#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h> // for EXIT_FAILURE
/*#include <int_list.h>*/
#include <stack.h>

/*
 * test program for the stack implementation in stack.h.
 * Uses different test functions to check if the stack implementation
 * works as intended.
 *
 * Author: Marc Meunier (mame0264@student.umu.se).
 *
 * Version information:
 *   2025-04-22: v1.0.  First version.
 *   2025-05-01: v2.0.  fixed comments from labres, see changes.txt for details.
 */

#define VERSION "v2.0"
#define VERSION_DATE "2025-05-01"


//
// Function to compare the values stored in the list.
bool value_equal(int v1, int v2)
{
    return v1 == v2;
}


// int_create() - make a dynamic copy of an integer
// @i: Integer to copy
//
// Returns: A pointer to a dynamic copy of i
int *int_create(int i)
{
    // Allocate memory for an integer and set the value
    int *v = malloc(sizeof(*v));
    *v = i;
    return v;
}


// Return the memory used by the integer.
//
void int_kill(void *v)
{
    int *p = v;
    free(p);
}


// test that the stack_empty() function creates an empty stack.
// no input parameters
// returns nothing
void test_stack_empty(void)
{

    fprintf(stderr, "Starting test_stack_empty()...\n");

    // initialize stack
    stack *s = stack_empty(int_kill);

    // check that stack initialized correctly
    if (s == NULL)
    {
        fprintf(stderr, "FAIL: stack_empty() returned NULL.\n");
        exit(1);
    }

    // returns memory and exit message.
    stack_kill(s);
    fprintf(stderr, "done.\n");
}


// test that the stack_is_empty() function returns true for an empty stack
// no input parameters
// returns nothing
void isempty_return_true(void)
{
    fprintf(stderr, "Starting isempty_return_true()...\n");

    // initialize stack
    stack *s = stack_empty(int_kill);

    // prints if function returns false
    if (!stack_is_empty(s))
    {
        fprintf(stderr, "\nStack is empty but \"stack_is_empty\" reports non empty\n");
        exit(1);
    }

    // adds values to stack
    s = stack_push(s, int_create(10));

    // test if stack prints false with values inside

    if (stack_is_empty(s))
    {
        fprintf(stderr, "\nStack is non empty but \"stack_is_empty\" reports empty.\n");
        exit(1);
    }

    // returns memory and exit message.
    stack_kill(s);
    fprintf(stderr, "done.\n");
}


// tests if stack returns top value in stack.
// no input parameters
// returns nothing
void push_stack_on_top(void)
{
    fprintf(stderr, "Starting push_stack_on_top()...\n");

    // initialize stack
    stack *s = stack_empty(int_kill);

    // how many numbers that should be added to stack
    int numberofelements = 10;

    // adds nonlinear values to stack 
    for (int i = 1; i <= numberofelements; i++)
    {

        if (i > 5)
        {
            int a = 5 * i;
            s = stack_push(s, int_create((a)));
        }
        else
        {
            s = stack_push(s, int_create(i));
        }
    }

    // top value of stack
    int a = 0;

    // checks return order
    for (int i = 0; i <= numberofelements - 1; i++)
    {
        a = numberofelements - i;
        
        // converts pointer to an intedger value.
        int *stored_ptr = stack_top(s);
        int stored_value = *stored_ptr;

        // checks if value higher then 5 so it has same values as inserted into stack.
        if (a > 5)
        { 
            if (!value_equal(stored_value, a * 5))
            {
                fprintf(stderr, "FAIL: Expected <%d>, got <%d>.\n", (a * 5), stored_value);
                exit(1);
            }
        }
        else
        { 
            if (!value_equal(stored_value, a))
            {
                fprintf(stderr, "FAIL: Expected <%d>, got <%d>.\n", a, stored_value);
                exit(1);
            }
        }

        // removes one value from the stack so that the next value can be checked.
        s = stack_pop(s);
    }

    // Check if stack is empty after running test.
    if (!stack_is_empty(s))
    {
        fprintf(stderr, "\nStack is non empty but should be empty.\n");
        exit(1);
    }

    // returns memory and exit message.
    stack_kill(s);
    fprintf(stderr, "done.\n");
}


// tests if the top reads wrong value.
// no input parameters
// returns nothing
void top_read_wrong(void)
{
    fprintf(stderr, "Starting top_read_wrong()...\n");

    // initialize stack
    stack *s = stack_empty(int_kill);

    // loops over some values to add to the stack.
    for (int i = 0; i <= 3; i++)
    {
        s = stack_push(s, int_create(i));

        // converts the pointer to an intedger value.
        int *stored_ptr = stack_top(s);
        int stored_value = *stored_ptr;

        // checks values in stack and compare to inputed value.
        if (!value_equal(stored_value, i))
        {
            fprintf(stderr, "FAIL: Expected <%d>, got <%d>.\n", i, stored_value);
            exit(1);
        }
    }

    // returns memory and exit message.
    stack_kill(s);
    fprintf(stderr, "done.\n");
}


// tests if the pop function removes the wrong value or not.
// no input parameters
// returns nothing
void pop_remove_wrong(void)
{
    fprintf(stderr, "Starting pop_remove_wrong()...\n");

    // how many numbers that should be added to stack
    int iter = 3; 

    // initialize stack
    stack *s = stack_empty(int_kill);

    // adds values to stack
    for (int i = 0; i <= iter; i++)
    {
        s = stack_push(s, int_create(i));
    }

    // check if values are correct order in stack
    for (int i = 0; i <= iter; i++)
    { 
        int *stored_ptr = stack_top(s);
        int stored_value = *stored_ptr;
        
        if (!value_equal(stored_value, 3 - i))
        {
            fprintf(stderr, "FAIL: Expected <%d>, got <%d>.\n", i, stored_value);
            exit(1);
        }
        
        s = stack_pop(s);
    }

    // Check if stack is empty after running test.
    if (!stack_is_empty(s))
    {
        fprintf(stderr, "\nStack is non empty but should be empty.\n");
        exit(1);
    }

    // returns memory and exit message.
    stack_kill(s);
    fprintf(stderr, "done.\n");
}



// main function that runs all the tests.
int main(void)
{
    // prints the version and date of the program
    printf("%s, %s %s: Test program for the typed stack datatype.\n",
           __FILE__, VERSION, VERSION_DATE);

    // tests each function.
    test_stack_empty();
    isempty_return_true();
    push_stack_on_top();
    top_read_wrong();
    pop_remove_wrong();

    // test sucessful
    fprintf(stderr, "\nSUCCESS: Implementation passed all tests. Normal exit.\n");
    return 0;
}