#include <stdio.h>
#include <head-unit.h>
#include "prof_history.h"

void previous_on_empty_returns_current(void)
{
    PHistory history = p_history_new(10);
    char *item = p_history_previous(history, "inp");

    assert_string_equals("inp", item);
}

void next_on_empty_returns_null(void)
{
    PHistory history = p_history_new(10);
    char *item = p_history_next(history, "inp");

    assert_is_null(item);
}

void previous_once_returns_last(void)
{
    PHistory history = p_history_new(10);
    p_history_append(history, "Hello");

    char *item = p_history_previous(history, "inp");

    assert_string_equals("Hello", item);
}

void previous_twice_when_one_returns_first(void)
{
    PHistory history = p_history_new(10);
    p_history_append(history, "Hello");

    char *item1 = p_history_previous(history, NULL);
    char *item2 = p_history_previous(history, item1);

    assert_string_equals("Hello", item2);
}

void previous_always_stops_at_first(void)
{
    PHistory history = p_history_new(10);
    p_history_append(history, "Hello");

    char *item1 = p_history_previous(history, NULL);
    char *item2 = p_history_previous(history, item1);
    char *item3 = p_history_previous(history, item2);
    char *item4 = p_history_previous(history, item3);
    char *item5 = p_history_previous(history, item4);
    char *item6 = p_history_previous(history, item5);

    assert_string_equals("Hello", item6);
}

void previous_goes_to_correct_element(void)
{
    PHistory history = p_history_new(10);
    p_history_append(history, "Hello");
    p_history_append(history, "world");
    p_history_append(history, "whats");
    p_history_append(history, "going");
    p_history_append(history, "on");
    p_history_append(history, "here");

    char *item1 = p_history_previous(history, NULL);
    char *item2 = p_history_previous(history, item1);
    char *item3 = p_history_previous(history, item2);
    
    assert_string_equals("going", item3); 
}

void prev_then_next_returns_null(void)
{
    PHistory history = p_history_new(10);
    p_history_append(history, "Hello");

    char *item1 = p_history_previous(history, NULL);
    char *item2 = p_history_next(history, item1);

    assert_is_null(item2);
}

void register_prof_history_tests(void)
{
    TEST_MODULE("prof_history tests");
    TEST(previous_on_empty_returns_current);
    TEST(next_on_empty_returns_null);
    TEST(previous_once_returns_last);
    TEST(previous_twice_when_one_returns_first);
    TEST(previous_always_stops_at_first);
    TEST(previous_goes_to_correct_element);
    TEST(prev_then_next_returns_null);
}