t.Fatalf("clear on empty returned true")
	}
	s.push(toastInfo, "a")
	s.push(toastError, "b")
	s.push(toastAttention, "c")
	if !s.clear() {
		t.Fatalf("clear returned false with items present")
	}
	if s.length() != 0 {
		t.Fatalf("length after clear = %d, want 0", s.length())
	}
	if snap := s.snapshot(); snap != nil {
		t.Fatalf("snapshot after clear = %#v, want nil", snap)
	}
}

func TestToastStackSnapshotIsCopy(t *testing.T) {
	var s toastStack
	s.push(toastInfo, "a")
	snap := s.snapshot()
	snap[0].text = "mutated"
	again := s.snapshot()
	if again[0].text != "a" {
		t.Fatalf("snapshot is not an independent copy: %#v", again)
	}
}