/****************************************************************************
 *                                                                          *
 * 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-3.c                                            *
 *                                                                          *
 * It can then be run with:                                                 *
 *                                                                          *
 *     ./chetyre                                                            *
 *                                                                          *
 * This source code has been tested on Linux and should probably work on    *
 * other UNIX systems as well.                                              *
 *                                                                          *
 * This source code, as well as binaries for some systems, are available at *
 *      http://haddonthethird.net/chetyre                                   *
 *                                                                          *
 * Copyright 2011, 2018 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 <stdint.h>
#include <string.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\n"
"  `~,\033[1;30m##\033[0m\\    `~,\033[1;30m##\033[0m\\      "
    "\033[1;34m|\033[0;34m[]\033[1;34m|\033[0m\n"
"    /\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/      "
    "\033[1;34m+~~+~~+\033[0m\n"
"   /\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\n"
"  /\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/        "
    "\033[1;34m+~~+~~+\033[0m\n"
" /\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/         "
    "\033[1;34m|\033[0;34m[]\033[1;34m|\033[0m\n"
"/\033[1;30m##\033[0m/      /\033[1;30m##\033[0m/          "
    "\033[1;34m+~~+\033[0m\n"
"|\033[1;30m##\033[0m|    ,\"\033[1;30m##\033[0m/  ,~~~,  ,~~~,,~~~~,,~~~,  "
    ",~~~,   ,~~~~,\033[1;33m+~\033[0m,~~~,,~~~~,     ,~~~,\n"
"\\\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\\\n"
" \\\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\\\n"
"  `~~\"/\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|\n"
"     /\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/\n"
"    /\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,\"\n"
"   /\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,~~~~~~\"\n"
"  /\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|\n"
" /\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\\___/\\\n"
" \\\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/\n"
"  `~~~\"\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  `~~~~\"\n"
"      \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\n"
"      \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\n"
"      \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\n"
"      \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\n"
"          +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+\033[1;31m+~~\033[0m\\,\""
    "\033[1;31m+~~+ \033[1;36m+~~+~~+ \033[1;33m+~~+~~+\033[0m\n";

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];
uint32_t dirty_lines;
int score;
int speed;

size_t get_input();
void wait_key();
int display_splash();
int display_board(int);
struct tetromino *copy_tetromino(struct tetromino *);
struct tetromino *rotate_tetromino(struct tetromino *);
void fill_tetromino(struct tetromino *, int, int, char);
void place_tetromino(struct tetromino *, int, int);
void clear_tetromino(struct tetromino *, int, int);
int obstacle_tetromino(struct tetromino *, int, int);
void move_tetromino(struct tetromino *, int *, int *, int, int);
void rotate_in_place(struct tetromino **, int, int);
int input_loop(struct tetromino **, int *, int *);
int drop_tetromino();
void clear_display();
void clear_board();
void check_lines();
void play();
void setup();
void unsetup();

size_t get_input()
{
    int i;
    for (i = 0; i < 3; i++)
        input_array[i] = 0;
    return read(0, &input_array, 3);
}

void wait_key()
{
    while (1)
    {
        if (get_input())
            break;
        usleep(1000);
    }
}

int display_splash()
{
    int i;
    
    clear_display();
    printf("%s", splash);
    
    while (1)
    {
        get_input();
        switch (input_array[0])
        {
            case 'q':
            case 'Q':
                return 0;
            case '\n':
                return 1;
        }
        usleep(1000);
    }
}

char *tiles[] = {
    "  ", /* A */ "  ", /* B */ "  ", /* C */ "  ", /* D */ "  ", /* E */ "  ",
    /* F */ "  ", /* G */ "  ", /* H */ "  ",
    /* I - Line (Purple) */ "\033[0;35m[]",
    /* J - Reverse L (Red) */ "\033[0;31m[]", /* K */ "  ",
    /* L (Green) */ "\033[0;32m[]", /* M */ "  ", /* N */ "  ",
    /* O - Square (Cyan) */ "\033[0;36m[]", /* P */ "  ", /* Q */ "  ",
    /* R */ "  ", /* S (Yellow) */ "\033[0;33m[]",
    /* T (Blue) */ "\033[0;34m[]", /* U */ "  ", /* V */ "  ", /* W */ "  ",
    /* X */ "  ", /* Y */ "  ",
    /* Z - Reverse S (Default Color) */ "\033[0m[]", "  ", "  ", "  ", "  ",
    "  "};

