termbox.h

// termbox.h
#ifndef H_TERMBOX
#define H_TERMBOX
#include <stdint.h>

// shared objects
#if __GNUC__ >= 4
	#define SO_IMPORT __attribute__((visibility("default")))
#else
	#define SO_IMPORT
#endif

// c++
#ifdef __cplusplus
extern "C" {
#endif

// Key constants. See also struct tb_event's key field.
// These are a safe subset of terminfo keys, which exist on all popular
// terminals. Termbox uses only them to stay truly portable.
#define TB_KEY_F1               (0xFFFF-0)
#define TB_KEY_F2               (0xFFFF-1)
#define TB_KEY_F3               (0xFFFF-2)
#define TB_KEY_F4               (0xFFFF-3)
#define TB_KEY_F5               (0xFFFF-4)
#define TB_KEY_F6               (0xFFFF-5)
#define TB_KEY_F7               (0xFFFF-6)
#define TB_KEY_F8               (0xFFFF-7)
#define TB_KEY_F9               (0xFFFF-8)
#define TB_KEY_F10              (0xFFFF-9)
#define TB_KEY_F11              (0xFFFF-10)
#define TB_KEY_F12              (0xFFFF-11)
#define TB_KEY_INSERT           (0xFFFF-12)
#define TB_KEY_DELETE           (0xFFFF-13)
#define TB_KEY_HOME             (0xFFFF-14)
#define TB_KEY_END              (0xFFFF-15)
#define TB_KEY_PGUP             (0xFFFF-16)
#define TB_KEY_PGDN             (0xFFFF-17)
#define TB_KEY_ARROW_UP         (0xFFFF-18)
#define TB_KEY_ARROW_DOWN       (0xFFFF-19)
#define TB_KEY_ARROW_LEFT       (0xFFFF-20)
#define TB_KEY_ARROW_RIGHT      (0xFFFF-21)
#define TB_KEY_MOUSE_LEFT       (0xFFFF-22)
#define TB_KEY_MOUSE_RIGHT      (0xFFFF-23)
#define TB_KEY_MOUSE_MIDDLE     (0xFFFF-24)
#define TB_KEY_MOUSE_RELEASE    (0xFFFF-25)
#define TB_KEY_MOUSE_WHEEL_UP   (0xFFFF-26)
#define TB_KEY_MOUSE_WHEEL_DOWN (0xFFFF-27)

// These are all ASCII code points below SPACE character and a BACKSPACE key.
#define TB_KEY_CTRL_TILDE       0x00
#define TB_KEY_CTRL_2           0x00 // clash with 'CTRL_TILDE'
#define TB_KEY_CTRL_A           0x01
#define TB_KEY_CTRL_B           0x02
#define TB_KEY_CTRL_C           0x03
#define TB_KEY_CTRL_D           0x04
#define TB_KEY_CTRL_E           0x05
#define TB_KEY_CTRL_F           0x06
#define TB_KEY_CTRL_G           0x07
#define TB_KEY_BACKSPACE        0x08
#define TB_KEY_CTRL_H           0x08 // clash with 'CTRL_BACKSPACE'
#define TB_KEY_TAB              0x09
#define TB_KEY_CTRL_I           0x09 // clash with 'TAB'
#define TB_KEY_CTRL_J           0x0A
#define TB_KEY_CTRL_K           0x0B
#define TB_KEY_CTRL_L           0x0C
#define TB_KEY_ENTER            0x0D
#define TB_KEY_CTRL_M           0x0D // clash with 'ENTER'
#define TB_KEY_CTRL_N           0x0E
#define TB_KEY_CTRL_O           0x0F
#define TB_KEY_CTRL_P           0x10
#define TB_KEY_CTRL_Q           0x11
#define TB_KEY_CTRL_R           0x12
#define TB_KEY_CTRL_S           0x13
#define TB_KEY_CTRL_T           0x14
#define TB_KEY_CTRL_U           0x15
#define TB_KEY_CTRL_V           0x16
#define TB_KEY_CTRL_W           0x17
#define TB_KEY_CTRL_X           0x18
#define TB_KEY_CTRL_Y           0x19
#define TB_KEY_CTRL_Z           0x1A
#define TB_KEY_ESC              0x1B
#define TB_KEY_CTRL_LSQ_BRACKET 0x1B // clash with 'ESC'
#define TB_KEY_CTRL_3           0x1B // clash with 'ESC'
#define TB_KEY_CTRL_4           0x1C
#define TB_KEY_CTRL_BACKSLASH   0x1C // clash with 'CTRL_4'
#define TB_KEY_CTRL_5           0x1D
#define TB_KEY_CTRL_RSQ_BRACKET 0x1D // clash with 'CTRL_5'
#define TB_KEY_CTRL_6           0x1E
#define TB_KEY_CTRL_7           0x1F
#define TB_KEY_CTRL_SLASH       0x1F // clash with 'CTRL_7'
#define TB_KEY_CTRL_UNDERSCORE  0x1F // clash with 'CTRL_7'
#define TB_KEY_SPACE            0x20
#define TB_KEY_BACKSPACE2       0x7F
#define TB_KEY_CTRL_8           0x7F // clash with 'BACKSPACE2'

// These are non-existing ones.
// #define TB_KEY_CTRL_1 clash with '1'
// #define TB_KEY_CTRL_9 clash with '9'
// #define TB_KEY_CTRL_0 clash with '0'

// Alt modifier constant, see tb_event.mod field and tb_select_input_mode function.
// Mouse-motion modifier
#define TB_MOD_ALT    0x01
#define TB_MOD_MOTION 0x02

// Colors (see struct tb_cell's fg and bg fields).
#define TB_DEFAULT 0x00
#define TB_BLACK   0x01
#define TB_RED     0x02
#define TB_GREEN   0x03
#define TB_YELLOW  0x04
#define TB_BLUE    0x05
#define TB_MAGENTA 0x06
#define TB_CYAN    0x07
#define TB_WHITE   0x08

//  Attributes, it is possible to use multiple attributes by combining them
//  using bitwise OR ('|'). Although, colors cannot be combined. But you can
//  combine attributes and a single color. See also struct tb_cell's fg and bg
//  fields.
#define TB_BOLD      0x01000000
#define TB_UNDERLINE 0x02000000
#define TB_REVERSE   0x04000000

// A cell, single conceptual entity on the terminal screen. The terminal screen
// is basically a 2d array of cells. It has the following fields:
// - 'ch' is a unicode character
// - 'fg' foreground color and attributes
// - 'bg' background color and attributes
struct tb_cell
{
	uint32_t ch;
	uint32_t fg;
	uint32_t bg;
};

#define TB_EVENT_KEY    1
#define TB_EVENT_RESIZE 2
#define TB_EVENT_MOUSE  3

// An event, single interaction from the user. The 'mod' and 'ch' fields are
// valid if 'type' is TB_EVENT_KEY. The 'w' and 'h' fields are valid if 'type'
// is TB_EVENT_RESIZE. The 'x' and 'y' fields are valid if 'type' is
// TB_EVENT_MOUSE. The 'key' field is valid if 'type' is either TB_EVENT_KEY
// or TB_EVENT_MOUSE. The fields 'key' and 'ch' are mutually exclusive; only
// one of them can be non-zero at a time.
struct tb_event
{
	uint8_t type;
	uint8_t mod; // modifiers to either 'key' or 'ch' below
	uint16_t key; // one of the TB_KEY_* constants
	uint32_t ch; // unicode character
	int32_t w;
	int32_t h;
	int32_t x;
	int32_t y;
};

//  Error codes returned by tb_init(). All of them are self-explanatory, except
//  the pipe trap error. Termbox uses unix pipes in order to deliver a message
//  from a signal handler (SIGWINCH) to the main event reading loop. Honestly in
//  most cases you should just check the returned code as < 0.
#define TB_EUNSUPPORTED_TERMINAL -1
#define TB_EFAILED_TO_OPEN_TTY   -2
#define TB_EPIPE_TRAP_ERROR      -3

// Initializes the termbox library. This function should be called before any
// other functions. Function tb_init is same as tb_init_file("/dev/tty"). After successful initialization, the library must be
// finalized using the tb_shutdown() function.
SO_IMPORT int tb_init(void);
SO_IMPORT int tb_init_file(const char* name);
SO_IMPORT void tb_shutdown(void);

