/*
 * String -> number wrappers: aksl_atoi / atol / atoll / atof.
 *
 * TODO.md section 1.4, complete. The cases that used to live in
 * tests/test_convert_strict.c -- registered as a known failure because the ato*
 * family had no error channel at all (2.1.5) -- are folded back in here now that
 * they pass: non-numeric input, empty input, trailing junk and overflow are all
 * errors rather than silent wrong answers.
 *
 * The strto* family these are built on is tested in tests/test_strto.c.
 */

#include "aksl_capture.h"

#include <errno.h>
#include <limits.h>

static int test_atoi_converts_positive(void)
{
    int out = -1;

    AKSL_CHECK_OK(aksl_atoi("1234", &out));
    AKSL_CHECK(out == 1234);
    return 0;
}

static int test_atoi_converts_negative(void)
{
    int out = 0;

    AKSL_CHECK_OK(aksl_atoi("-42", &out));
    AKSL_CHECK(out == -42);
    return 0;
}

static int test_atoi_skips_leading_whitespace(void)
{
    int out = 0;

    AKSL_CHECK_OK(aksl_atoi("   \t 7", &out));
    AKSL_CHECK(out == 7);
    return 0;
}

static int test_atoi_rejects_null_arguments(void)
{
    int out = 0;

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_atoi(NULL, &out),
				   AKERR_NULLPOINTER, "nptr=");
    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_atoi("1", NULL),
				   AKERR_NULLPOINTER, "dest=");
    return 0;
}

/*
 * The whole reason 2.1.5 mattered. atoi("not a number") returned success and 0,
 * so a caller could not tell a parse failure from a legitimate zero -- and
 * akbasic had to write ~60 lines of its own strtoll/strtod wrapper to avoid
 * turning four diagnosable BASIC errors into four wrong answers.
 */
static int test_non_numeric_input_is_a_value_error(void)
{
    int out = 99;

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_atoi("not a number", &out),
				   AKERR_VALUE, "no digits");
    /* *dest is 0 on every failure path, never left holding a partial answer. */
    AKSL_CHECK(out == 0);
    return 0;
}

static int test_empty_input_is_a_value_error(void)
{
    int out = 99;

    AKSL_CHECK_STATUS(aksl_atoi("", &out), AKERR_VALUE);
    AKSL_CHECK(out == 0);
    AKSL_CHECK_STATUS(aksl_atoi("   ", &out), AKERR_VALUE);
    AKSL_CHECK(out == 0);
    return 0;
}

static int test_trailing_junk_is_a_value_error(void)
{
    int out = 99;

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_atoi("12abc", &out),
				   AKERR_VALUE, "trailing junk");
    AKSL_CHECK(out == 0);
    /* Trailing whitespace counts as junk too: the whole string must be a number. */
    AKSL_CHECK_STATUS(aksl_atoi("12 ", &out), AKERR_VALUE);
    return 0;
}

/*
 * "0x10" through the ato* forms is base 10, so parsing stops at the 'x' and the
 * rest is trailing junk. TODO.md 1.4 left this open; the answer is that the
 * prefix-honouring parse is aksl_strtol(nptr, NULL, 0, &dest), and tests/
 * test_strto.c holds that half.
 */
static int test_hex_literal_is_rejected_by_the_base_10_forms(void)
{
    int out = 99;

    AKSL_CHECK_STATUS(aksl_atoi("0x10", &out), AKERR_VALUE);
    AKSL_CHECK(out == 0);
    return 0;
}

static int test_overflow_is_erange(void)
{
    int out = 99;
    long lout = 99;
    long long llout = 99;

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_atoi("99999999999999999999", &out),
				   ERANGE, "out of range");
    AKSL_CHECK(out == 0);
    AKSL_CHECK_STATUS(aksl_atol("99999999999999999999999999", &lout), ERANGE);
    AKSL_CHECK(lout == 0);
    AKSL_CHECK_STATUS(aksl_atoll("99999999999999999999999999", &llout), ERANGE);
    AKSL_CHECK(llout == 0);
    return 0;
}

