#include "video.h"
#include "scene.h"
#include "vector.h"
#include "quadtree.h"
#include "shader.h"

#include <SDL_image.h>
#include <FTGL/ftgl.h>
#include <boost/format.hpp>
#include <boost/shared_ptr.hpp>

#define GL_GLEXT_PROTOTYPES
#include <SDL_opengl.h>
//#include <GL/gl.h>
#include <GL/gl.h>
//#include <GL/glu.h>

#include <iostream>
#include <cmath>
#include <list>
#include <vector>
#include <map>
#include <queue>

FTFont *font;

Scene scene;

struct hit_record {
	uint32_t hits;
	int32_t min_z;
	int32_t max_z;
	uint32_t name;
};

// TODO: reimplement
int _select(Quadtree& qt, int x, int y) {
	y = 600-y;
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	GLuint buf[64] = {0};
	GLint hits, view[4] = {0};
	uint32_t id = 0;
	glSelectBuffer(64, buf);
	glGetIntegerv(GL_VIEWPORT, view);
	glRenderMode(GL_SELECT);
	glInitNames();

	//glPushName(0);
	glMatrixMode(GL_PROJECTION);
	glPushMatrix();
		glLoadIdentity();
		gluPickMatrix(x, y, 1, 1, view);
		gluPerspective(45, (float)view[2] / (float)view[3], 1, 10000);
		glMatrixMode(GL_MODELVIEW);
		glLoadIdentity();
		scene.lookat();

		std::vector<Quadtree::QuadNode*> nodes;
		uint32_t index = 0;
		std::queue<Quadtree::QuadNode*> q;
		q.push(qt.root);
		while(!q.empty()) {
			Quadtree::QuadNode *node = q.front();
			q.pop();
			if(node->vertex_array) {
				glPushName(++index);
				/*glBegin(GL_QUADS);
					glVertex3f(node->x - node->width/2,
				glEnd();*/
				glPopName();
				node->draw();
			} else
				for(int i = 0; i < 4; i++)
					q.push(node->children[i]);
		}
		glMatrixMode(GL_PROJECTION);
	glPopMatrix();
	//glMatrixMode(GL_MODELVIEW);
	//glFlush();
	hits = glRenderMode(GL_RENDER);
	//std::cout << "hits: " << hits << std::endl;
	for(int i = 0; i < hits; i++) {
		struct hit_record *hit = (struct hit_record*)(buf + i*sizeof(hit_record));
		//std::cout << "  hits: " << hit->hits << "  min_z: " << hit->min_z << "  max_z: " << hit->max_z << std::endl;
		if(hit->hits == 1 && hit->name > 0)
			id = hit->name;
	}
	glMatrixMode(GL_MODELVIEW);
	//std::cout << "id: " << id << std::endl;
	if(id > 0) {
		//return map[vectors[id-1]];
	}
	//return Vector3::p();
	//return id;
	return 0;
}

bool select(Quadtree& qt, int x, int y, float& px, float& py, float& pz) {
	GLint view[4] = {0};
	GLdouble mvmatrix[16] = {0}, projmatrix[16] = {0};
	glGetDoublev(GL_PROJECTION_MATRIX, projmatrix);
	glGetDoublev(GL_MODELVIEW_MATRIX, mvmatrix);
	glGetIntegerv(GL_VIEWPORT, view);

	y = view[3] - y - 1;

	float z;
	glReadBuffer(GL_BACK);
	glReadPixels(x, y, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &z);

	GLdouble _px, _py, _pz;
	if(gluUnProject(x, y, z, mvmatrix, projmatrix, view, &_px, &_py, &_pz) == GLU_TRUE) {
		px = _px;
		py = _py;
		pz = _pz;
		return true;
	}

	return false;
}

int main(int argc, char **argv) {
	video::width = 1280;
	video::height = 720;
	video::init();
	GLShaderProgram program;
	GLVertexShader terrain_vertex("terrain_vertex.glsl");
	GLFragmentShader terrain_fragment("terrain_fragment.glsl");
	program.attach(terrain_vertex);
	program.attach(terrain_fragment);
	program.link();

	font = new FTTextureFont("font.ttf");
	font->FaceSize(10);

	SDL_Surface *hm = IMG_Load("heightmap6.png");
	unsigned char *pixels = (unsigned char*)hm->pixels;
	float *heightmap = new float[hm->w * hm->h];
	for(int x = 0; x < hm->w; x++) {
		for(int y = 0; y < hm->h; y++) {
			heightmap[y*hm->w + x] = ((float)(pixels[y*hm->w + x]) / 256) * 20;
		}
	}
	int level = 3;
	Quadtree *qt = new Quadtree(hm->w, hm->h, heightmap, level);
	//Quadtree qt(qt_size, qt_size, (int)ceil(sqrt(qt_size)));