// Returns the size of the internal back buffer (which is the same as
// terminal's window size in characters). The internal buffer can be resized
// after tb_clear() or tb_present() function calls. Both dimensions have an
// unspecified negative value when called before tb_init() or after
// tb_shutdown().
SO_IMPORT int tb_width(void);
SO_IMPORT int tb_height(void);

// Clears the internal back buffer using TB_DEFAULT color or the
// color/attributes set by tb_set_clear_attributes() function.
SO_IMPORT void tb_clear(void);
SO_IMPORT void tb_set_clear_attributes(uint32_t fg, uint32_t bg);

// Synchronizes the internal back buffer with the terminal.
SO_IMPORT void tb_present(void);

#define TB_HIDE_CURSOR -1

// Sets the position of the cursor. Upper-left character is (0, 0). If you pass
// TB_HIDE_CURSOR as both coordinates, then the cursor will be hidden. Cursor
// is hidden by default.
SO_IMPORT void tb_set_cursor(int cx, int cy);

// Changes cell's parameters in the internal back buffer at the specified
// position.
SO_IMPORT void tb_put_cell(int x, int y, const struct tb_cell* cell);
SO_IMPORT void tb_change_cell(int x, int y, uint32_t ch, uint32_t fg,
	uint32_t bg);

// Copies the buffer from 'cells' at the specified position, assuming the
// buffer is a two-dimensional array of size ('w' x 'h'), represented as a
// one-dimensional buffer containing lines of cells starting from the top.
// (DEPRECATED: use tb_cell_buffer() instead and copy memory on your own)
SO_IMPORT void tb_blit(int x, int y, int w, int h, const struct tb_cell* cells);

// Returns a pointer to internal cell back buffer. You can get its dimensions
// using tb_width() and tb_height() functions. The pointer stays valid as long
// as no tb_clear() and tb_present() calls are made. The buffer is
// one-dimensional buffer containing lines of cells starting from the top.
SO_IMPORT struct tb_cell* tb_cell_buffer(void);

#define TB_INPUT_CURRENT 0 // 000
#define TB_INPUT_ESC     1 // 001
#define TB_INPUT_ALT     2 // 010
#define TB_INPUT_MOUSE   4 // 100

//  Sets the termbox input mode. Termbox has two input modes:
//  1. Esc input mode.
//    When ESC sequence is in the buffer and it doesn't match any known
//    ESC sequence => ESC means TB_KEY_ESC.
//  2. Alt input mode.
//    When ESC sequence is in the buffer and it doesn't match any known
//    sequence => ESC enables TB_MOD_ALT modifier for the next keyboard event.
//
//  You can also apply TB_INPUT_MOUSE via bitwise OR operation to either of the
//  modes (e.g. TB_INPUT_ESC | TB_INPUT_MOUSE). If none of the main two modes
//  were set, but the mouse mode was, TB_INPUT_ESC mode is used. If for some
//  reason you've decided to use (TB_INPUT_ESC | TB_INPUT_ALT) combination, it
//  will behave as if only TB_INPUT_ESC was selected.
//
//  If 'mode' is TB_INPUT_CURRENT, it returns the current input mode.
//
//  Default termbox input mode is TB_INPUT_ESC.
SO_IMPORT int tb_select_input_mode(int mode);

#define TB_OUTPUT_CURRENT   0
#define TB_OUTPUT_NORMAL    1
#define TB_OUTPUT_256       2
#define TB_OUTPUT_216       3
#define TB_OUTPUT_GRAYSCALE 4
#define TB_OUTPUT_TRUECOLOR 5

// Sets the termbox output mode. Termbox has three output options:
// 1. TB_OUTPUT_NORMAL     => [1..8]
//   This mode provides 8 different colors:
//   black, red, green, yellow, blue, magenta, cyan, white
//   Shortcut: TB_BLACK, TB_RED, ...
//   Attributes: TB_BOLD, TB_UNDERLINE, TB_REVERSE
//
//   Example usage:
//       tb_change_cell(x, y, '@', TB_BLACK | TB_BOLD, TB_RED);
//
// 2. TB_OUTPUT_256        => [0..256]
//   In this mode you can leverage the 256 terminal mode:
//   0x00 - 0x07: the 8 colors as in TB_OUTPUT_NORMAL
//   0x08 - 0x0f: TB_* | TB_BOLD
//   0x10 - 0xe7: 216 different colors
//   0xe8 - 0xff: 24 different shades of grey
//
//   Example usage:
//       tb_change_cell(x, y, '@', 184, 240);
//       tb_change_cell(x, y, '@', 0xb8, 0xf0);
//
// 3. TB_OUTPUT_216        => [0..216]
//   This mode supports the 3rd range of the 256 mode only.
//   But you don't need to provide an offset.
//
// 4. TB_OUTPUT_GRAYSCALE  => [0..23]
//   This mode supports the 4th range of the 256 mode only.
//   But you dont need to provide an offset.
//
// 5. TB_OUTPUT_TRUECOLOR  => [0x000000..0xFFFFFF]
//   This mode supports 24-bit true color. Format is 0xRRGGBB.
//
// Execute build/src/demo/output to see its impact on your terminal.
//
// If 'mode' is TB_OUTPUT_CURRENT, it returns the current output mode.
//
// Default termbox output mode is TB_OUTPUT_NORMAL.
SO_IMPORT int tb_select_output_mode(int mode);

// Wait for an event up to 'timeout' milliseconds and fill the 'event'
// structure with it, when the event is available. Returns the type of the
// event (one of TB_EVENT_* constants) or -1 if there was an error or 0 in case
// there were no event during 'timeout' period.
SO_IMPORT int tb_peek_event(struct tb_event* event, int timeout);

// Wait for an event forever and fill the 'event' structure with it, when the
// event is available. Returns the type of the event (one of TB_EVENT_
// constants) or -1 if there was an error.
SO_IMPORT int tb_poll_event(struct tb_event* event);

// Utility utf8 functions.
#define TB_EOF -1
SO_IMPORT int utf8_char_length(char c);
SO_IMPORT int utf8_char_to_unicode(uint32_t* out, const char* c);
SO_IMPORT int utf8_unicode_to_char(char* out, uint32_t c);

// c++
#ifdef __cplusplus
}
#endif

#endif
// ringbuffer.h
#ifndef H_RINGBUFFER
#define H_RINGBUFFER

#include <stddef.h>

#define ERINGBUFFER_ALLOC_FAIL -1

struct ringbuffer
{
	char* buf;
	size_t size;

	char* begin;
	char* end;
};

int init_ringbuffer(struct ringbuffer* r, size_t size);
void free_ringbuffer(struct ringbuffer* r);
void clear_ringbuffer(struct ringbuffer* r);
size_t ringbuffer_free_space(struct ringbuffer* r);
size_t ringbuffer_data_size(struct ringbuffer* r);
void ringbuffer_push(struct ringbuffer* r, const void* data, size_t size);
void ringbuffer_pop(struct ringbuffer* r, void* data, size_t size);
void ringbuffer_read(struct ringbuffer* r, void* data, size_t size);

#endif
// memstream.h
#ifndef H_MEMSTREAM
#define H_MEMSTREAM

#include <stddef.h>
#include <stdio.h>

struct memstream
{
	size_t  pos;
	size_t capa;
	int file;
	unsigned char* data;
};

void memstream_init(struct memstream* s, int fd, void* buffer, size_t len);
void memstream_flush(struct memstream* s);
void memstream_write(struct memstream* s, void* source, size_t len);
void memstream_puts(struct memstream* s, const char* str);

