text: /* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to
   * deal in the Software without restriction, including without limitation the
   * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   * sell copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
   * IN THE SOFTWARE.
   */
  
  #include <assert.h>
  #include <io.h>
  #include <string.h>
  #include <stdlib.h>
  
  #if defined(_MSC_VER) && _MSC_VER < 1600
  # include "stdint-msvc2008.h"
  #else
  # include <stdint.h>
  #endif
  
  #ifndef COMMON_LVB_REVERSE_VIDEO
  # define COMMON_LVB_REVERSE_VIDEO 0x4000
  #endif
  
  #include "uv.h"
  #include "internal.h"
  #include "handle-inl.h"
  #include "stream-inl.h"
  #include "req-inl.h"
  
  #ifndef InterlockedOr
  # define InterlockedOr _InterlockedOr
  #endif
  
  #define UNICODE_REPLACEMENT_CHARACTER (0xfffd)
  
  #define ANSI_NORMAL           0x00
  #define ANSI_ESCAPE_SEEN      0x02
  #define ANSI_CSI              0x04
  #define ANSI_ST_CONTROL       0x08
  #define ANSI_IGNORE           0x10
  #define ANSI_IN_ARG           0x20
  #define ANSI_IN_STRING        0x40
  #define ANSI_BACKSLASH_SEEN   0x80
  
  #define MAX_INPUT_BUFFER_LENGTH 8192
  #define MAX_CONSOLE_CHAR 8192
  
  #ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
  #define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
  #endif
  
  static void uv_tty_capture_initial_style(CONSOLE_SCREEN_BUFFER_INFO* info);
  static void uv_tty_update_virtual_window(CONSOLE_SCREEN_BUFFER_INFO* info);
  static int uv__cancel_read_console(uv_tty_t* handle);
  
  
  /* Null uv_buf_t */
  static const uv_buf_t uv_null_buf_ = { 0, NULL };
  
  enum uv__read_console_status_e {
    NOT_STARTED,
    IN_PROGRESS,
    TRAP_REQUESTED,
    COMPLETED
  };
  
  static volatile LONG uv__read_console_status = NOT_STARTED;
  static volatile LONG uv__restore_screen_state;
  static CONSOLE_SCREEN_BUFFER_INFO uv__saved_screen_state;
  
  
  /*
   * The console virtual window.
   *
   * Normally cursor movement in windows is relative to the console screen buffer,
   * e.g. the application is allowed to overwrite the 'history'. This is very
   * inconvenient, it makes absolute cursor movement pretty useless. There is
   * also the concept of 'client rect' which is defined by the actual size of
   * the console window and the scroll position of the screen buffer, but it's
   * very volatile because it changes when the user scrolls.
   *
   * To make cursor movement behave sensibly we define a virtual window to which
   * cursor movement is confined. The virtual window is always as wide as the
   * console screen buffer, but it's height is defined by the size of the
   * console window. The top of the virtual window aligns with the position
   * of the caret when the first stdout/err handle is created, unless that would
   * mean that it would extend beyond the bottom of the screen buffer -  in that
   * that case it's located as far down as possible.
   *
   * When the user writes a long text or many newlines, such that the output
   * reaches beyond the bottom of the virtual window, the virtual window is
   * shifted downwards, but not resized.
   *
   * Since all tty i/o happens on the same console, this window is shared
   * between all stdout/stderr handles.
   */
  
  static int uv_tty_virtual_offset = -1;
  static int uv_tty_virtual_height = -1;
  static int uv_tty_virtual_width = -1;
  
  /* We use a semaphore rather than a mutex or critical section because in some
     cases (uv__cancel_read_console) we need take the lock in the main thread and
     release it in another thread. Using a semaphore ensures that in such
     scenario the main thread will still block when trying to acquire the lock. */
  static uv_sem_t uv_tty_output_lock;
  
  static HANDLE uv_tty_output_handle = INVALID_HANDLE_VALUE;
  
  static WORD uv_tty_default_text_attributes =
      FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE;
  
  static char uv_tty_default_fg_color = 7;
  static char uv_tty_default_bg_color = 0;
  static char uv_tty_default_fg_bright = 0;
  static char uv_tty_default_bg_bright = 0;
  static char uv_tty_default_inverse = 0;
  
  typedef enum {
    UV_SUPPORTED,
    UV_UNCHECKED,
    UV_UNSUPPORTED
  } uv_vtermstate_t;
  /* Determine whether or not ANSI support is enabled. */
  static uv_vtermstate_t uv__vterm_state = UV_UNCHECKED;
  static void uv__determine_vterm_state(HANDLE handle);
  
  void uv_console_init() {
    if (uv_sem_init(&uv_tty_output_lock, 1))
      abort();
  }
  
  
  int uv_tty_init(uv_loop_t* loop, uv_tty_t* tty, uv_file fd, int readable) {
    HANDLE handle;
    CONSOLE_SCREEN_BUFFER_INFO screen_buffer_info;
  
    handle = (HANDLE) uv__get_osfhandle(fd);
    if (handle == INVALID_HANDLE_VALUE)
      return UV_EBADF;
  
    if (fd <= 2) {
      /* In order to avoid closing a stdio file descriptor 0-2, duplicate the
       * underlying OS handle and forget about the original fd.
       * We could also opt to use the original OS handle and just never close it,
       * but then there would be no reliable way to cancel pending read operations
       * upon close.
       */
      if (!DuplicateHandle(INVALID_HANDLE_VALUE,
                           handle,
                           INVALID_HANDLE_VALUE,
                           &handle,
                           0,
                           FALSE,
                           DUPLICATE_SAME_ACCESS))
        return uv_translate_sys_error(GetLastError());
      fd = -1;
    }
  
    if (!readable) {
      /* Obtain the screen buffer info with the output handle. */
      if (!GetConsoleScreenBufferInfo(handle, &screen_buffer_info)) {
        return uv_translate_sys_error(GetLastError());
      }
  
      /* Obtain the the tty_output_lock because the virtual window state is */
      /* shared between all uv_tty_t handles. */
      uv_sem_wait(&uv_tty_output_lock);
  
      if (uv__vterm_state == UV_UNCHECKED)
        uv__determine_vterm_state(handle);
  
      /* Store the global tty output handle. This handle is used by TTY read */
      /* streams to update the virtual window when a CONSOLE_BUFFER_SIZE_EVENT */
      /* is received. */
      uv_tty_output_handle = handle;
  
      /* Remember the original console text attributes. */
      uv_tty_capture_initial_style(&screen_buffer_info);
  
      uv_tty_update_virtual_window(&screen_buffer_info);
  
      uv_sem_post(&uv_tty_output_lock);
    }
  
  
    uv_stream_init(loop, (uv_stream_t*) tty, UV_TTY);
    uv_connection_init((uv_stream_t*) tty);
  
    tty->handle = handle;
    tty->u.fd = fd;
    tty->reqs_pending = 0;
    tty->flags |= UV_HANDLE_BOUND;
  
    if (readable) {
      /* Initialize TTY input specific fields. */
      tty->flags |= UV_HANDLE_TTY_READABLE | UV_HANDLE_READABLE;
      /* TODO: remove me in v2.x. */
      tty->tty.rd.unused_ = NULL;
      tty->tty.rd.read_line_buffer = uv_null_buf_;
      tty->tty.rd.read_raw_wait = NULL;
  
