/* 
 * Copyright 2011 Stefan Lankes, Chair for Operating Systems,
 *                               RWTH Aachen University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This file is part of MetalSVM. 
 */
#include <metalsvm/stddef.h>
#include <metalsvm/time.h>

#include "lwip/debug.h"
#include "lwip/sys.h"
#include "lwip/opt.h"
#include "lwip/stats.h"

#ifndef TRUE
#define TRUE	1
#endif

#ifndef FALSE
#define FALSE	0
#endif

/** Returns the current time in milliseconds,
 * may be the same as sys_jiffies or at least based on it. */
u32_t
sys_now(void)
{
  return (get_clock_tick() / TIMER_FREQ) * 1000;
}

u32_t
sys_jiffies(void)
{
  return (get_clock_tick() / TIMER_FREQ) * 1000;
}

#if !NO_SYS

/* sys_init(): init needed system resources
 * Note: At the moment there are none
 */
void
sys_init(void)
{
}

/**
 * Sleep for some ms. Timeouts are NOT processed while sleeping.
 *
 * @param ms number of milliseconds to sleep
 */
void
sys_msleep(u32_t ms)
{
  if (ms > 0) {
    sys_sem_t delaysem;
    err_t err = sys_sem_new(&delaysem, 0);
    if (err == ERR_OK) {
      sys_arch_sem_wait(&delaysem, ms);
      sys_sem_free(&delaysem);
    }
  }
}

/* sys_thread_new(): Spawns a new thread with given attributes as supportet
 * Note: In MetalSVM this is realized as kernel tasks
 */
sys_thread_t sys_thread_new(const char *name, lwip_thread_fn thread, void *arg, int stacksize, int prio)
{
	tid_t	tmp;
	create_kernel_task(&tmp,thread,arg);
	return tmp;
}

/* sys_sem_free(): destroy's given semaphore
 * and releases system resources.
 * This semaphore also gets invalid.
 */
void sys_sem_free(sys_sem_t* sem)
{
	sem->valid = FALSE;
	sem_destroy(&sem->sem);
}

/* sys_sem_valid(): returns if semaphore is valid 
 * at the moment
 */
int sys_sem_valid(sys_sem_t* sem)
{
	return sem->valid;
}

/* sys_sem_new(): creates a new semaphre with given count.
 * This semaphore becomes valid
 */
err_t sys_sem_new(sys_sem_t* sem,u8_t count)
{
	sem->valid = TRUE;
	return sem_init(&sem->sem,count);
}

/* sys_sem_set_invalid(): this semapohore becomes invalid
 * Note: this does not mean it is destroyed
 */
void sys_sem_set_invalid(sys_sem_t * sem)
{
	sem->valid = FALSE;
}

/* sys_sem_signal(): this semaphore is signaled
 *
 */
void sys_sem_signal(sys_sem_t* sem)
{
	sem_post(&sem->sem);
}

/* sys_arch_sem_wait): wait for the given semaphore for
 * a given timeout
 * Note: timeout = 0 means wait forever
 */
u32_t sys_arch_sem_wait(sys_sem_t *sem, u32_t timeout)
{
	int err;
	if (!timeout)
		return sem_wait(&sem->sem);
	while (timeout)
	{
		err = sem_trywait(&sem->sem);
		if (err != -1)
			return err;
		timeout--;
	}
	return SYS_ARCH_TIMEOUT;
}

/* sys_mbox_valid() : returns if the given mailbox
 * is valid
 */
int sys_mbox_valid(sys_mbox_t * mbox)
{
	return mbox->valid;
}

/* sys_arch_mbox_fetch(): wait for the given mailbox for a specified
 * amount of time.
 * Note: timeout = 0 means wait forever
 */
u32_t sys_arch_mbox_fetch(sys_mbox_t * mbox, void **msg, u32_t timeout)
{
	if (!timeout)
		return mailbox_ptr_fetch(&mbox->mailbox,msg);

	while(timeout)
	{
		if (!mailbox_ptr_tryfetch(&mbox->mailbox,msg))
			return 0;
		timeout--;
	}

	return SYS_ARCH_TIMEOUT;
}

/* sys_mbox_free() : free the given mailbox, release the system resources
 * and set mbox to invalid
 */
void sys_mbox_free(sys_mbox_t* mbox)
{
	mbox->valid = FALSE;
	mailbox_ptr_destroy(&mbox->mailbox);
}

/* sys_arch_mbox_tryfetch(): poll for new data in mailbox
 *
 */
u32_t sys_arch_mbox_tryfetch(sys_mbox_t* mbox, void** msg)
{
	return mailbox_ptr_tryfetch(&mbox->mailbox,msg);
}

/* sys_mbox_new(): create a new mailbox with a minimum size of "size"
 *
 */
err_t sys_mbox_new(sys_mbox_t* mbox,int size)
{
	mbox->valid = TRUE;
	return mailbox_ptr_init(&mbox->mailbox);
}

/* sys_mbox_set_invalid(): set the given mailbox to invald
 * Note: system resources are NOT freed
 */
void sys_mbox_set_invalid(sys_mbox_t* mbox)
{
	mbox->valid = FALSE;
}

/* sys_mbox_trypost(): try to post data to the mailbox
 * Note: There is at the moment no try post implemented
 * so we use the normal post instead
 */
err_t sys_mbox_trypost(sys_mbox_t *mbox, void *msg)
{
	return mailbox_ptr_post(&mbox->mailbox,msg);
}

/* sys_mbox_post(): post new data to the mailbox
 *
 */
void sys_mbox_post(sys_mbox_t* mbox,void* msg)
{
	mailbox_ptr_post(&mbox->mailbox,msg);
}

/* sys_mutex_lock(): lock the given mutex
 * Note: There is no specific mutex in MetalSVM
 * so we use a semaphore with 1 element
 */
void sys_mutex_lock(sys_mutex_t* mutex)
{
	sem_wait(mutex);
}

/* sys_mutex_unlock(): unlock the given mutex
 *
 */
void sys_mutex_unlock(sys_mutex_t* mutex)
{
	sem_post(mutex);
}

/* sys_mutex_new(): create a new mutex
 *
 */
err_t sys_mutex_new(sys_mutex_t * mutex)
{
	sem_init(mutex,1);
	return 0;
}

#endif /* !NO_SYS */