/****************************************************************************
 *                                                                          *
 * Chetyre - A falling tetromino game                                       *
 *                                                                          *
 * The game runs in a UNIX terminal and uses no libraries other than the    *
 * C standard library. Therefore it can be compiled with:                   *
 *                                                                          *
 *     cc -o chetyre chetyre.c                                              *
 *                                                                          *
 * It can then be run with:                                                 *
 *                                                                          *
 *     ./chetyre                                                            *
 *                                                                          *
 * This source code should probably compile and run successfully on typical *
 * current UNIX systems such as Linux, BSD, and Mac OS X. Windows will      *
 * probably be more difficult.                                              *
 *                                                                          *
 * This source code, as well as binaries for some systems, are available at *
 *      http://haddonthethird.net/chetyre                                   *
 *                                                                          *
 * Copyright 2011 William Haddon <william@haddonthethird.net>               *
 *                                                                          *
 * Permission to use, copy, modify, and/or distribute this software for any *
 * purpose with or without fee is hereby granted, provided that the above   *
 * copyright notice and this permission notice appear in all copies.        *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
 *                                                                          *
 ****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

#define WIDTH 11
#define HEIGHT 23

struct tetromino
{
    char width;
    char height;
    char data;
    char color;
};

char *splash[] = {
"  ,~~~,     ,~~~,       \033[1;34m+~~+\033[0m",
"  `~,\033[1;30m##\033[0m\\    `~,\033[1;30m##\033[0m\\      \033[1;34m|\033[0;34m[]\033[1;34m|\033[0m",
"    /\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/      \033[1;34m+~~+~~+\033[0m",
"   /\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/       \033[1;34m|\033[0;34m[]\033[1;34m|\033[0;34m[]\033[1;34m|\033[0m",
"  /\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/        \033[1;34m+~~+~~+\033[0m",
" /\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/         \033[1;34m|\033[0;34m[]\033[1;34m|\033[0m",
"/\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/          \033[1;34m+~~+\033[0m",
"|\033[1;30m##\033[0m|    ,\"\033[1;30m##\033[0m/  ,~~~,  ,~~~,,~~~~,,~~~,  ,~~~,   ,~~~~,\033[1;33m+~\033[0m,~~~,,~~~~,     ,~~~,",
"\\\033[1;30m##\033[0m\\__,\"\033[1;30m###\033[0m/ ,\"\033[1;30m##\033[0m_\033[1;30m##\033[0m\\ `~,\033[1;30m####\033[0m_\033[1;30m#####\033[0m_\033[1;30m##\033[0m\\ `~,\033[1;30m##\033[0m\\  `~~,\033[1;30m##\033[0m\\\033[0;33m[\033[0m`~,\033[1;30m####\033[0m_\033[1;30m###\033[0m\\  ,\"\033[1;30m##\033[0m_\033[1;30m##\033[0m\\",