      /* Init keycode-to-vt100 mapper state. */
      tty->tty.rd.last_key_len = 0;
      tty->tty.rd.last_key_offset = 0;
      tty->tty.rd.last_utf16_high_surrogate = 0;
      memset(&tty->tty.rd.last_input_record, 0, sizeof tty->tty.rd.last_input_record);
    } else {
      /* TTY output specific fields. */
      tty->flags |= UV_HANDLE_WRITABLE;
  
      /* Init utf8-to-utf16 conversion state. */
      tty->tty.wr.utf8_bytes_left = 0;
      tty->tty.wr.utf8_codepoint = 0;
  
      /* Initialize eol conversion state */
      tty->tty.wr.previous_eol = 0;
  
      /* Init ANSI parser state. */
      tty->tty.wr.ansi_parser_state = ANSI_NORMAL;
    }
  
    return 0;
  }
  
  
  /* Set the default console text attributes based on how the console was
   * configured when libuv started.
   */
  static void uv_tty_capture_initial_style(CONSOLE_SCREEN_BUFFER_INFO* info) {
    static int style_captured = 0;
  
    /* Only do this once.
       Assumption: Caller has acquired uv_tty_output_lock. */
    if (style_captured)
      return;
  
    /* Save raw win32 attributes. */
    uv_tty_default_text_attributes = info->wAttributes;
  
    /* Convert black text on black background to use white text. */
    if (uv_tty_default_text_attributes == 0)
      uv_tty_default_text_attributes = 7;
  
    /* Convert Win32 attributes to ANSI colors. */
    uv_tty_default_fg_color = 0;
    uv_tty_default_bg_color = 0;
    uv_tty_default_fg_bright = 0;
    uv_tty_default_bg_bright = 0;
    uv_tty_default_inverse = 0;
  
    if (uv_tty_default_text_attributes & FOREGROUND_RED)
      uv_tty_default_fg_color |= 1;
  
    if (uv_tty_default_text_attributes & FOREGROUND_GREEN)
      uv_tty_default_fg_color |= 2;
  
    if (uv_tty_default_text_attributes & FOREGROUND_BLUE)
      uv_tty_default_fg_color |= 4;
  
    if (uv_tty_default_text_attributes & BACKGROUND_RED)
      uv_tty_default_bg_color |= 1;
  
    if (uv_tty_default_text_attributes & BACKGROUND_GREEN)
      uv_tty_default_bg_color |= 2;
  
    if (uv_tty_default_text_attributes & BACKGROUND_BLUE)
      uv_tty_default_bg_color |= 4;
  
    if (uv_tty_default_text_attributes & FOREGROUND_INTENSITY)
      uv_tty_default_fg_bright = 1;
  
    if (uv_tty_default_text_attributes & BACKGROUND_INTENSITY)
      uv_tty_default_bg_bright = 1;
  
    if (uv_tty_default_text_attributes & COMMON_LVB_REVERSE_VIDEO)
      uv_tty_default_inverse = 1;
  
    style_captured = 1;
  }
  
  
  int uv_tty_set_mode(uv_tty_t* tty, uv_tty_mode_t mode) {
    DWORD flags;
    unsigned char was_reading;
    uv_alloc_cb alloc_cb;
    uv_read_cb read_cb;
    int err;
  
    if (!(tty->flags & UV_HANDLE_TTY_READABLE)) {
      return UV_EINVAL;
    }
  
    if (!!mode == !!(tty->flags & UV_HANDLE_TTY_RAW)) {
      return 0;
    }
  
    switch (mode) {
      case UV_TTY_MODE_NORMAL:
        flags = ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT;
        break;
      case UV_TTY_MODE_RAW:
        flags = ENABLE_WINDOW_INPUT;
        break;
      case UV_TTY_MODE_IO:
        return UV_ENOTSUP;
      default:
        return UV_EINVAL;
    }
  
    /* If currently reading, stop, and restart reading. */
    if (tty->flags & UV_HANDLE_READING) {
      was_reading = 1;
      alloc_cb = tty->alloc_cb;
      read_cb = tty->read_cb;
      err = uv_tty_read_stop(tty);
      if (err) {
        return uv_translate_sys_error(err);
      }
    } else {
      was_reading = 0;
    }
  
    uv_sem_wait(&uv_tty_output_lock);
    if (!SetConsoleMode(tty->handle, flags)) {
      err = uv_translate_sys_error(GetLastError());
      uv_sem_post(&uv_tty_output_lock);
      return err;
    }
    uv_sem_post(&uv_tty_output_lock);
  
    /* Update flag. */
    tty->flags &= ~UV_HANDLE_TTY_RAW;
    tty->flags |= mode ? UV_HANDLE_TTY_RAW : 0;
  
    /* If we just stopped reading, restart. */
    if (was_reading) {
      err = uv_tty_read_start(tty, alloc_cb, read_cb);
      if (err) {
        return uv_translate_sys_error(err);
      }
    }
  
    return 0;
  }
  
  
  int uv_is_tty(uv_file file) {
    DWORD result;
    return GetConsoleMode((HANDLE) _get_osfhandle(file), &result) != 0;
  }
  
  
  int uv_tty_get_winsize(uv_tty_t* tty, int* width, int* height) {
    CONSOLE_SCREEN_BUFFER_INFO info;
  
    if (!GetConsoleScreenBufferInfo(tty->handle, &info)) {
      return uv_translate_sys_error(GetLastError());
    }
  
    uv_sem_wait(&uv_tty_output_lock);
    uv_tty_update_virtual_window(&info);
    uv_sem_post(&uv_tty_output_lock);
  
    *width = uv_tty_virtual_width;
    *height = uv_tty_virtual_height;
  
    return 0;
  }
  
  
  static void CALLBACK uv_tty_post_raw_read(void* data, BOOLEAN didTimeout) {
    uv_loop_t* loop;
    uv_tty_t* handle;
    uv_req_t* req;
  
    assert(data);
    assert(!didTimeout);
  
    req = (uv_req_t*) data;
    handle = (uv_tty_t*) req->data;
    loop = handle->loop;
  
    UnregisterWait(handle->tty.rd.read_raw_wait);
    handle->tty.rd.read_raw_wait = NULL;
  
    SET_REQ_SUCCESS(req);
    POST_COMPLETION_FOR_REQ(loop, req);
  }
  
  
  static void uv_tty_queue_read_raw(uv_loop_t* loop, uv_tty_t* handle) {
    uv_read_t* req;
    BOOL r;
  
    assert(handle->flags & UV_HANDLE_READING);
    assert(!(handle->flags & UV_HANDLE_READ_PENDING));
  
    assert(handle->handle && handle->handle != INVALID_HANDLE_VALUE);
  
    handle->tty.rd.read_line_buffer = uv_null_buf_;
  
    req = &handle->read_req;
    memset(&req->u.io.overlapped, 0, sizeof(req->u.io.overlapped));
  
    r = RegisterWaitForSingleObject(&handle->tty.rd.read_raw_wait,
                                    handle->handle,
                                    uv_tty_post_raw_read,
                                    (void*) req,
                                    INFINITE,
                                    WT_EXECUTEINWAITTHREAD | WT_EXECUTEONLYONCE);
    if (!r) {
      handle->tty.rd.read_raw_wait = NULL;
      SET_REQ_ERROR(req, GetLastError());
      uv_insert_pending_req(loop, (uv_req_t*)req);
    }
  
    handle->flags |= UV_HANDLE_READ_PENDING;
    handle->reqs_pending++;
  }
  
  
  static DWORD CALLBACK uv_tty_line_read_thread(void* data) {
    uv_loop_t* loop;
    uv_tty_t* handle;
    uv_req_t* req;
    DWORD bytes, read_bytes;
    WCHAR utf16[MAX_INPUT_BUFFER_LENGTH / 3];
    DWORD chars, read_chars;
    LONG status;
    COORD pos;
    BOOL read_console_success;
  
    assert(data);
  
    req = (uv_req_t*) data;
    handle = (uv_tty_t*) req->data;
    loop = handle->loop;
  
    assert(handle->tty.rd.read_line_buffer.base != NULL);
    assert(handle->tty.rd.read_line_buffer.len > 0);
  
