/*
 * The strto* family -- TODO.md section 3.1.
 *
 * These are the real implementation behind the ato* wrappers and the thing
 * akbasic had to hand-write for itself (its src/convert.c, ~60 lines) because
 * the library would not do it. What they add over the ato* forms is a base and
 * an endptr: pass a non-NULL endptr to parse a number off the front of a longer
 * string and find out where it stopped, and the trailing-junk check goes away
 * because the caller has taken responsibility for what follows.
 *
 * tests/test_convert.c covers what the two families share; this file is the part
 * that is specific to having a base and an endptr.
 */

#include "aksl_capture.h"

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

/* ---------------------------------------------------------------------- */
/* Base handling                                                          */
/* ---------------------------------------------------------------------- */

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

    AKSL_CHECK_OK(aksl_strtol("ff", NULL, 16, &out));
    AKSL_CHECK(out == 255);
    AKSL_CHECK_OK(aksl_strtol("1010", NULL, 2, &out));
    AKSL_CHECK(out == 10);
    AKSL_CHECK_OK(aksl_strtol("777", NULL, 8, &out));
    AKSL_CHECK(out == 511);
    AKSL_CHECK_OK(aksl_strtol("z", NULL, 36, &out));
    AKSL_CHECK(out == 35);
    return 0;
}

/* Base 0 auto-detects the 0x and 0 prefixes, which is the counterpart to
 * tests/test_convert.c's test that aksl_atoi refuses "0x10". */
static int test_base_zero_detects_the_prefix(void)
{
    long out = 0;

    AKSL_CHECK_OK(aksl_strtol("0x10", NULL, 0, &out));
    AKSL_CHECK(out == 16);
    AKSL_CHECK_OK(aksl_strtol("010", NULL, 0, &out));
    AKSL_CHECK(out == 8);
    AKSL_CHECK_OK(aksl_strtol("10", NULL, 0, &out));
    AKSL_CHECK(out == 10);
    return 0;
}

/* A digit that does not belong to the base is where the number ends. */
static int test_digits_outside_the_base_end_the_number(void)
{
    long out = 0;
    char *end = NULL;

    /* "9" is not an octal digit, so with a NULL endptr it is trailing junk. */
    AKSL_CHECK_STATUS(aksl_strtol("129", NULL, 8, &out), AKERR_VALUE);
    /* With an endptr the caller gets the partial parse and the stopping point. */
    AKSL_CHECK_OK(aksl_strtol("129", &end, 8, &out));
    AKSL_CHECK(out == 10);          /* 012 octal */
    AKSL_CHECK(end != NULL && *end == '9');
    return 0;
}

/* An invalid base is EINVAL from strtol(3) rather than a silent answer. */
static int test_invalid_base_is_rejected(void)
{
    long out = 99;

    AKSL_CHECK_STATUS(aksl_strtol("10", NULL, 37, &out), EINVAL);
    AKSL_CHECK(out == 0);
    AKSL_CHECK_STATUS(aksl_strtol("10", NULL, 1, &out), EINVAL);
    AKSL_CHECK(out == 0);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* endptr                                                                 */
/* ---------------------------------------------------------------------- */

/*
 * With an endptr, trailing text is the caller's business and not an error. This
 * is the shape a tokenizer wants: parse a number, carry on from where it ended.
 */
static int test_endptr_reports_where_parsing_stopped(void)
{
    const char *input = "42 rest of the line";
    char *end = NULL;
    long out = 0;

    AKSL_CHECK_OK(aksl_strtol(input, &end, 10, &out));
    AKSL_CHECK(out == 42);
    AKSL_CHECK(end == input + 2);
    AKSL_CHECK(strcmp(end, " rest of the line") == 0);
    return 0;
}

/* Consuming nothing is still an error, endptr or not: there was no number. */
static int test_no_digits_is_an_error_even_with_an_endptr(void)
{
    char *end = (char *)0x1;
    long out = 99;

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_strtol("nope", &end, 10, &out),
				   AKERR_VALUE, "no digits");
    AKSL_CHECK(out == 0);
    return 0;
}

