/*
 * main.c
 *
 * Where it all begins
 *
 * Copyright (c) 2008 Thomas White <taw27@cam.ac.uk>
 *
 * This file is part of Thrust3D - a silly game
 *
 * Thrust3D is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Thrust3D is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Thrust3D.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <SDL.h>
#include <assert.h>
#include <getopt.h>

#include "types.h"
#include "model.h"
#include "game.h"
#include "render.h"
#include "physics.h"
#include "utils.h"

typedef enum {
	RES_640,
	RES_800,
	RES_1024,
	RES_1280,
	RES_1280W,
	RES_1330,
	RES_1440,
	RES_1680
} ScreenResolution;

static void main_version() {
	printf("Thrust3D version "PACKAGE_VERSION", (c) 2008 Thomas White <taw27@srcf.ucam.org>\n");
}

static void main_help(const char *n) {
	printf("Syntax: %s [options]\n\n", n);
	printf("Post-apocalyptic Jet Set Willy, set in a 3D nuclear power station.\n\n");
	printf("  -h,  --help                Display this help message and exit.\n");
	printf("  -v,  --version             Display version number and exit.\n");
	printf("  -r,  --resolution <res>    Set display resolution. See below for possible values for <res>.\n");
	printf("  -f,  --fullscreen          Use the full screen.\n");
	printf("  -n,  --no-music            Don't play any background music.\n");
	printf("\nAdvanced options:\n\n");
	printf("       --disable-vbos        Disable the use of vertex buffer objects.\n");
	printf("       --disable-fbos        Disable the use of framebuffer objects.\n");
	printf("       --disable-shaders     Disable the use of shaders.\n");
	printf("       --audio-debug         Print audio debugging messages to stdout.\n");
	printf("       --game-debug          Print game control debugging messages to stdout.\n");
	printf("       --no-framerate-limit  Do not wait between frames.\n");
	printf("       --status-line         Show game status on the terminal.\n");
	printf("\n");
	printf("Allowable values for <res> are as follows:\n\n");
	printf("<res>    Width   Height\n");
	printf("  640  -   640 x  480\n");
	printf("  800  -   800 x  600 (this is the default)\n");
	printf(" 1024  -  1024 x  768\n");
	printf(" 1280  -  1280 x 1024\n");
	printf(" 1280W -  1280 x  768 (widescreen)\n");
	printf(" 1330  -  1330 x  900 (widescreen)\n");
	printf(" 1440  -  1440 x  900 (widescreen)\n");
	printf(" 1680  -  1680 x 1050 (widescreen)\n");
	printf("\n");
	main_version();
}

int main_event_filter(const SDL_Event *event) {
	if ( event->type == SDL_MOUSEMOTION ) return 0;
	return 1;
}

int main(int argc, char *argv[]) {

	SDL_Event event;
	int finished;
	SDL_Surface *screen;
	int width, height;
	int c;
	Uint32 video_flags;
	ScreenResolution res;
	GameOptions gameopts;
	Uint16 cx, cy;
	double vyaw_scale, vang_scale;
	
	gameopts.disable_vbos = 0;
	gameopts.disable_fbos = 0;
	gameopts.disable_shaders = 0;
	gameopts.audio_debug = 0;
	gameopts.game_debug = 0;
	gameopts.no_music = 0;
	gameopts.no_framerate_limit = 0;
	gameopts.status_line = 0;
	
	const struct option longopts[] = {	{"fullscreen", 0, NULL, 'f'},
						{"resolution", 1, NULL, 'r'},
						{"help", 0, NULL, 'h'},
						{"version", 0, NULL, 'v'},
						{"disable-vbos", 0, &gameopts.disable_vbos, 1},
						{"disable-fbos", 0, &gameopts.disable_fbos, 1},
						{"disable-shaders", 0, &gameopts.disable_shaders, 1},
						{"audio-debug", 0, &gameopts.audio_debug, 1},
						{"game-debug", 0, &gameopts.game_debug, 1},
						{"no-framerate-limit", 0, &gameopts.no_framerate_limit, 1},
						{"status-line", 0, &gameopts.status_line, 1},
						{"no-music", 0, NULL, 'n'},
						{0, 0, NULL, 0}				};