    /* ReadConsole can't handle big buffers. */
    if (handle->tty.rd.read_line_buffer.len < MAX_INPUT_BUFFER_LENGTH) {
      bytes = handle->tty.rd.read_line_buffer.len;
    } else {
      bytes = MAX_INPUT_BUFFER_LENGTH;
    }
  
    /* At last, unicode! */
    /* One utf-16 codeunit never takes more than 3 utf-8 codeunits to encode */
    chars = bytes / 3;
  
    status = InterlockedExchange(&uv__read_console_status, IN_PROGRESS);
    if (status == TRAP_REQUESTED) {
      SET_REQ_SUCCESS(req);
      req->u.io.overlapped.InternalHigh = 0;
      POST_COMPLETION_FOR_REQ(loop, req);
      return 0;
    }
  
    read_console_success = ReadConsoleW(handle->handle,
                                        (void*) utf16,
                                        chars,
                                        &read_chars,
                                        NULL);
  
    if (read_console_success) {
      read_bytes = WideCharToMultiByte(CP_UTF8,
                                       0,
                                       utf16,
                                       read_chars,
                                       handle->tty.rd.read_line_buffer.base,
                                       bytes,
                                       NULL,
                                       NULL);
      SET_REQ_SUCCESS(req);
      req->u.io.overlapped.InternalHigh = read_bytes;
    } else {
      SET_REQ_ERROR(req, GetLastError());
    }
  
    status = InterlockedExchange(&uv__read_console_status, COMPLETED);
  
    if (status ==  TRAP_REQUESTED) {
      /* If we canceled the read by sending a VK_RETURN event, restore the
         screen state to undo the visual effect of the VK_RETURN */
      if (read_console_success && InterlockedOr(&uv__restore_screen_state, 0)) {
        HANDLE active_screen_buffer;
        active_screen_buffer = CreateFileA("conout$",
                                           GENERIC_READ | GENERIC_WRITE,
                                           FILE_SHARE_READ | FILE_SHARE_WRITE,
                                           NULL,
                                           OPEN_EXISTING,
                                           FILE_ATTRIBUTE_NORMAL,
                                           NULL);
        if (active_screen_buffer != INVALID_HANDLE_VALUE) {
          pos = uv__saved_screen_state.dwCursorPosition;
  
          /* If the cursor was at the bottom line of the screen buffer, the
             VK_RETURN would have caused the buffer contents to scroll up by one
             line. The right position to reset the cursor to is therefore one line
             higher */
          if (pos.Y == uv__saved_screen_state.dwSize.Y - 1)
            pos.Y--;
  
          SetConsoleCursorPosition(active_screen_buffer, pos);
          CloseHandle(active_screen_buffer);
        }
      }
      uv_sem_post(&uv_tty_output_lock);
    }
    POST_COMPLETION_FOR_REQ(loop, req);
    return 0;
  }
  
  
  static void uv_tty_queue_read_line(uv_loop_t* loop, uv_tty_t* handle) {
    uv_read_t* req;
    BOOL r;
  
    assert(handle->flags & UV_HANDLE_READING);
    assert(!(handle->flags & UV_HANDLE_READ_PENDING));
    assert(handle->handle && handle->handle != INVALID_HANDLE_VALUE);
  
    req = &handle->read_req;
    memset(&req->u.io.overlapped, 0, sizeof(req->u.io.overlapped));
  
    handle->tty.rd.read_line_buffer = uv_buf_init(NULL, 0);
    handle->alloc_cb((uv_handle_t*) handle, 8192, &handle->tty.rd.read_line_buffer);
    if (handle->tty.rd.read_line_buffer.base == NULL ||
        handle->tty.rd.read_line_buffer.len == 0) {
      handle->read_cb((uv_stream_t*) handle,
                      UV_ENOBUFS,
                      &handle->tty.rd.read_line_buffer);
      return;
    }
    assert(handle->tty.rd.read_line_buffer.base != NULL);
  
    /* Reset flags  No locking is required since there cannot be a line read
       in progress. We are also relying on the memory barrier provided by
       QueueUserWorkItem*/
    uv__restore_screen_state = FALSE;
    uv__read_console_status = NOT_STARTED;
    r = QueueUserWorkItem(uv_tty_line_read_thread,
                          (void*) req,
                          WT_EXECUTELONGFUNCTION);
    if (!r) {
      SET_REQ_ERROR(req, GetLastError());
      uv_insert_pending_req(loop, (uv_req_t*)req);
    }
  
    handle->flags |= UV_HANDLE_READ_PENDING;
    handle->reqs_pending++;
  }
  
  
  static void uv_tty_queue_read(uv_loop_t* loop, uv_tty_t* handle) {
    if (handle->flags & UV_HANDLE_TTY_RAW) {
      uv_tty_queue_read_raw(loop, handle);
    } else {
      uv_tty_queue_read_line(loop, handle);
    }
  }
  
  
  static const char* get_vt100_fn_key(DWORD code, char shift, char ctrl,
      size_t* len) {
  #define VK_CASE(vk, normal_str, shift_str, ctrl_str, shift_ctrl_str)          \
      case (vk):                                                                \
        if (shift && ctrl) {                                                    \
          *len = sizeof shift_ctrl_str;                                         \
          return "\033" shift_ctrl_str;                                         \
        } else if (shift) {                                                     \
          *len = sizeof shift_str ;                                             \
          return "\033" shift_str;                                              \
        } else if (ctrl) {                                                      \
          *len = sizeof ctrl_str;                                               \
          return "\033" ctrl_str;                                               \
        } else {                                                                \
          *len = sizeof normal_str;                                             \
          return "\033" normal_str;                                             \
        }
  
