/*
 * CS5600 University of Utah
 * Charles McGarvey
 * mcgarvey@eng.utah.edu
 */

#include <cerrno>

#include "light.hh"
#include "list.hh"
#include "vec.hh"

#include "scene.hh"


static int _scene_add_light(scene_t* s, FILE* file);
static int _scene_add_sphere(scene_t* s, FILE* file);
static int _scene_add_plane(scene_t* s, FILE* file);


struct scene
{
    int     w, h;
    vec_t   eye;
    vec_t   spot;
    vec_t   up;
    list_t* lights;
    list_t* spheres;
    list_t* planes;
    color_t ambient;
};


scene_t* scene_alloc(FILE* file)
{
    int w, h;
    double eyeX, eyeY, eyeZ, spotX, spotY, spotZ, upX, upY, upZ;
    double fovy, aspect;
    double aR, aG, aB;
    if (fscanf(file, "U5 %d %d %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf",
               &w, &h,
               &eyeX, &eyeY, &eyeZ, &spotX, &spotY, &spotZ, &upX, &upY, &upZ,
               &fovy, &aspect,
               &aR, &aG, &aB) != 16) {
        fprintf(stderr, "Cannot read scene header.\n");
        return NULL;
    }

    scene_t* s = (scene_t*)mem_alloc(sizeof(scene_t));
    s->w = w;
    s->h = h;
    s->eye = vec_new(eyeX, eyeY, eyeZ);
    s->spot = vec_new(spotX, spotY, spotZ);
    s->up = vec_new(upX, upY, upZ);
    // what to do with fovy and aspect...
    s->lights = NULL;
    s->spheres = NULL;
    s->planes = NULL;
    s->ambient = color_new((scal_t)aR, (scal_t)aG, (scal_t)aB, S(1.0));

    char type;
    while (fscanf(file, " %c", &type) == 1) {
        switch (type) {
            case 'l':
                if (_scene_add_light(s, file) != 0) {
                    goto fail;
                }
                break;

            case 's':
                if (_scene_add_sphere(s, file) != 0) {
                    goto fail;
                }
                break;

            case 'p':
                if (_scene_add_plane(s, file) != 0) {
                    goto fail;
                }
                break;

            case 'X':
                goto done;

            default:
                fprintf(stderr, "Unknown identifier: %c\n", type);
        }
    }
#undef _ASSERT_G

done:
    if (s->spheres) list_reverse(&s->spheres);
    if (s->planes) list_reverse(&s->planes);
    return s;

fail:
    scene_destroy(s);
    return NULL;
}

void scene_destroy(scene_t* s)
{
    if (s->lights) list_destroy(&s->lights);
    if (s->spheres) list_destroy(&s->spheres);
    if (s->planes) list_destroy(&s->planes);
    mem_free(s);
}


/*
 * Add a light to the scene.
 */
static int _scene_add_light(scene_t* s, FILE* file)
{
    double lx, ly, lz, r, g, b;
    if (fscanf(file, " %lf %lf %lf %lf %lf %lf",
               &lx, &ly, &lz, &r, &g, &b) != 6) {
        fprintf(stderr, "Cannot read light values from scene.\n");
        return -1;
    }
    light_t* l = light_alloc(
            vec_new(lx, ly, lz),
            color_new((scal_t)r, (scal_t)g, (scal_t)b, S(1.0)),
            color_new((scal_t)r, (scal_t)g, (scal_t)b, S(1.0))
    );
    list_push2(&s->lights, l, mem_free);
    return 0;
}

static int _scene_add_sphere(scene_t* s, FILE* file)
{
    double x, y, z, radius, r, g, b;
    if (fscanf(file, " %lf %lf %lf %lf %lf %lf %lf",
               &x, &y, &z, &radius, &r, &g, &b) != 7) {
        fprintf(stderr, "Cannot read sphere values from scene.\n");
        return -1;
    }
    /*list_push2(&s->spheres, s, mem_free);*/
    return 0;
}

static int _scene_add_plane(scene_t* s, FILE* file)
{
    double x, y, z, nx, ny, nz, r, g, b;
    if (fscanf(file, " %lf %lf %lf %lf %lf %lf %lf %lf %lf",
               &x, &y, &z, &nx, &ny, &nz, &r, &g, &b) != 9) {
        fprintf(stderr, "Cannot read plane values from scene.\n");
        return -1;
    }
    /*list_push2(&s->planes, s, mem_free);*/
    return 0;
}


raster_t* scene_render(scene_t* s)
{
#if VERBOSITY >= 3
    timer_start();
#endif

    raster_t* p = raster_alloc(s->w, s->h, COLOR_BLACK);

    /*for (list_t* i = s->lights; i; i = i->link) {*/
        /*raster_light(p, *(light_t*)i->val);*/
    /*}*/

#if VERBOSITY >= 3
    printf("rendering scene...\n");
#endif

    // RENDER IT

#if VERBOSITY >= 3
    long dt = timer_stop();
    printf("render complete!\ntime\t%.3fms\n", (float)dt / 1000.0f);
#endif

    return p;
}