// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/lib/listnode/listnode.h"

#include <zxtest/zxtest.h>

typedef struct list_elem {
  int value;
  list_node_t node;
} list_elem_t;

static void expect_list_sorted(list_node_t* list, int count) {
  EXPECT_EQ(list_length(list), (size_t)count);
  int index = 0;
  list_elem_t* entry = NULL;
  list_for_every_entry (list, entry, list_elem_t, node) {
    EXPECT_EQ(entry->value, index);
    EXPECT_EQ(list_next_wrap_type(list, &entry->node, list_elem_t, node)->value,
              (index + 1) % count);
    EXPECT_EQ(list_prev_wrap_type(list, &entry->node, list_elem_t, node)->value,
              (index + count - 1) % count);
    index++;
  }
}

TEST(ListnodeCTests, initialize_empty_list) {
  list_node_t list = LIST_INITIAL_CLEARED_VALUE;
  EXPECT_FALSE(list_in_list(&list));

  list_initialize(&list);
  EXPECT_TRUE(list_in_list(&list));
  EXPECT_TRUE(list_is_empty(&list));
  EXPECT_EQ(list_length(&list), 0u);

  EXPECT_NULL(list_peek_head(&list));
  EXPECT_NULL(list_peek_head_type(&list, list_elem_t, node));
  EXPECT_NULL(list_peek_tail(&list));
  EXPECT_NULL(list_peek_tail_type(&list, list_elem_t, node));

  EXPECT_NULL(list_remove_head(&list));
  EXPECT_NULL(list_remove_head_type(&list, list_elem_t, node));
  EXPECT_NULL(list_remove_tail(&list));
  EXPECT_NULL(list_remove_tail_type(&list, list_elem_t, node));

  EXPECT_NULL(list_next(&list, &list));
  EXPECT_NULL(list_next_type(&list, &list, list_elem_t, node));
  EXPECT_NULL(list_next_wrap(&list, &list));
  EXPECT_NULL(list_next_wrap_type(&list, &list, list_elem_t, node));
  EXPECT_NULL(list_prev(&list, &list));
  EXPECT_NULL(list_prev_type(&list, &list, list_elem_t, node));
  EXPECT_NULL(list_prev_wrap(&list, &list));
  EXPECT_NULL(list_prev_wrap_type(&list, &list, list_elem_t, node));
}

TEST(ListnodeCTests, element_add_remove) {
  list_elem_t first_set[5] = {
      {-1, {}}, {2, {}}, {3, {}}, {4, {}}, {-1, {}},
  };
  list_elem_t second_set[4] = {
      {0, {}},
      {6, {}},
      {1, {}},
      {5, {}},
  };

  // Fill a list with elements from first_set.  [ -1 2 3 4 -1 ]
  list_node_t list = LIST_INITIAL_CLEARED_VALUE;
  list_initialize(&list);
  for (int i = 0; i < 5; i++) {
    list_add_tail(&list, &first_set[i].node);
  }

  // Clear the first and last elements in the list, then add new elements in
  // numerical order.  [ 0 1 2 3 4 5 ]
  list_remove_head(&list);
  list_remove_tail(&list);
  list_add_head(&list, &second_set[0].node);
  list_add_tail(&list, &second_set[1].node);
  list_add_after(list_peek_head(&list), &second_set[2].node);
  list_add_before(list_peek_tail(&list), &second_set[3].node);

  // The list should be sorted now.
  expect_list_sorted(&list, 7);

  // Verify list deletion.
  list_node_t* node = NULL;
  list_node_t* to_del = NULL;
  list_for_every_safe(&list, node, to_del) { list_delete(node); }
  EXPECT_TRUE(list_is_empty(&list));
}

TEST(ListnodeCTests, list_splice_split) {
  list_elem_t first_set[3] = {
      {0, {}},
      {3, {}},
      {4, {}},
  };
  list_elem_t second_set[3] = {
      {5, {}},
      {1, {}},
      {2, {}},
  };

  list_node_t first_list;
  list_initialize(&first_list);
  list_node_t second_list;
  list_initialize(&second_list);

  for (int i = 0; i < 3; ++i) {
    list_add_tail(&first_list, &first_set[i].node);
    list_add_tail(&second_list, &second_set[i].node);
  }

  // Splice together the initial big list.  [ 0 3 4 5 1 2 ]
  list_splice_after(&second_list, list_peek_tail(&first_list));
  EXPECT_EQ(list_length(&first_list), 6u);
  EXPECT_EQ(list_length(&second_list), 0u);

  // Split off the last two elements of the list.  [ 0 3 4 5 ] [ 1 2 ]
  list_split_after(&first_list, list_peek_tail(&first_list)->prev->prev, &second_list);
  EXPECT_EQ(list_length(&first_list), 4u);
  EXPECT_EQ(list_length(&second_list), 2u);

  // Splice the split portion back in, in order.  [ 0 1 2 3 4 5 ]
  list_splice_after(&second_list, list_peek_head(&first_list));
  EXPECT_EQ(list_length(&first_list), 6u);
  EXPECT_EQ(list_length(&second_list), 0u);

  // The list should be sorted now.
  expect_list_sorted(&first_list, 6);

  // Move the lists and recheck.
  list_move(&first_list, &second_list);
  EXPECT_EQ(list_length(&first_list), 0u);
  EXPECT_EQ(list_length(&second_list), 6u);

  // The second list should be sorted now.
  expect_list_sorted(&second_list, 6);
}