    switch (code) {
      /* These mappings are the same as Cygwin's. Unmodified and alt-modified */
      /* keypad keys comply with linux console, modifiers comply with xterm */
      /* modifier usage. F1..f12 and shift-f1..f10 comply with linux console, */
      /* f6..f12 with and without modifiers comply with rxvt. */
      VK_CASE(VK_INSERT,  "[2~",  "[2;2~", "[2;5~", "[2;6~")
      VK_CASE(VK_END,     "[4~",  "[4;2~", "[4;5~", "[4;6~")
      VK_CASE(VK_DOWN,    "[B",   "[1;2B", "[1;5B", "[1;6B")
      VK_CASE(VK_NEXT,    "[6~",  "[6;2~", "[6;5~", "[6;6~")
      VK_CASE(VK_LEFT,    "[D",   "[1;2D", "[1;5D", "[1;6D")
      VK_CASE(VK_CLEAR,   "[G",   "[1;2G", "[1;5G", "[1;6G")
      VK_CASE(VK_RIGHT,   "[C",   "[1;2C", "[1;5C", "[1;6C")
      VK_CASE(VK_UP,      "[A",   "[1;2A", "[1;5A", "[1;6A")
      VK_CASE(VK_HOME,    "[1~",  "[1;2~", "[1;5~", "[1;6~")
      VK_CASE(VK_PRIOR,   "[5~",  "[5;2~", "[5;5~", "[5;6~")
      VK_CASE(VK_DELETE,  "[3~",  "[3;2~", "[3;5~", "[3;6~")
      VK_CASE(VK_NUMPAD0, "[2~",  "[2;2~", "[2;5~", "[2;6~")
      VK_CASE(VK_NUMPAD1, "[4~",  "[4;2~", "[4;5~", "[4;6~")
      VK_CASE(VK_NUMPAD2, "[B",   "[1;2B", "[1;5B", "[1;6B")
      VK_CASE(VK_NUMPAD3, "[6~",  "[6;2~", "[6;5~", "[6;6~")
      VK_CASE(VK_NUMPAD4, "[D",   "[1;2D", "[1;5D", "[1;6D")
      VK_CASE(VK_NUMPAD5, "[G",   "[1;2G", "[1;5G", "[1;6G")
      VK_CASE(VK_NUMPAD6, "[C",   "[1;2C", "[1;5C", "[1;6C")
      VK_CASE(VK_NUMPAD7, "[A",   "[1;2A", "[1;5A", "[1;6A")
      VK_CASE(VK_NUMPAD8, "[1~",  "[1;2~", "[1;5~", "[1;6~")
      VK_CASE(VK_NUMPAD9, "[5~",  "[5;2~", "[5;5~", "[5;6~")
      VK_CASE(VK_DECIMAL, "[3~",  "[3;2~", "[3;5~", "[3;6~")
      VK_CASE(VK_F1,      "[[A",  "[23~",  "[11^",  "[23^" )
      VK_CASE(VK_F2,      "[[B",  "[24~",  "[12^",  "[24^" )
      VK_CASE(VK_F3,      "[[C",  "[25~",  "[13^",  "[25^" )
      VK_CASE(VK_F4,      "[[D",  "[26~",  "[14^",  "[26^" )
      VK_CASE(VK_F5,      "[[E",  "[28~",  "[15^",  "[28^" )
      VK_CASE(VK_F6,      "[17~", "[29~",  "[17^",  "[29^" )
      VK_CASE(VK_F7,      "[18~", "[31~",  "[18^",  "[31^" )
      VK_CASE(VK_F8,      "[19~", "[32~",  "[19^",  "[32^" )
      VK_CASE(VK_F9,      "[20~", "[33~",  "[20^",  "[33^" )
      VK_CASE(VK_F10,     "[21~", "[34~",  "[21^",  "[34^" )
      VK_CASE(VK_F11,     "[23~", "[23$",  "[23^",  "[23@" )
      VK_CASE(VK_F12,     "[24~", "[24$",  "[24^",  "[24@" )
  
      default:
        *len = 0;
        return NULL;
    }
  #undef VK_CASE
  }
  
  
  void uv_process_tty_read_raw_req(uv_loop_t* loop, uv_tty_t* handle,
      uv_req_t* req) {
    /* Shortcut for handle->tty.rd.last_input_record.Event.KeyEvent. */
  #define KEV handle->tty.rd.last_input_record.Event.KeyEvent
  
    DWORD records_left, records_read;
    uv_buf_t buf;
    off_t buf_used;
  
    assert(handle->type == UV_TTY);
    assert(handle->flags & UV_HANDLE_TTY_READABLE);
    handle->flags &= ~UV_HANDLE_READ_PENDING;
  
    if (!(handle->flags & UV_HANDLE_READING) ||
        !(handle->flags & UV_HANDLE_TTY_RAW)) {
      goto out;
    }
  
    if (!REQ_SUCCESS(req)) {
      /* An error occurred while waiting for the event. */
      if ((handle->flags & UV_HANDLE_READING)) {
        handle->flags &= ~UV_HANDLE_READING;
        handle->read_cb((uv_stream_t*)handle,
                        uv_translate_sys_error(GET_REQ_ERROR(req)),
                        &uv_null_buf_);
      }
      goto out;
    }
  
    /* Fetch the number of events  */
    if (!GetNumberOfConsoleInputEvents(handle->handle, &records_left)) {
      handle->flags &= ~UV_HANDLE_READING;
      DECREASE_ACTIVE_COUNT(loop, handle);
      handle->read_cb((uv_stream_t*)handle,
                      uv_translate_sys_error(GetLastError()),
                      &uv_null_buf_);
      goto out;
    }
  
    /* Windows sends a lot of events that we're not interested in, so buf */
    /* will be allocated on demand, when there's actually something to emit. */
    buf = uv_null_buf_;
    buf_used = 0;
  
    while ((records_left > 0 || handle->tty.rd.last_key_len > 0) &&
           (handle->flags & UV_HANDLE_READING)) {
      if (handle->tty.rd.last_key_len == 0) {
        /* Read the next input record */
        if (!ReadConsoleInputW(handle->handle,
                               &handle->tty.rd.last_input_record,
                               1,
                               &records_read)) {
          handle->flags &= ~UV_HANDLE_READING;
          DECREASE_ACTIVE_COUNT(loop, handle);
          handle->read_cb((uv_stream_t*) handle,
                          uv_translate_sys_error(GetLastError()),
                          &buf);
          goto out;
        }
        records_left--;
  
        /* If the window was resized, recompute the virtual window size. This */
        /* will trigger a SIGWINCH signal if the window size changed in an */
        /* way that matters to libuv. */
        if (handle->tty.rd.last_input_record.EventType == WINDOW_BUFFER_SIZE_EVENT) {
          CONSOLE_SCREEN_BUFFER_INFO info;
  
          uv_sem_wait(&uv_tty_output_lock);
  
          if (uv_tty_output_handle != INVALID_HANDLE_VALUE &&
              GetConsoleScreenBufferInfo(uv_tty_output_handle, &info)) {
            uv_tty_update_virtual_window(&info);
          }
  
          uv_sem_post(&uv_tty_output_lock);
  
          continue;
        }
  
        /* Ignore other events that are not key or resize events. */
        if (handle->tty.rd.last_input_record.EventType != KEY_EVENT) {
          continue;
        }
  
        /* Ignore keyup events, unless the left alt key was held and a valid */
        /* unicode character was emitted. */
        if (!KEV.bKeyDown && !(((KEV.dwControlKeyState & LEFT_ALT_PRESSED) ||
            KEV.wVirtualKeyCode==VK_MENU) && KEV.uChar.UnicodeChar != 0)) {
          continue;
        }
  