	GLuint grass_texture;
	{
		SDL_Surface *surface = IMG_Load("Grass0073_3_S.jpg");
		SDL_Surface *image = SDL_CreateRGBSurface(SDL_SWSURFACE, surface->w, surface->h, 32,
				0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000);
		SDL_Rect area;
		area.x = area.y = 0;
		area.w = surface->w;
		area.h = surface->h;
		SDL_BlitSurface(surface, &area, image, &area);
		//glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
		glGenTextures(1, &grass_texture);
		glBindTexture(GL_TEXTURE_2D, grass_texture);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		if(image->format->Amask) {
			//glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image->w, image->h, 0, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
			gluBuild2DMipmaps(GL_TEXTURE_2D, 4, image->w, image->h, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
		} else {
			//glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, image->w, image->h, 0, GL_RGB, GL_UNSIGNED_BYTE, image->pixels);
			gluBuild2DMipmaps(GL_TEXTURE_2D, 3, image->w, image->h, GL_RGB, GL_UNSIGNED_BYTE, image->pixels);
		}
		SDL_FreeSurface(surface);
		SDL_FreeSurface(image);
	}

	//SDL_WM_GrabInput(SDL_GRAB_ON);

	SDL_Event event;
	bool running = true;
	bool grid = false;
	bool gravity = true;
	SDL_WarpMouse(video::width/2, video::height/2);
	unsigned int last_time = SDL_GetTicks();
	/*boost::timer t;
	double last_time = 0;*/
	Vector3 selected;
	while(running) {
		unsigned int time = SDL_GetTicks();
		//double time = t.elapsed();
		//t.restart();
		unsigned int steps = time - last_time + 1;
		//double steps = (time - last_time) * 1000;
		last_time = time;
		bool do_select = 0;
		int sx, sy;
		while(SDL_PollEvent(&event)) {
			switch(event.type) {
				case SDL_QUIT:
					running = false;
					break;
				case SDL_KEYDOWN:
					switch(event.key.keysym.sym) {
						case SDLK_ESCAPE:
							running = false;
							break;
						case SDLK_g:
							grid = !grid;
							break;
						case SDLK_KP_PLUS:
						case SDLK_PLUS:
							qt->create_nodes(++level);
							level = qt->levels;
							break;
						case SDLK_KP_MINUS:
						case SDLK_MINUS:
							if(level > 1) {
								qt->create_nodes(--level);
							}
							break;
						case SDLK_SPACE:
							scene.yvel = .05;
							break;
						case SDLK_h:
							gravity = !gravity;
							break;
						default:
							break;
					}
					break;
				case SDL_MOUSEBUTTONUP:
					switch(event.button.button) {
						case SDL_BUTTON_LEFT:
							sx = event.button.x;
							sy = event.button.y;
							do_select = true;
							// TODO: reimplement selection
							break;
						case SDL_BUTTON_WHEELUP:
						case SDL_BUTTON_WHEELDOWN:
							// TODO: reimplement?
							break;
					}
				case SDL_MOUSEMOTION:
					if(event.motion.x == video::width/2 && event.motion.y == video::height/2)
						break;
					scene.yaw += (float)event.motion.xrel / 500;
					scene.pitch += (float)event.motion.yrel / 500;
					if(scene.yaw > 2*M_PI)
						scene.yaw -= 2*M_PI;
					else if(scene.yaw < 0)
						scene.yaw += 2*M_PI;
					if(scene.pitch > M_PI)
						scene.pitch = M_PI;
					else if(scene.pitch < 0)
						scene.pitch = 0;
					SDL_WarpMouse(video::width/2, video::height/2);
					break;
			}
		}