#endif
// utf8.c
// #include "termbox.h"

static const unsigned char utf8_length[256] =
{
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
	4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 1, 1
};

static const unsigned char utf8_mask[6] =
{
	0x7F,
	0x1F,
	0x0F,
	0x07,
	0x03,
	0x01
};

int utf8_char_length(char c)
{
	return utf8_length[(unsigned char)c];
}

int utf8_char_to_unicode(uint32_t* out, const char* c)
{
	if (*c == 0)
	{
		return TB_EOF;
	}

	int i;
	unsigned char len = utf8_char_length(*c);
	unsigned char mask = utf8_mask[len - 1];
	uint32_t result = c[0] & mask;

	for (i = 1; i < len; ++i)
	{
		result <<= 6;
		result |= c[i] & 0x3f;
	}

	*out = result;
	return (int)len;
}

int utf8_unicode_to_char(char* out, uint32_t c)
{
	int len = 0;
	int first;
	int i;

	if (c < 0x80)
	{
		first = 0;
		len = 1;
	}
	else if (c < 0x800)
	{
		first = 0xc0;
		len = 2;
	}
	else if (c < 0x10000)
	{
		first = 0xe0;
		len = 3;
	}
	else if (c < 0x200000)
	{
		first = 0xf0;
		len = 4;
	}
	else if (c < 0x4000000)
	{
		first = 0xf8;
		len = 5;
	}
	else
	{
		first = 0xfc;
		len = 6;
	}

	for (i = len - 1; i > 0; --i)
	{
		out[i] = (c & 0x3f) | 0x80;
		c >>= 6;
	}

	out[0] = c | first;

	return len;
}
// term.h
#ifndef H_TERM
#define H_TERM

// #include "termbox.h"
// #include "ringbuffer.h"
#include <stdbool.h>

#define EUNSUPPORTED_TERM -1

enum
{
	T_ENTER_CA,
	T_EXIT_CA,
	T_SHOW_CURSOR,
	T_HIDE_CURSOR,
	T_CLEAR_SCREEN,
	T_SGR0,
	T_UNDERLINE,
	T_BOLD,
	T_BLINK,
	T_REVERSE,
	T_ENTER_KEYPAD,
	T_EXIT_KEYPAD,
	T_ENTER_MOUSE,
	T_EXIT_MOUSE,
	T_FUNCS_NUM,
};

extern const char** keys;
extern const char** funcs;

// true on success, false on failure
bool extract_event(struct tb_event* event, struct ringbuffer* inbuf,
	int inputmode);
int init_term(void);
void shutdown_term(void);

#endif
// term.c
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>

// #include "term.h"
#define ENTER_MOUSE_SEQ "\x1b[?1000h\x1b[?1002h\x1b[?1015h\x1b[?1006h"
#define EXIT_MOUSE_SEQ "\x1b[?1006l\x1b[?1015l\x1b[?1002l\x1b[?1000l"

#define EUNSUPPORTED_TERM -1

// rxvt-256color
static const char* rxvt_256color_keys[] =
{
	"\033[11~", "\033[12~", "\033[13~", "\033[14~", "\033[15~", "\033[17~",
	"\033[18~", "\033[19~", "\033[20~", "\033[21~", "\033[23~", "\033[24~",
	"\033[2~", "\033[3~", "\033[7~", "\033[8~", "\033[5~", "\033[6~",
	"\033[A", "\033[B", "\033[D", "\033[C", NULL
};
static const char* rxvt_256color_funcs[] =
{
	"\0337\033[?47h", "\033[2J\033[?47l\0338", "\033[?25h", "\033[?25l",
	"\033[H\033[2J", "\033[m", "\033[4m", "\033[1m", "\033[5m", "\033[7m",
	"\033=", "\033>", ENTER_MOUSE_SEQ, EXIT_MOUSE_SEQ,
};

// Eterm
static const char* eterm_keys[] =
{
	"\033[11~", "\033[12~", "\033[13~", "\033[14~", "\033[15~", "\033[17~",
	"\033[18~", "\033[19~", "\033[20~", "\033[21~", "\033[23~", "\033[24~",
	"\033[2~", "\033[3~", "\033[7~", "\033[8~", "\033[5~", "\033[6~",
	"\033[A", "\033[B", "\033[D", "\033[C", NULL
};
static const char* eterm_funcs[] =
{
	"\0337\033[?47h", "\033[2J\033[?47l\0338", "\033[?25h", "\033[?25l",
	"\033[H\033[2J", "\033[m", "\033[4m", "\033[1m", "\033[5m", "\033[7m",
	"", "", "", "",
};

// screen
static const char* screen_keys[] =
{
	"\033OP", "\033OQ", "\033OR", "\033OS", "\033[15~", "\033[17~",
	"\033[18~", "\033[19~", "\033[20~", "\033[21~", "\033[23~", "\033[24~",
	"\033[2~", "\033[3~", "\033[1~", "\033[4~", "\033[5~", "\033[6~",
	"\033OA", "\033OB", "\033OD", "\033OC", NULL
};
static const char* screen_funcs[] =
{
	"\033[?1049h", "\033[?1049l", "\033[34h\033[?25h", "\033[?25l",
	"\033[H\033[J", "\033[m", "\033[4m", "\033[1m", "\033[5m", "\033[7m",
	"\033[?1h\033=", "\033[?1l\033>", ENTER_MOUSE_SEQ, EXIT_MOUSE_SEQ,
};

// rxvt-unicode
static const char* rxvt_unicode_keys[] =
{
	"\033[11~", "\033[12~", "\033[13~", "\033[14~", "\033[15~", "\033[17~",
	"\033[18~", "\033[19~", "\033[20~", "\033[21~", "\033[23~", "\033[24~",
	"\033[2~", "\033[3~", "\033[7~", "\033[8~", "\033[5~", "\033[6~",
	"\033[A", "\033[B", "\033[D", "\033[C", NULL
};
static const char* rxvt_unicode_funcs[] =
{
	"\033[?1049h", "\033[r\033[?1049l", "\033[?25h", "\033[?25l",
	"\033[H\033[2J", "\033[m\033(B", "\033[4m", "\033[1m", "\033[5m",
	"\033[7m", "\033=", "\033>", ENTER_MOUSE_SEQ, EXIT_MOUSE_SEQ,
};

// linux
static const char* linux_keys[] =
{
	"\033[[A", "\033[[B", "\033[[C", "\033[[D", "\033[[E", "\033[17~",
	"\033[18~", "\033[19~", "\033[20~", "\033[21~", "\033[23~", "\033[24~",
	"\033[2~", "\033[3~", "\033[1~", "\033[4~", "\033[5~", "\033[6~",
	"\033[A", "\033[B", "\033[D", "\033[C", NULL
};
static const char* linux_funcs[] =
{
	"", "", "\033[?25h\033[?0c", "\033[?25l\033[?1c", "\033[H\033[J",
	"\033[0;10m", "\033[4m", "\033[1m", "\033[5m", "\033[7m", "", "", "", "",
};

// xterm
static const char* xterm_keys[] =
{
	"\033OP", "\033OQ", "\033OR", "\033OS", "\033[15~", "\033[17~", "\033[18~",
	"\033[19~", "\033[20~", "\033[21~", "\033[23~", "\033[24~", "\033[2~",
	"\033[3~", "\033OH", "\033OF", "\033[5~", "\033[6~", "\033OA", "\033OB",
	"\033OD", "\033OC", NULL
};
static const char* xterm_funcs[] =
{
	"\033[?1049h", "\033[?1049l", "\033[?12l\033[?25h", "\033[?25l",
	"\033[H\033[2J", "\033(B\033[m", "\033[4m", "\033[1m", "\033[5m", "\033[7m",
	"\033[?1h\033=", "\033[?1l\033>", ENTER_MOUSE_SEQ, EXIT_MOUSE_SEQ,
};

struct term
{
	const char* name;
	const char** keys;
	const char** funcs;
};

static struct term terms[] =
{
	{"rxvt-256color", rxvt_256color_keys, rxvt_256color_funcs},
	{"Eterm", eterm_keys, eterm_funcs},
	{"screen", screen_keys, screen_funcs},
	{"rxvt-unicode", rxvt_unicode_keys, rxvt_unicode_funcs},
	{"linux", linux_keys, linux_funcs},
	{"xterm", xterm_keys, xterm_funcs},
	{0, 0, 0},
};

static int init_from_terminfo = 0;
const char** keys;
const char** funcs;

static int try_compatible(const char* term, const char* name,
	const char** tkeys, const char** tfuncs)
{
	if (strstr(term, name))
	{
		keys = tkeys;
		funcs = tfuncs;
		return 0;
	}

	return EUNSUPPORTED_TERM;
}

static int init_term_builtin(void)
{
	int i;
	const char* term = getenv("TERM");

	if (term)
	{
		for (i = 0; terms[i].name; i++)
		{
			if (!strcmp(terms[i].name, term))
			{
				keys = terms[i].keys;
				funcs = terms[i].funcs;
				return 0;
			}
		}