        /* Ignore keypresses to numpad number keys if the left alt is held */
        /* because the user is composing a character, or windows simulating */
        /* this. */
        if ((KEV.dwControlKeyState & LEFT_ALT_PRESSED) &&
            !(KEV.dwControlKeyState & ENHANCED_KEY) &&
            (KEV.wVirtualKeyCode == VK_INSERT ||
            KEV.wVirtualKeyCode == VK_END ||
            KEV.wVirtualKeyCode == VK_DOWN ||
            KEV.wVirtualKeyCode == VK_NEXT ||
            KEV.wVirtualKeyCode == VK_LEFT ||
            KEV.wVirtualKeyCode == VK_CLEAR ||
            KEV.wVirtualKeyCode == VK_RIGHT ||
            KEV.wVirtualKeyCode == VK_HOME ||
            KEV.wVirtualKeyCode == VK_UP ||
            KEV.wVirtualKeyCode == VK_PRIOR ||
            KEV.wVirtualKeyCode == VK_NUMPAD0 ||
            KEV.wVirtualKeyCode == VK_NUMPAD1 ||
            KEV.wVirtualKeyCode == VK_NUMPAD2 ||
            KEV.wVirtualKeyCode == VK_NUMPAD3 ||
            KEV.wVirtualKeyCode == VK_NUMPAD4 ||
            KEV.wVirtualKeyCode == VK_NUMPAD5 ||
            KEV.wVirtualKeyCode == VK_NUMPAD6 ||
            KEV.wVirtualKeyCode == VK_NUMPAD7 ||
            KEV.wVirtualKeyCode == VK_NUMPAD8 ||
            KEV.wVirtualKeyCode == VK_NUMPAD9)) {
          continue;
        }
  
        if (KEV.uChar.UnicodeChar != 0) {
          int prefix_len, char_len;
  
          /* Character key pressed */
          if (KEV.uChar.UnicodeChar >= 0xD800 &&
              KEV.uChar.UnicodeChar < 0xDC00) {
            /* UTF-16 high surrogate */
            handle->tty.rd.last_utf16_high_surrogate = KEV.uChar.UnicodeChar;
            continue;
          }
  
          /* Prefix with \u033 if alt was held, but alt was not used as part */
          /* a compose sequence. */
          if ((KEV.dwControlKeyState & (LEFT_ALT_PRESSED | RIGHT_ALT_PRESSED))
              && !(KEV.dwControlKeyState & (LEFT_CTRL_PRESSED |
              RIGHT_CTRL_PRESSED)) && KEV.bKeyDown) {
            handle->tty.rd.last_key[0] = '\033';
            prefix_len = 1;
          } else {
            prefix_len = 0;
          }
  
          if (KEV.uChar.UnicodeChar >= 0xDC00 &&
              KEV.uChar.UnicodeChar < 0xE000) {
            /* UTF-16 surrogate pair */
            WCHAR utf16_buffer[2] = { handle->tty.rd.last_utf16_high_surrogate,
                                      KEV.uChar.UnicodeChar};
            char_len = WideCharToMultiByte(CP_UTF8,
                                           0,
                                           utf16_buffer,
                                           2,
                                           &handle->tty.rd.last_key[prefix_len],
                                           sizeof handle->tty.rd.last_key,
                                           NULL,
                                           NULL);
          } else {
            /* Single UTF-16 character */
            char_len = WideCharToMultiByte(CP_UTF8,
                                           0,
                                           &KEV.uChar.UnicodeChar,
                                           1,
                                           &handle->tty.rd.last_key[prefix_len],
                                           sizeof handle->tty.rd.last_key,
                                           NULL,
                                           NULL);
          }
  
          /* Whatever happened, the last character wasn't a high surrogate. */
          handle->tty.rd.last_utf16_high_surrogate = 0;
  
          /* If the utf16 character(s) couldn't be converted something must */
          /* be wrong. */
          if (!char_len) {
            handle->flags &= ~UV_HANDLE_READING;
            DECREASE_ACTIVE_COUNT(loop, handle);
            handle->read_cb((uv_stream_t*) handle,
                            uv_translate_sys_error(GetLastError()),
                            &buf);
            goto out;
          }
  
          handle->tty.rd.last_key_len = (unsigned char) (prefix_len + char_len);
          handle->tty.rd.last_key_offset = 0;
          continue;
  
        } else {
          /* Function key pressed */
          const char* vt100;
          size_t prefix_len, vt100_len;
  
          vt100 = get_vt100_fn_key(KEV.wVirtualKeyCode,
                                    !!(KEV.dwControlKeyState & SHIFT_PRESSED),
                                    !!(KEV.dwControlKeyState & (
                                      LEFT_CTRL_PRESSED |
                                      RIGHT_CTRL_PRESSED)),
                                    &vt100_len);
  
          /* If we were unable to map to a vt100 sequence, just ignore. */
          if (!vt100) {
            continue;
          }
  
          /* Prefix with \x033 when the alt key was held. */
          if (KEV.dwControlKeyState & (LEFT_ALT_PRESSED | RIGHT_ALT_PRESSED)) {
            handle->tty.rd.last_key[0] = '\033';
            prefix_len = 1;
          } else {
            prefix_len = 0;
          }
  
          /* Copy the vt100 sequence to the handle buffer. */
          assert(prefix_len + vt100_len < sizeof handle->tty.rd.last_key);
          memcpy(&handle->tty.rd.last_key[prefix_len], vt100, vt100_len);
  
          handle->tty.rd.last_key_len = (unsigned char) (prefix_len + vt100_len);
          handle->tty.rd.last_key_offset = 0;
          continue;
        }
      } else {
        /* Copy any bytes left from the last keypress to the user buffer. */
        if (handle->tty.rd.last_key_offset < handle->tty.rd.last_key_len) {
          /* Allocate a buffer if needed */
          if (buf_used == 0) {
            buf = uv_buf_init(NULL, 0);
            handle->alloc_cb((uv_handle_t*) handle, 1024, &buf);
            if (buf.base == NULL || buf.len == 0) {
              handle->read_cb((uv_stream_t*) handle, UV_ENOBUFS, &buf);
              goto out;
            }
            assert(buf.base != NULL);
          }
  
          buf.base[buf_used++] = handle->tty.rd.last_key[handle->tty.rd.last_key_offset++];
  
          /* If the buffer is full, emit it */
          if ((size_t) buf_used == buf.len) {
            handle->read_cb((uv_stream_t*) handle, buf_used, &buf);
            buf = uv_null_buf_;
            buf_used = 0;
          }
  
          continue;
        }
  
        /* Apply dwRepeat from the last input record. */
        if (--KEV.wRepeatCount > 0) {
          handle->tty.rd.last_key_offset = 0;
          continue;
        }
  
        handle->tty.rd.last_key_len = 0;
        continue;
      }
    }
  
    /* Send the buffer back to the user */
    if (buf_used > 0) {
      handle->read_cb((uv_stream_t*) handle, buf_used, &buf);
    }
  
   out:
    /* Wait for more input events. */
    if ((handle->flags & UV_HANDLE_READING) &&
        !(handle->flags & UV_HANDLE_READ_PENDING)) {
      uv_tty_queue_read(loop, handle);
    }
  
    DECREASE_PENDING_REQ_COUNT(handle);
  
  #undef KEV
  }
  
  
  
  void uv_process_tty_read_line_req(uv_loop_t* loop, uv_tty_t* handle,
      uv_req_t* req) {
    uv_buf_t buf;
  
    assert(handle->type == UV_TTY);
    assert(handle->flags & UV_HANDLE_TTY_READABLE);
  
    buf = handle->tty.rd.read_line_buffer;
  
    handle->flags &= ~UV_HANDLE_READ_PENDING;
    handle->tty.rd.read_line_buffer = uv_null_buf_;
  
    if (!REQ_SUCCESS(req)) {
      /* Read was not successful */
      if (handle->flags & UV_HANDLE_READING) {
        /* Real error */
        handle->flags &= ~UV_HANDLE_READING;
        DECREASE_ACTIVE_COUNT(loop, handle);
        handle->read_cb((uv_stream_t*) handle,
                        uv_translate_sys_error(GET_REQ_ERROR(req)),
                        &buf);
      } else {
        /* The read was cancelled, or whatever we don't care */
        handle->read_cb((uv_stream_t*) handle, 0, &buf);
      }
  