/*
 * aksl_atoi narrows from long to int, so a value that fits a long and not an int
 * is ERANGE from the wrapper rather than from strtol. On a platform where long
 * and int are the same width there is nothing to narrow and strtol has already
 * caught it, so the case is skipped rather than asserted into a false pass.
 */
static int test_atoi_narrows_to_int_range(void)
{
#if LONG_MAX > INT_MAX
    int out = 99;
    char buf[64];

    snprintf(buf, sizeof(buf), "%ld", (long)INT_MAX + 1);
    AKSL_CHECK_STATUS(aksl_atoi(buf, &out), ERANGE);
    AKSL_CHECK(out == 0);

    snprintf(buf, sizeof(buf), "%ld", (long)INT_MIN - 1);
    AKSL_CHECK_STATUS(aksl_atoi(buf, &out), ERANGE);
    AKSL_CHECK(out == 0);
#else
    fprintf(stderr, "     (skipped: long and int are the same width here)\n");
#endif
    return 0;
}

/* TODO.md 1.4: the type boundaries round-trip exactly rather than nearly. */
static int test_type_boundaries_round_trip(void)
{
    char buf[64];
    int iout = 0;
    long lout = 0;
    long long llout = 0;

    snprintf(buf, sizeof(buf), "%d", INT_MAX);
    AKSL_CHECK_OK(aksl_atoi(buf, &iout));
    AKSL_CHECK(iout == INT_MAX);
    snprintf(buf, sizeof(buf), "%d", INT_MIN);
    AKSL_CHECK_OK(aksl_atoi(buf, &iout));
    AKSL_CHECK(iout == INT_MIN);

    snprintf(buf, sizeof(buf), "%ld", LONG_MAX);
    AKSL_CHECK_OK(aksl_atol(buf, &lout));
    AKSL_CHECK(lout == LONG_MAX);
    snprintf(buf, sizeof(buf), "%ld", LONG_MIN);
    AKSL_CHECK_OK(aksl_atol(buf, &lout));
    AKSL_CHECK(lout == LONG_MIN);

    snprintf(buf, sizeof(buf), "%lld", LLONG_MAX);
    AKSL_CHECK_OK(aksl_atoll(buf, &llout));
    AKSL_CHECK(llout == LLONG_MAX);
    snprintf(buf, sizeof(buf), "%lld", LLONG_MIN);
    AKSL_CHECK_OK(aksl_atoll(buf, &llout));
    AKSL_CHECK(llout == LLONG_MIN);
    return 0;
}

static int test_atol_converts_and_rejects_null(void)
{
    long out = 0;

    AKSL_CHECK_OK(aksl_atol("2147483648", &out));
    AKSL_CHECK(out == 2147483648L);
    AKSL_CHECK_OK(aksl_atol("-2147483648", &out));
    AKSL_CHECK(out == -2147483648L);

    AKSL_CHECK_STATUS(aksl_atol(NULL, &out), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_atol("1", NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_atol("nope", &out), AKERR_VALUE);
    return 0;
}

static int test_atoll_converts_and_rejects_null(void)
{
    long long out = 0;

    AKSL_CHECK_OK(aksl_atoll("9007199254740993", &out));
    AKSL_CHECK(out == 9007199254740993LL);
    AKSL_CHECK_OK(aksl_atoll("-9007199254740993", &out));
    AKSL_CHECK(out == -9007199254740993LL);

    AKSL_CHECK_STATUS(aksl_atoll(NULL, &out), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_atoll("1", NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_atoll("nope", &out), AKERR_VALUE);
    return 0;
}

static int test_atof_converts_and_rejects_null(void)
{
    double out = 0.0;

    AKSL_CHECK_OK(aksl_atof("2.5", &out));
    AKSL_CHECK(out == 2.5);
    AKSL_CHECK_OK(aksl_atof("  -0.125", &out));
    AKSL_CHECK(out == -0.125);
    AKSL_CHECK_OK(aksl_atof("1e3", &out));
    AKSL_CHECK(out == 1000.0);