		// let's do some heuristic, maybe it's a compatible terminal
		if (try_compatible(term, "xterm", xterm_keys, xterm_funcs) == 0)
		{
			return 0;
		}

		if (try_compatible(term, "rxvt", rxvt_unicode_keys, rxvt_unicode_funcs) == 0)
		{
			return 0;
		}

		if (try_compatible(term, "linux", linux_keys, linux_funcs) == 0)
		{
			return 0;
		}

		if (try_compatible(term, "Eterm", eterm_keys, eterm_funcs) == 0)
		{
			return 0;
		}

		if (try_compatible(term, "screen", screen_keys, screen_funcs) == 0)
		{
			return 0;
		}

		// let's assume that 'cygwin' is xterm compatible
		if (try_compatible(term, "cygwin", xterm_keys, xterm_funcs) == 0)
		{
			return 0;
		}
	}

	return EUNSUPPORTED_TERM;
}

// terminfo
static char* read_file(const char* file)
{
	FILE* f = fopen(file, "rb");

	if (!f)
	{
		return 0;
	}

	struct stat st;

	if (fstat(fileno(f), &st) != 0)
	{
		fclose(f);
		return 0;
	}

	char* data = malloc(st.st_size);

	if (!data)
	{
		fclose(f);
		return 0;
	}

	if (fread(data, 1, st.st_size, f) != (size_t)st.st_size)
	{
		fclose(f);
		free(data);
		return 0;
	}

	fclose(f);
	return data;
}

static char* terminfo_try_path(const char* path, const char* term)
{
	char tmp[4096];
	snprintf(tmp, sizeof(tmp), "%s/%c/%s", path, term[0], term);
	tmp[sizeof(tmp) - 1] = '\0';
	char* data = read_file(tmp);

	if (data)
	{
		return data;
	}

	// fallback to darwin specific dirs structure
	snprintf(tmp, sizeof(tmp), "%s/%x/%s", path, term[0], term);
	tmp[sizeof(tmp) - 1] = '\0';
	return read_file(tmp);
}

static char* load_terminfo(void)
{
	char tmp[4096];
	const char* term = getenv("TERM");

	if (!term)
	{
		return 0;
	}

	// if TERMINFO is set, no other directory should be searched
	const char* terminfo = getenv("TERMINFO");

	if (terminfo)
	{
		return terminfo_try_path(terminfo, term);
	}

	// next, consider ~/.terminfo
	const char* home = getenv("HOME");

	if (home)
	{
		snprintf(tmp, sizeof(tmp), "%s/.terminfo", home);
		tmp[sizeof(tmp) - 1] = '\0';
		char* data = terminfo_try_path(tmp, term);

		if (data)
		{
			return data;
		}
	}

	// next, TERMINFO_DIRS
	const char* dirs = getenv("TERMINFO_DIRS");

	if (dirs)
	{
		snprintf(tmp, sizeof(tmp), "%s", dirs);
		tmp[sizeof(tmp) - 1] = '\0';
		char* dir = strtok(tmp, ":");

		while (dir)
		{
			const char* cdir = dir;

			if (strcmp(cdir, "") == 0)
			{
				cdir = "/usr/share/terminfo";
			}

			char* data = terminfo_try_path(cdir, term);

			if (data)
			{
				return data;
			}

			dir = strtok(0, ":");
		}
	}

	// fallback to /usr/share/terminfo
	return terminfo_try_path("/usr/share/terminfo", term);
}

#define TI_MAGIC 0432
#define TI_ALT_MAGIC 542
#define TI_HEADER_LENGTH 12
#define TB_KEYS_NUM 22

static const char* terminfo_copy_string(char* data, int str, int table)
{
	const int16_t off = *(int16_t*)(data + str);
	const char* src = data + table + off;
	int len = strlen(src);
	char* dst = malloc(len + 1);
	strcpy(dst, src);
	return dst;
}

const int16_t ti_funcs[] =
{
	28, 40, 16, 13, 5, 39, 36, 27, 26, 34, 89, 88,
};

const int16_t ti_keys[] =
{
	// apparently not a typo; 67 is F10 for whatever reason
	66, 68, 69, 70, 71, 72, 73, 74, 75, 67, 216, 217, 77, 59, 76, 164, 82,
	81, 87, 61, 79, 83,
};

int init_term(void)
{
	int i;
	char* data = load_terminfo();

	if (!data)
	{
		init_from_terminfo = 0;
		return init_term_builtin();
	}

	int16_t* header = (int16_t*)data;

	const int number_sec_len = header[0] == TI_ALT_MAGIC ? 4 : 2;

	if ((header[1] + header[2]) % 2)
	{
		// old quirk to align everything on word boundaries
		header[2] += 1;
	}

	const int str_offset = TI_HEADER_LENGTH +
		header[1] + header[2] +	number_sec_len * header[3];
	const int table_offset = str_offset + 2 * header[4];

	keys = malloc(sizeof(const char*) * (TB_KEYS_NUM + 1));

	for (i = 0; i < TB_KEYS_NUM; i++)
	{
		keys[i] = terminfo_copy_string(data,
				str_offset + 2 * ti_keys[i], table_offset);
	}

	keys[i] = NULL;

	funcs = malloc(sizeof(const char*) * T_FUNCS_NUM);

	// the last two entries are reserved for mouse. because the table offset is
	// not there, the two entries have to fill in manually
	for (i = 0; i < T_FUNCS_NUM - 2; i++)
	{
		funcs[i] = terminfo_copy_string(data,
				str_offset + 2 * ti_funcs[i], table_offset);
	}

	funcs[T_FUNCS_NUM - 2] = ENTER_MOUSE_SEQ;
	funcs[T_FUNCS_NUM - 1] = EXIT_MOUSE_SEQ;
	init_from_terminfo = 1;
	free(data);
	return 0;
}

void shutdown_term(void)
{
	if (init_from_terminfo)
	{
		int i;

		for (i = 0; i < TB_KEYS_NUM; i++)
		{
			free((void*)keys[i]);
		}

		// the last two entries are reserved for mouse. because the table offset
		// is not there, the two entries have to fill in manually and do not
		// need to be freed.
		for (i = 0; i < T_FUNCS_NUM - 2; i++)
		{
			free((void*)funcs[i]);
		}

		free(keys);
		free(funcs);
	}
}
// ringbuffer.c
// #include "ringbuffer.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stddef.h> // for ptrdiff_t

int init_ringbuffer(struct ringbuffer* r, size_t size)
{
	r->buf = (char*)malloc(size);

	if (!r->buf)
	{
		return ERINGBUFFER_ALLOC_FAIL;
	}

	r->size = size;
	clear_ringbuffer(r);

	return 0;
}

void free_ringbuffer(struct ringbuffer* r)
{
	free(r->buf);
}

void clear_ringbuffer(struct ringbuffer* r)
{
	r->begin = 0;
	r->end = 0;
}

size_t ringbuffer_free_space(struct ringbuffer* r)
{
	if (r->begin == 0 && r->end == 0)
	{
		return r->size;
	}

	if (r->begin < r->end)
	{
		return r->size - (r->end - r->begin) - 1;
	}
	else
	{
		return r->begin - r->end - 1;
	}
}

size_t ringbuffer_data_size(struct ringbuffer* r)
{
	if (r->begin == 0 && r->end == 0)
	{
		return 0;
	}

	if (r->begin <= r->end)
	{
		return r->end - r->begin + 1;
	}
	else
	{
		return r->size - (r->begin - r->end) + 1;
	}
}


void ringbuffer_push(struct ringbuffer* r, const void* data, size_t size)
{
	if (ringbuffer_free_space(r) < size)
	{
		return;
	}

	if (r->begin == 0 && r->end == 0)
	{
		memcpy(r->buf, data, size);
		r->begin = r->buf;
		r->end = r->buf + size - 1;
		return;
	}

	r->end++;

	if (r->begin < r->end)
	{
		if ((size_t)(r->buf + (ptrdiff_t)r->size - r->begin) >= size)
		{
			// we can fit without cut
			memcpy(r->end, data, size);
			r->end += size - 1;
		}
		else
		{
			// make a cut
			size_t s = r->buf + r->size - r->end;
			memcpy(r->end, data, s);
			size -= s;
			memcpy(r->buf, (char*)data + s, size);
			r->end = r->buf + size - 1;
		}
	}
	else
	{
		memcpy(r->end, data, size);
		r->end += size - 1;
	}
}