" \\\033[1;30m########\033[0m/ /\033[1;30m##\033[0m,\" \",\033[1;30m#\033[0m\\  /\033[1;30m##\033[0m,\" )\033[1;30m##\033[0m,\" )\033[1;30m#\033[0m|   /\033[1;30m##\033[0m/     |\033[1;30m##\033[0m|\033[1;33m~~+\033[0m/\033[1;30m##\033[0m,\" )\033[1;30m##\033[0m| /\033[1;30m##\033[0m,\" \",\033[1;30m#\033[0m\\",
"  `~~\"/\033[1;30m##\033[0m/ /\033[1;30m##\033[0m/    |\033[1;30m#\033[0m| /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  \033[1;36m+~~+\033[0m/\033[1;30m##\033[0m/\033[0;33m[]\033[0m/\033[1;30m##\033[0m/   /\033[1;30m##\033[0m//\033[1;30m##\033[0m/    |\033[1;30m#\033[0m|",
"     /\033[1;30m##\033[0m/ /\033[1;30m##\033[0m/____/\033[1;30m##\033[0m//\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/\033[1;34m~~+\033[1;36m|\033[0;36m[]\033[0m/\033[1;30m##\033[0m/\033[1;33m+~\033[0m/\033[1;30m##\033[0m/\033[1;33m+\033[0m  /\033[1;30m##\033[0m//\033[1;30m##\033[0m/____/\033[1;30m##\033[0m/",
"    /\033[1;30m##\033[0m/ /\033[1;30m#########\033[0m,\"/\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m###\033[0m\",\033[0;34m]\033[1;34m|\033[1;36m+~\033[0m/\033[1;30m##\033[0m/\033[1;36m+~\033[0m/\033[1;30m##\033[0m/\033[0;33m]\033[1;33m|\033[0m /\033[1;30m##\033[0m//\033[1;30m#########\033[0m,\"",
"   /\033[1;30m##\033[0m/ /\033[1;30m##\033[0m,~~~~~~\" /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m,~,\033[1;30m#\033[0m\\\033[1;34m+~\033[0m/\033[1;30m##\033[0m/\033[0;36m]\033[1;36m|\033[0m/\033[1;30m##\033[0m/\033[1;33m~~+\033[0m/\033[1;30m##\033[0m//\033[1;30m##\033[0m,~~~~~~\"",
"  /\033[1;30m##\033[0m/  |\033[1;30m##\033[0m|       /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m#\033[0m|\033[1;34m|\033[0m/\033[1;30m##\033[0m/\033[1;36m~~\033[0m/\033[1;30m##\033[0m/  ,\"\033[1;30m#\033[0m,\"\033[1;31m|\033[0m|\033[1;30m##\033[0m|",
" /\033[1;30m##\033[0m(_/\\\\\033[1;30m##\033[0m\\___/\\ /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/  /\033[1;30m##\033[0m(_,\"\033[1;30m##\033[0m//\033[1;30m##\033[0m/\033[1;32m+~\033[0m/\033[1;30m##\033[0m/\033[1;32m+\033[0m,\"\033[1;30m#\033[0m,\"\033[1;31m~~+\033[0m\\\033[1;30m##\033[0m\\___/\\",
" \\\033[1;30m#####\033[0m/\033[0;31m]\033[0m\\\033[1;30m######\033[0m//\033[1;30m##\033[0m/  /\033[1;30m##\033[0m/   \\\033[1;30m##\033[0m`~,\\\033[1;30m######\033[0m,\"\033[0;34m]\033[0m\\\033[1;30m##\033[0m`,/\033[1;30m##\033[0m/\033[0;32m]\033[0m(\033[1;30m###\033[0m`~,\033[0;31m]\033[1;31m|\033[0m \\\033[1;30m######\033[0m/",
"  `~~~\"\033[1;31m~~+\033[0m`~~~~\" \\,\"   \\,\"     \"~~\"  `~~~~\"\033[1;34m+~~+\033[0m\"~\"/\033[1;30m##\033[0m/\033[1;32m~~+\033[0m\"~~~\"\033[1;31m~~+\033[0m  `~~~~\"",
"      \033[1;31m|\033[0;31m[]\033[1;31m|\033[0m+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+\033[1;31m+~~+\033[0m  /\033[1;30m##\033[0m/\033[1;32m|\033[1;36m+~~+~~+\033[1;31m|\033[0;31m[]\033[1;31m|\033[1;33m+~~+~~+\033[0m",
"      \033[1;31m+~~+\033[0m|                               |\033[1;31m|\033[0;31m[]\033[1;31m|\033[0m /\033[1;30m##\033[0m/\033[1;32m~+\033[1;36m|\033[0;36m[]\033[1;36m|\033[0;36m[]\033[1;36m|\033[1;31m+~~+\033[1;33m|\033[0;33m[]\033[1;33m|\033[0;33m[]\033[1;33m|\033[0m",
"      \033[1;31m|\033[0;31m[]\033[1;31m|\033[0m|     Press <Enter> to play     |\033[1;31m+~~+\033[0m/\033[1;30m##\033[0m/\033[1;31m~+ \033[1;36m+~~+~~+ \033[1;33m+~~+~~+~~+\033[0m",
"      \033[1;31m+~~+\033[0m|       Press <Q> to quit       |\033[1;31m|\033[0;31m[]\033[0m/\033[1;30m##\033[0m/\033[0;31m[]\033[1;31m| \033[1;36m|\033[0;36m[]\033[1;36m|\033[0;36m[]\033[1;36m| \033[1;33m|\033[0;33m[]\033[1;33m|\033[0;33m[]\033[1;33m|\033[0m",
"          +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+\033[1;31m+~~\033[0m\\,\"\033[1;31m+~~+ \033[1;36m+~~+~~+ \033[1;33m+~~+~~+\033[0m",
NULL};

