package containers_test

import (
	"testing"

	"git.mstar.dev/mstar/goutils/containers"
	"git.mstar.dev/mstar/goutils/other"
)

func TestStack(t *testing.T) {
	stack := containers.BuildStack[int]()
	elem, err := stack.Top()
	switch err {
	case containers.ErrEmptyQueue:
	// Expected, continue
	case containers.ErrInvalidQueue:
		t.Fatal("New queue is invalid")
	case nil:
		t.Fatalf("New queue shouldn't have any elements yet: %v", elem)
	}
	elem, err = stack.Pop()
	switch err {
	case containers.ErrEmptyQueue:
	// Expected, continue
	case containers.ErrInvalidQueue:
		t.Fatal("New queue is invalid")
	case nil:
		t.Fatalf("New queue shouldn't have any elements yet: %v", elem)
	}
	if !stack.IsEmpty() {
		t.Fatal("New queue isn't empty")
	}

	if err = stack.Push(other.IntoPointer(10)); err != nil {
		t.Fatal("Failed to push value onto new queue")
	}
	if stack.IsEmpty() {
		t.Fatal("Queue is empty after pushing a value")
	}

	elem, err = stack.Top()
	if err != nil {
		t.Fatalf("Failed to get top element from queue after inserting one: %v", err)
	}
	switch {
	case elem == nil:
		t.Fatal("Got nil elem; want &10")
	case *elem == 10:
	// Expected, continue
	default:
		t.Fatalf("Got %v; want &10", *elem)
	}

	if err = stack.Push(other.IntoPointer(20)); err != nil {
		t.Fatal("Failed to push value onto queue")
	}

	elem, err = stack.Top()
	if err != nil {
		t.Fatalf("Failed to get top element from queue after inserting one: %v", err)
	}
	switch {
	case elem == nil:
		t.Fatal("Got nil elem; want &20")
	case *elem == 20:
	// Expected, continue
	default:
		t.Fatalf("Got %v; want &20", *elem)
	}

	if stack.IsEmpty() {
		t.Fatal("Top shouldn't pop an element from the queue")
	}

	elem, err = stack.Pop()
	if err != nil {
		t.Fatalf("Expected no error while popping a value: %v", err)
	}
	switch {
	case elem == nil:
		t.Fatal("Got nil elem; want &20")
	case *elem == 20:
	// Expected, continue
	default:
		t.Fatalf("Got %v; want &20", *elem)
	}

	if stack.IsEmpty() {
		t.Fatal("Queue should still have one element left")
	}

	elem, err = stack.Pop()
	if err != nil {
		t.Fatalf("Expected no error while popping a value: %v", err)
	}
	switch {
	case elem == nil:
		t.Fatal("Got nil elem; want &10")
	case *elem == 10:
	// Expected, continue
	default:
		t.Fatalf("Got %v; want &10", *elem)
	}

	if !stack.IsEmpty() {
		t.Fatal("Queue should be empty now")
	}
}