void ringbuffer_pop(struct ringbuffer* r, void* data, size_t size)
{
	if (ringbuffer_data_size(r) < size)
	{
		return;
	}

	int need_clear = 0;

	if (ringbuffer_data_size(r) == size)
	{
		need_clear = 1;
	}

	if (r->begin < r->end)
	{
		if (data)
		{
			memcpy(data, r->begin, size);
		}

		r->begin += size;
	}
	else
	{
		if ((size_t)(r->buf + (ptrdiff_t)r->size - r->begin) >= size)
		{
			if (data)
			{
				memcpy(data, r->begin, size);
			}

			r->begin += size;
		}
		else
		{
			size_t s = r->buf + r->size - r->begin;

			if (data)
			{
				memcpy(data, r->begin, s);
			}

			size -= s;

			if (data)
			{
				memcpy((char*)data + s, r->buf, size);
			}

			r->begin = r->buf + size;
		}
	}

	if (need_clear)
	{
		clear_ringbuffer(r);
	}
}

void ringbuffer_read(struct ringbuffer* r, void* data, size_t size)
{
	if (ringbuffer_data_size(r) < size)
	{
		return;
	}

	if (r->begin < r->end)
	{
		memcpy(data, r->begin, size);
	}
	else
	{
		if ((size_t)(r->buf + (ptrdiff_t)r->size - r->begin) >= size)
		{
			memcpy(data, r->begin, size);
		}
		else
		{
			size_t s = r->buf + r->size - r->begin;
			memcpy(data, r->begin, s);
			size -= s;
			memcpy((char*)data + s, r->buf, size);
		}
	}
}
// memstream.c
#include <string.h>
#include <stdio.h>
#include <unistd.h>
// #include "memstream.h"

void memstream_init(struct memstream* s, int fd, void* buffer, size_t len)
{
	s->file = fd;
	s->data = buffer;
	s->pos = 0;
	s->capa = len;
}

void memstream_flush(struct memstream* s)
{
	write(s->file, s->data, s->pos);
	s->pos = 0;
}

void memstream_write(struct memstream* s, void* source, size_t len)
{
	unsigned char* data = source;

	if (s->pos + len > s->capa)
	{
		memstream_flush(s);
	}

	memcpy(s->data + s->pos, data, len);
	s->pos += len;
}

void memstream_puts(struct memstream* s, const char* str)
{
	memstream_write(s, (void*) str, strlen(str));
}
// input.c
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>

// #include "term.h"

#define BUFFER_SIZE_MAX 16

// if s1 starts with s2 returns 1, else 0
static int starts_with(const char* s1, const char* s2)
{
	// nice huh?
	while (*s2)
	{
		if (*s1++ != *s2++)
		{
			return 0;
		}
	}

	return 1;
}

static int parse_mouse_event(struct tb_event* event, const char* buf, int len)
{
	if ((len >= 6) && starts_with(buf, "\033[M"))
	{
		// X10 mouse encoding, the simplest one
		// \033 [ M Cb Cx Cy
		int b = buf[3] - 32;

		switch (b & 3)
		{
			case 0:
				if ((b & 64) != 0)
				{
					event->key = TB_KEY_MOUSE_WHEEL_UP;
				}
				else
				{
					event->key = TB_KEY_MOUSE_LEFT;
				}

				break;

			case 1:
				if ((b & 64) != 0)
				{
					event->key = TB_KEY_MOUSE_WHEEL_DOWN;
				}
				else
				{
					event->key = TB_KEY_MOUSE_MIDDLE;
				}

				break;

			case 2:
				event->key = TB_KEY_MOUSE_RIGHT;
				break;

			case 3:
				event->key = TB_KEY_MOUSE_RELEASE;
				break;

			default:
				return -6;
		}

		event->type = TB_EVENT_MOUSE; // TB_EVENT_KEY by default

		if ((b & 32) != 0)
		{
			event->mod |= TB_MOD_MOTION;
		}

		// the coord is 1,1 for upper left
		event->x = (uint8_t)buf[4] - 1 - 32;
		event->y = (uint8_t)buf[5] - 1 - 32;
		return 6;
	}
	else if (starts_with(buf, "\033[<") || starts_with(buf, "\033["))
	{
		// xterm 1006 extended mode or urxvt 1015 extended mode
		// xterm: \033 [ < Cb ; Cx ; Cy (M or m)
		// urxvt: \033 [ Cb ; Cx ; Cy M
		int i, mi = -1, starti = -1;
		int isM, isU, s1 = -1, s2 = -1;
		int n1 = 0, n2 = 0, n3 = 0;

		for (i = 0; i < len; i++)
		{
			// We search the first (s1) and the last (s2) ';'
			if (buf[i] == ';')
			{
				if (s1 == -1)
				{
					s1 = i;
				}

				s2 = i;
			}

			// We search for the first 'm' or 'M'
			if ((buf[i] == 'm' || buf[i] == 'M') && mi == -1)
			{
				mi = i;
				break;
			}
		}

		if (mi == -1)
		{
			return 0;
		}

		// whether it's a capital M or not
		isM = (buf[mi] == 'M');

		if (buf[2] == '<')
		{
			isU = 0;
			starti = 3;
		}
		else
		{
			isU = 1;
			starti = 2;
		}

		if (s1 == -1 || s2 == -1 || s1 == s2)
		{
			return 0;
		}

		n1 = strtoul(&buf[starti], NULL, 10);
		n2 = strtoul(&buf[s1 + 1], NULL, 10);
		n3 = strtoul(&buf[s2 + 1], NULL, 10);

		if (isU)
		{
			n1 -= 32;
		}

		switch (n1 & 3)
		{
			case 0:
				if ((n1 & 64) != 0)
				{
					event->key = TB_KEY_MOUSE_WHEEL_UP;
				}
				else
				{
					event->key = TB_KEY_MOUSE_LEFT;
				}

				break;

			case 1:
				if ((n1 & 64) != 0)
				{
					event->key = TB_KEY_MOUSE_WHEEL_DOWN;
				}
				else
				{
					event->key = TB_KEY_MOUSE_MIDDLE;
				}

				break;

			case 2:
				event->key = TB_KEY_MOUSE_RIGHT;
				break;

			case 3:
				event->key = TB_KEY_MOUSE_RELEASE;
				break;

			default:
				return mi + 1;
		}

		if (!isM)
		{
			// on xterm mouse release is signaled by lowercase m
			event->key = TB_KEY_MOUSE_RELEASE;
		}

		event->type = TB_EVENT_MOUSE; // TB_EVENT_KEY by default

		if ((n1 & 32) != 0)
		{
			event->mod |= TB_MOD_MOTION;
		}

		event->x = (uint8_t)n2 - 1;
		event->y = (uint8_t)n3 - 1;
		return mi + 1;
	}

	return 0;
}

// convert escape sequence to event, and return consumed bytes on success (failure == 0)
static int parse_escape_seq(struct tb_event* event, const char* buf, int len)
{
	int mouse_parsed = parse_mouse_event(event, buf, len);

	if (mouse_parsed != 0)
	{
		return mouse_parsed;
	}

	// it's pretty simple here, find 'starts_with' match and return success, else return failure
	int i;

	for (i = 0; keys[i]; i++)
	{
		if (starts_with(buf, keys[i]))
		{
			event->ch = 0;
			event->key = 0xFFFF - i;
			return strlen(keys[i]);
		}
	}

	return 0;
}

bool extract_event(struct tb_event* event, struct ringbuffer* inbuf,
	int inputmode)
{
	char buf[BUFFER_SIZE_MAX + 1];
	int nbytes = ringbuffer_data_size(inbuf);

	if (nbytes > BUFFER_SIZE_MAX)
	{
		nbytes = BUFFER_SIZE_MAX;
	}

	if (nbytes == 0)
	{
		return false;
	}

	ringbuffer_read(inbuf, buf, nbytes);
	buf[nbytes] = '\0';

	if (buf[0] == '\033')
	{
		int n = parse_escape_seq(event, buf, nbytes);

		if (n != 0)
		{
			bool success = true;

			if (n < 0)
			{
				success = false;
				n = -n;
			}

			ringbuffer_pop(inbuf, 0, n);
			return success;
		}
		else
		{
			// it's not escape sequence, then it's ALT or ESC, check inputmode
			if (inputmode & TB_INPUT_ESC)
			{
				// if we're in escape mode, fill ESC event, pop buffer, return success
				event->ch = 0;
				event->key = TB_KEY_ESC;
				event->mod = 0;
				ringbuffer_pop(inbuf, 0, 1);
				return true;
			}
			else if (inputmode & TB_INPUT_ALT)
			{
				// if we're in alt mode, set ALT modifier to event and redo parsing
				event->mod = TB_MOD_ALT;
				ringbuffer_pop(inbuf, 0, 1);
				return extract_event(event, inbuf, inputmode);
			}

			assert(!"never got here");
		}
	}

	//  if we're here, this is not an escape sequence and not an alt sequence
	//  so, it's a FUNCTIONAL KEY or a UNICODE character