struct tetromino tetrominoes[7] = {
        {1, 4, 0xf, 'I'}, /* Line */
        {2, 3, 0x3a, 'J'}, /* Reverse L */
        {2, 3, 0x35, 'L'}, /* L */
        {2, 2, 0xf, 'O'}, /* Square */
        {2, 3, 0x2d, 'S'}, /* S */
        {2, 3, 0x2e, 'T'}, /* T */
        {2, 3, 0x1e, 'Z'}}; /* Reverse S */

char board[HEIGHT][WIDTH];
char input_array[3];
int score;
int speed;

void wait_key();
int display_splash();
int display_board(int);
struct tetromino *copy_tetromino(struct tetromino *);
struct tetromino *rotate_tetromino(struct tetromino *);
void place_tetromino(struct tetromino *, int, int);
void clear_tetromino(struct tetromino *, int, int);
int obstacle_tetromino(struct tetromino *, int, int);
void move_right(struct tetromino *, int *, int *);
void move_left(struct tetromino *, int *, int *);
void push_down(struct tetromino *, int *, int *);
void rotate_in_place(struct tetromino **, int, int);
int input_loop(struct tetromino **, int *, int *);
int drop_tetromino(struct tetromino **);
void clear_board();
void check_lines();
void play();
void setup_keyboard();
void unsetup_keyboard();

void wait_key()
{
    int i;
    size_t s;
    
    while (1)
    {
        for (i = 0; i < 3; i++)
            input_array[i] = 0;
        s = read(0, &input_array, 3);
        if (s)
            break;
        usleep(1000);
    }
}

int display_splash()
{
    int i;
    size_t s;
    
    printf("\033[2J\033[1;1H\n");
    for (i = 0; splash[i] != NULL; i++)
        puts(splash[i]);
    
    while (1)
    {
        for (i = 0; i < 3; i++)
            input_array[i] = 0;
        s = read(0, &input_array, 3);
        if (s)
        {
            switch (input_array[0])
            {
                case 'q':
                case 'Q':
                    return 0;
                case '\n':
                    return 1;
            }
        }
        usleep(1000);
    }
}

/*
 * ' '   No piece
 * 'I'   Line (Purple)
 * 'J'   Reverse L (Red)
 * 'L'   L (Green)
 * 'O'   Square (Cyan)
 * 'S'   S (Yellow)
 * 'T'   T (Blue)
 * 'Z'   Reverse S (Gray)
 */
int display_board(int gameover)
{
    int i, j;
    
    printf("\033[2J\033[1;1H\n");
    for (i = 0; i < HEIGHT; i++)
    {
        printf("  ||");
        for (j = 0; j < WIDTH; j++)
        {
            if (board[i][j] == ' ')
            {
                printf("  ");
            }
            else
            {
                switch (board[i][j])
                {
                    case 'I':
                        printf("\033[0;35m");
                        break;
                    case 'J':
                        printf("\033[0;31m");
                        break;
                    case 'L':
                        printf("\033[0;32m");
                        break;
                    case 'O':
                        printf("\033[0;36m");
                        break;
                    case 'S':
                        printf("\033[0;33m");
                        break;
                    case 'T':
                        printf("\033[0;34m");
                        break;
                    case 'Z':
                        printf("\033[1;30m");
                        break;
                }
                printf("[]");
            }
        }
        printf("\033[0m||");
        switch (i)
        {
            case 7:
                printf("                Score: %d points", score);
                break;
            case 8:
                printf("                Speed: %.2f lines per second",
                                                            (1000.0 / speed));
                break;
            case 10:
                if (gameover)
                    printf("                GAME OVER");
                else
                    printf("                Press <Q> to end game");
                break;
            case 11:
                if (gameover)
                    printf("                Press any key to continue");
        }
        printf("\n");
    }
}

