/*
 * main.c
 *
 * Where it all begins
 *
 * (c) 2008 Thomas White <taw27@cam.ac.uk>
 *
 *  thrust3d - a silly game
 *
 */

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

#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <SDL.h>
#include <gl.h>
#include <glu.h>
#include <assert.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_1280,
	RES_1330,
	RES_1440,
	RES_1600
} ScreenResolution;

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

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

	SDL_Event event;
	int finished;
	SDL_Surface *screen;
	int width, height;
	int c;
	Uint32 video_flags;
	ScreenResolution res;
	Uint32 t;
	
	res = RES_800;
	width = 800;  height = 600;
	video_flags = SDL_OPENGL;
	
	while ((c = getopt(argc, argv, "hvr:f")) != -1) {
	
		switch ( c ) {
		
			case 'r' : {
				if ( strcasecmp(optarg,   "640") == 0 ) res = RES_640;
				if ( strcasecmp(optarg,   "800") == 0 ) res = RES_800;
				if ( strcasecmp(optarg,  "1280") == 0 ) res = RES_1280;
				if ( strcasecmp(optarg,  "1330") == 0 ) res = RES_1330;
				if ( strcasecmp(optarg,  "1440") == 0 ) res = RES_1440;
				if ( strcasecmp(optarg,  "1600") == 0 ) res = RES_1600;
				break;
			}
			
			case 'f' : {
				video_flags = video_flags | SDL_FULLSCREEN;
				break;
			}
			
			case 'v' : {
				main_version();
				return 0;
			}
						
			case 'h' : {
				printf("Syntax: %s [-h] [-r <res>] [-f]\n\n", argv[0]);
				printf("Post-apocalyptic Jet Set Willy, set in a 3D nuclear power station.\n\n");
				printf("  -h              Display this help message and exit.\n");
				printf("  -v              Display version number and exit.\n");
				printf("  -r <res>        Set display resolution.  See below for possible values for <res>.\n");
				printf("  -f              Use the full screen.\n\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(" 1280  -  1280 x 1024\n");
				printf(" 1330  -  1330 x  900 (widescreen)\n");
				printf(" 1440  -  1440 x  900 (widescreen)\n");
				printf(" 1600  -  1600 x 1050 (widescreen)\n");
				printf("\n");
				main_version();
				return 0;
			}
			
			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_1280  : { width = 1280;  height = 1024;  break; }
		case RES_1330  : { width = 1330;  height =  900;  break; }
		case RES_1440  : { width = 1440;  height =  900;  break; }
		case RES_1600  : { 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);
	
	/* World setup */
	Game *game;
	game = game_new(width, height);
	
	/* Main loop */
	finished = 0;
	t = SDL_GetTicks();
	while ( !finished ) {
	
		/* Timer advances only when game is not paused */
		t = SDL_GetTicks();
		if ( game->paused ) {
			game->tlast = t;
		}
		
		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_p ) game_pause(game);
				if ( event.key.keysym.sym == SDLK_q ) finished = 1;
				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_VIDEOEXPOSE :
				/* Don't bother redrawing if not paused - not long to wait! */
				if ( game->paused ) render_draw(game, t);
				break;
			case SDL_QUIT :
				finished = 1;
				break;
		}
		if ( !game->paused ) {
			physics_step(game, t);
			render_draw(game, t);
		}
		
		printf("%+7.4f %+7.4f %+7.4f    %+5.1f deg   %+7.5f %+7.5f %+7.5f     %2i %2i %2i   %3i fps\r",
						      game->lander->x, game->lander->y, game->lander->z,
						      rad2deg(game->lander->yaw), game->lander->vx, game->lander->vy, game->lander->vz,
						      game->cur_room_x, game->cur_room_y, game->cur_room_z, game->fps);
		fflush(stdout);
		
		/* Calculate FPS every half a second */
		game->frames++;
		if ( t - game->t_fps > 500 ) {
			game->fps = (500*game->frames) / (t - game->t_fps);
			game->t_fps = t;
			game->frames = 0;
			game->frame_delay_fiddled = 0;
		}
		
		/* Attempt to hold output FPS close to some target value */
		if ( (!game->frame_delay_fiddled) && (game->fps < 30) ) {
			game->frame_delay -= game->frame_delay/20;
			game->frame_delay_fiddled = 1;
		}
		if ( (!game->frame_delay_fiddled) && (game->fps > 50) ) {
			game->frame_delay += game->frame_delay/20;
			game->frame_delay_fiddled = 1;
		}
		
		/* Sleep for a bit to avoid hogging the CPU. */
		usleep(game->frame_delay);
		
	}
	
	render_shutdown(game->render);
	SDL_CloseAudio();
	SDL_Quit();
	
	printf("\n");
	
	return 0;

}