#include "scene.h"
#include "video.h"
#include "terrain.h"

#include <SDL_image.h>
#include <boost/format.hpp>
#include <boost/bind.hpp>
#include <assimp/aiPostProcess.h>

#include "gl.h"

#include <cmath>

using models::ModelManager;

Scene::Scene() {
	running = true;
	grid = false;
	normals = false;
	render_terrain = true;
	gravity = true;
	flying = true;
	underwater = false;

	last_node = NULL;

	do_select = false;
	show_selection = false;
	dialog = false;
	tool = NULL;

	/* setup shader programs */
	GLFragmentShader fog_fragment("shaders/fog_fragment.glsl");

	GLVertexShader terrain_vertex("shaders/terrain_vertex.glsl");
	GLFragmentShader terrain_fragment("shaders/terrain_fragment.glsl");
	terrain_program.attach(terrain_vertex);
	terrain_program.attach(terrain_fragment);
	terrain_program.attach(fog_fragment);
	terrain_program.link();

	GLFragmentShader water_fragment("shaders/water_fragment.glsl");
	water_program.attach(terrain_vertex);
	water_program.attach(water_fragment);
	water_program.link();

	GLVertexShader tree_vertex("shaders/tree_vertex.glsl");
	GLFragmentShader tree_fragment("shaders/tree_fragment.glsl");
	tree_program.attach(tree_vertex);
	tree_program.attach(tree_fragment);
	tree_program.attach(fog_fragment);
	tree_program.link();

	terrain_program.use();
	GLint tex = glGetUniformLocation(terrain_program.get_program(), "tex");
	GLint texv[] = {0, 1, 2};
	glUniform1iv(tex, 3, texv);
	GLint markloc = glGetUniformLocation(terrain_program.get_program(), "marktex");
	glUniform1i(markloc, 3);

	tree_program.use();
	tex = glGetUniformLocation(tree_program.get_program(), "tex");
	glUniform1iv(tex, 1, texv);

	glUseProgram(0);

	/* load textures */
	grass_texture = load_texture("textures/zooboing-366-grass.jpg");
	rock_texture = load_texture("textures/zooboing-825-stone-modified.jpg");
	soil_texture = load_texture("textures/zooboing-469-sand-modified.jpg");
	water_texture = load_texture("textures/zooboing-688-water.jpg");
	marker_texture = load_texture("textures/cross.png");
	placeholder_texture = load_texture("textures/placeholder.png");

	Assimp::Importer ai_importer;
	const aiScene *tree_scene = ai_importer.ReadFile("models/trees.blend", aiProcess_Triangulate);

	for(unsigned int i = 0; i < tree_scene->mNumTextures; i++) {
		aiTexture *texture = tree_scene->mTextures[i];
		GLuint tx = load_texture(texture);
		std::string name = (boost::format("*%d") % i).str();
		scene_textures.insert(std::pair<std::string, GLuint>(name, tx));
	}

	Model::p tree = Model::p(new models::Tree(tree_scene, scene_textures));
	ModelManager::get_instance().add_model("tree", tree);

	/* init terrain */
	terrain = new Terrain();

	/* load font */
	font = new FTTextureFont("fonts/VeraMono.ttf");
	font->FaceSize(10);

	lua = new Lua();

	GUI::init();

	console = new ConsoleWindow(lua);
	console->hide();

	chat = new ChatWindow();

	void (ConsoleWindow::*add_line)(const char*) = &ConsoleWindow::add_line;
	lua->set_log_func(boost::bind(add_line, console, _1));
}

Scene::~Scene() {
	delete lua;
	if(tool)
		delete tool;
	if(terrain)
		delete terrain;
	delete font;
	delete console;
	delete chat;
}

void Scene::lookat() {
	const float cam_height = 1.7;
	/* calculate cartesian coordinates for the center vector where yaw is Φ and pitch is θ
	 * x = cos Φ sin θ
	 * y = cos θ
	 * z = sin Φ sin θ
	 */
	Vector3 center(sinf(pitch) * cosf(yaw), cosf(pitch), sinf(pitch) * sinf(yaw));
	center.y += cam_height;
	Vector3 up(-cosf(pitch) * cosf(yaw), sinf(pitch), -cosf(pitch) * sinf(yaw));
	gluLookAt(0, cam_height, 0,
			center.x, center.y, center.z,
			up.x, up.y, up.z);
}

void Scene::move(float forward, float right, int steps) {
	Vector2 dir;
	dir.x += forward*cosf(yaw);
	dir.y += forward*sinf(yaw);

	dir.x += right*cosf(yaw+M_PI_2);
	dir.y += right*sinf(yaw+M_PI_2);

