#include "gtest/gtest.h"

#define private public
#include "libconcur/intrusive_stack.h"

TEST(intrusive_stack, construct) {
  concur::intrusive_stack<int> s;
  EXPECT_TRUE(s.empty());
}

TEST(intrusive_stack, construct_node) {
  concur::intrusive_stack<int>::node n;
  EXPECT_TRUE(n.next.load(std::memory_order_relaxed) == nullptr);
}

TEST(intrusive_stack, copyable) {
  EXPECT_FALSE(std::is_copy_constructible<concur::intrusive_stack<int>>::value);
  EXPECT_FALSE(std::is_copy_assignable<concur::intrusive_stack<int>>::value);
}

TEST(intrusive_stack, moveable) {
  EXPECT_FALSE(std::is_move_constructible<concur::intrusive_stack<int>>::value);
  EXPECT_FALSE(std::is_move_assignable<concur::intrusive_stack<int>>::value);
}

TEST(intrusive_stack, push_one) {
  concur::intrusive_stack<int> s;
  concur::intrusive_stack<int>::node n;
  s.push(&n);
  EXPECT_FALSE(s.empty());
  EXPECT_TRUE(s.top_.load(std::memory_order_relaxed) == &n);
  EXPECT_TRUE(n.next.load(std::memory_order_relaxed) == nullptr);
}

TEST(intrusive_stack, push_many) {
  concur::intrusive_stack<int> s;
  concur::intrusive_stack<int>::node n1;
  concur::intrusive_stack<int>::node n2;
  concur::intrusive_stack<int>::node n3;
  s.push(&n1);
  s.push(&n2);
  s.push(&n3);
  EXPECT_FALSE(s.empty());
  EXPECT_TRUE(s.top_.load(std::memory_order_relaxed) == &n3);
  EXPECT_TRUE(n3.next.load(std::memory_order_relaxed) == &n2);
  EXPECT_TRUE(n2.next.load(std::memory_order_relaxed) == &n1);
  EXPECT_TRUE(n1.next.load(std::memory_order_relaxed) == nullptr);
}

TEST(intrusive_stack, push_same) {
  concur::intrusive_stack<int> s;
  concur::intrusive_stack<int>::node n;
  s.push(&n);
  s.push(&n);
  EXPECT_FALSE(s.empty());
  EXPECT_TRUE(s.top_.load(std::memory_order_relaxed) == &n);
  EXPECT_TRUE(n.next.load(std::memory_order_relaxed) == &n);
}

TEST(intrusive_stack, pop_empty) {
  concur::intrusive_stack<int> s;
  EXPECT_TRUE(s.pop() == nullptr);
}

TEST(intrusive_stack, pop_one) {
  concur::intrusive_stack<int> s;
  concur::intrusive_stack<int>::node n;
  s.push(&n);
  EXPECT_TRUE(s.pop() == &n);
  EXPECT_TRUE(s.empty());
  EXPECT_TRUE(s.top_.load(std::memory_order_relaxed) == nullptr);
  EXPECT_TRUE(n.next.load(std::memory_order_relaxed) == nullptr);
}

TEST(intrusive_stack, pop_many) {
  concur::intrusive_stack<int> s;
  concur::intrusive_stack<int>::node n1;
  concur::intrusive_stack<int>::node n2;
  concur::intrusive_stack<int>::node n3;
  s.push(&n1);
  s.push(&n2);
  s.push(&n3);
  EXPECT_TRUE(s.pop() == &n3);
  EXPECT_TRUE(s.pop() == &n2);
  EXPECT_TRUE(s.pop() == &n1);
  EXPECT_TRUE(s.empty());
  EXPECT_TRUE(s.top_.load(std::memory_order_relaxed) == nullptr);
  EXPECT_TRUE(n3.next.load(std::memory_order_relaxed) == &n2);
  EXPECT_TRUE(n2.next.load(std::memory_order_relaxed) == &n1);
  EXPECT_TRUE(n1.next.load(std::memory_order_relaxed) == nullptr);
}