#include <stubs.h>

#include <stdint.h>
#include <string.h>

#include "utility.h"
#include "mem_registers.h"
#include "mem_map.h"
#include "input.h"
#include "game_logic.h"
#include "game_graphics.h"
#include "monitor_subroutines.h"

// Make sure the loading screen is included
#pragma require __loading_screen

#define MOVES_TEXT_X 32
#define MOVES_TEXT_Y 61
#define MOVES_TEXT_WIDTH 5

#define SCORE_TEXT_X 32
#define SCORE_TEXT_Y 29
#define SCORE_TEXT_WIDTH 5

#define HIGH_TEXT_X 32
#define HIGH_TEXT_Y 107

#define WIN_SCORE_BONUS 10000

void init(void);

// Low level initialization
void init(void) {
	POKE(P3_PWRDUP, 0); // Dirty the value checked by the reset vector
	PEEK(IO_ROMSEL); // Make sure the ROM is selected
	
	PEEK(IO_DISPLAY_BW); // Disable colors
	
	// Clear display memory
	clear_display_buffers();
}

__task int main(void) {
	uint16_t moves_count;
	uint16_t score = 0;
	uint16_t hi_score = 0;
	int8_t done = 0;
	
	init();
				
	while(1){ // Outer loop
		moves_count = 0;

		// Draw a screen and wait for a key press here here
		BELL1();
		ddraw_endgame_box(done, score, hi_score);
		while(!read_any_key()) {
			lfsr_update();
		}
		BELL1();
		clear_display_buffers(); // Clear display again
	
		// Check if we have a new high-score from a previous game
		if (score > hi_score) hi_score = score;
	
		// Reset the game, calculate the initial score depending on which tiles we randomly get
		score = reset_game();

		// Draw the initial state of the game
		draw_game_background(hi_score);
		draw_number(moves_count, MOVES_TEXT_WIDTH, MOVES_TEXT_X, MOVES_TEXT_Y);
		draw_number(score, SCORE_TEXT_WIDTH, SCORE_TEXT_X, SCORE_TEXT_Y);
		draw_tiles();

		// Swap graphical buffers
		swap_display_buffers();

		while(1) { // Game loop
			lfsr_update();
		
			switch(read_kb()) {
				case K_UP:
					BELL1();
					done = step_game(STEP_UP);
					ddraw_direction_arrows(ARROW_UP);
					break;
				case K_DOWN:
					BELL1();
					done = step_game(STEP_DOWN);
					ddraw_direction_arrows(ARROW_DOWN);
					break;
				case K_LEFT:
					BELL1();
					done = step_game(STEP_LEFT);
					ddraw_direction_arrows(ARROW_LEFT);
					break;
				case K_RIGHT:
					BELL1();
					done = step_game(STEP_RIGHT);
					ddraw_direction_arrows(ARROW_RIGHT);
					break;
				default:
					continue; // Do nothing, loop again
			}
			
			// Increase the count of moves we made
			moves_count++;
	
			// If we have won, break out of this loop
			if(done) {
				score += WIN_SCORE_BONUS;
				break;
			}
				
			// Draw the number of moves
			draw_number(moves_count, MOVES_TEXT_WIDTH, MOVES_TEXT_X, MOVES_TEXT_Y);
			
			// Draw the moved tiles
			draw_tiles();
			
			// Unable to add a tile: we ran out of space and lost!!!
			uint8_t random_tile_off = add_random_tile();
			if(!random_tile_off) {
				done = -1; // Lost the game
				break;
			}
			
			score = calculate_score();
			
			// Draw the score
			draw_number(score, SCORE_TEXT_WIDTH, SCORE_TEXT_X, SCORE_TEXT_Y);

			swap_display_buffers();

			// Draw the new tile directly on the front buffer, this way we make it appear with an "animation"
			ddraw_single_tile(random_tile_off - 1);
		}

	};
	
	return 0; 
}