	// first of all check if it's a functional key*/
	if ((unsigned char)buf[0] <= TB_KEY_SPACE ||
		(unsigned char)buf[0] == TB_KEY_BACKSPACE2)
	{
		// fill event, pop buffer, return success
		event->ch = 0;
		event->key = (uint16_t)buf[0];
		ringbuffer_pop(inbuf, 0, 1);
		return true;
	}

	// feh... we got utf8 here

	// check if there is all bytes
	if (nbytes >= utf8_char_length(buf[0]))
	{
		// everything ok, fill event, pop buffer, return success
		utf8_char_to_unicode(&event->ch, buf);
		event->key = 0;
		ringbuffer_pop(inbuf, 0, utf8_char_length(buf[0]));
		return true;
	}

	return false;
}
// termbox.c
// #include "term.h"
// #include "termbox.h"
// #include "memstream.h"

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdbool.h>
#include <sys/select.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <termios.h>
#include <unistd.h>
#include <wchar.h>

struct cellbuf
{
	int width;
	int height;
	struct tb_cell* cells;
};

#define CELL(buf, x, y) (buf)->cells[(y) * (buf)->width + (x)]
#define IS_CURSOR_HIDDEN(cx, cy) (cx == -1 || cy == -1)
#define LAST_COORD_INIT -1

static struct termios orig_tios;

static struct cellbuf back_buffer;
static struct cellbuf front_buffer;
static unsigned char write_buffer_data[32 * 1024];
static struct memstream write_buffer;

static int termw = -1;
static int termh = -1;

static int inputmode = TB_INPUT_ESC;
static int outputmode = TB_OUTPUT_NORMAL;

static struct ringbuffer inbuf;

static int out;
static FILE* in;

static int out_fileno;
static int in_fileno;

static int winch_fds[2];

static int lastx = LAST_COORD_INIT;
static int lasty = LAST_COORD_INIT;
static int cursor_x = -1;
static int cursor_y = -1;

static uint32_t background = TB_DEFAULT;
static uint32_t foreground = TB_DEFAULT;

static void write_cursor(int x, int y);
static void write_sgr(uint32_t fg, uint32_t bg);

static void cellbuf_init(struct cellbuf* buf, int width, int height);
static void cellbuf_resize(struct cellbuf* buf, int width, int height);
static void cellbuf_clear(struct cellbuf* buf);
static void cellbuf_free(struct cellbuf* buf);

static void update_size(void);
static void update_term_size(void);
static void send_attr(uint32_t fg, uint32_t bg);
static void send_char(int x, int y, uint32_t c);
static void send_clear(void);
static void sigwinch_handler(int xxx);
static int wait_fill_event(struct tb_event* event, struct timeval* timeout);

// may happen in a different thread
static volatile int buffer_size_change_request;

int tb_init_file(const char* name)
{
	out = open(name, O_WRONLY);
	in = fopen(name, "r");

	if (out == -1 || !in)
	{
		if (out != -1)
		{
			close(out);
		}

		if (in)
		{
			fclose(in);
		}

		return TB_EFAILED_TO_OPEN_TTY;
	}

	out_fileno = out;
	in_fileno = fileno(in);

	if (init_term() < 0)
	{
		close(out);
		fclose(in);

		return TB_EUNSUPPORTED_TERMINAL;
	}

	if (pipe(winch_fds) < 0)
	{
		close(out);
		fclose(in);

		return TB_EPIPE_TRAP_ERROR;
	}

	struct sigaction sa;

	memset(&sa, 0, sizeof(sa));
	sa.sa_handler = sigwinch_handler;
	sa.sa_flags = 0;
	sigaction(SIGWINCH, &sa, 0);
	tcgetattr(out_fileno, &orig_tios);

	struct termios tios;

	memcpy(&tios, &orig_tios, sizeof(tios));
	tios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
			| INLCR | IGNCR | ICRNL | IXON);
	tios.c_oflag &= ~OPOST;
	tios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
	tios.c_cflag &= ~(CSIZE | PARENB);
	tios.c_cflag |= CS8;
	tios.c_cc[VMIN] = 0;
	tios.c_cc[VTIME] = 0;
	tcsetattr(out_fileno, TCSAFLUSH, &tios);

	memstream_init(&write_buffer, out_fileno, write_buffer_data,
		sizeof(write_buffer_data));
	memstream_puts(&write_buffer, funcs[T_ENTER_CA]);
	memstream_puts(&write_buffer, funcs[T_ENTER_KEYPAD]);
	memstream_puts(&write_buffer, funcs[T_HIDE_CURSOR]);
	send_clear();

	update_term_size();
	cellbuf_init(&back_buffer, termw, termh);
	cellbuf_init(&front_buffer, termw, termh);
	cellbuf_clear(&back_buffer);
	cellbuf_clear(&front_buffer);
	init_ringbuffer(&inbuf, 4096);
	return 0;
}

int tb_init(void)
{
	return tb_init_file("/dev/tty");
}

void tb_shutdown(void)
{
	if (termw == -1)
	{
		fputs("tb_shutdown() should not be called twice.", stderr);
		abort();
	}

	memstream_puts(&write_buffer, funcs[T_SHOW_CURSOR]);
	memstream_puts(&write_buffer, funcs[T_SGR0]);
	memstream_puts(&write_buffer, funcs[T_CLEAR_SCREEN]);
	memstream_puts(&write_buffer, funcs[T_EXIT_CA]);
	memstream_puts(&write_buffer, funcs[T_EXIT_KEYPAD]);
	memstream_puts(&write_buffer, funcs[T_EXIT_MOUSE]);
	memstream_flush(&write_buffer);
	tcsetattr(out_fileno, TCSAFLUSH, &orig_tios);

	shutdown_term();
	close(out);
	fclose(in);
	close(winch_fds[0]);
	close(winch_fds[1]);

	cellbuf_free(&back_buffer);
	cellbuf_free(&front_buffer);
	free_ringbuffer(&inbuf);
	termw = termh = -1;
}

int wcwidth(wchar_t c); // ???
void tb_present(void)
{
	int x, y, w, i;
	struct tb_cell* back, *front;

