/* Copyright  (C) 2018 - M4xw <m4x@m4xw.net>, RetroArch Team
 *
 * ---------------------------------------------------------------------------------------
 * The following license statement only applies to this file (switch_pthread.h).
 * ---------------------------------------------------------------------------------------
 *
 * Permission is hereby granted, free of charge,
 * to any person obtaining a copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef _SWITCH_PTHREAD_WRAP_
#define _SWITCH_PTHREAD_WRAP_

#include <time.h>
#include <stdio.h>
#include <switch.h>
#include <errno.h>

#include "../include/retro_inline.h"
#include "../../verbosity.h"

#define THREADVARS_MAGIC 0x21545624 // !TV$

// This structure is exactly 0x20 bytes, if more is needed modify getThreadVars() below
typedef struct
{
   // Magic value used to check if the struct is initialized
   u32 magic;

   // Thread handle, for mutexes
   Handle handle;

   // Pointer to the current thread (if exists)
   Thread *thread_ptr;

   // Pointer to this thread's newlib state
   struct _reent *reent;

   // Pointer to this thread's thread-local segment
   void *tls_tp; // !! Offset needs to be TLS+0x1F8 for __aarch64_read_tp !!
} ThreadVars;

static INLINE ThreadVars *getThreadVars(void)
{
   return (ThreadVars *)((u8 *)armGetTls() + 0x1E0);
}

#define STACKSIZE (8 * 1024)

/* libnx threads return void but pthreads return void pointer */

static uint32_t threadCounter = 1;

int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
{
   u32 prio = 0;
   Thread new_switch_thread;

   svcGetThreadPriority(&prio, CUR_THREAD_HANDLE);

   // Launch threads on Core 1
   int rc = threadCreate(&new_switch_thread, (void (*)(void *))start_routine, arg, STACKSIZE, prio - 1, 1);

   if (R_FAILED(rc))
   {
      return EAGAIN;
   }

   printf("[Threading]: Starting Thread(#%i)\n", threadCounter);
   if (R_FAILED(threadStart(&new_switch_thread)))
   {
      threadClose(&new_switch_thread);
      return -1;
   }

   *thread = new_switch_thread;

   return 0;
}

void pthread_exit(void *retval)
{
   (void)retval;
   printf("[Threading]: Exiting Thread\n");
   svcExitThread();
}

static INLINE Thread threadGetCurrent(void)
{
   ThreadVars *tv = getThreadVars();
   return *tv->thread_ptr;
}

static INLINE pthread_t pthread_self(void)
{
   return threadGetCurrent();
}

static INLINE int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
{
   mutexInit(mutex);

   return 0;
}

INLINE int pthread_mutex_destroy(pthread_mutex_t *mutex)
{
   // Nothing
   *mutex = 0;

   return 0;
}

static INLINE int pthread_mutex_lock(pthread_mutex_t *mutex)
{
   mutexLock(mutex);
   return 0;
}

static INLINE int pthread_mutex_unlock(pthread_mutex_t *mutex)
{
   mutexUnlock(mutex);

   return 0;
}

INLINE int pthread_detach(pthread_t thread)
{
   (void)thread;
   // Nothing for now
   return 0;
}

static INLINE int pthread_join(pthread_t thread, void **retval)
{
   printf("[Threading]: Waiting for Thread Exit\n");
   threadWaitForExit(&thread);
   threadClose(&thread);

   return 0;
}

static INLINE int pthread_mutex_trylock(pthread_mutex_t *mutex)
{
   return mutexTryLock(mutex) ? 0 : 1;
}

static INLINE int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
{
   condvarWait(cond, mutex);

   return 0;
}

static INLINE int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, const struct timespec *abstime)
{
   condvarWaitTimeout(cond, mutex, abstime->tv_nsec);

   return 0;
}

static INLINE int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr)
{
   condvarInit(cond);

   return 0;
}

static INLINE int pthread_cond_signal(pthread_cond_t *cond)
{
   condvarWakeOne(cond);
   return 0;
}

static INLINE int pthread_cond_broadcast(pthread_cond_t *cond)
{
   condvarWakeAll(cond);
   return 0;
}

INLINE int pthread_cond_destroy(pthread_cond_t *cond)
{
   // Nothing
   return 0;
}

INLINE int pthread_equal(pthread_t t1, pthread_t t2)
{
   if (t1.handle == t2.handle)
      return 1;

   return 0;
}

#endif