    AKSL_CHECK_STATUS(aksl_atof(NULL, &out), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_atof("1", NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_atof("nope", &out), AKERR_VALUE);
    AKSL_CHECK_STATUS(aksl_atof("1.5xyz", &out), AKERR_VALUE);
    return 0;
}

/*
 * TODO.md 1.4 left "inf" and "nan" open. They are accepted, because strtod(3)
 * accepts them and because they are exact round-trips rather than approximations
 * of something else -- a caller who did not want them has a domain check to make
 * that this library cannot make for it.
 */
static int test_atof_accepts_infinity_and_nan(void)
{
    double out = 0.0;

    AKSL_CHECK_OK(aksl_atof("inf", &out));
    AKSL_CHECK(out > 0.0 && (out * 2.0) == out);
    AKSL_CHECK_OK(aksl_atof("-INFINITY", &out));
    AKSL_CHECK(out < 0.0 && (out * 2.0) == out);
    AKSL_CHECK_OK(aksl_atof("nan", &out));
    /* The only value that is not equal to itself. */
    AKSL_CHECK(out != out);
    return 0;
}

/* Overflow and underflow both come back as ERANGE, which is strtod's only signal. */
static int test_atof_range_errors(void)
{
    double out = 1.0;

    AKSL_CHECK_STATUS(aksl_atof("1e400", &out), ERANGE);
    AKSL_CHECK(out == 0.0);
    AKSL_CHECK_STATUS(aksl_atof("1e-400", &out), ERANGE);
    AKSL_CHECK(out == 0.0);
    return 0;
}

/* The wrappers hold no state: the same input converts the same way twice. */
static int test_conversions_are_repeatable(void)
{
    int first = 0;
    int second = 0;

    AKSL_CHECK_OK(aksl_atoi("321", &first));
    AKSL_CHECK_OK(aksl_atoi("321", &second));
    AKSL_CHECK(first == second);
    AKSL_CHECK(first == 321);
    return 0;
}

/*
 * errno is cleared before each wrapped call, so a failure left over from an
 * earlier unrelated call cannot be reported as this one's. Set errno to
 * something conspicuous first and check that a successful conversion still
 * succeeds -- the old code could report a stale errno as its own status.
 */
static int test_stale_errno_does_not_leak_into_the_result(void)
{
    int out = 0;

    errno = ERANGE;
    AKSL_CHECK_OK(aksl_atoi("5", &out));
    AKSL_CHECK(out == 5);

    errno = ENOMEM;
    AKSL_CHECK_STATUS(aksl_atoi("junk", &out), AKERR_VALUE);
    return 0;
}

int main(void)
{
    int failures = 0;

    akerr_init();

    AKSL_RUN(failures, test_atoi_converts_positive);
    AKSL_RUN(failures, test_atoi_converts_negative);
    AKSL_RUN(failures, test_atoi_skips_leading_whitespace);
    AKSL_RUN(failures, test_atoi_rejects_null_arguments);

    AKSL_RUN(failures, test_non_numeric_input_is_a_value_error);
    AKSL_RUN(failures, test_empty_input_is_a_value_error);
    AKSL_RUN(failures, test_trailing_junk_is_a_value_error);
    AKSL_RUN(failures, test_hex_literal_is_rejected_by_the_base_10_forms);
    AKSL_RUN(failures, test_overflow_is_erange);
    AKSL_RUN(failures, test_atoi_narrows_to_int_range);
    AKSL_RUN(failures, test_type_boundaries_round_trip);

    AKSL_RUN(failures, test_atol_converts_and_rejects_null);
    AKSL_RUN(failures, test_atoll_converts_and_rejects_null);
    AKSL_RUN(failures, test_atof_converts_and_rejects_null);
    AKSL_RUN(failures, test_atof_accepts_infinity_and_nan);
    AKSL_RUN(failures, test_atof_range_errors);

    AKSL_RUN(failures, test_conversions_are_repeatable);
    AKSL_RUN(failures, test_stale_errno_does_not_leak_into_the_result);

    AKSL_REPORT(failures);
}