#ifndef GUF_COMMON_UTILS_H
#define GUF_COMMON_UTILS_H
#include "guf_assert.h"
#include <limits.h>

// The GUFCAT/GUF_TOK_CAT indirection is necessary because the ## operation alone does not evaluate the macro arguments.
#define GUF_TOK_CAT(a, b) a##b
#define GUFCAT(a, b) GUF_TOK_CAT(a, b)

#define GUF_FOREACH(CNT_PTR, CNT_TYPE, IT_NAME) for (GUFCAT(CNT_TYPE, _iter) IT_NAME = GUFCAT(CNT_TYPE, _begin)(CNT_PTR); IT_NAME.cur != IT_NAME.end; IT_NAME = IT_NAME.next(&IT_NAME, 1))

#define GUF_STATIC_BUF_SIZE(BUF) (sizeof((BUF)) / (sizeof((BUF)[0])))

#define GUF_ABS(X) ((X) >= 0 ? (X) : -(X))
#define GUF_MIN(X, Y) ((X) <= (Y) ? (X) : (Y))
#define GUF_MAX(X, Y) ((X) >= (Y) ? (X) : (Y))
#define GUF_CLAMP(X, MIN, MAX) GUF_MAX(GUF_MIN((X), (MAX)), (MIN)) 

static inline int     guf_abs_int(int x)     {if (x >= 0) {return x;} GUF_ASSERT_RELEASE(x > INT_MIN  ); return -x;}
static inline long    guf_abs_lng(long x)    {if (x >= 0) {return x;} GUF_ASSERT_RELEASE(x > LONG_MIN ); return -x;}
static inline int8_t  guf_abs_i8 (int8_t x)  {if (x >= 0) {return x;} GUF_ASSERT_RELEASE(x > INT8_MIN ); return -x;}
static inline int16_t guf_abs_i16(int16_t x) {if (x >= 0) {return x;} GUF_ASSERT_RELEASE(x > INT16_MIN); return -x;}
static inline int32_t guf_abs_i32(int32_t x) {if (x >= 0) {return x;} GUF_ASSERT_RELEASE(x > INT32_MIN); return -x;}
static inline int64_t guf_abs_i64(int64_t x) {if (x >= 0) {return x;} GUF_ASSERT_RELEASE(x > INT64_MIN); return -x;}

static inline bool guf_is_mul_overflow_size_t(size_t a, size_t b) 
{
    size_t c = a * b; 
    return a != 0 && ((c / a) != b);    
}

static inline size_t guf_safe_mul_size_t(size_t a, size_t b) 
{
    GUF_ASSERT_RELEASE(!guf_is_mul_overflow_size_t(a, b));
    return a * b;
}

static inline bool guf_is_safe_size_calc(ptrdiff_t count, ptrdiff_t sizeof_elem)
{
    if (count < 0 || sizeof_elem <= 0) {
        return false;
    }
    size_t size = guf_safe_mul_size_t(count, sizeof_elem);
    return size <= PTRDIFF_MAX;
}

static inline ptrdiff_t guf_safe_size_calc(ptrdiff_t count, ptrdiff_t sizeof_elem)
{
    GUF_ASSERT_RELEASE(count >= 0);
    GUF_ASSERT_RELEASE(sizeof_elem > 0);
    size_t size = guf_safe_mul_size_t(count, sizeof_elem);
    GUF_ASSERT_RELEASE(size <= PTRDIFF_MAX);
    return size;
}

static inline bool guf_is_big_endian(void)
{
    unsigned i = 1;
    const char *bytes = (const char*)&i;
    return bytes[0] != 1;
}

#endif