#include <stdbool.h>
#include "string.h"
#include "stdlib.h"
#include <stddef.h>

#include "kernel.h"

static void strreverse( char *s )
{
	char *end = s + strlen( s ) - 1;
	
	while( s < end ) {
		// XOR swap;
		*s ^= *end;
		*end ^= *s;
		*s ^= *end;
		s++;
		end--;
	}
}
    
char *itoa( int v, char *s, int base )
{
	static char digit[] = "0123456789ABCDEF";
	bool sign = false;
	char *p = s;
	
	if( base < 2 || base > 16 ) {
		return NULL;
	}
	
	if( v < 0 ) {
		v = -v;
		sign = true;
	} 
	
	do {
		*p++ = digit[v % base];
	} while( ( v /= base ) > 0 );

	if( sign ) {
		*p++ = '-';
	}
	*p = '\0';
	
	strreverse( s );
	
	return s;
}

void __attribute__( ( noreturn ) ) exit( int status )
{
#ifdef OS_ABAOS
	// TODO: this should be done on process level, terminating
	// the process (by signalling SIGABRT for instance)
	kernel_panic( "exited with exit code %d", status );
#endif
#ifdef OS_LINUX
	syscall1( __NR_exit, status );
#endif

	// make gcc happy ("error: ‘noreturn’ function does return")
	for( ;; );
}

void __attribute__( ( noreturn ) ) abort( void )
{
	// TODO: this should be done on process level, terminating
	// the process (by signalling SIGABRT for instance)
#ifdef OS_ABAOS
	kernel_panic( "aborted" );
#endif
#ifdef OS_LINUX
	// TODO: this clearly wrong, but for now we exit with a 255 exit code
	// on abort..
	syscall1( __NR_exit, 255 );
#endif
	
	// make gcc happy ("error: ‘noreturn’ function does return")
	for( ;; );
}

// TODO: we should have a global memory manager and one per
// user process later
static memory_manager_t *stdlib_memory_manager = NULL;
  
void *malloc( size_t size )
{
	return memory_manager_allocate( stdlib_memory_manager, size );
}

void free( void *p )
{
	memory_manager_deallocate( stdlib_memory_manager, &p );
}

void __stdlib_set_memory_manager( memory_manager_t *memory_manager )
{
	stdlib_memory_manager = memory_manager;
}