	// ensure that the vector length is 1.0
	dir /= dir.length();
	dir *= 0.005;
	dir *= steps;

	pos.x += dir.x;
	pos.z += dir.y;
}

bool Scene::select(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;
}

void Scene::update() {
	terrain->update(pos.x, pos.z);

	// sort players once a second
	if(SDL_GetTicks() - last_sort > 1000) {
		sort_players();
		last_sort = SDL_GetTicks();
	}
}

void Scene::events() {
	SDL_Event event;
	while(SDL_PollEvent(&event)) {
		if(tool && !dialog && tool->handle_event(event, selected))
			continue;

		switch(event.type) {
			case SDL_QUIT:
				running = false;
				break;
			case SDL_KEYDOWN:
				// TODO: FIX!
#ifdef WIN32
				if(console->showing() && event.key.keysym.sym != SDLK_BACKQUOTE) {
#else
				if(console->showing() && event.key.keysym.sym != 124) {
#endif
					CEGUI::System::getSingleton().injectKeyDown(event.key.keysym.scancode);
					if(CEGUI::System::getSingleton().injectChar(event.key.keysym.unicode))
						break;
				}
				switch(event.key.keysym.sym) {
					case SDLK_ESCAPE:
						if(tool) {
							delete tool;
							tool = NULL;
						} else if(console->showing()) {
							console->hide();
							dialog = false;
						} else
							running = false;
						break;
					case SDLK_g:
						grid = !grid;
						break;
					case SDLK_n:
						normals = !normals;
						break;
					case SDLK_t:
						render_terrain = !render_terrain;
						break;
					case SDLK_SPACE:
						if(!flying || underwater) {
							yvel = underwater ? .005 : .02;
							flying = true;
						}
						break;
					case SDLK_h:
						gravity = !gravity;
						break;
					case SDLK_u:
						update();
						break;
					case SDLK_TAB:
						dialog = !dialog && tool;
						if(tool) {
							if(dialog)
								tool->gui_show();
							else
								tool->gui_hide();
						}
						break;
					case SDLK_1:
						if(tool) delete tool;
						tool = new RaiseTool(terrain);
						break;
					// TODO: change/make configurable
#ifdef WIN32
					case SDLK_BACKQUOTE:
#else
					case 124:
#endif
						if(console->showing()) {
							console->hide();
							dialog = false;
						} else {
							console->show();
							dialog = true;
						}
						break;
					default:
						break;
				}
				break;
			case SDL_KEYUP:
				if(console->showing() && event.key.keysym.sym != 124) {
					CEGUI::System::getSingleton().injectKeyUp(event.key.keysym.scancode);
				}
				break;
			case SDL_MOUSEBUTTONDOWN:
				switch(event.button.button) {
					case SDL_BUTTON_LEFT:
						if(dialog)
							CEGUI::System::getSingleton().injectMouseButtonDown(CEGUI::LeftButton);
						break;
					case SDL_BUTTON_RIGHT:
						if(dialog)
							CEGUI::System::getSingleton().injectMouseButtonDown(CEGUI::RightButton);
						break;
				}
				break;
			case SDL_MOUSEBUTTONUP:
				switch(event.button.button) {
					case SDL_BUTTON_LEFT:
						if(dialog)
							CEGUI::System::getSingleton().injectMouseButtonUp(CEGUI::LeftButton);
						else {
							sx = event.button.x;
							sy = event.button.y;
							do_select = true;
						}
						break;
					case SDL_BUTTON_RIGHT:
						if(dialog)
							CEGUI::System::getSingleton().injectMouseButtonUp(CEGUI::RightButton);
						else
							show_selection = false;
						break;
					case SDL_BUTTON_WHEELUP:
						if(dialog)
							CEGUI::System::getSingleton().injectMouseWheelChange(1);
						break;
					case SDL_BUTTON_WHEELDOWN:
						if(dialog)
							CEGUI::System::getSingleton().injectMouseWheelChange(-1);
						break;
				}
				break;
			case SDL_MOUSEMOTION:
				if(dialog) {
					CEGUI::System::getSingleton().injectMousePosition(event.motion.x, event.motion.y);
					break;
				}
				if(event.motion.x == video::width/2 && event.motion.y == video::height/2)
					break;
				yaw += (float)event.motion.xrel / 500;
				pitch += (float)event.motion.yrel / 500;
				if(yaw > 2*M_PI)
					yaw -= 2*M_PI;
				else if(yaw < 0)
					yaw += 2*M_PI;
				if(pitch > M_PI)
					pitch = M_PI;
				else if(pitch < 0)
					pitch = 0;
				SDL_WarpMouse(video::width/2, video::height/2);
				break;
			case SDL_VIDEORESIZE:
				CEGUI::System::getSingleton().notifyDisplaySizeChanged(CEGUI::Size(event.resize.w, event.resize.h));
				break;
		}
	}
}