	
	res = RES_800;
	width = 800;  height = 600;
	video_flags = SDL_OPENGL;
	
	while ((c = getopt_long(argc, argv, "hvr:fn", longopts, NULL)) != -1) {
	
		switch ( c ) {
		
			case 'r' : {
				     if ( strcasecmp(optarg,   "640") == 0 ) res = RES_640;
				else if ( strcasecmp(optarg,   "800") == 0 ) res = RES_800;
				else if ( strcasecmp(optarg,  "1024") == 0 ) res = RES_1024;
				else if ( strcasecmp(optarg,  "1280") == 0 ) res = RES_1280;
				else if ( strcasecmp(optarg, "1280W") == 0 ) res = RES_1280W;
				else if ( strcasecmp(optarg,  "1330") == 0 ) res = RES_1330;
				else if ( strcasecmp(optarg,  "1440") == 0 ) res = RES_1440;
				else if ( strcasecmp(optarg,  "1680") == 0 ) res = RES_1680;
				else {
					fprintf(stderr, "Unrecognised resolution '%s'\n", optarg);
					exit(1);
				}
				break;
			}
			
			case 'f' : {
				video_flags = video_flags | SDL_FULLSCREEN;
				break;
			}
			
			case 'v' : {
				main_version();
				return 0;
			}
			
			case 'n' : {
				gameopts.no_music = 1;
				break;
			}
						
			case 'h' : {
				main_help(argv[0]);
				return 0;
			}
			
			case 0 : {
				break;
			}
			
			default : {
				return 1;
			}
		
		}
	
	}
	
	/* SDL initial setup */
	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
		fprintf(stderr, "Couldn't initialise SDL: %s\n", SDL_GetError());
		return 1;
	}
	atexit(SDL_Quit);
	
	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
	switch ( res ) {
		case RES_640   : { width =  640;  height =  480;  break; }
		case RES_800   : { width =  800;  height =  600;  break; }
		case RES_1024  : { width = 1024;  height =  768;  break; }
		case RES_1280W : { width = 1280;  height =  768;  break; }
		case RES_1280  : { width = 1280;  height = 1024;  break; }
		case RES_1330  : { width = 1330;  height =  900;  break; }
		case RES_1440  : { width = 1440;  height =  900;  break; }
		case RES_1680  : { width = 1680;  height = 1050;  break; }
		default : { assert(this_point_not_reached); break; }
	}
	screen = SDL_SetVideoMode(width, height, 16, video_flags);
	if ( screen == NULL ) {
		fprintf(stderr, "Couldn't set video mode: %s\n", SDL_GetError());
		SDL_Quit();
		return 1;
	}
	
	SDL_WM_SetCaption("Thrust3D", "Thrust3D");
	SDL_ShowCursor(SDL_DISABLE);
	//SDL_WM_GrabInput(SDL_GRAB_ON);
	SDL_SetEventFilter(main_event_filter);
	cx = width/2;  cy = height/2;
	SDL_WarpMouse(cx, cy);
	vyaw_scale = (2*M_PI/width);
	vang_scale = (2*M_PI/height);
	
	/* World setup */
	Game *game;
	game = game_new(width, height, gameopts);
	
	/* Main loop */
	finished = 0;
	game->time = 0.0;
	game->tlast = utils_highresms();
	game->t_fps = game->time;
	while ( !finished ) {
	
		int mx, my;
		Uint8 buttons;
		int mouse_thrust = 0;
		double us, dt;
		
		/* Tick size is measured, ... */
		us = utils_highresms();
		dt = us - game->tlast;
		game->tlast = us;
		/* ... but timer advances only when game is not paused */
		if ( !game->paused ) {
			game->time += dt;
		}
		
