#include "util.h"
#include "util-inl.h"

#include "gtest/gtest.h"

TEST(UtilTest, ListHead) {
  struct Item { node::ListNode<Item> node_; };
  typedef node::ListHead<Item, &Item::node_> List;

  List list;
  EXPECT_TRUE(list.IsEmpty());

  Item one;
  EXPECT_TRUE(one.node_.IsEmpty());

  list.PushBack(&one);
  EXPECT_FALSE(list.IsEmpty());
  EXPECT_FALSE(one.node_.IsEmpty());

  {
    List::Iterator it = list.begin();
    EXPECT_NE(list.end(), it);
    EXPECT_EQ(&one, *it);
    ++it;
    EXPECT_FALSE(it != list.end());  // Iterator only implements != operator.
  }

  Item two;
  list.PushBack(&two);

  {
    List::Iterator it = list.begin();
    EXPECT_NE(list.end(), it);
    EXPECT_EQ(&one, *it);
    ++it;
    EXPECT_NE(list.end(), it);
    EXPECT_EQ(&two, *it);
    ++it;
    EXPECT_FALSE(it != list.end());  // Iterator only implements != operator.
  }

  EXPECT_EQ(&one, list.PopFront());
  EXPECT_TRUE(one.node_.IsEmpty());
  EXPECT_FALSE(list.IsEmpty());

  {
    List::Iterator it = list.begin();
    EXPECT_NE(list.end(), it);
    EXPECT_EQ(&two, *it);
    ++it;
    EXPECT_FALSE(it != list.end());  // Iterator only implements != operator.
  }

  EXPECT_EQ(&two, list.PopFront());
  EXPECT_TRUE(two.node_.IsEmpty());
  EXPECT_TRUE(list.IsEmpty());
  EXPECT_FALSE(list.begin() != list.end());
}