void Scene::render() {
	unsigned int time = SDL_GetTicks();
	unsigned int steps = time - last_time + 1;
	last_time = time;

	CEGUI::System::getSingleton().injectTimePulse(0.001*(float)steps);

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

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

	// handle vertical movement
	std::string move_str;
	Terrain::Node *node = terrain->find(pos.x, pos.z);
	if(node) {
		if(gravity) {
			float y = node->get_height(pos.x, pos.z);
			underwater = pos.y < 30 - 1.7;
			if(pos.y < 30 - 1.5 || (pos.y < 30 - 1 && y < 30 - 1))
				yvel -= 9.81 / 2000000. * steps;
			else if(pos.y > y && !keystate[SDLK_e])
				yvel -= 9.81 / 200000. * steps;
			if(yvel < -.1)
				yvel = -.1;
			pos.y += yvel * steps;
			if(pos.y < y) {
				pos.y = y;
				yvel = 0;
				flying = false;
			}
		}
		move_str = (boost::format("%s n: %.2f,%.2f c: %d,%d %dx%d")
				% pos.str() % node->x % node->y
				% node->chunk->x % node->chunk->y % node->chunk->width % node->chunk->height).str();

		if(last_node != node) {
			last_node = node;
			update();
		}
	}

	lookat();

	glEnable(GL_CULL_FACE);
	glCullFace(GL_BACK);

	Terrain::Chunk::ObjectList trees;

	// render terrain
	if(render_terrain) {
		const float fog_color[4] = {1, 1, 1, 0};
		glFogfv(GL_FOG_COLOR, fog_color);
		terrain_program.use();
		GLint show_sel = glGetUniformLocation(terrain_program.get_program(), "show_sel");
		glUniform1i(show_sel, show_selection ? 1 : 0);
		if(show_selection) {
			GLint selpos = glGetUniformLocation(terrain_program.get_program(), "selpos");
			glUniform3f(selpos, selected.x, selected.y, selected.z);
		}
		GLint chunk_pos = glGetUniformLocation(terrain_program.get_program(), "chunk_pos");
		GLint player_pos = glGetUniformLocation(terrain_program.get_program(), "player_pos");
		glUniform3f(player_pos, pos.x, pos.y, pos.z);

		glEnable(GL_TEXTURE_2D);

		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, grass_texture);

		glActiveTexture(GL_TEXTURE1);
		glBindTexture(GL_TEXTURE_2D, rock_texture);

		glActiveTexture(GL_TEXTURE2);
		glBindTexture(GL_TEXTURE_2D, soil_texture);

		glActiveTexture(GL_TEXTURE3);
		glBindTexture(GL_TEXTURE_2D, marker_texture);

		// enable arrays, disabled after water rendering
		glEnableClientState(GL_VERTEX_ARRAY);
		glEnableClientState(GL_NORMAL_ARRAY);
		glEnableClientState(GL_TEXTURE_COORD_ARRAY);

		// draw chunk VBOs
		for(std::list<Terrain::Chunk*>::iterator it = terrain->chunks.begin(); it != terrain->chunks.end(); it++) {
			Terrain::Chunk *chunk = *it;

			trees.insert(trees.end(), chunk->objects.begin(), chunk->objects.end());

			glPushMatrix();
			glTranslatef(-pos.x + chunk->x, -pos.y, -pos.z + chunk->y);
			glUniform2f(chunk_pos, chunk->x, chunk->y);

			glBindBuffer(GL_ARRAY_BUFFER, chunk->vbo_object);
			glVertexPointer(3, GL_FLOAT, 0, NULL);
			glNormalPointer(GL_FLOAT, 0, (GLvoid*)(chunk->vertices*3*sizeof(float)));
			glTexCoordPointer(2, GL_FLOAT, 0, (GLvoid*)(chunk->vertices*3*sizeof(float)*2));
			glDrawArrays(GL_TRIANGLES, 0, chunk->vertices);

			glPopMatrix();
		}
		glBindBuffer(GL_ARRAY_BUFFER, 0);