struct tetromino *copy_tetromino(struct tetromino *t)
{
    struct tetromino *new;
    
    new = malloc(sizeof(struct tetromino));
    new->width = t->width;
    new->height = t->height;
    new->data = t->data;
    new->color = t->color;
}

struct tetromino *rotate_tetromino(struct tetromino *t)
{
    struct tetromino *new;
    char i, j, n, width, height, data;
    
    width = t->height;
    height = t->width;
    n = 1;
    data = 0;
    for (i = 0; i < width; i++)
    {
        for (j = 0; j < height; j++)
        {
            if (t->data & n)
                data |= (1 << ((height - j - 1) * width) << i);
            n <<= 1;
        }
    }
    
    new = malloc(sizeof(struct tetromino));
    new->width = width;
    new->height = height;
    new->data = data;
    new->color = t->color;
    return new;
}

void place_tetromino(struct tetromino *t, int line, int pos)
{
    int i, j, n;
    if (line + t->height > HEIGHT)
        return;
    if (pos + t->width > WIDTH)
        return;
    n = 1;
    for (j = 0; j < t->height; j++)
    {
        for (i = 0; i < t->width; i++)
        {
            if (t->data & n)
                board[line+j][pos+i] = t->color;
            n = n << 1;
        }
    }
}

void clear_tetromino(struct tetromino *t, int line, int pos)
{
    int i, j, n;
    
    n = 1;
    for (j = 0; j < t->height; j++)
    {
        for (i = 0; i < t->width; i++)
        {
            if (t->data & n)
                board[line+j][pos+i] = ' ';
            n = n << 1;
        }
    }
}

int obstacle_tetromino(struct tetromino *t, int line, int pos)
{
    int i, j, n;
    if (line < 0)
        return 1;
    if (pos < 0)
        return 1;
    if (line + t->height > HEIGHT)
        return 1;
    if (pos + t->width > WIDTH)
        return 1;
    n = 1;
    for (j = 0; j < t->height; j++)
    {
        for (i = 0; i < t->width; i++)
        {
            if ((t->data) & n && board[line+j][pos+i] != ' ')
                return 1;
            n <<= 1;
        }
    }
    
    return 0;
}

void move_right(struct tetromino *t, int *x, int *y)
{
        clear_tetromino(t, *x, *y);
        if (!obstacle_tetromino(t, *x, *y + 1))
            *y = *y + 1;
        place_tetromino(t, *x, *y);
        display_board(0);
}

void move_left(struct tetromino *t, int *x, int *y)
{
        clear_tetromino(t, *x, *y);
        if (!obstacle_tetromino(t, *x, *y - 1))
            *y = *y - 1;
        place_tetromino(t, *x, *y);
        display_board(0);
}

void push_down(struct tetromino *t, int *x, int *y)
{
        int i;
        
        clear_tetromino(t, *x, *y);
        for (i = 0; i < 5; i++)
            if (!obstacle_tetromino(t, *x + 1, *y))
                *x = *x + 1;
        place_tetromino(t, *x, *y);
        display_board(0);
}

void rotate_in_place(struct tetromino **t, int x, int y)
{
    struct tetromino *new;
    
    new = rotate_tetromino(*t);
    clear_tetromino(*t, x, y);
    if (!obstacle_tetromino(new, x, y))
    {
        free(*t);
        *t = new;
    }
    place_tetromino(*t, x, y);
    display_board(0);
}

