/** Utilities.
 *
 * @file
 * @author Steffen Vogel <github@daniel-krebs.net>
 * @author Daniel Krebs <github@daniel-krebs.net>
 * @copyright 2014-2020, Institute for Automation of Complex Power Systems, EONERC
 * @license GNU General Public License (version 3)
 *
 * VILLAScommon
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************************/

#pragma once

#include <string>
#include <vector>
#include <list>

#include <signal.h>
#include <cstdlib>
#include <cstdint>
#include <sched.h>
#include <cassert>
#include <sys/types.h>

#include <openssl/sha.h>

#include <villas/config.h>
#include <villas/log.h>

#ifdef __GNUC__
  #define LIKELY(x)	__builtin_expect((x),1)
  #define UNLIKELY(x)	__builtin_expect((x),0)
#else
  #define LIKELY(x)	(x)
  #define UNLIKELY(x)	(x)
#endif

/** Check assertion and exit if failed. */
#ifndef assert
  #define assert(exp) do { \
	if (!EXPECT(exp, 0)) \
		error("Assertion failed: '%s' in %s(), %s:%d", \
			XSTR(exp), __FUNCTION__, __BASE_FILE__, __LINE__); \
	} while (0)
#endif

/* CPP stringification */
#define XSTR(x)		STR(x)
#define  STR(x)		#x

#define CONCAT_DETAIL(x, y)	x##y
#define CONCAT(x, y)		CONCAT_DETAIL(x, y)
#define UNIQUE(x)		CONCAT(x, __COUNTER__)

#ifdef ALIGN
  #undef ALIGN
#endif
#define ALIGN(x, a)	 ALIGN_MASK(x, (uintptr_t) (a) - 1)
#define ALIGN_MASK(x, m) (((uintptr_t) (x) + (m)) & ~(m))
#define IS_ALIGNED(x, a) (ALIGN(x, a) == (uintptr_t) x)

#define SWAP(x, y) do {	\
  auto t = x;		\
  x = y;		\
  y = t;		\
} while (0)

/** Round-up integer division */
#define CEIL(x, y)	(((x) + (y) - 1) / (y))

/** Get nearest up-rounded power of 2 */
#define LOG2_CEIL(x)	(1 << (villas::utils::log2i((x) - 1) + 1))

/** Check if the number is a power of 2 */
#define IS_POW2(x)	(((x) != 0) && !((x) & ((x) - 1)))

/** Calculate the number of elements in an array. */
#define ARRAY_LEN(a)	( sizeof (a) / sizeof (a)[0] )

/* Return the bigger value */
#ifdef MAX
  #undef MAX
#endif
#define MAX(a, b)	({ __typeof__ (a) _a = (a); \
			   __typeof__ (b) _b = (b); \
			   _a > _b ? _a : _b; })

/* Return the smaller value */
#ifdef MIN
  #undef MIN
#endif
#define MIN(a, b)	({ __typeof__ (a) _a = (a); \
			   __typeof__ (b) _b = (b); \
			   _a < _b ? _a : _b; })

#ifndef offsetof
  #define offsetof(type, member)  __builtin_offsetof(type, member)
#endif

#ifndef container_of
  #define container_of(ptr, type, member) ({ const typeof( ((type *) 0)->member ) *__mptr = (ptr); \
					  (type *) ( (char *) __mptr - offsetof(type, member) ); \
					})
#endif

#define BITS_PER_LONGLONG	(sizeof(long long) * 8)

/* Some helper macros */
#define BITMASK(h, l)		(((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONGLONG - 1 - (h))))
#define BIT(nr)			(1UL << (nr))

namespace villas {
namespace utils {

std::vector<std::string>
tokenize(std::string s, std::string delimiter);

template<typename T>
void
assertExcept(bool condition, const T &exception)
{
	if (not condition)
		throw exception;
}

/** Register a exit callback for program termination: SIGINT, SIGKILL & SIGALRM. */
int signals_init(void (*cb)(int signal, siginfo_t *sinfo, void *ctx), std::list<int> cbSignals = {}, std::list<int> ignoreSignals = { SIGCHLD }) __attribute__ ((warn_unused_result));

/** Fill buffer with random data */
ssize_t read_random(char *buf, size_t len);

/** Remove ANSI control sequences for colored output. */
char * decolor(char *str);

/** Normal random variate generator using the Box-Muller method
 *
 * @param m Mean
 * @param s Standard deviation
 * @return Normal variate random variable (Gaussian)
 */
double box_muller(float m, float s);

/** Double precission uniform random variable */
double randf();

/** Concat formatted string to an existing string.
 *
 * This function uses realloc() to resize the destination.
 * Please make sure to only on dynamic allocated destionations!!!
 *
 * @param dest A pointer to a malloc() allocated memory region
 * @param fmt A format string like for printf()
 * @param ... Optional parameters like for printf()
 * @retval The the new value of the dest buffer.
 */
char * strcatf(char **dest, const char *fmt, ...)
	__attribute__ ((format(printf, 2, 3)));

/** Variadic version of strcatf() */
char * vstrcatf(char **dest, const char *fmt, va_list va)
	__attribute__ ((format(printf, 2, 0)));

char * strf(const char *fmt, ...);
char * vstrf(const char *fmt, va_list va);

/** Allocate and copy memory. */
void * memdup(const void *src, size_t bytes);

/** Call quit() in the main thread. */
void die();

/** Get log2 of long long integers */
int log2i(long long x);

/** Send signal \p sig to main thread. */
void killme(int sig);

pid_t spawn(const char *name, char *const argv[]);

/** Determines the string length as printed on the screen (ignores escable sequences). */
size_t strlenp(const char *str);

/** Calculate SHA1 hash of complete file \p f and place it into \p sha1.
 *
 * @param sha1[out] Must be SHA_DIGEST_LENGTH (20) in size.
 * @retval 0 Everything was okay.
 */
int sha1sum(FILE *f, unsigned char *sha1);

namespace base64 {

using byte = std::uint8_t;

std::string encode(const std::vector<byte> &input);
std::vector<byte> decode(const std::string &input);

} /* namespace base64 */
} /* namespace utils */
} /* namespace villas */