    } else {
      if (!(handle->flags & UV_HANDLE_CANCELLATION_PENDING)) {
        /* Read successful */
        /* TODO: read unicode, convert to utf-8 */
        DWORD bytes = req->u.io.overlapped.InternalHigh;
        handle->read_cb((uv_stream_t*) handle, bytes, &buf);
      } else {
        handle->flags &= ~UV_HANDLE_CANCELLATION_PENDING;
        handle->read_cb((uv_stream_t*) handle, 0, &buf);
      }
    }
  
    /* Wait for more input events. */
    if ((handle->flags & UV_HANDLE_READING) &&
        !(handle->flags & UV_HANDLE_READ_PENDING)) {
      uv_tty_queue_read(loop, handle);
    }
  
    DECREASE_PENDING_REQ_COUNT(handle);
  }
  
  
  void uv_process_tty_read_req(uv_loop_t* loop, uv_tty_t* handle,
      uv_req_t* req) {
    assert(handle->type == UV_TTY);
    assert(handle->flags & UV_HANDLE_TTY_READABLE);
  
    /* If the read_line_buffer member is zero, it must have been an raw read. */
    /* Otherwise it was a line-buffered read. */
    /* FIXME: This is quite obscure. Use a flag or something. */
    if (handle->tty.rd.read_line_buffer.len == 0) {
      uv_process_tty_read_raw_req(loop, handle, req);
    } else {
      uv_process_tty_read_line_req(loop, handle, req);
    }
  }
  
  
  int uv_tty_read_start(uv_tty_t* handle, uv_alloc_cb alloc_cb,
      uv_read_cb read_cb) {
    uv_loop_t* loop = handle->loop;
  
    if (!(handle->flags & UV_HANDLE_TTY_READABLE)) {
      return ERROR_INVALID_PARAMETER;
    }
  
    handle->flags |= UV_HANDLE_READING;
    INCREASE_ACTIVE_COUNT(loop, handle);
    handle->read_cb = read_cb;
    handle->alloc_cb = alloc_cb;
  
    /* If reading was stopped and then started again, there could still be a */
    /* read request pending. */
    if (handle->flags & UV_HANDLE_READ_PENDING) {
      return 0;
    }
  
    /* Maybe the user stopped reading half-way while processing key events. */
    /* Short-circuit if this could be the case. */
    if (handle->tty.rd.last_key_len > 0) {
      SET_REQ_SUCCESS(&handle->read_req);
      uv_insert_pending_req(handle->loop, (uv_req_t*) &handle->read_req);
      /* Make sure no attempt is made to insert it again until it's handled. */
      handle->flags |= UV_HANDLE_READ_PENDING;
      handle->reqs_pending++;
      return 0;
    }
  
    uv_tty_queue_read(loop, handle);
  
    return 0;
  }
  
  
  int uv_tty_read_stop(uv_tty_t* handle) {
    INPUT_RECORD record;
    DWORD written, err;
  
    handle->flags &= ~UV_HANDLE_READING;
    DECREASE_ACTIVE_COUNT(handle->loop, handle);
  
    if (!(handle->flags & UV_HANDLE_READ_PENDING))
      return 0;
  
    if (handle->flags & UV_HANDLE_TTY_RAW) {
      /* Cancel raw read */
      /* Write some bullshit event to force the console wait to return. */
      memset(&record, 0, sizeof record);
      if (!WriteConsoleInputW(handle->handle, &record, 1, &written)) {
        return GetLastError();
      }
    } else if (!(handle->flags & UV_HANDLE_CANCELLATION_PENDING)) {
      /* Cancel line-buffered read if not already pending */
      err = uv__cancel_read_console(handle);
      if (err)
        return err;
  
      handle->flags |= UV_HANDLE_CANCELLATION_PENDING;
    }
  
    return 0;
  }
  
  static int uv__cancel_read_console(uv_tty_t* handle) {
    HANDLE active_screen_buffer = INVALID_HANDLE_VALUE;
    INPUT_RECORD record;
    DWORD written;
    DWORD err = 0;
    LONG status;
  
    assert(!(handle->flags & UV_HANDLE_CANCELLATION_PENDING));
  
    /* Hold the output lock during the cancellation, to ensure that further
       writes don't interfere with the screen state. It will be the ReadConsole
       thread's responsibility to release the lock. */
    uv_sem_wait(&uv_tty_output_lock);
    status = InterlockedExchange(&uv__read_console_status, TRAP_REQUESTED);
    if (status != IN_PROGRESS) {
      /* Either we have managed to set a trap for the other thread before
         ReadConsole is called, or ReadConsole has returned because the user
         has pressed ENTER. In either case, there is nothing else to do. */
      uv_sem_post(&uv_tty_output_lock);
      return 0;
    }
  
    /* Save screen state before sending the VK_RETURN event */
    active_screen_buffer = CreateFileA("conout$",
                                       GENERIC_READ | GENERIC_WRITE,
                                       FILE_SHARE_READ | FILE_SHARE_WRITE,
                                       NULL,
                                       OPEN_EXISTING,
                                       FILE_ATTRIBUTE_NORMAL,
                                       NULL);
  
    if (active_screen_buffer != INVALID_HANDLE_VALUE &&
        GetConsoleScreenBufferInfo(active_screen_buffer,
                                   &uv__saved_screen_state)) {
      InterlockedOr(&uv__restore_screen_state, 1);
    }
  
    /* Write enter key event to force the console wait to return. */
    record.EventType = KEY_EVENT;
    record.Event.KeyEvent.bKeyDown = TRUE;
    record.Event.KeyEvent.wRepeatCount = 1;
    record.Event.KeyEvent.wVirtualKeyCode = VK_RETURN;
    record.Event.KeyEvent.wVirtualScanCode =
      MapVirtualKeyW(VK_RETURN, MAPVK_VK_TO_VSC);
    record.Event.KeyEvent.uChar.UnicodeChar = L'\r';
    record.Event.KeyEvent.dwControlKeyState = 0;
    if (!WriteConsoleInputW(handle->handle, &record, 1, &written))
      err = GetLastError();
  
    if (active_screen_buffer != INVALID_HANDLE_VALUE)
      CloseHandle(active_screen_buffer);
  
    return err;
  }
  
  
  static void uv_tty_update_virtual_window(CONSOLE_SCREEN_BUFFER_INFO* info) {
    int old_virtual_width = uv_tty_virtual_width;
    int old_virtual_height = uv_tty_virtual_height;
  
    uv_tty_virtual_width = info->dwSize.X;
    uv_tty_virtual_height = info->srWindow.Bottom - info->srWindow.Top + 1;
  