	// invalidate cursor position
	lastx = LAST_COORD_INIT;
	lasty = LAST_COORD_INIT;

	if (buffer_size_change_request)
	{
		update_size();
		buffer_size_change_request = 0;
	}

	for (y = 0; y < front_buffer.height; ++y)
	{
		for (x = 0; x < front_buffer.width;)
		{
			back = &CELL(&back_buffer, x, y);
			front = &CELL(&front_buffer, x, y);
			w = wcwidth(back->ch);

			if (w < 1)
			{
				w = 1;
			}

			if (memcmp(back, front, sizeof(struct tb_cell)) == 0)
			{
				x += w;
				continue;
			}

			memcpy(front, back, sizeof(struct tb_cell));
			send_attr(back->fg, back->bg);

			if (w > 1 && x >= front_buffer.width - (w - 1))
			{
				// Not enough room for wide ch, so send spaces
				for (i = x; i < front_buffer.width; ++i)
				{
					send_char(i, y, ' ');
				}
			}
			else
			{
				send_char(x, y, back->ch);

				for (i = 1; i < w; ++i)
				{
					front = &CELL(&front_buffer, x + i, y);
					front->ch = 0;
					front->fg = back->fg;
					front->bg = back->bg;
				}
			}

			x += w;
		}
	}

	if (!IS_CURSOR_HIDDEN(cursor_x, cursor_y))
	{
		write_cursor(cursor_x, cursor_y);
	}

	memstream_flush(&write_buffer);
}

void tb_set_cursor(int cx, int cy)
{
	if (IS_CURSOR_HIDDEN(cursor_x, cursor_y) && !IS_CURSOR_HIDDEN(cx, cy))
	{
		memstream_puts(&write_buffer, funcs[T_SHOW_CURSOR]);
	}

	if (!IS_CURSOR_HIDDEN(cursor_x, cursor_y) && IS_CURSOR_HIDDEN(cx, cy))
	{
		memstream_puts(&write_buffer, funcs[T_HIDE_CURSOR]);
	}

	cursor_x = cx;
	cursor_y = cy;

	if (!IS_CURSOR_HIDDEN(cursor_x, cursor_y))
	{
		write_cursor(cursor_x, cursor_y);
	}
}

void tb_put_cell(int x, int y, const struct tb_cell* cell)
{
	if ((unsigned)x >= (unsigned)back_buffer.width)
	{
		return;
	}

	if ((unsigned)y >= (unsigned)back_buffer.height)
	{
		return;
	}

	CELL(&back_buffer, x, y) = *cell;
}

void tb_change_cell(int x, int y, uint32_t ch, uint32_t fg, uint32_t bg)
{
	struct tb_cell c = {ch, fg, bg};
	tb_put_cell(x, y, &c);
}

void tb_blit(int x, int y, int w, int h, const struct tb_cell* cells)
{
	if (x + w < 0 || x >= back_buffer.width)
	{
		return;
	}

	if (y + h < 0 || y >= back_buffer.height)
	{
		return;
	}

	int xo = 0, yo = 0, ww = w, hh = h;

	if (x < 0)
	{
		xo = -x;
		ww -= xo;
		x = 0;
	}

	if (y < 0)
	{
		yo = -y;
		hh -= yo;
		y = 0;
	}

	if (ww > back_buffer.width - x)
	{
		ww = back_buffer.width - x;
	}

	if (hh > back_buffer.height - y)
	{
		hh = back_buffer.height - y;
	}

	int sy;
	struct tb_cell* dst = &CELL(&back_buffer, x, y);
	const struct tb_cell* src = cells + yo * w + xo;
	size_t size = sizeof(struct tb_cell) * ww;

	for (sy = 0; sy < hh; ++sy)
	{
		memcpy(dst, src, size);
		dst += back_buffer.width;
		src += w;
	}
}

struct tb_cell* tb_cell_buffer(void)
{
	return back_buffer.cells;
}

int tb_poll_event(struct tb_event* event)
{
	return wait_fill_event(event, 0);
}

int tb_peek_event(struct tb_event* event, int timeout)
{
	struct timeval tv;
	tv.tv_sec = timeout / 1000;
	tv.tv_usec = (timeout - (tv.tv_sec * 1000)) * 1000;
	return wait_fill_event(event, &tv);
}

int tb_width(void)
{
	return termw;
}

int tb_height(void)
{
	return termh;
}

void tb_clear(void)
{
	if (buffer_size_change_request)
	{
		update_size();
		buffer_size_change_request = 0;
	}

	cellbuf_clear(&back_buffer);
}

int tb_select_input_mode(int mode)
{
	if (mode)
	{
		if ((mode & (TB_INPUT_ESC | TB_INPUT_ALT)) == 0)
		{
			mode |= TB_INPUT_ESC;
		}

		// technically termbox can handle that, but let's be nice
		// and show here what mode is actually used
		if ((mode & (TB_INPUT_ESC | TB_INPUT_ALT)) == (TB_INPUT_ESC | TB_INPUT_ALT))
		{
			mode &= ~TB_INPUT_ALT;
		}

		inputmode = mode;

		if (mode & TB_INPUT_MOUSE)
		{
			memstream_puts(&write_buffer, funcs[T_ENTER_MOUSE]);
			memstream_flush(&write_buffer);
		}
		else
		{
			memstream_puts(&write_buffer, funcs[T_EXIT_MOUSE]);
			memstream_flush(&write_buffer);
		}
	}

	return inputmode;
}

int tb_select_output_mode(int mode)
{
	if (mode)
	{
		outputmode = mode;
	}

	return outputmode;
}

void tb_set_clear_attributes(uint32_t fg, uint32_t bg)
{
	foreground = fg;
	background = bg;
}

static unsigned convertnum(uint32_t num, char* buf)
{
	unsigned i, l = 0;
	int ch;

	do
	{
		buf[l++] = '0' + (num % 10);
		num /= 10;
	}
	while (num);

	for (i = 0; i < l / 2; i++)
	{
		ch = buf[i];
		buf[i] = buf[l - 1 - i];
		buf[l - 1 - i] = ch;
	}

	return l;
}

#define WRITE_LITERAL(X) memstream_write(&write_buffer, (X), sizeof(X) -1)
#define WRITE_INT(X) memstream_write(&write_buffer, buf, convertnum((X), buf))

static void write_cursor(int x, int y)
{
	char buf[32];
	WRITE_LITERAL("\033[");
	WRITE_INT(y + 1);
	WRITE_LITERAL(";");
	WRITE_INT(x + 1);
	WRITE_LITERAL("H");
}

static void write_sgr(uint32_t fg, uint32_t bg)
{
	char buf[32];

	if (outputmode != TB_OUTPUT_TRUECOLOR && fg == TB_DEFAULT && bg == TB_DEFAULT)
	{
		return;
	}

	switch (outputmode)
	{
		case TB_OUTPUT_TRUECOLOR:
			WRITE_LITERAL("\033[38;2;");
			WRITE_INT(fg >> 16 & 0xFF);
			WRITE_LITERAL(";");
			WRITE_INT(fg >> 8 & 0xFF);
			WRITE_LITERAL(";");
			WRITE_INT(fg & 0xFF);
			WRITE_LITERAL(";48;2;");
			WRITE_INT(bg >> 16 & 0xFF);
			WRITE_LITERAL(";");
			WRITE_INT(bg >> 8 & 0xFF);
			WRITE_LITERAL(";");
			WRITE_INT(bg & 0xFF);
			WRITE_LITERAL("m");
			break;

		case TB_OUTPUT_256:
		case TB_OUTPUT_216:
		case TB_OUTPUT_GRAYSCALE:
			WRITE_LITERAL("\033[");

			if (fg != TB_DEFAULT)
			{
				WRITE_LITERAL("38;5;");
				WRITE_INT(fg);

				if (bg != TB_DEFAULT)
				{
					WRITE_LITERAL(";");
				}
			}

			if (bg != TB_DEFAULT)
			{
				WRITE_LITERAL("48;5;");
				WRITE_INT(bg);
			}

			WRITE_LITERAL("m");
			break;

		case TB_OUTPUT_NORMAL:
		default:
			WRITE_LITERAL("\033[");

			if (fg != TB_DEFAULT)
			{
				WRITE_LITERAL("3");
				WRITE_INT(fg - 1);

				if (bg != TB_DEFAULT)
				{
					WRITE_LITERAL(";");
				}
			}

			if (bg != TB_DEFAULT)
			{
				WRITE_LITERAL("4");
				WRITE_INT(bg - 1);
			}

			WRITE_LITERAL("m");
			break;
	}
}

static void cellbuf_init(struct cellbuf* buf, int width, int height)
{
	buf->cells = (struct tb_cell*)malloc(sizeof(struct tb_cell) * width * height);
	assert(buf->cells);
	buf->width = width;
	buf->height = height;
}

static void cellbuf_resize(struct cellbuf* buf, int width, int height)
{
	if (buf->width == width && buf->height == height)
	{
		return;
	}

	int oldw = buf->width;
	int oldh = buf->height;
	struct tb_cell* oldcells = buf->cells;

	cellbuf_init(buf, width, height);
	cellbuf_clear(buf);

	int minw = (width < oldw) ? width : oldw;
	int minh = (height < oldh) ? height : oldh;
	int i;

	for (i = 0; i < minh; ++i)
	{
		struct tb_cell* csrc = oldcells + (i * oldw);
		struct tb_cell* cdst = buf->cells + (i * width);
		memcpy(cdst, csrc, sizeof(struct tb_cell) * minw);
	}

