#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <drm.h>
#include <i915_drm.h>
#include <intel_bufmgr.h>

const int BATCH_BUFFER_SIZE = 524288; /* From media_libva.c */

int drm_fd = 0;
drm_intel_bufmgr *buf_mgr;

unsigned int FourCC = 842094158;
#define Width 720
#define Height 576 

int alignedW = (Width  + 127) & ~127;
int iSize    = (3 * ((Height +  31) &  ~31)) / 2;

drm_intel_bo *surface_bo = NULL;


void init()
{
    static int drm_fd = -1;

    drm_fd = open("/dev/dri/card0", O_RDWR);
    if (drm_fd < 0)
    {
        printf("error: can't open DRM connection!\n");
        _exit(-1);
    }
    
    buf_mgr = intel_bufmgr_gem_init(drm_fd, BATCH_BUFFER_SIZE);
    if (buf_mgr == NULL)
    {
        printf("intel_bufmgr_gem_init Failed!\n");
        _exit(-1);
    }
    intel_bufmgr_gem_enable_reuse(buf_mgr);
}

void create()
{
    int cpp = 1;
    uint32_t tiling_mode = I915_TILING_Y;
    unsigned long pitch = 0;
    unsigned long flags = 0;
    
    surface_bo = 
      drm_intel_bo_alloc_tiled(buf_mgr, "Surface", alignedW, iSize, cpp, &tiling_mode, 
                           &pitch, flags);
    if (surface_bo == NULL)
    {
        printf("intel_bo_alloc_tiled error\n");
        _exit(-1);
    }
}

void writeOrTestFrame(unsigned long child, unsigned int frame, int test)
{
    unsigned int totalBytes = alignedW * iSize;
    unsigned int totalDWords = totalBytes >> 2;
    unsigned long i;
    unsigned int  v = (frame << 20) | (child << 24);

    volatile unsigned int *image_data = NULL;
    volatile unsigned int r;

    drm_intel_bo_reference(surface_bo);
    
    drm_intel_bo_wait_rendering(surface_bo);
    drm_intel_gem_bo_map_gtt(surface_bo);
    image_data = (unsigned int *)surface_bo->virtual;
   
    for (i = 0; i < totalDWords; ++i)
    {
       if (test)
       {
         r = image_data[i];
         if (r != v)
         {
           printf("Child %2lu:  Readback failed at Frame: %lu, DWord: %lu", child, (unsigned long) frame, (unsigned long)i);
           printf(" (Expected 0x%08lx, Got: 0x%08lx)\n", (unsigned long) v, (unsigned long)r);
           _exit (-1);
         }

         ++v;
       }
       else 
       {
         image_data[i] = v;

         r = image_data[i];
         if (r != v)
         {
           printf("Child %2lu:  Write failed at Frame: %lu, DWord: %lu", child, (unsigned long) frame, (unsigned long)i);
           printf(" (Write 0x%08lx, Got: 0x%08lx)\n", (unsigned long) v, (unsigned long)r);
           _exit (-1);
         }
         ++v;
       }
    }

    drm_intel_gem_bo_unmap_gtt(surface_bo);
    surface_bo->virtual = NULL;
    
    drm_intel_bo_unreference(surface_bo);
}

void test_proc(unsigned long child)
{
  unsigned int i;

  init();
  create();

  for (i = 0; i < 10; ++i)
  {
    writeOrTestFrame(child, i, 0);
    writeOrTestFrame(child, i, 1);
  }
  
  _exit(0);
}

int main(int argc, char **argv)
{
  unsigned long num_forks = 0;
  unsigned long i;
  int have_procs = 0;
  pid_t *pids = NULL;
  int   *results = NULL;
  int result = -1;

  for (i = 1; i < argc; ++i)
  {
    if (strcmp(argv[i], "-procs") == 0)
    {
      ++i;
      num_forks = strtoul(argv[i], 0, 10);
      have_procs = 1;
    }
  }

  if (have_procs == 0)
  {
    fprintf(stderr, "Usage: %s -procs <num-procs>\n", argv[0]);
    exit(-1);
  }

  /* Fork the processes */
  pids    = calloc(sizeof(pid_t), num_forks);
  results = calloc(sizeof(results[0]), num_forks);
  for (i = 0; i < num_forks; ++i)
  {
    printf("Forking child %lu...\n", i);
    pid_t stat = fork();
    if (stat == 0)
    {
      /* A Child */
      test_proc(i);
    }
    else if (stat > 0)
    {
      /* The Parent, saved PID */
      pids[i] = stat;
    }
    else
    {
      fprintf(stderr, "Failed to fork child %lu\n", i);
      exit(-1);
    }
  }

  /* Wait for the children to complete */
  result = 0;
  printf("Waiting for child processes...\n");
  for (i = 0; i < num_forks; ++i)
  {
    if (waitpid(pids[i], results+i, 0) < 0)
    {
      fprintf(stderr, "Failed to waitpid on child %lu (Process %lu)\n", i, (unsigned long)pids[i]);
      result = -1;
    }
  }

  /* Report results */
  if (result == 0)
  {
    for (i = 0; i < num_forks; ++i)
    {
      if (results[i]== 0)
	printf("Child %lu (process %lu) PASSED\n", i, (unsigned long)pids[i]);
      else
      {
	printf("Child %lu (process %lu) FAILED\n", i, (unsigned long)pids[i]);
	result = -1;
      }
    }
  }

  if (result == 0)
    printf("\nPASSED\n");
  else
    printf("\nFAILED\n");
  return result;
}