    /* Recompute virtual window offset row. */
    if (uv_tty_virtual_offset == -1) {
      uv_tty_virtual_offset = info->dwCursorPosition.Y;
    } else if (uv_tty_virtual_offset < info->dwCursorPosition.Y -
               uv_tty_virtual_height + 1) {
      /* If suddenly find the cursor outside of the virtual window, it must */
      /* have somehow scrolled. Update the virtual window offset. */
      uv_tty_virtual_offset = info->dwCursorPosition.Y -
                              uv_tty_virtual_height + 1;
    }
    if (uv_tty_virtual_offset + uv_tty_virtual_height > info->dwSize.Y) {
      uv_tty_virtual_offset = info->dwSize.Y - uv_tty_virtual_height;
    }
    if (uv_tty_virtual_offset < 0) {
      uv_tty_virtual_offset = 0;
    }
  
    /* If the virtual window size changed, emit a SIGWINCH signal. Don't emit */
    /* if this was the first time the virtual window size was computed. */
    if (old_virtual_width != -1 && old_virtual_height != -1 &&
        (uv_tty_virtual_width != old_virtual_width ||
         uv_tty_virtual_height != old_virtual_height)) {
      uv__signal_dispatch(SIGWINCH);
    }
  }
  
  
  static COORD uv_tty_make_real_coord(uv_tty_t* handle,
      CONSOLE_SCREEN_BUFFER_INFO* info, int x, unsigned char x_relative, int y,
      unsigned char y_relative) {
    COORD result;
  
    uv_tty_update_virtual_window(info);
  
    /* Adjust y position */
    if (y_relative) {
      y = info->dwCursorPosition.Y + y;
    } else {
      y = uv_tty_virtual_offset + y;
    }
    /* Clip y to virtual client rectangle */
    if (y < uv_tty_virtual_offset) {
      y = uv_tty_virtual_offset;
    } else if (y >= uv_tty_virtual_offset + uv_tty_virtual_height) {
      y = uv_tty_virtual_offset + uv_tty_virtual_height - 1;
    }
  
    /* Adjust x */
    if (x_relative) {
      x = info->dwCursorPosition.X + x;
    }
    /* Clip x */
    if (x < 0) {
      x = 0;
    } else if (x >= uv_tty_virtual_width) {
      x = uv_tty_virtual_width - 1;
    }
  
    result.X = (unsigned short) x;
    result.Y = (unsigned short) y;
    return result;
  }
  
  
  static int uv_tty_emit_text(uv_tty_t* handle, WCHAR buffer[], DWORD length,
      DWORD* error) {
    DWORD written;
  
    if (*error != ERROR_SUCCESS) {
      return -1;
    }
  
    if (!WriteConsoleW(handle->handle,
                       (void*) buffer,
                       length,
                       &written,
                       NULL)) {
      *error = GetLastError();
      return -1;
    }
  
    return 0;
  }
  
  
  static int uv_tty_move_caret(uv_tty_t* handle, int x, unsigned char x_relative,
      int y, unsigned char y_relative, DWORD* error) {
    CONSOLE_SCREEN_BUFFER_INFO info;
    COORD pos;
  
    if (*error != ERROR_SUCCESS) {
      return -1;
    }
  
   retry:
    if (!GetConsoleScreenBufferInfo(handle->handle, &info)) {
      *error = GetLastError();
    }
  
    pos = uv_tty_make_real_coord(handle, &info, x, x_relative, y, y_relative);
  
    if (!SetConsoleCursorPosition(handle->handle, pos)) {
      if (GetLastError() == ERROR_INVALID_PARAMETER) {
        /* The console may be resized - retry */
        goto retry;
      } else {
        *error = GetLastError();
        return -1;
      }
    }
  
    return 0;
  }
  
  
  static int uv_tty_reset(uv_tty_t* handle, DWORD* error) {
    const COORD origin = {0, 0};
    const WORD char_attrs = uv_tty_default_text_attributes;
    CONSOLE_SCREEN_BUFFER_INFO info;
    DWORD count, written;
  
    if (*error != ERROR_SUCCESS) {
      return -1;
    }
  
    /* Reset original text attributes. */
    if (!SetConsoleTextAttribute(handle->handle, char_attrs)) {
      *error = GetLastError();
      return -1;
    }
  
    /* Move the cursor position to (0, 0). */
    if (!SetConsoleCursorPosition(handle->handle, origin)) {
      *error = GetLastError();
      return -1;
    }
  
    /* Clear the screen buffer. */
   retry:
    if (!GetConsoleScreenBufferInfo(handle->handle, &info)) {
      *error = GetLastError();
      return -1;
    }
  
    count = info.dwSize.X * info.dwSize.Y;
  
    if (!(FillConsoleOutputCharacterW(handle->handle,
                                      L'\x20',
                                      count,
                                      origin,
                                      &written) &&
          FillConsoleOutputAttribute(handle->handle,
                                     char_attrs,
                                     written,
                                     origin,
                                     &written))) {
      if (GetLastError() == ERROR_INVALID_PARAMETER) {
        /* The console may be resized - retry */
        goto retry;
      } else {
        *error = GetLastError();
        return -1;
      }
    }
  
    /* Move the virtual window up to the top. */
    uv_tty_virtual_offset = 0;
    uv_tty_update_virtual_window(&info);
  
    return 0;
  }
  
  
  static int uv_tty_clear(uv_tty_t* handle, int dir, char entire_screen,
      DWORD* error) {
    CONSOLE_SCREEN_BUFFER_INFO info;
    COORD start, end;
    DWORD count, written;
  
    int x1, x2, y1, y2;
    int x1r, x2r, y1r, y2r;
  
    if (*error != ERROR_SUCCESS) {
      return -1;
    }
  
    if (dir == 0) {
      /* Clear from current position */
      x1 = 0;
      x1r = 1;
    } else {
      /* Clear from column 0 */
      x1 = 0;
      x1r = 0;
    }
  
    if (dir == 1) {
      /* Clear to current position */
      x2 = 0;
      x2r = 1;
    } else {
      /* Clear to end of row. We pretend the console is 65536 characters wide, */
      /* uv_tty_make_real_coord will clip it to the actual console width. */
      x2 = 0xffff;
      x2r = 0;
    }
  
    if (!entire_screen) {
      /* Stay on our own row */
      y1 = y2 = 0;
      y1r = y2r = 1;
    } else {
      /* Apply columns direction to row */
      y1 = x1;
      y1r = x1r;
      y2 = x2;
      y2r = x2r;
    }
  
   retry:
    if (!GetConsoleScreenBufferInfo(handle->handle, &info)) {
      *error = GetLastError();
      return -1;
    }
  
    start = uv_tty_make_real_coord(handle, &info, x1, x1r, y1, y1r);
    end = uv_tty_make_real_coord(handle, &info, x2, x2r, y2, y2r);
    count = (end.Y * info.dwSize.X + end.X) -
            (start.Y * info.dwSize.X + start.X) + 1;
  
    if (!(FillConsoleOutputCharacterW(handle->handle,
                                L'\x20',
                                count,
                                start,
                                &written) &&
          FillConsoleOutputAttribute(handle->handle,
                                     info.wAttributes,
                                     written,
                                     start,
                                     &written))) {
      if (GetLastError() == ERROR_INVALID_PARAMETER) {
        /* The console may be resized - retry */
        goto retry;
      } else {
        *error = GetLastError();
        return -1;
      }
    }
  
    return 0;
  }
  
  #define FLIP_FGBG                                                             \
      do {                                                                      \
        WORD fg = info.wAttributes & 0xF;                                       \
        WORD bg = info.wAttributes & 0xF0;                                      \
        info.wAttributes &= 0xFF00;                                             \
        info.wAttributes |= fg << 4;                                            \
        info.wAttributes |= bg >> 4;                                            \
      } while (0)
  
