#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>
#include <math.h>
#include <locale.h>

#include <glib.h>

#include <g3dviewer_plugin.h>

/*****************************************************************************/
/* plugin interface                                                          */
/*****************************************************************************/

#define NFF_SEC_NOSECTION	  0
#define NFF_SEC_VIEWPOINT	  1
#define NFF_SEC_BGCOLOR		  2
#define NFF_SEC_POSLIGHT	  3
#define NFF_SEC_MATERIAL	  4
#define NFF_SEC_CONECYL		  5
#define NFF_SEC_SPHERE		  6
#define NFF_SEC_POLYGON		  7
#define NFF_SEC_POLPATCH	  8

int nff_readline(FILE *f, char *line, int maxlen);

int plugin_load(const char *filename, G3DModel *model)
{
  FILE *f;
  char line[1024];
  G3DObject *object;
  G3DMaterial *material = NULL;
  int section = NFF_SEC_NOSECTION;
  GLfloat r,g,b, Kd, Ks, Sh, T, refr;
  GLfloat v1,v2,v3, n1,n2,n3;
  int i, num;

  setlocale(LC_NUMERIC, "C");

  g_return_val_if_fail(model != NULL, EXIT_FAILURE);

  f = fopen(filename, "r");
  if(f == NULL)
  {
    g_warning("can't open file '%s'", filename);
    return EXIT_FAILURE;
  }

  object = g_new0(G3DObject, 1);
  object->name = g_strdup("NFF Object");
  model->objects = g_slist_append(model->objects, object);

  while(nff_readline(f, line, 1024) == EXIT_SUCCESS)
  {
#if DEBUG > 3
    g_printerr("DEBUG: %s\n", line);
#endif
    if(strcmp(line, "v") == 0) { section = NFF_SEC_VIEWPOINT; }
    else if(sscanf(line, "b %g %g %g", &r, &g, &b) == 3)
    {
      model->bgcolor[0] = r;
      model->bgcolor[1] = g;
      model->bgcolor[2] = b;
    }
    else if(sscanf(line, "f %g %g %g %g %g %g %g %g", 
                   &r, &g, &b, &Kd, &Ks, &Sh, &T, &refr) == 8)
    {
      char name[128];

      material = g3d_new_G3DMaterial();
      material->r = r;
      material->g = g;
      material->b = b;
      material->a = 1.0 - T;
      material->shininess = Sh;
      material->specular[0] = r * Ks;
      material->specular[1] = g * Ks;
      material->specular[2] = b * Ks;
      if(T > 0) material->flags |= G3D_FLAG_MAT_TWOSIDE;
      object->materials = g_slist_append(object->materials, material);
      g_snprintf(name, 128, "material #%d", g_slist_length(object->materials));
      material->name = g_strdup(name);
    }
    else if((sscanf(line, "pp %d", &num) == 1) ||
            (sscanf(line, "p %d", &num) == 1))
    {
      G3DFace *face = g_new0(G3DFace, 1);

      if(strncmp(line, "pp", 2) == 0) section = NFF_SEC_POLPATCH;
      else section = NFF_SEC_POLYGON;

      object->vertex_count += num;
      object->vertices = g_realloc(object->vertices, 
        object->vertex_count * 3 * sizeof(GLfloat));
      face->material = material;
      face->num_vertices = num;
      face->index_vertex = g_malloc0(num * sizeof(int));
      object->faces = g_slist_prepend(object->faces, face);
      if(section == NFF_SEC_POLPATCH)
      {
        face->flags |= G3D_FLAG_FAC_NORMALS;
        face->normals = g_malloc0(num * 3 * sizeof(GLfloat));
      }
      /* most faces are in this direction, but there are wrong models */
      for(i=num-1; i>=0; i--)
      {
        if(nff_readline(f, line, 1024) != EXIT_SUCCESS) 
        {
          fclose(f);
          g_printerr("reading vertices failed\n");
          return EXIT_FAILURE;
        }
        if((section == NFF_SEC_POLPATCH) && 
           (sscanf(line, "%g %g %g %g %g %g", &v1,&v2,&v3, &n1,&n2,&n3) == 6))
        {
          int index = object->vertex_count - num + i;
          object->vertices[index*3+0] = v1;
          object->vertices[index*3+1] = v2;
          object->vertices[index*3+2] = v3;
          face->index_vertex[i] = index;
          face->normals[i*3+0] = -n1;
          face->normals[i*3+1] = -n2;
          face->normals[i*3+2] = -n3;
        }
        else if(sscanf(line, "%g %g %g", &v1,&v2,&v3) == 3)
        {
          int index = object->vertex_count - num + i;
          object->vertices[index*3+0] = v1;
          object->vertices[index*3+1] = v2;
          object->vertices[index*3+2] = v3;
          face->index_vertex[i] = index;
        }
        else g_printerr("error in line '%s'\n", line);
      }
    }
  }
  fclose(f);
  return EXIT_SUCCESS;
}

char *plugin_description(void)
{
  return g_strdup(
    "Neutral File Format import plugin\n");
}

char **plugin_extensions(void)
{
  return g_strsplit("nff", ":", 0);
}

/*****************************************************************************/
/* private functions                                                         */
/*****************************************************************************/

int nff_readline(FILE *f, char *line, int maxlen)
{
  if(fgets(line, maxlen, f) == NULL) return EXIT_FAILURE;
  g_strstrip(line);

  if((strlen(line) == 0) || (line[0] == '#')) 
  {
    /* get next line if empty or comment */
    return nff_readline(f, line, maxlen);
  }
  return EXIT_SUCCESS;
}