	free(oldcells);
}

static void cellbuf_clear(struct cellbuf* buf)
{
	int i;
	int ncells = buf->width * buf->height;

	for (i = 0; i < ncells; ++i)
	{
		buf->cells[i].ch = ' ';
		buf->cells[i].fg = foreground;
		buf->cells[i].bg = background;
	}
}

static void cellbuf_free(struct cellbuf* buf)
{
	free(buf->cells);
}

static void get_term_size(int* w, int* h)
{
	struct winsize sz;
	memset(&sz, 0, sizeof(sz));

	ioctl(out_fileno, TIOCGWINSZ, &sz);

	if (w)
	{
		*w = sz.ws_col;
	}

	if (h)
	{
		*h = sz.ws_row;
	}
}

static void update_term_size(void)
{
	struct winsize sz;
	memset(&sz, 0, sizeof(sz));

	ioctl(out_fileno, TIOCGWINSZ, &sz);

	termw = sz.ws_col;
	termh = sz.ws_row;
}

static void send_attr(uint32_t fg, uint32_t bg)
{
#define LAST_ATTR_INIT 0xFFFFFFFF
	static uint32_t lastfg = LAST_ATTR_INIT, lastbg = LAST_ATTR_INIT;

	if (fg != lastfg || bg != lastbg)
	{
		memstream_puts(&write_buffer, funcs[T_SGR0]);
		uint32_t fgcol;
		uint32_t bgcol;

		switch (outputmode)
		{
			case TB_OUTPUT_TRUECOLOR:
				fgcol = fg;
				bgcol = bg;
				break;

			case TB_OUTPUT_256:
				fgcol = fg & 0xFF;
				bgcol = bg & 0xFF;
				break;

			case TB_OUTPUT_216:
				fgcol = fg & 0xFF;

				if (fgcol > 215)
				{
					fgcol = 7;
				}

				bgcol = bg & 0xFF;

				if (bgcol > 215)
				{
					bgcol = 0;
				}

				fgcol += 0x10;
				bgcol += 0x10;
				break;

			case TB_OUTPUT_GRAYSCALE:
				fgcol = fg & 0xFF;

				if (fgcol > 23)
				{
					fgcol = 23;
				}

				bgcol = bg & 0xFF;

				if (bgcol > 23)
				{
					bgcol = 0;
				}

				fgcol += 0xe8;
				bgcol += 0xe8;
				break;

			case TB_OUTPUT_NORMAL:
			default:
				fgcol = fg & 0x0F;
				bgcol = bg & 0x0F;
		}

		if (fg & TB_BOLD)
		{
			memstream_puts(&write_buffer, funcs[T_BOLD]);
		}

		if (bg & TB_BOLD)
		{
			memstream_puts(&write_buffer, funcs[T_BLINK]);
		}

		if (fg & TB_UNDERLINE)
		{
			memstream_puts(&write_buffer, funcs[T_UNDERLINE]);
		}

		if ((fg & TB_REVERSE) || (bg & TB_REVERSE))
		{
			memstream_puts(&write_buffer, funcs[T_REVERSE]);
		}

		write_sgr(fgcol, bgcol);

		lastfg = fg;
		lastbg = bg;
	}
}

static void send_char(int x, int y, uint32_t c)
{
	char buf[7];
	int bw = utf8_unicode_to_char(buf, c);
	buf[bw] = '\0';

	if (x - 1 != lastx || y != lasty)
	{
		write_cursor(x, y);
	}

	lastx = x;
	lasty = y;

	if (!c)
	{
		buf[0] = ' '; // replace 0 with whitespace
	}

	memstream_puts(&write_buffer, buf);
}

static void send_clear(void)
{
	send_attr(foreground, background);
	memstream_puts(&write_buffer, funcs[T_CLEAR_SCREEN]);

	if (!IS_CURSOR_HIDDEN(cursor_x, cursor_y))
	{
		write_cursor(cursor_x, cursor_y);
	}

	memstream_flush(&write_buffer);

	// we need to invalidate cursor position too and these two vars are
	// used only for simple cursor positioning optimization, cursor
	// actually may be in the correct place, but we simply discard
	// optimization once and it gives us simple solution for the case when
	// cursor moved
	lastx = LAST_COORD_INIT;
	lasty = LAST_COORD_INIT;
}

static void sigwinch_handler(int xxx)
{
	(void) xxx;
	const int zzz = 1;
	write(winch_fds[1], &zzz, sizeof(int));
}

static void update_size(void)
{
	update_term_size();
	cellbuf_resize(&back_buffer, termw, termh);
	cellbuf_resize(&front_buffer, termw, termh);
	cellbuf_clear(&front_buffer);
	send_clear();
}

static int wait_fill_event(struct tb_event* event, struct timeval* timeout)
{
#define ENOUGH_DATA_FOR_INPUT_PARSING 128
	int result;
	char buf[ENOUGH_DATA_FOR_INPUT_PARSING];
	fd_set events;
	memset(event, 0, sizeof(struct tb_event));

	// try to extract event from input buffer, return on success
	event->type = TB_EVENT_KEY;

	if (extract_event(event, &inbuf, inputmode))
	{
		return event->type;
	}

	// it looks like input buffer is incomplete, let's try the short path
	size_t r = fread(buf, 1, ENOUGH_DATA_FOR_INPUT_PARSING, in);

	if (r < ENOUGH_DATA_FOR_INPUT_PARSING && feof(in))
	{
		clearerr(in);
	}

	if (r > 0)
	{
		if (ringbuffer_free_space(&inbuf) < r)
		{
			return -1;
		}

		ringbuffer_push(&inbuf, buf, r);

		if (extract_event(event, &inbuf, inputmode))
		{
			return event->type;
		}
	}

	// no stuff in FILE's internal buffer, block in select
	while (1)
	{
		FD_ZERO(&events);
		FD_SET(in_fileno, &events);
		FD_SET(winch_fds[0], &events);
		int maxfd = (winch_fds[0] > in_fileno) ? winch_fds[0] : in_fileno;
		result = select(maxfd + 1, &events, 0, 0, timeout);

		if (!result)
		{
			return 0;
		}

		if (FD_ISSET(in_fileno, &events))
		{
			event->type = TB_EVENT_KEY;
			size_t r = fread(buf, 1, ENOUGH_DATA_FOR_INPUT_PARSING, in);

			if (r < ENOUGH_DATA_FOR_INPUT_PARSING && feof(in))
			{
				clearerr(in);
			}

			if (r == 0)
			{
				continue;
			}

			// if there is no free space in input buffer, return error
			if (ringbuffer_free_space(&inbuf) < r)
			{
				return -1;
			}

			// fill buffer
			ringbuffer_push(&inbuf, buf, r);

			if (extract_event(event, &inbuf, inputmode))
			{
				return event->type;
			}
		}

		if (FD_ISSET(winch_fds[0], &events))
		{
			event->type = TB_EVENT_RESIZE;
			int zzz = 0;
			read(winch_fds[0], &zzz, sizeof(int));
			buffer_size_change_request = 1;
			get_term_size(&event->w, &event->h);
			return TB_EVENT_RESIZE;
		}
	}
}

void tb_print(int x, int y, uint32_t fg, uint32_t bg, const char* str)
{
	while (*str)
	{
		uint32_t uni;
		str += utf8_char_to_unicode(&uni, str);
		tb_change_cell(x, y, uni, fg, bg);
		x++;
	}
}

#include <stdarg.h>
void tb_printf(int x, int y, uint32_t fg, uint32_t bg, const char* fmt, ...)
{
	char buf[4096];
	va_list vl;
	va_start(vl, fmt);
	vsnprintf(buf, sizeof(buf), fmt, vl);
	va_end(vl);
	tb_print(x, y, fg, bg, buf);
}

void tb_pixel(int x, int y, uint32_t col)
{
	struct tb_cell* buf = tb_cell_buffer();
	
//	if ((unsigned)x >= (unsigned)back_buffer.width) return;
//	if ((unsigned)y >= (unsigned)back_buffer.height) return;

	buf += (y>>1) * back_buffer.width +x;
	buf->ch = 0x2580;//'▀'; // Unicode Character “▀” (U+2580)
	if (y&1) buf->bg = col;
	else buf->fg = col;
}