/* Copyright (C) 2014 Stony Brook University
   This file is part of Graphene Library OS.

   Graphene Library OS is free software: you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public License
   as published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   Graphene Library OS is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef API_H
#define API_H

#include <assert.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdarg.h>

/* WARNING: this declaration may conflict with some header files */
#ifndef ssize_t
typedef ptrdiff_t ssize_t;
#endif

/* Macros */

#ifndef likely
# define likely(x)	__builtin_expect((!!(x)),1)
#endif
#ifndef unlikely
# define unlikely(x)	__builtin_expect((!!(x)),0)
#endif

#ifndef MIN
#define MIN(a,b) \
   ({ __typeof__(a) _a = (a); \
      __typeof__(b) _b = (b); \
      _a < _b ? _a : _b; })
#endif
#ifndef MAX
#define MAX(a,b) \
   ({ __typeof__(a) _a = (a); \
      __typeof__(b) _b = (b); \
      _a > _b ? _a : _b; })
#endif

#define SATURATED_ADD(a, b, limit) \
    ({ __typeof__(a) _a = (a); \
       __typeof__(b) _b = (b); \
       __typeof__(limit) _limit = (limit); \
       _b > _limit ? _limit : (_a > _limit - _b ? _limit : _a + _b); })

#define SATURATED_SUB(a, b, limit) \
    ({ __typeof__(a) _a = (a); \
       __typeof__(b) _b = (b); \
       __typeof__(limit) _limit = (limit); \
       _a < _limit ? _limit : (_b > _a - _limit ? _limit : _a - _b); })

#define SATURATED_P_ADD(ptr_a, b, limit) \
   ((__typeof__(ptr_a))SATURATED_ADD((uintptr_t)(ptr_a), (uintptr_t)(b), (uintptr_t)(limit)))

#define SATURATED_P_SUB(ptr_a, b, limit) \
   ((__typeof__(ptr_a))SATURATED_SUB((uintptr_t)(ptr_a), (uintptr_t)(b), (uintptr_t)(limit)))

#define IS_POWER_OF_2(x) (((x) & ((x) - 1)) == 0)

#define IS_ALIGNED(val, alignment) ((val) % (alignment) == 0)
#define ALIGN_DOWN(val, alignment) ((val) - (val) % (alignment))
#define ALIGN_UP(val, alignment)   ALIGN_DOWN((val) + (alignment) - 1, alignment)
#define IS_ALIGNED_PTR(val, alignment) IS_ALIGNED((uintptr_t)(val), alignment)
#define ALIGN_DOWN_PTR(ptr, alignment) ((__typeof__(ptr))(ALIGN_DOWN((uintptr_t)(ptr), alignment)))
#define ALIGN_UP_PTR(ptr, alignment)   ((__typeof__(ptr))(ALIGN_UP((uintptr_t)(ptr), alignment)))

/* Useful only when the alignment is a power of two, but when that's not known compile-time. */
#define IS_ALIGNED_POW2(val, alignment) (((val) & ((alignment) - 1)) == 0)
#define ALIGN_DOWN_POW2(val, alignment) \
    ((val) - ((val) & ((alignment) - 1))) // `~` doesn't work if `alignment` is of a smaller type
                                          // than `val` and unsigned.
#define ALIGN_UP_POW2(val, alignment)       ALIGN_DOWN_POW2((val) + (alignment) - 1, alignment)
#define IS_ALIGNED_PTR_POW2(val, alignment) IS_ALIGNED_POW2((uintptr_t)(val), alignment)
#define ALIGN_DOWN_PTR_POW2(ptr, alignment) ((__typeof__(ptr))(ALIGN_DOWN_POW2((uintptr_t)(ptr), \
                                                                               alignment)))
#define ALIGN_UP_PTR_POW2(ptr, alignment)   ((__typeof__(ptr))(ALIGN_UP_POW2((uintptr_t)(ptr), \
                                                                             alignment)))

#define SAME_TYPE(a, b) __builtin_types_compatible_p(__typeof__(a), __typeof__(b))
#define IS_STATIC_ARRAY(a) (!SAME_TYPE(a, &*(a)))
#define FORCE_STATIC_ARRAY(a) sizeof(int[IS_STATIC_ARRAY(a) - 1]) // evaluates to 0

#ifndef ARRAY_SIZE
#define ARRAY_SIZE(a) (FORCE_STATIC_ARRAY(a) + sizeof(a) / sizeof(a[0]))
#endif

#ifndef container_of
/**
 * container_of - cast a member of a structure out to the containing structure
 * @ptr:    the pointer to the member.
 * @type:   the type of the container struct this is embedded in.
 * @member: the name of the member within the struct.
 *
 */
# define container_of(ptr, type, member) ((type *)((char *)(ptr) - offsetof(type, member)))
#endif