		SDL_PollEvent(&event);
		switch ( event.type ) {
			case SDL_KEYDOWN :
				if ( !game->paused ) {
					if ( event.key.keysym.sym == SDLK_SPACE ) game->thrusting = 1;
					if ( event.key.keysym.sym == SDLK_LEFT ) game->turn_left = 1;
					if ( event.key.keysym.sym == SDLK_RIGHT ) game->turn_right = 1;
					if ( event.key.keysym.sym == SDLK_UP ) game->forward = 1;
					if ( event.key.keysym.sym == SDLK_DOWN ) game->reverse = 1;
					if ( event.key.keysym.sym == SDLK_w ) render_set_wireframe(1);
					if ( event.key.keysym.sym == SDLK_e ) render_set_wireframe(0);
				}
				if ( event.key.keysym.sym == SDLK_p ) game_pause(game);
				if ( event.key.keysym.sym == SDLK_q ) finished = 1;
				if ( event.key.keysym.sym == SDLK_ESCAPE ) finished = 1;
				if ( event.key.keysym.sym == SDLK_r ) SDL_WarpMouse(cx, cy);
				break;
			case SDL_KEYUP :
				/* Process key releases even when paused */
				if ( event.key.keysym.sym == SDLK_SPACE ) game->thrusting = 0;
				if ( event.key.keysym.sym == SDLK_LEFT ) game->turn_left = 0;
				if ( event.key.keysym.sym == SDLK_RIGHT ) game->turn_right = 0;
				if ( event.key.keysym.sym == SDLK_UP ) game->forward = 0;
				if ( event.key.keysym.sym == SDLK_DOWN ) game->reverse = 0;
				if ( event.key.keysym.sym == SDLK_p ) game->pause_rel = 1;
				break;
			case SDL_QUIT :
				finished = 1;
				break;
		}
		
		buttons = SDL_GetMouseState(&mx, &my);
		game->view_yaw = -(mx-cx)*vyaw_scale;
		game->view_angle = deg2rad(-20.0) + (my-cy)*vang_scale;
		if ( game->view_angle > deg2rad(89.0) ) game->view_angle = deg2rad(89.0);
		if ( game->view_angle < deg2rad(-89.0) ) game->view_angle = deg2rad(-89.0);
		if ( !game->thrusting && ((buttons & SDL_BUTTON(1)) || (buttons & SDL_BUTTON(3))) ) {
			game->thrusting = 1;
			mouse_thrust = 1;
		}
		
		/* Physics steps only happen when game is not paused */
		if ( !game->paused ) {
			physics_step(game, dt);
		}
		/* Draw in any case */
		render_draw(game);
		
		if ( mouse_thrust ) game->thrusting = 0;
		
		if ( gameopts.status_line ) {
			printf("%+13.3f %+5.3f %+7.5f %+7.5f %+7.5f  %2i %2i %2i  %3i fps (r:%6lli p:%6lli)  \r",
				game->time, dt,
				game->lander->vx, game->lander->vy, game->lander->vz,
				game->cur_room_x, game->cur_room_y, game->cur_room_z, game->fps,
				game->time_render, game->time_physics);
			fflush(stdout);
		}
		
		/* Calculate FPS every half a second */
		game->frames++;
		if ( game->time - game->t_fps > 500.0 ) {
			game->fps = (500*game->frames) / (game->time - game->t_fps);
			game->t_fps = game->time;
			game->frames = 0;
		}
		
		/* Wait for how long it takes the graphics card to catch up, at the most recent measurement. */
		if ( !gameopts.no_framerate_limit && (game->time_physics < game->time_render) ) {
			usleep(game->time_render-game->time_physics);
		}
		
	}
	
	game_shutdown(game);
	SDL_Quit();
	
	if ( gameopts.status_line ) printf("\n");
	
	return 0;

}