#import "model.h"
#import "vector.h"
#import "memory.h"
#import "oops.h"
#import "array_utilities.h"

#import "gl_headers.h"

#include <string.h>
#include <lib3ds/file.h>
#include <lib3ds/mesh.h>
#include <lib3ds/node.h>
#include <lib3ds/material.h>

typedef struct {
    int vertex_1, vertex_2, vertex_3;
} triangle_indices;

typedef struct {
    vector *vertices;
    triangle_indices *triangles;
} autodesk_3ds_model;

void add_node_to_3ds_model(Lib3dsFile *file, Lib3dsNode *node, autodesk_3ds_model *m)
{
    if ((node->type == LIB3DS_OBJECT_NODE) && (strcmp(node->name,"$$$DUMMY") != 0)) {
        Lib3dsMesh *mesh;
        mesh = lib3ds_file_mesh_by_name(file, node->name);
        if (mesh) {
            unsigned int last_count = array_count(m->triangles);
            m->triangles = resize_array(m->triangles, last_count + mesh->faces);
            int i;
            for (i=0; i<mesh->faces; i++) {
                Lib3dsFace *face = &mesh->faceL[i];
                triangle_indices new_tri;
                new_tri.vertex_1 = face->points[0];
                new_tri.vertex_2 = face->points[1];
                new_tri.vertex_3 = face->points[2];
                m->triangles[last_count + i] = new_tri;
            }
            
            last_count = array_count(m->vertices);
            m->vertices = resize_array(m->vertices, last_count + mesh->points);
            for (i=0; i<mesh->points; i++) {
                float *pos = mesh->pointL[i].pos;
                m->vertices[i + last_count] = make_vector(pos[0], pos[1], pos[2]);
            }
        }
    }
}

void draw_3ds(autodesk_3ds_model *m)
{
    glBegin(GL_TRIANGLES);
    triangle_indices triangle;
    foreach (m->triangles, i, triangle) {
        glVertex3f(UNPACK_VECTOR(m->vertices[triangle.vertex_1]));
        glVertex3f(UNPACK_VECTOR(m->vertices[triangle.vertex_2]));
        glVertex3f(UNPACK_VECTOR(m->vertices[triangle.vertex_3]));
    }
    glEnd();
}

autodesk_3ds_model *load_3ds(char *filename)
{
    Lib3dsFile *file = lib3ds_file_load(filename);
    
    if (file == NULL) {
        oops(recoverable_error, "Couldn't load file.");
        return NULL;
    }

    // Read the first frame only.
    lib3ds_file_eval(file, 0);

    autodesk_3ds_model *m = alloc(sizeof(autodesk_3ds_model));
    m->vertices = alloc_array(sizeof(vector), 0);
    m->triangles = alloc_array(sizeof(triangle_indices), 0);
    
    Lib3dsNode *node;
    for (node = file->nodes; node != NULL; node = node->next) {
        add_node_to_3ds_model(file, node, m);
    }
#warning following line is probably important
    lib3ds_file_free(file);

    return autorelease(m);
}

model_class autodesk_3ds = {&load_3ds, &draw_3ds};