		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		glLoadIdentity();
		video::persp();

		unsigned char *keystate = SDL_GetKeyState(NULL);
		float forward = 0;
		float right = 0;
		bool moved = false;
		if(keystate[SDLK_w]) {
			moved = true;
			forward++;
		}
		if(keystate[SDLK_s]) {
			moved = true;
			forward--;
		}
		if(keystate[SDLK_a]) {
			moved = true;
			right--;
		}
		if(keystate[SDLK_d]) {
			moved = true;
			right++;
		}
		if(keystate[SDLK_q])
			scene.pos.y -= 0.002*steps*(keystate[SDLK_LSHIFT]?10:1);
		if(keystate[SDLK_e])
			scene.pos.y += 0.002*steps*(keystate[SDLK_LSHIFT]?10:1);
		if(moved && (forward || right))
			scene.move(forward, right, steps*(keystate[SDLK_LSHIFT]?10:1));

		std::string move_str;
		Quadtree::QuadNode *node = qt->find(scene.pos.x, scene.pos.z);
		if(node) {
			if(gravity) {
				float y = node->get_height(scene.pos.x, scene.pos.z);
				if(scene.pos.y > y && !keystate[SDLK_e])
					scene.yvel -= 9.81 * steps / 85000;
				if(scene.yvel < -.5)
					scene.yvel = -.5;
				scene.pos.y += scene.yvel * steps;
				if(scene.pos.y < y) {
					scene.pos.y = y;
					scene.yvel = 0;
				}
			}
			move_str = (boost::format("%s %.2f,%.2f %.2fx%.2f %d") % scene.pos.str() % node->x % node->y % node->width % node->height % node->level).str();
		}

		scene.lookat();

		glEnable(GL_LIGHTING);
		const float light_pos[4] = {50, 100, 50, 1};
		//const float light_pos[4] = {0, 1, 0, 0};
		glLightfv(GL_LIGHT0, GL_POSITION, light_pos);

		if(!grid) {
			program.use();
			glBindTexture(GL_TEXTURE_2D, grass_texture);
			glEnable(GL_TEXTURE_2D);
			glBindBuffer(GL_ARRAY_BUFFER, qt->vbo_object);
			glVertexPointer(3, GL_FLOAT, 0, NULL);
			glNormalPointer(GL_FLOAT, 0, (GLvoid*)(qt->vertices*3*sizeof(float)));
			glTexCoordPointer(2, GL_FLOAT, 0, (GLvoid*)(qt->vertices*3*sizeof(float)*2));
			glEnableClientState(GL_VERTEX_ARRAY);
			glEnableClientState(GL_NORMAL_ARRAY);
			glEnableClientState(GL_TEXTURE_COORD_ARRAY);
			glDrawArrays(GL_TRIANGLES, 0, qt->vertices);
			glDisableClientState(GL_VERTEX_ARRAY);
			glDisableClientState(GL_NORMAL_ARRAY);
			glDisableClientState(GL_TEXTURE_COORD_ARRAY);
			glDisable(GL_TEXTURE_2D);
			glUseProgram(0);
		} else {
			std::queue<Quadtree::QuadNode*> q;
			q.push(qt->root);
			while(!q.empty()) {
				Quadtree::QuadNode *node = q.front();
				q.pop();
				if(node->vertex_array) {
					grid ? node->draw_grid() : node->draw();
				} else
					for(int i = 0; i < 4; i++)
						q.push(node->children[i]);
			}
		}

		glDisable(GL_LIGHTING);

		float px, py, pz;
		if(do_select && select(*qt, sx, sy, px, py, pz)) {
			selected = Vector3(px, py, pz);
		}
		glColor3f(1, 0, 0);
		glBegin(GL_TRIANGLE_FAN);
			glVertex3f(selected.x, selected.y, selected.z);
			glVertex3f(selected.x+.5, selected.y+1, selected.z-.5);
			glVertex3f(selected.x+.5, selected.y+1, selected.z+.5);
			glVertex3f(selected.x-.5, selected.y+1, selected.z+.5);
			glVertex3f(selected.x-.5, selected.y+1, selected.z-.5);
			glVertex3f(selected.x+.5, selected.y+1, selected.z-.5);
		glEnd();

		video::ortho();
		float height = font->LineHeight();
		glColor3f(1, 1, 1);
		glTranslatef(0, video::height-height, 0);
		font->Render((boost::format("%dx%d  %d levels  %d nodes  tree creation time: %f  steps: %d")
					% qt->width % qt->height % qt->levels % qt->nodes % qt->init_time % steps).str().c_str());
		//glTranslatef(0, height, 0);
		//font->Render((boost::format("selected: %x") % selected).str().c_str());
		glTranslatef(0, -height, 0);
		font->Render(move_str.c_str());
		/*if(selected) {
			glTranslatef(0, height, 0);
			//font->Render((boost::format("(%s %s %s %s)") % selected->a->str() % selected->b->str() % selected->c->str() % selected->d->str()).str().c_str());
			font->Render(selected->str().c_str());
		}*/

		SDL_GL_SwapBuffers();

		usleep(1000);
	}

	video::free();

	return 0;
}