#define epsilon 2.2204460492503131E-16

#define testresult int
#define pass 1
#define fail 0

#define print_assert_equal_fail(variable, value, type, format)  \
    printf("\n\tAssertion failed for '" #variable "'"           \
           "\n\t  in %s:%d"                                     \
           "\n\texpected: " format                              \
           "\n\tgot:      " format "\n",                        \
           __FILE__, __LINE__, (type)value, (type)variable)

#define print_assert_not_equal_fail(variable, value, type, format)      \
    printf("\n\tAssertion failed for '" #variable "'"                   \
           "\n\t  in %s:%d"                                             \
           "\n\texpected not: " format                                  \
           "\n\tgot anyways:  " format "\n",                            \
           __FILE__, __LINE__, (type)value, (type)variable)

        /* print_assert_not_equal_fail(error, 0, int, "%d");               \ */
#define assert_no_error(error)                                          \
    if (error) {                                                        \
        printf("\n\tExpected no error to occur,"                        \
               " but an error occured anyways:\n");                     \
        log_error();                                                    \
        return fail;                                                    \
    }                                                                   \

#define assert_equal_int(variable, value)                               \
    if (variable != value) {                                            \
        print_assert_equal_fail(variable, value, int, "%d");            \
        return fail;                                                    \
    }

#define assert_not_equal_int(variable, value)                           \
    if (variable == value) {                                            \
        print_assert_not_equal_fail(variable, value, int, "%d");        \
        return fail;                                                    \
    }

#define assert_equal_double(variable, value)                            \
    if (fabs((double)variable - (double)value) > epsilon) {             \
        print_assert_equal_fail(variable, value, double, "%f");         \
        return fail;                                                    \
    }

#define assert_not_equal_double(variable, value)                        \
    if (fabs((double)variable - (double)value) <= epsilon) {            \
        print_assert_not_equal_fail(variable, value, double, "%f");     \
        return fail;                                                    \
    }

#define assert_null(variable)                   \
    assert_equal_int(variable, NULL)

#define assert_not_null(variable)               \
    assert_not_equal_int(variable, NULL)


#define invoke_test(name)                                       \
    printf("" #name ":");                                       \
    for(int i = 0; i < 45 - strlen(#name); ++i)                 \
        printf(" ");                                            \
    if (name() == pass)                                         \
        printf("%spassed%s\n", console_green, console_normal);  \
    else {                                                      \
        printf("%sfailed%s\n", console_red, console_normal);    \
        if(error) {                                             \
            free(error);                                        \
            error = NULL;                                       \
        }                                                       \
    }                                                           \


testresult test_built_in_add() {
    Ast_Node* plus = create_ast_node_symbol("+");
    Ast_Node* ten  = create_ast_node_number(10);
    Ast_Node* four = create_ast_node_number(4);
    Ast_Node* nil  = create_ast_node_nil();
    Ast_Node* form = create_ast_node_pair(
        plus,
        create_ast_node_pair(
            ten,
            create_ast_node_pair(
                four,
                nil)));

    Ast_Node* result = eval_expr(form, new(Environment));

    assert_no_error(error);
    assert_not_null(result);
    assert_equal_int(result->type, Ast_Node_Type_Number);
    assert_equal_double(result->value.number->value, 14);

    return pass;
}

testresult test_built_in_substract() {
    Ast_Node* minus = create_ast_node_symbol("-");
    Ast_Node* ten   = create_ast_node_number(10);
    Ast_Node* four  = create_ast_node_number(4);
    Ast_Node* nil   = create_ast_node_nil();
    Ast_Node* form  = create_ast_node_pair(
        minus,
        create_ast_node_pair(
            ten,
            create_ast_node_pair(
                four,
                nil)));