/*
 * Every form writes through endptr, not just the two the other tests happen to
 * use. Each type has its own function body, so "strtol handles endptr" says
 * nothing whatsoever about strtoull.
 */
static int test_every_form_writes_the_endptr(void)
{
    const char *input = "42rest";
    char *end = NULL;
    long lout = 0;
    long long llout = 0;
    unsigned long ulout = 0;
    unsigned long long ullout = 0;
    double dout = 0.0;
    float fout = 0.0f;
    long double ldout = 0.0L;

    end = NULL;
    AKSL_CHECK_OK(aksl_strtol(input, &end, 10, &lout));
    AKSL_CHECK(lout == 42 && strcmp(end, "rest") == 0);

    end = NULL;
    AKSL_CHECK_OK(aksl_strtoll(input, &end, 10, &llout));
    AKSL_CHECK(llout == 42 && strcmp(end, "rest") == 0);

    end = NULL;
    AKSL_CHECK_OK(aksl_strtoul(input, &end, 10, &ulout));
    AKSL_CHECK(ulout == 42 && strcmp(end, "rest") == 0);

    end = NULL;
    AKSL_CHECK_OK(aksl_strtoull(input, &end, 10, &ullout));
    AKSL_CHECK(ullout == 42 && strcmp(end, "rest") == 0);

    end = NULL;
    AKSL_CHECK_OK(aksl_strtod(input, &end, &dout));
    AKSL_CHECK(dout == 42.0 && strcmp(end, "rest") == 0);

    end = NULL;
    AKSL_CHECK_OK(aksl_strtof(input, &end, &fout));
    AKSL_CHECK(fout == 42.0f && strcmp(end, "rest") == 0);

    end = NULL;
    AKSL_CHECK_OK(aksl_strtold(input, &end, &ldout));
    AKSL_CHECK(ldout == 42.0L && strcmp(end, "rest") == 0);
    return 0;
}

/* Successive calls chained through endptr walk a whole list of numbers. */
static int test_endptr_chains_across_a_list(void)
{
    const char *input = "1,2,3";
    char *cursor = (char *)input;
    long out = 0;
    long total = 0;
    int seen = 0;

    while ( *cursor != '\0' ) {
	AKSL_CHECK_OK(aksl_strtol(cursor, &cursor, 10, &out));
	total += out;
	seen += 1;
	if ( *cursor == ',' ) {
	    cursor++;
	}
    }
    AKSL_CHECK(seen == 3);
    AKSL_CHECK(total == 6);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* Ranges and signs                                                       */
/* ---------------------------------------------------------------------- */

static int test_range_errors_per_type(void)
{
    long lout = 99;
    long long llout = 99;
    unsigned long ulout = 99;
    unsigned long long ullout = 99;
    char buf[64];

    snprintf(buf, sizeof(buf), "%lld9", (long long)LLONG_MAX);
    AKSL_CHECK_STATUS(aksl_strtol(buf, NULL, 10, &lout), ERANGE);
    AKSL_CHECK(lout == 0);
    AKSL_CHECK_STATUS(aksl_strtoll(buf, NULL, 10, &llout), ERANGE);
    AKSL_CHECK(llout == 0);

    snprintf(buf, sizeof(buf), "%llu9", (unsigned long long)ULLONG_MAX);
    AKSL_CHECK_STATUS(aksl_strtoul(buf, NULL, 10, &ulout), ERANGE);
    AKSL_CHECK(ulout == 0);
    AKSL_CHECK_STATUS(aksl_strtoull(buf, NULL, 10, &ullout), ERANGE);
    AKSL_CHECK(ullout == 0);
    return 0;
}

/*
 * strtoul(3) and strtoull(3) accept a leading '-' and hand back the negation
 * wrapped into the unsigned range, so "-1" parses as ULONG_MAX and reports
 * nothing at all. That is exactly the silent failure this library exists to
 * surface, so the sign is refused before the call.
 */
static int test_unsigned_forms_refuse_a_negative(void)
{
    unsigned long ulout = 99;
    unsigned long long ullout = 99;

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_strtoul("-1", NULL, 10, &ulout),
				   AKERR_VALUE, "negative");
    AKSL_CHECK(ulout == 0);
    /* Including behind leading whitespace, which strtoul skips. */
    AKSL_CHECK_STATUS(aksl_strtoul("   -1", NULL, 10, &ulout), AKERR_VALUE);
    AKSL_CHECK_STATUS(aksl_strtoull("-1", NULL, 10, &ullout), AKERR_VALUE);
    AKSL_CHECK(ullout == 0);

