#include <SDL.h>

#include "raytracer.h"
#include <iostream>
#include <fstream>

int w = 320;
int h = 200;
Float *render_buffer;

Raytracer rt;
Camera cam;

void load_ply(const char *filename, Material *mat, Float scale)
{
	vector<NormalVertex*> vertices;
	vector<Vector3> normals;
	vector<int> vertex_face_num;
	ifstream f(filename);
	string token = "a";
	if (!f.is_open())
	{
		cout << "File not found: " << filename <<endl;
		exit(1);
	}
	// read header
	int vertex_num, face_num;
	while (token != "end_header")
	{
		f >> token;
		if (token == "element")
		{
			f >> token;
			if (token == "vertex")
				f >> vertex_num;
			if (token == "face")
				f >> face_num;
		}
	}

	// read vertices
	Vector3 P;
	int num = vertex_num;
	while (num--)
	{
		f >> P.x >> P.y >> P.z;
		P.x = -scale*P.x;
		P.y = scale*P.y - 3.6;
		P.z = -scale*P.z;
		vertices.push_back(new NormalVertex(P));
		normals.push_back(Vector3());
		vertex_face_num.push_back(0);
	}

	// read faces
	Triangle *face;
	int v1, v2, v3;
	while (face_num--)
	{
		f >> num;
		if (num != 3)
		{
			printf("ply error: faces of %d vertices not supported", num);
			return;
		}
		f >> v1 >> v2 >> v3;
		face = new Triangle(vertices.at(v1), vertices.at(v2), vertices.at(v3), mat);
		rt.addshape(face);
		face->setSmooth();

		normals.at(v1) += face->getNormal();
		vertex_face_num.at(v1)++;
		normals.at(v2) += face->getNormal();
		vertex_face_num.at(v2)++;
		normals.at(v3) += face->getNormal();
		vertex_face_num.at(v3)++;
	}

	for (int i; i < vertex_num; i++)
	{
		normals.at(i) /= vertex_face_num.at(i);
		normals.at(i).normalize();
		vertices.at(i)->N = normals.at(i);
	}

	f.close();
}

void update(SDL_Surface *screen)
{
	rt.render(w, h, render_buffer);

	if (SDL_MUSTLOCK(screen))
		if (SDL_LockSurface(screen) < 0)
			return;

	Uint32 *bufp = (Uint32 *)screen->pixels;
	unsigned char c[3];
	for (Float *fd = render_buffer; fd != render_buffer + w*h*3; fd += 3)
	{
		for (int i = 0; i < 3; i++)
		{
			if (fd[i] > 1.0)
				c[i] = 255;
			else
				c[i] = (unsigned char)(fd[i] * 255.0);
		}
		*bufp = SDL_MapRGB(screen->format, c[0], c[1], c[2]);
		bufp++;
	}

	if (SDL_MUSTLOCK(screen))
		SDL_UnlockSurface(screen);

	if (screen->flags & SDL_DOUBLEBUF)
		SDL_Flip(screen);
	else
		SDL_UpdateRect(screen, 0, 0, w, h);
}

int main()
{
	/* initialize SDL */
	SDL_Surface *screen;

	if( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
		fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
		exit(1);
	}

	atexit(SDL_Quit);

	screen = SDL_SetVideoMode(w, h, 32, SDL_SWSURFACE|SDL_DOUBLEBUF|SDL_RESIZABLE);
	if ( screen == NULL ) {
		fprintf(stderr, "Unable to set video mode: %s\n", SDL_GetError());
		exit(1);
	}

	/* initialize raytracer and prepare scene */
	render_buffer = (Float *) malloc(w*h*3*sizeof(Float));

	rt.setThreads(1);
	rt.setMaxDepth(3);

	KdTree top;
	rt.setTop(&top);

	Light light1(Vector3(-5.0, 2.0, 8.0), Colour(0.9, 0.3, 0.6));
	light1.castShadows(false);
	rt.addlight(&light1);

	//Light light2(Vector3(-2.0, 10.0, 2.0), Colour(0.4, 0.6, 0.3));
	//light2.castShadows(false);
	//rt.addlight(&light2);

	Material mat(Colour(0.9, 0.9, 0.9));
	load_ply("../models/dragon/dragon_vrip_res4.ply", &mat, 29);

	rt.setCamera(&cam);
	cam.setEye(Vector3(0,0,10));

	/* build kd-tree */
	top.setMaxDepth(100);
	top.optimize();

	/* loop... */
	SDL_Event event;
	bool quit = false;
	Float roty = 0.0, rotx = 0.0, move = 0.0;
	while (!quit)
	{
		while (SDL_PollEvent(&event))
		{
			switch (event.type) {
				case SDL_VIDEORESIZE:
					w = event.resize.w;
					h = event.resize.h;
					render_buffer = (Float *) realloc(render_buffer, w*h*3*sizeof(Float));
					screen = SDL_SetVideoMode(w, h, 32, SDL_HWSURFACE|SDL_DOUBLEBUF|SDL_RESIZABLE);
					break;
				case SDL_KEYDOWN:
					if (event.key.keysym.sym == SDLK_ESCAPE) {
						quit = true;
						break;
					}
					if (event.key.keysym.sym == SDLK_LEFT) {
						roty = -0.01;
						break;
					}
					if (event.key.keysym.sym == SDLK_RIGHT) {
						roty = +0.01;
						break;
					}
					if (event.key.keysym.sym == SDLK_DOWN) {
						rotx = +0.01;
						break;
					}
					if (event.key.keysym.sym == SDLK_UP) {
						rotx = -0.01;
						break;
					}
					if (event.key.keysym.sym == SDLK_w) {
						move = +0.5;
						break;
					}
					if (event.key.keysym.sym == SDLK_s) {
						move = -0.5;
						break;
					}
					break;
				case SDL_KEYUP:
					if (event.key.keysym.sym == SDLK_LEFT || event.key.keysym.sym == SDLK_RIGHT) {
						roty = 0.0;
						break;
					}
					if (event.key.keysym.sym == SDLK_UP || event.key.keysym.sym == SDLK_DOWN) {
						rotx = 0.0;
						break;
					}
					if (event.key.keysym.sym == SDLK_w || event.key.keysym.sym == SDLK_s) {
							move = 0.0;
							break;
						}
					break;
				case SDL_QUIT:
					quit = true;
			}
		}
		cam.rotate(Quaternion(cos(roty),0,sin(roty),0).normalize());
		cam.rotate(Quaternion(cos(rotx),cam.u[0]*sin(rotx),0,cam.u[2]*sin(rotx)).normalize());
		cam.u.y = 0;
		cam.u.normalize();
		cam.move(move,0,0);
		update(screen);
	}

	free(render_buffer);
}