int input_loop(struct tetromino **t, int *x, int *y)
{
    int i, j;
    size_t s;
    
    for (i = 0; i < speed; i++)
    {
        for (j = 0; j < 3; j++)
            input_array[j] = 0;
        s = read(0, &input_array, 3);
        switch (input_array[0])
        {
            case 033:
                if (input_array[1] == '[')
                {
                    switch (input_array[2])
                    {
                        case 'A': /* Up arrow */
                            rotate_in_place(t, *x, *y);
                            break;
                        case 'B': /* Down arrow */
                            push_down(*t, x, y);
                            break;
                        case 'C': /* Right arrow */
                            move_right(*t, x, y);
                            break;
                        case 'D': /* Left arrow */
                            move_left(*t, x, y);
                            break;
                    }
                }
                break;
            case 'q':
            case 'Q':
                return 1;
        }
        usleep(1000);
    }
    return 0;
}

int drop_tetromino(struct tetromino **t)
{
    int i, j, result;
    
    i = 0;
    j = WIDTH / 2;
    if (obstacle_tetromino(*t, i, j))
        return 0;
    while(1)
    {
        place_tetromino(*t, i, j);
        display_board(0);
        result = input_loop (t, &i, &j);
        if (result) return 0;
        clear_tetromino(*t, i, j);
        if (obstacle_tetromino(*t, i + 1, j))
        {
            place_tetromino(*t, i, j);
            return 1;
        }
        i++;
    }
}

void clear_board()
{
    int i, j;
    
    for (i = 0; i < HEIGHT; i++)
        for (j = 0; j < WIDTH; j++)
            board[i][j] = ' ';
}

void check_lines()
{
    int i, j, k, c, test;
    
    c = 0;
    for (i = 0; i < HEIGHT; i++)
    {
        test = 1;
        for (j = 0; j < WIDTH; j++)
            if (board[i][j] == ' ')
                test = 0;
        if (test)
        {
            for (k = i; k > 0; k--)
                for (j = 0; j < WIDTH; j++)
                    board[k][j] = board[k-1][j];
            for (j = 0; j < WIDTH; j++)
                board[0][j] = ' ';
            c++;
        }
    }
    speed -= c * 2;
    if (c == 1)
        score++;
    else if (c == 2)
        score += 3;
    else if (c == 3)
        score += 10;
    else if (c >= 4)
        score += 50;
}

void play()
{
    struct tetromino *curr_t, *old_t;
    int i;
    
    score = 0;
    speed = 500;
    clear_board();
    curr_t = copy_tetromino(&tetrominoes[rand() % 7]);
    for (i = 0; i < rand() % 4; i++)
    {
        old_t = curr_t;
        curr_t = rotate_tetromino(old_t);
        free(old_t);
    }
    while (drop_tetromino(&curr_t))
    {
        check_lines();
        display_board(0);
        curr_t = copy_tetromino(&tetrominoes[rand() % 7]);
        for (i = 0; i < rand() % 4; i++)
        {
            old_t = curr_t;
            curr_t = rotate_tetromino(old_t);
            free(old_t);
        }
    }
    display_board(1);
    wait_key();
}

struct termios stored_keyboard_settings;
struct termios new_keyboard_settings;

void setup_keyboard()
{
    tcgetattr(0, &stored_keyboard_settings);
    new_keyboard_settings = stored_keyboard_settings;
    new_keyboard_settings.c_lflag &= (~(ECHO | ICANON));
    new_keyboard_settings.c_cc[VTIME] = 0;
    new_keyboard_settings.c_cc[VMIN] = 0;
    tcsetattr(0, TCSANOW, &new_keyboard_settings);
}

void unsetup_keyboard()
{
    tcsetattr(0, TCSANOW, &stored_keyboard_settings);
    printf("\033[0m");
}

int main()
{
    int i;
    
    setup_keyboard();
    srand(time(NULL));
    while (display_splash())
        play();
    unsetup_keyboard();
}