#define __alloca __builtin_alloca

#define XSTRINGIFY(x) STRINGIFY(x)
#define STRINGIFY(x) #x

#define __UNUSED(x) do { (void)(x); } while (0)
#define static_strlen(str) (ARRAY_SIZE(str) - 1)

/* Libc functions */

/* Libc String functions string.h/stdlib.h */
size_t strnlen (const char *str, size_t maxlen);
size_t strlen (const char *str);

long strtol (const char *s, char **endptr, int base);
int atoi (const char *nptr);
long int atol (const char *nptr);

char * strchr (const char *s, int c_in);

void * memcpy (void *dstpp, const void *srcpp, size_t len);
void * memmove (void *dstpp, const void *srcpp, size_t len);
void * memset (void *dstpp, int c, size_t len);
int memcmp (const void *s1, const void *s2, size_t len);

bool strendswith(const char* haystack, const char* needle);

/* Libc memory allocation functions. stdlib.h. */
void *malloc(size_t size);
void free(void *ptr);
void *calloc(size_t nmemb, size_t size);

/* force failure if str is not a static string */
#define force_literal_cstr(str)   ("" str "")

/* check if the var is exactly the same as the static string */
#define strcmp_static(var, str) \
    (memcmp(var, force_literal_cstr(str), static_strlen(force_literal_cstr(str)) + 1))

/* check if the var starts with the static string */
#define strstartswith_static(var, str) \
    (!memcmp(var, force_literal_cstr(str), static_strlen(force_literal_cstr(str))))

/* copy static string and return the address of the null end (null if the dest
 * is not large enough).*/
#define strcpy_static(var, str, max)                                                      \
    (static_strlen(force_literal_cstr(str)) + 1 > (max) ? NULL :                          \
     memcpy((var), force_literal_cstr(str), static_strlen(force_literal_cstr(str)) + 1) + \
     static_strlen(force_literal_cstr(str)))

/* Copy a fixed size array. */
#define COPY_ARRAY(dst, src)                                                    \
    do {                                                                        \
        /* Using pointers because otherwise the compiler would try to allocate  \
         * memory for the fixed size arrays and complain about invalid          \
         * initializers.                                                        \
         */                                                                     \
        __typeof__(src)* _s = &(src);                                           \
        __typeof__(dst)* _d = &(dst);                                           \
                                                                                \
        static_assert(SAME_TYPE((*_s)[0], (*_d)[0]), "types must match");       \
        static_assert(ARRAY_SIZE(*_s) == ARRAY_SIZE(*_d), "sizes must match");  \
                                                                                \
        memcpy(*_d, *_s, sizeof(*_d));                                          \
    } while (0)

/* Libc printf functions. stdio.h/stdarg.h. */
void fprintfmt (int (*_fputch)(void *, int, void *), void * f, void * putdat,
                const char * fmt, ...) __attribute__((format(printf, 4, 5)));

void vfprintfmt (int (*_fputch)(void *, int, void *), void * f, void * putdat,
                 const char * fmt, va_list ap) __attribute__((format(printf, 4, 0)));

int snprintf (char * buf, int n, const char * fmt, ...) __attribute__((format(printf, 3, 4)));

/* Miscelleneous */

int inet_pton4 (const char *src, size_t len, void *dst);
int inet_pton6 (const char *src, size_t len, void *dst);

uint32_t __htonl (uint32_t x);
uint32_t __ntohl (uint32_t x);
uint16_t __htons (uint16_t x);
uint16_t __ntohs (uint16_t x);

extern const char * const * sys_errlist_internal;

/* Graphene functions */

int get_norm_path(const char* path, char* buf, size_t* size);
int get_base_name(const char* path, char* buf, size_t* size);

/* Loading configs / manifests */

#include <list.h>

struct config;
DEFINE_LISTP(config);
struct config_store {
    LISTP_TYPE(config) root;
    LISTP_TYPE(config) entries;
    void *           raw_data;
    int              raw_size;
    void *           (*malloc) (size_t);
    void             (*free) (void *);
};

int read_config (struct config_store * store, int (*filter) (const char *, int),
                 const char ** errstring);
int free_config (struct config_store * store);
int copy_config (struct config_store * store, struct config_store * new_store);
int write_config (void * file, int (*write) (void *, void *, int),
                  struct config_store * store);
ssize_t get_config (struct config_store * cfg, const char * key,
                    char * val_buf, size_t buf_size);
int get_config_entries (struct config_store * cfg, const char * key,
                        char * key_buf, size_t key_bufsize);
ssize_t get_config_entries_size (struct config_store * cfg, const char * key);
int set_config (struct config_store * cfg, const char * key, const char * val);

#define CONFIG_MAX      4096

#endif /* API_H */
