#ifndef __UTIL_H
#define __UTIL_H

#include <stdio.h>
#include <pthread.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <inttypes.h>

void *xrealloc(void *ptr, size_t size);
void *xmalloc(size_t size);

typedef void (cleanup_handler) (void * /* context */ ,
				int /* is fatal? */ );

/* set from 0 - 5 depending on what level of verbosity you want */
extern int log_level;

/* set up the error globals */
void error_init(void);

/* some context for the overall process that appears on each log line */
extern char *log_context;


void exit_err(const char *);

/* error_set_handler must be a macro not a function due to setjmp stack rules */
#include <setjmp.h>

struct error_handler_context {
    jmp_buf jmp;
    cleanup_handler *handler;
    void *data;
};

#define DECLARE_ERROR_CONTEXT(name) \
  struct error_handler_context *name = (struct error_handler_context*) \
  pthread_getspecific(cleanup_handler_key);

/* clean up with the given function & data when error_handler() is invoked,
 * non-fatal errors will also return here (if that's dangerous, use fatal()
 * instead of error()).
 *
 * error handlers are thread-local, so you need to call this when starting a
 * new thread.
 */
extern pthread_key_t cleanup_handler_key;
#define error_set_handler(cleanfn, cleandata) \
{ \
	DECLARE_ERROR_CONTEXT(old); \
	struct error_handler_context *context = \
	  xmalloc(sizeof(struct error_handler_context)); \
	context->handler = (cleanfn); \
	context->data = (cleandata); \
	\
	switch (setjmp(context->jmp)) \
	{ \
	case 0: /* setup time */ \
 		if (old) { free(old); }\
		if( EINVAL == pthread_setspecific(cleanup_handler_key, context) ) { \
			fprintf(stderr, "Tried to set an error handler at %s:%d" \
					" without calling error_init().\n", \
					__FILE__, __LINE__ );\
			abort();\
		}\
		break; \
	case 1: /* fatal error, terminate process */ \
		debug( "Fatal error in thread %p", pthread_self() ); \
		abort(); \
		/* abort() can't return, so we can't fall through */ \
	case 2: /* non-fatal error, call cleanup and terminate thread */ \
		debug( "Error in thread %p", pthread_self() ); \
		context->handler(context->data, 0); \
		pthread_exit((void*) 1);\
		/* pthread_exit() can't return, so we can't fall through
		 * */\
	default: \
		 abort(); \
	} \
}


/* invoke the error handler - longjmps away, don't use directly */
void error_handler(int fatal);

/* mylog a line at the given level (0 being most verbose) */
void mylog(int line_level, const char *format, ...);

/* Returns the current time, in milliseconds, from CLOCK_MONOTONIC */
uint64_t monotonic_time_ms(void);


#define levstr(i) (i==0?'D':(i==1?'I':(i==2?'W':(i==3?'E':'F'))))

#define myloglev(level, msg, ...) mylog( level, "%"PRIu64":%c:%d %p %s %s:%d: "msg"\n", monotonic_time_ms(), levstr(level), getpid(),pthread_self(), log_context, __FILE__, __LINE__, ##__VA_ARGS__ )

#ifdef DEBUG
#define debug(msg, ...) myloglev(0, msg, ##__VA_ARGS__)
#else
#define debug(msg, ...)		/* no-op */
#endif

/* informational message, not expected to be compiled out */
#define info(msg, ...) myloglev(1, msg, ##__VA_ARGS__)

/* messages that might indicate a problem */
#define warn(msg, ...) myloglev(2, msg, ##__VA_ARGS__)

/* mylog a message and invoke the error handler to recover */
#define error(msg, ...) do { \
	myloglev(3, msg, ##__VA_ARGS__); \
	error_handler(0); \
} while(0)

/* mylog a message and invoke the error handler to kill the current thread */
#define fatal(msg, ...) do { \
	myloglev(4, msg, ##__VA_ARGS__); \
	error_handler(1); \
	exit(1); /* never-reached, this is to make static code analizer happy */ \
} while(0)


#define ERROR_IF( test, msg, ... ) do { if ((test)) { error(msg, ##__VA_ARGS__); } } while(0)
#define FATAL_IF( test, msg, ... ) do { if ((test)) { fatal(msg, ##__VA_ARGS__); } } while(0)

#define ERROR_UNLESS( test, msg, ... ) ERROR_IF( !(test), msg, ##__VA_ARGS__ )
#define FATAL_UNLESS( test, msg, ... ) FATAL_IF( !(test), msg, ##__VA_ARGS__ )


#define ERROR_IF_NULL(value, msg, ...) \
	ERROR_IF( NULL == value, msg " (errno=%d, %s)", ##__VA_ARGS__, errno, strerror(errno) )
#define FATAL_IF_NULL(value, msg, ...) \
	FATAL_IF( NULL == value, msg " (errno=%d, %s)", ##__VA_ARGS__, errno, strerror(errno) )

#define ERROR_IF_NEGATIVE( value, msg, ... ) ERROR_IF( value < 0, msg, ##__VA_ARGS__ )
#define FATAL_IF_NEGATIVE( value, msg, ... ) FATAL_IF( value < 0, msg, ##__VA_ARGS__ )

#define ERROR_IF_ZERO( value, msg, ... ) ERROR_IF( 0 == value, msg, ##__VA_ARGS__ )
#define FATAL_IF_ZERO( value, msg, ... ) FATAL_IF( 0 == value, msg, ##__VA_ARGS__ )



#define ERROR_UNLESS_NULL(value, msg, ...) \
	ERROR_UNLESS( NULL == value, msg " (errno=%d, %s)", ##__VA_ARGS__, errno, strerror(errno) )
#define FATAL_UNLESS_NULL(value, msg, ...) \
	FATAL_UNLESS( NULL == value, msg " (errno=%d, %s)", ##__VA_ARGS__, errno, strerror(errno) )

#define ERROR_UNLESS_NEGATIVE( value, msg, ... ) ERROR_UNLESS( value < 0, msg, ##__VA_ARGS__ )
#define FATAL_UNLESS_NEGATIVE( value, msg, ... ) FATAL_UNLESS( value < 0, msg, ##__VA_ARGS__ )

#define ERROR_UNLESS_ZERO( value, msg, ... ) ERROR_UNLESS( 0 == value, msg, ##__VA_ARGS__ )
#define FATAL_UNLESS_ZERO( value, msg, ... ) FATAL_UNLESS( 0 == value, msg, ##__VA_ARGS__ )


#define NULLCHECK(value) FATAL_IF_NULL(value, "BUG: " #value " is null")

#define SHOW_ERRNO( msg, ... ) msg ": %s (%i)", ##__VA_ARGS__, ( errno == 0 ? "EOF" : strerror(errno) ), errno

#define WARN_IF_NEGATIVE( value, msg, ... ) if ( value < 0 ) { warn( msg, ##__VA_ARGS__ ); }

#endif