int display_board(int gameover)
{
    int i, j;
    
    printf("\033[1;1H");
    for (i = 0; i < HEIGHT; i++)
    {
        if (dirty_lines & (1 << i))
        {
            printf("  ||");
            for (j = 0; j < WIDTH; j++)
            {
                if (board[i][j] >= 64 && board[i][j] < 96)
                    printf("%s", tiles[board[i][j] - 64]);
                else
                    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");
                    break;
            }
        }
        printf("\n");
    }
    dirty_lines = 0;
}

struct tetromino *copy_tetromino(struct tetromino *t)
{
    struct tetromino *new;
    
    new = malloc(sizeof(struct tetromino));
    memcpy(new, t, sizeof(struct tetromino));
    return new;
}

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 fill_tetromino(struct tetromino *t, int line, int pos, char c)
{
    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] = c;
                dirty_lines |= 1 << (line+j);
            }
            n = n << 1;
        }
    }
}

void place_tetromino(struct tetromino *t, int line, int pos)
{
    if (line + t->height <= HEIGHT && pos + t->width <= WIDTH)
        fill_tetromino(t, line, pos, t->color);
}

void clear_tetromino(struct tetromino *t, int line, int pos)
{
    fill_tetromino(t, line, pos, ' ');
}

int obstacle_tetromino(struct tetromino *t, int line, int pos)
{
    int i, j, n;
    if (line < 0 || pos < 0)
        return 1;
    if (line + t->height > HEIGHT || 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_tetromino(struct tetromino *t, int *x, int *y, int dx, int dy)
{
    int i;

    clear_tetromino(t, *x, *y);
    for (i = 0; i < abs(dx) || i < abs(dy); i++)
    {
        if (i < abs(dx) && !obstacle_tetromino(t, *x + dx / abs(dx), *y))
            *x += dx / abs(dx);
        if (i < abs(dy) && !obstacle_tetromino(t, *x, *y + dy / abs(dy)))
            *y += dy / abs(dy);
    }
    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;

    for (i = 0; i < speed; i++)
    {
        get_input();
        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 */
                            move_tetromino(*t, x, y, 5, 0);
                            break;
                        case 'C': /* Right arrow */
                            move_tetromino(*t, x, y, 0, 1);
                            break;
                        case 'D': /* Left arrow */
                            move_tetromino(*t, x, y, 0, -1);
                            break;
                    }
                }
                break;
            case 'q':
            case 'Q':
                return 1;
        }
        usleep(1000);
    }
    return 0;
}

int drop_tetromino()
{
    struct tetromino *curr_t, *old_t;
    int i, j;
    
    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);
    }
    j = WIDTH / 2;
    if (obstacle_tetromino(curr_t, i, j))
        return 0;
    for (i = 0; i < HEIGHT; i++)
    {
        place_tetromino(curr_t, i, j);
        display_board(0);
        if (input_loop (&curr_t, &i, &j))
            return 0;
        clear_tetromino(curr_t, i, j);
        if (obstacle_tetromino(curr_t, i + 1, j))
        {
            place_tetromino(curr_t, i, j);
            return 1;
        }
    }
}

void clear_display()
{
    printf("\033[2J\033[1;1H");
    dirty_lines = 0xffffffffU;
}

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 * (speed / 80 + 1);
    score += c * c * ((c - 1) + !(c - 1));
    if (c)
        dirty_lines = 0xffffffffU;
}

void play()
{
    int i;
    
    score = 0;
    speed = 500;
    clear_board();
    clear_display();
    while (drop_tetromino())
    {
        check_lines();
        display_board(0);
    }
    dirty_lines = 0xffffffffU;
    display_board(1);
    wait_key();
}

struct termios stored_keyboard_settings;
struct termios new_keyboard_settings;

void setup()
{
    srand(time(NULL));
    printf("\033[?25l\033[?47h");
    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()
{
    tcsetattr(0, TCSANOW, &stored_keyboard_settings);
    printf("\033[?25h\033[?47l\033[0m");
}

int main()
{
    setup();
    while (display_splash())
        play();
    unsetup();
}