    Ast_Node* result = eval_expr(form, new(Environment));

    assert_no_error(error);
    assert_not_null(result);
    assert_equal_int(result->type, Ast_Node_Type_Number);
    assert_equal_double(result->value.number->value, 6);

    return pass;
}


testresult test_built_in_multiply() {
    Ast_Node* times = create_ast_node_symbol("*");
    Ast_Node* ten  = create_ast_node_number(10);
    Ast_Node* four = create_ast_node_number(4);
    Ast_Node* nil  = create_ast_node_nil();
    Ast_Node* form = create_ast_node_pair(
        times,
        create_ast_node_pair(
            ten,
            create_ast_node_pair(
                four,
                nil)));

    Ast_Node* result = eval_expr(form, new(Environment));

    assert_no_error(error);
    assert_not_null(result);
    assert_equal_int(result->type, Ast_Node_Type_Number);
    assert_equal_double(result->value.number->value, 40);

    return pass;
}


testresult test_built_in_divide() {
    Ast_Node* over = create_ast_node_symbol("/");
    Ast_Node* ten  = create_ast_node_number(20);
    Ast_Node* four = create_ast_node_number(4);
    Ast_Node* nil  = create_ast_node_nil();
    Ast_Node* form = create_ast_node_pair(
        over,
        create_ast_node_pair(
            ten,
            create_ast_node_pair(
                four,
                nil)));

    Ast_Node* result = eval_expr(form, new(Environment));

    assert_null(error);
    assert_not_null(result);
    assert_equal_int(result->type, Ast_Node_Type_Number);
    assert_equal_double(result->value.number->value, 5);

    return pass;
}


testresult test_built_in_if() {
    Ast_Node* _if    = create_ast_node_symbol("if");
    Ast_Node* cond   = create_ast_node_number(1);
    Ast_Node* four   = create_ast_node_number(4);
    Ast_Node* five   = create_ast_node_number(5);
    Ast_Node* nil    = create_ast_node_nil();
    Ast_Node* form   = create_ast_node_pair(
        _if,
        create_ast_node_pair(
            cond,
            create_ast_node_pair(
                four,
                create_ast_node_pair(
                    five,
                    nil))));
    Ast_Node* result;

    // test *then* case
    result = eval_expr(form, new(Environment));

    assert_no_error(error);
    assert_not_null(result);
    assert_equal_int(result->type, Ast_Node_Type_Number);
    assert_equal_double(result->value.number->value, 4);

    // test *else* case
    cond->value.number->value = 0;
    result = eval_expr(form, new(Environment));

    assert_null(error);
    assert_not_null(result);
    assert_equal_int(result->type, Ast_Node_Type_Number);
    assert_equal_double(result->value.number->value, 5);

    return pass;
}

testresult test_built_in_and() {
    Ast_Node* _and  = create_ast_node_symbol("and");
    Ast_Node* cond1 = create_ast_node_number(1);
    Ast_Node* cond2 = create_ast_node_string("asd");
    Ast_Node* cond3 = create_ast_node_number(4);
    Ast_Node* nil   = create_ast_node_nil();
    Ast_Node* form  = create_ast_node_pair(
        _and,
        create_ast_node_pair(
            cond1,
            create_ast_node_pair(
                cond2,
                create_ast_node_pair(
                    cond3,
                    nil))));
    Ast_Node* result;

    // a true case
    result = eval_expr(form, new(Environment));

    assert_no_error(error);
    assert_not_null(result);
    assert_equal_int(result->type, Ast_Node_Type_Number);
    assert_equal_double(result->value.number->value, 1);

    // a false case
    cond1->value.number->value = 0;
    result = eval_expr(form, new(Environment));

    assert_no_error(error);
    assert_not_null(result);
    assert_equal_int(result->type, Ast_Node_Type_Number);
    assert_equal_double(result->value.number->value, 0);

    return pass;
}


void run_all_tests() {
    log_level = Log_Level_None;

    invoke_test(test_built_in_add);
    invoke_test(test_built_in_substract);
    invoke_test(test_built_in_multiply);
    invoke_test(test_built_in_divide);
    invoke_test(test_built_in_if);
    invoke_test(test_built_in_and);

}