    /* A leading '+' is fine: it is a sign, not a negation. */
    AKSL_CHECK_OK(aksl_strtoul("+7", NULL, 10, &ulout));
    AKSL_CHECK(ulout == 7);
    return 0;
}

static int test_unsigned_boundaries_round_trip(void)
{
    unsigned long ulout = 0;
    unsigned long long ullout = 0;
    char buf[64];

    snprintf(buf, sizeof(buf), "%lu", ULONG_MAX);
    AKSL_CHECK_OK(aksl_strtoul(buf, NULL, 10, &ulout));
    AKSL_CHECK(ulout == ULONG_MAX);

    snprintf(buf, sizeof(buf), "%llu", ULLONG_MAX);
    AKSL_CHECK_OK(aksl_strtoull(buf, NULL, 10, &ullout));
    AKSL_CHECK(ullout == ULLONG_MAX);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* Floating point                                                         */
/* ---------------------------------------------------------------------- */

static int test_floating_point_forms(void)
{
    double dout = 0.0;
    float fout = 0.0f;
    long double ldout = 0.0L;
    char *end = NULL;

    AKSL_CHECK_OK(aksl_strtod("2.5", NULL, &dout));
    AKSL_CHECK(dout == 2.5);
    AKSL_CHECK_OK(aksl_strtof("2.5", NULL, &fout));
    AKSL_CHECK(fout == 2.5f);
    AKSL_CHECK_OK(aksl_strtold("2.5", NULL, &ldout));
    AKSL_CHECK(ldout == 2.5L);

    AKSL_CHECK_OK(aksl_strtod("2.5rest", &end, &dout));
    AKSL_CHECK(dout == 2.5);
    AKSL_CHECK(strcmp(end, "rest") == 0);

    AKSL_CHECK_STATUS(aksl_strtod("2.5rest", NULL, &dout), AKERR_VALUE);
    AKSL_CHECK_STATUS(aksl_strtof("nope", NULL, &fout), AKERR_VALUE);
    AKSL_CHECK_STATUS(aksl_strtold("nope", NULL, &ldout), AKERR_VALUE);

    /* float has a much smaller range than double, and says so. */
    AKSL_CHECK_STATUS(aksl_strtof("1e300", NULL, &fout), ERANGE);
    AKSL_CHECK(fout == 0.0f);
    AKSL_CHECK_OK(aksl_strtod("1e300", NULL, &dout));
    AKSL_CHECK(dout > 0.0);
    return 0;
}

/* ---------------------------------------------------------------------- */
/* Argument validation                                                    */
/* ---------------------------------------------------------------------- */

static int test_every_form_rejects_null_arguments(void)
{
    long lout = 0;
    long long llout = 0;
    unsigned long ulout = 0;
    unsigned long long ullout = 0;
    double dout = 0.0;
    float fout = 0.0f;
    long double ldout = 0.0L;

    AKSL_CHECK_STATUS(aksl_strtol(NULL, NULL, 10, &lout), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtol("1", NULL, 10, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtoll(NULL, NULL, 10, &llout), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtoll("1", NULL, 10, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtoul(NULL, NULL, 10, &ulout), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtoul("1", NULL, 10, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtoull(NULL, NULL, 10, &ullout), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtoull("1", NULL, 10, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtod(NULL, NULL, &dout), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtod("1", NULL, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtof(NULL, NULL, &fout), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtof("1", NULL, NULL), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtold(NULL, NULL, &ldout), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_strtold("1", NULL, NULL), AKERR_NULLPOINTER);
    return 0;
}

int main(void)
{
    int failures = 0;

    akerr_init();

    AKSL_RUN(failures, test_base_is_honoured);
    AKSL_RUN(failures, test_base_zero_detects_the_prefix);
    AKSL_RUN(failures, test_digits_outside_the_base_end_the_number);
    AKSL_RUN(failures, test_invalid_base_is_rejected);

    AKSL_RUN(failures, test_endptr_reports_where_parsing_stopped);
    AKSL_RUN(failures, test_every_form_writes_the_endptr);
    AKSL_RUN(failures, test_no_digits_is_an_error_even_with_an_endptr);
    AKSL_RUN(failures, test_endptr_chains_across_a_list);

    AKSL_RUN(failures, test_range_errors_per_type);
    AKSL_RUN(failures, test_unsigned_forms_refuse_a_negative);
    AKSL_RUN(failures, test_unsigned_boundaries_round_trip);

    AKSL_RUN(failures, test_floating_point_forms);

    AKSL_RUN(failures, test_every_form_rejects_null_arguments);

    AKSL_REPORT(failures);
}