/**
 * \file model.c
 *
 * \brief Implementação das funções de manipulação do modelo 3D.
 *
 * \author
 * Petrucio Ricardo Tavares de Medeiros \n
 * Universidade Federal Rural do Semi-Árido \n
 * Departamento de Engenharias e Tecnologia \n
 * petrucio at ufersa (dot) edu (dot) br
 *
 * \version 1.0
 * \date May 2025
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "model.h"

unsigned char image[HEIGHT][WIDTH][3];

void set_pixel(int x, int y, unsigned char r, unsigned char g, unsigned char b) {
  if (x >= 0 && x < WIDTH && y >= 0 && y < HEIGHT) {
    image[y][x][0] = r;
    image[y][x][1] = g;
    image[y][x][2] = b;
  }
}

void draw_line(int x0, int y0, int x1, int y1) {
  for (float t = 0.0; t < 1.0; t = t + 0.0001)
    set_pixel((int)x0+(x1-x0)*t, (int)y0+(y1-y0)*t, 0, 0, 0);
}

void clr(){
  for(int i = 0; i < WIDTH; i++)
    for(int j = 0; j < HEIGHT; j++)
      for(int c = 0; c < 3; c++)
	image[i][j][c] = 255;
}

void save(){
  printf("P3\n %d \t %d\n 255\n", WIDTH, HEIGHT);
  for(int i = 0; i < WIDTH; i++){
    for(int j = 0; j < HEIGHT; j++){
      for(int c = 0; c < 3; c++){
	printf("%d \t", image[i][j][c]);
      }
      printf("\n");
    }
  }
}

int load_obj(const char *filename, Vertex *vertices, int *vcount, Face *faces,
	     int *fcount) {
    FILE *file = fopen(filename, "r");
    if (!file) {
        perror("Erro ao abrir o arquivo");
        return 0;
    }

    char line[512];
    *vcount = 0;
    *fcount = 0;

    while (fgets(line, sizeof(line), file)) {
        if (strncmp(line, "v ", 2) == 0) {
            if (sscanf(line + 2, "%f %f %f", &vertices[*vcount].x,
		       &vertices[*vcount].y, &vertices[*vcount].z) == 3) {
                (*vcount)++;
            }
        } else if (strncmp(line, "f ", 2) == 0) {
            Face face = {.n = 0};
            char *token = strtok(line + 2, " \n");
            while (token && face.n < MAX_FACE_VERTS) {
                int index;
                if (sscanf(token, "%d", &index) == 1) {
                    face.verts[face.n++] = index;
                }
                token = strtok(NULL, " \n");
            }
            faces[(*fcount)++] = face;
        }
    }

    fclose(file);
    return 1;
}

void resizing( Vertex v0, Vertex v1 ){
  int x0 = (int)((v0.x + 1.0f) * WIDTH / 2.0f);
  int y0 = (int)((1.0f - v0.y) * HEIGHT / 2.0f);
  int x1 = (int)((v1.x + 1.0f) * WIDTH / 2.0f);
  int y1 = (int)((1.0f - v1.y) * HEIGHT / 2.0f);
  
  draw_line(x0, y0, x1, y1);
}


void render_faces(Vertex *vertices, Face *faces, int vcount, int fcount) {
    for (int i = 0; i < fcount; i++) {
        Face face = faces[i];
        for (int j = 0; j < face.n; j++) {
            Vertex v0 = vertices[face.verts[j] - 1];
            Vertex v1 = vertices[face.verts[(j + 1) % face.n] - 1];
	    resizing(v0, v1);
        }
    }
}