/*
The Exceedingly Tetris-Inspired Sport (TETr-IS)
C++ Version
		
Eric Marcarelli
November 2008
*/

#include <SDL/SDL.h>
#include <iostream>
#include "block.h"
#include "grid.h"

using namespace std;

SDL_Surface *loadImg(string file); 
bool checkKey(int key); 
void drawSurface(int x, int y, SDL_Surface *src, SDL_Surface *dest);

int main (int argc, char *argv[]) {
	bool quit = false;
	int startTime = SDL_GetTicks();
	SDL_Surface *screen = NULL;		
	
	// Set up SDL	
	if (SDL_Init(SDL_INIT_VIDEO) != 0) {
		cerr << "SDL init failed. You lose!" << endl;
		return 1;	
	}
	 
	SDL_WM_SetCaption("TETr-IS", 0);
	
	screen = SDL_SetVideoMode(300, 550, 32, SDL_DOUBLEBUF); 		
	
	if (screen == NULL) {
		cerr << "SDL init failed. You lose!" << endl;
		return 1;
	}
	
	// these have to be below SDL init because their constructors load images
	Block block("block.bmp");
	Grid grid("background.bmp", "block.bmp", 300, 550);	
	SDL_Surface *gameover = loadImg("gameover.bmp");	
	block.newBlock();

	// game loop
	while (!quit) {
		// keep track of how long it takes			
		startTime = SDL_GetTicks();	
								
		//	move block left or right
		if (checkKey(SDLK_RIGHT)) 
			block.move(1, 0);
		if (checkKey(SDLK_LEFT)) 
			block.move(-1, 0);
			
		//	rotate block
		if (checkKey(SDLK_SPACE)) 
			block.rotate();
			
		if (checkKey(SDLK_ESCAPE))
			quit = true;
		
		// make block fall
		block.move(0, 1);
 
		// if the block has reached a filled in area in the grid, it is added to 
		// the grid and a new block starts to fall. 
		if (grid.checkBlock(&block))
			block.newBlock();
		
		// delete filled in rows and move the blocks accordingly
		grid.process();

		// draw everything to screen surface, then actually display screen			
		grid.draw(screen);
		block.draw(screen);			
		SDL_Flip(screen);

		// end the game if the 3rd row to the top is reached
		if (grid.gameOver()) {
			drawSurface(50, 250, gameover, screen);
			SDL_Flip(screen);
			while (!checkKey(SDLK_ESCAPE));
			quit = true;
		}

		// keep it running at a fairly constant speed--100 is an arbitrary number
		while ((SDL_GetTicks() - startTime) < 100)
			SDL_Delay(5);
	}

	SDL_FreeSurface(gameover); 
	SDL_Quit();	
}

// check if a key is pressed
bool checkKey(int key) {
	// get updated kb states
	SDL_PumpEvents(); 
	Uint8 *keystatus = SDL_GetKeyState(NULL);
	
	if (keystatus[key])
		return true;
	else 
		return false;	
}

// load a bmp as an SDL surface
SDL_Surface *loadImg(string file) { 	
	SDL_Surface* img = NULL; 
	
 	img = SDL_LoadBMP(file.c_str());
	
	if (img != NULL) 
		img = SDL_DisplayFormat(img);
	
	if (img == NULL) {
		cerr << "Couldn't load the image " << file << ". You lose!" << endl;
		exit(1);	
	}

	return img;	
} 

// draw one surface onto another 
void drawSurface(int x, int y, SDL_Surface *src, SDL_Surface *dest) { 	
	SDL_Rect loc; 	
	loc.x = x; 
	loc.y = y;
	
	SDL_BlitSurface(src, NULL, dest, &loc); 
}