		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, water_texture);

		glDisable(GL_CULL_FACE);
		glEnable(GL_BLEND);
		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

		water_program.use();
		chunk_pos = glGetUniformLocation(water_program.get_program(), "chunk_pos");
		player_pos = glGetUniformLocation(water_program.get_program(), "player_pos");
		glUniform3f(player_pos, pos.x, pos.y, pos.z);
		GLint t_pos = glGetUniformLocation(water_program.get_program(), "t");
		static float t = 0.0;
		t += 0.00002 * steps;
		glUniform1f(t_pos, t);

		// draw chunk water
		for(std::list<Terrain::Chunk*>::iterator it = terrain->chunks.begin(); it != terrain->chunks.end(); it++) {
			Terrain::Chunk *chunk = *it;
			glPushMatrix();
			glTranslatef(-pos.x + chunk->x, -pos.y, -pos.z + chunk->y);
			glUniform2f(chunk_pos, chunk->x, chunk->y);

			float v[4*3];
			v[0] = v[2] = v[3] = v[11] = 0;
			v[5] = v[6] = v[8] = v[9] = terrain->chunk_size;
			v[1] = v[4] = v[7] = v[10] = 30;

			float n[4*3];
			n[0] = n[2] = n[3] = n[5] = n[6] = n[8] = n[9] = n[11] = 0;
			n[1] = n[4] = n[7] = n[10] = 1;

			float tc[4*2];
			tc[0] = tc[1] = tc[2] = tc[7] = 0;
			tc[3] = tc[4] = tc[5] = tc[6] = terrain->chunk_size / 2;

			glVertexPointer(3, GL_FLOAT, 0, v);
			glNormalPointer(GL_FLOAT, 0, n);
			glTexCoordPointer(2, GL_FLOAT, 0, tc);
			glDrawArrays(GL_QUADS, 0, 4);

			glPopMatrix();
		}

		glDisableClientState(GL_VERTEX_ARRAY);
		glDisableClientState(GL_NORMAL_ARRAY);
		glDisableClientState(GL_TEXTURE_COORD_ARRAY);

		glDisable(GL_BLEND);

		glUseProgram(0);
	}

	if(grid) {
		if(terrain)
			glColor3f(0, 0, 0);
		else
			glColor3f(1, 1, 1);
		for(std::list<Terrain::Chunk*>::iterator it = terrain->chunks.begin(); it != terrain->chunks.end(); it++) {
			Terrain::Chunk *chunk = *it;
			glPushMatrix();
			glTranslatef(-pos.x, -pos.y, -pos.z);
			for(unsigned int i = 0; i < chunk->node_count; i++)
				chunk->nodes[i]->draw_grid();
			glPopMatrix();
		}
	}
	if(normals) {
		for(std::list<Terrain::Chunk*>::iterator it = terrain->chunks.begin(); it != terrain->chunks.end(); it++) {
			Terrain::Chunk *chunk = *it;
			glPushMatrix();
			glTranslatef(-pos.x, -pos.y, -pos.z);
			for(unsigned int i = 0; i < chunk->node_count; i++)
				chunk->nodes[i]->draw_normal();
			glPopMatrix();
		}
	}

	float px, py, pz;
	if(do_select && select(sx, sy, px, py, pz)) {
		do_select = false;
		selected = Vector3(pos.x + px, pos.y + py, pos.z + pz);
		show_selection = true;
	}

	glDisable(GL_TEXTURE_2D);

	// draw sky
	glPushMatrix();
	glTranslatef(700*cosf(yaw), 0, 700*sinf(yaw));
	glRotatef(-yaw*180/M_PI+180, 0, 1, 0);
	glBegin(GL_QUADS);
		glColor3f(1, 1, 1);
		glVertex3f(0, 0, -700);
		glVertex3f(0, 0, 700);
		glColor3f(.5, .5, 1);
		glVertex3f(0, 550, 700);
		glVertex3f(0, 550, -700);

		glVertex3f(0, 550, -700);
		glVertex3f(0, 550, 700);
		glColor3f(0, 0, .3);
		glVertex3f(1000, 550, 700);
		glVertex3f(1000, 550, -700);
	glEnd();
	glPopMatrix();

	// player rendering
	glPushMatrix();
	glTranslatef(-pos.x, -pos.y, -pos.z);
	glColor3f(1, 1, 1);

	font->FaceSize(30);
	for(PlayerList::iterator it = players.begin(); it != players.end(); it++) {
		(*it)->render(font, steps, placeholder_texture);
	}

	// don't pop matrix; use translated player position

	// rotate to point upwards along the y-aksis
	glRotatef(-90, 1, 0, 0);
	glEnable(GL_TEXTURE_2D);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glEnable(GL_BLEND);
	tree_program.use();

	GLint player_pos = glGetUniformLocation(tree_program.get_program(), "player_pos");
	glUniform3f(player_pos, pos.x, pos.y, pos.z);

	GLint tree_pos = glGetUniformLocation(tree_program.get_program(), "tree_pos");

	//tree->render();
	for(Terrain::Chunk::ObjectList::iterator it = trees.begin(); it != trees.end(); it++) {
		glPushMatrix();
			Vector3 pos(it->second);
			glUniform3f(tree_pos, pos.x, pos.y, pos.z);
			// rotated around x-axis; swap y and z, do magic to fix positions
			glTranslatef(pos.x, -pos.z, pos.y+.5);
			it->first->render();
		glPopMatrix();
	}

	glPopMatrix();
	glDisable(GL_TEXTURE_2D);
	glDisable(GL_BLEND);

	glUseProgram(0);

	// active texture # must be reset before rendering UI stuff
	glActiveTexture(GL_TEXTURE0);

	// HUD
	video::ortho();
	font->FaceSize(10);
	float height = font->LineHeight();
	glColor3f(1, 1, 1);
	glTranslatef(0, video::height-height, 0);
	font->Render((boost::format("chunks: %d  cache: %d  gravity: %d  flying: %d  water: %d  steps: %d  trees: %d")
				% terrain->chunks.size() % terrain->tc->get_size() % gravity % flying % underwater % steps % trees.size()).str().c_str());
	glTranslatef(0, -height, 0);
	font->Render(move_str.c_str());
	glTranslatef(0, -height, 0);
	font->Render(selected.str().c_str());
	if(tool) {
		glTranslatef(0, -height, 0);
		font->Render((boost::format("Tool: %s") % tool->get_name()).str().c_str());
	}

	GUI::pre_render();

	if(tool && dialog) {
		tool->gui_update();
	}

	if(console->showing()) {
		console->update();
	}

	GUI::render();

	SDL_GL_SwapBuffers();
}

GLuint Scene::load_texture(const char *filename) {
	GLuint texture;
	SDL_Surface *surface = IMG_Load(filename);
	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, &texture);
	glBindTexture(GL_TEXTURE_2D, 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) {
		gluBuild2DMipmaps(GL_TEXTURE_2D, 4, image->w, image->h, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
	} else {
		gluBuild2DMipmaps(GL_TEXTURE_2D, 3, image->w, image->h, GL_RGB, GL_UNSIGNED_BYTE, image->pixels);
	}
	SDL_FreeSurface(surface);
	SDL_FreeSurface(image);

	return texture;
}

GLuint Scene::load_texture(aiTexture *texture) {
	GLuint tex;
	glGenTextures(1, &tex);
	glBindTexture(GL_TEXTURE_2D, tex);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	if(texture->mHeight == 0) {
		SDL_RWops *rw = SDL_RWFromConstMem(texture->pcData, texture->mWidth);
		SDL_Surface *image = IMG_Load_RW(rw, 1);
		if(image->format->Amask) {
			gluBuild2DMipmaps(GL_TEXTURE_2D, 4, image->w, image->h, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
		} else {
			gluBuild2DMipmaps(GL_TEXTURE_2D, 3, image->w, image->h, GL_RGB, GL_UNSIGNED_BYTE, image->pixels);
		}

		SDL_FreeSurface(image);
	} else {
		gluBuild2DMipmaps(GL_TEXTURE_2D, 4, texture->mWidth, texture->mHeight, GL_BGRA, GL_UNSIGNED_BYTE, texture->pcData);
	}

	return tex;
}

static bool playerlist_sort(Vector3 pos, Player::p a, Player::p b) {
	return (a->get_pos() - pos).length() > (b->get_pos() - pos).length();
}

void Scene::sort_players() {
	players.sort(boost::bind(&playerlist_sort, pos, _1, _2));
}