  static int uv_tty_set_style(uv_tty_t* handle, DWORD* error) {
    unsigned short argc = handle->tty.wr.ansi_csi_argc;
    unsigned short* argv = handle->tty.wr.ansi_csi_argv;
    int i;
    CONSOLE_SCREEN_BUFFER_INFO info;
  
    char fg_color = -1, bg_color = -1;
    char fg_bright = -1, bg_bright = -1;
    char inverse = -1;
  
    if (argc == 0) {
      /* Reset mode */
      fg_color = uv_tty_default_fg_color;
      bg_color = uv_tty_default_bg_color;
      fg_bright = uv_tty_default_fg_bright;
      bg_bright = uv_tty_default_bg_bright;
      inverse = uv_tty_default_inverse;
    }
  
    for (i = 0; i < argc; i++) {
      short arg = argv[i];
  
      if (arg == 0) {
        /* Reset mode */
        fg_color = uv_tty_default_fg_color;
        bg_color = uv_tty_default_bg_color;
        fg_bright = uv_tty_default_fg_bright;
        bg_bright = uv_tty_default_bg_bright;
        inverse = uv_tty_default_inverse;
  
      } else if (arg == 1) {
        /* Foreground bright on */
        fg_bright = 1;
  
      } else if (arg == 2) {
        /* Both bright off */
        fg_bright = 0;
        bg_bright = 0;
  
      } else if (arg == 5) {
        /* Background bright on */
        bg_bright = 1;
  
      } else if (arg == 7) {
        /* Inverse: on */
        inverse = 1;
  
      } else if (arg == 21 || arg == 22) {
        /* Foreground bright off */
        fg_bright = 0;
  
      } else if (arg == 25) {
        /* Background bright off */
        bg_bright = 0;
  
      } else if (arg == 27) {
        /* Inverse: off */
        inverse = 0;
  
      } else if (arg >= 30 && arg <= 37) {
        /* Set foreground color */
        fg_color = arg - 30;
  
      } else if (arg == 39) {
        /* Default text color */
        fg_color = uv_tty_default_fg_color;
        fg_bright = uv_tty_default_fg_bright;
  
      } else if (arg >= 40 && arg <= 47) {
        /* Set background color */
        bg_color = arg - 40;
  
      } else if (arg ==  49) {
        /* Default background color */
        bg_color = uv_tty_default_bg_color;
        bg_bright = uv_tty_default_bg_bright;
  
      } else if (arg >= 90 && arg <= 97) {
        /* Set bold foreground color */
        fg_bright = 1;
        fg_color = arg - 90;
  
      } else if (arg >= 100 && arg <= 107) {
        /* Set bold background color */
        bg_bright = 1;
        bg_color = arg - 100;
  
      }
    }
  
    if (fg_color == -1 && bg_color == -1 && fg_bright == -1 &&
        bg_bright == -1 && inverse == -1) {
      /* Nothing changed */
      return 0;
    }
  
    if (!GetConsoleScreenBufferInfo(handle->handle, &info)) {
      *error = GetLastError();
      return -1;
    }
  
    if ((info.wAttributes & COMMON_LVB_REVERSE_VIDEO) > 0) {
      FLIP_FGBG;
    }
  
    if (fg_color != -1) {
      info.wAttributes &= ~(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);
      if (fg_color & 1) info.wAttributes |= FOREGROUND_RED;
      if (fg_color & 2) info.wAttributes |= FOREGROUND_GREEN;
      if (fg_color & 4) info.wAttributes |= FOREGROUND_BLUE;
    }
  
    if (fg_bright != -1) {
      if (fg_bright) {
        info.wAttributes |= FOREGROUND_INTENSITY;
      } else {
        info.wAttributes &= ~FOREGROUND_INTENSITY;
      }
    }
  
    if (bg_color != -1) {
      info.wAttributes &= ~(BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE);
      if (bg_color & 1) info.wAttributes |= BACKGROUND_RED;
      if (bg_color & 2) info.wAttributes |= BACKGROUND_GREEN;
      if (bg_color & 4) info.wAttributes |= BACKGROUND_BLUE;
    }
  
    if (bg_bright != -1) {
      if (bg_bright) {
        info.wAttributes |= BACKGROUND_INTENSITY;
      } else {
        info.wAttributes &= ~BACKGROUND_INTENSITY;
      }
    }
  
    if (inverse != -1) {
      if (inverse) {
        info.wAttributes |= COMMON_LVB_REVERSE_VIDEO;
      } else {
        info.wAttributes &= ~COMMON_LVB_REVERSE_VIDEO;
      }
    }
  
    if ((info.wAttributes & COMMON_LVB_REVERSE_VIDEO) > 0) {
      FLIP_FGBG;
    }
  
    if (!SetConsoleTextAttribute(handle->handle, info.wAttributes)) {
      *error = GetLastError();
      return -1;
    }
  
    return 0;
  }
  
  
  static int uv_tty_save_state(uv_tty_t* handle, unsigned char save_attributes,
      DWORD* error) {
    CONSOLE_SCREEN_BUFFER_INFO info;
  
    if (*error != ERROR_SUCCESS) {
      return -1;
    }
  
    if (!GetConsoleScreenBufferInfo(handle->handle, &info)) {
      *error = GetLastError();
      return -1;
    }
  
    uv_tty_update_virtual_window(&info);
  
    handle->tty.wr.saved_position.X = info.dwCursorPosition.X;
    handle->tty.wr.saved_position.Y = info.dwCursorPosition.Y - uv_tty_virtual_offset;
    handle->flags |= UV_HANDLE_TTY_SAVED_POSITION;
  
    if (save_attributes) {
      handle->tty.wr.saved_attributes = info.wAttributes &
          (FOREGROUND_INTENSITY | BACKGROUND_INTENSITY);
      handle->flags |= UV_HANDLE_TTY_SAVED_ATTRIBUTES;
    }
  
    return 0;
  }
  
  
  static int uv_tty_restore_state(uv_tty_t* handle,
      unsigned char restore_attributes, DWORD* error) {
    CONSOLE_SCREEN_BUFFER_INFO info;
    WORD new_attributes;
  
    if (*error != ERROR_SUCCESS) {
      return -1;
    }
  
    if (handle->flags & UV_HANDLE_TTY_SAVED_POSITION) {
      if (uv_tty_move_caret(handle,
                            handle->tty.wr.saved_position.X,
                            0,
                            handle->tty.wr.saved_position.Y,
                            0,
                            error) != 0) {
        return -1;
      }
    }
  
    if (restore_attributes &&
        (handle->flags & UV_HANDLE_TTY_SAVED_ATTRIBUTES)) {
      if (!GetConsoleScreenBufferInfo(handle->handle, &info)) {
        *error = GetLastError();
        return -1;
      }
  
      new_attributes = info.wAttributes;
      new_attributes &= ~(FOREGROUND_INTENSITY | BACKGROUND_INTENSITY);
      new_attributes |= handle->tty.wr.saved_attributes;
  
      if (!SetConsoleTextAttribute(handle->handle, new_attributes)) {
        *error = GetLastError();
        return -1;
      }
    }
  
    return 0;
  }
  
  static int uv_tty_set_cursor_visibility(uv_tty_t* handle,
                                          BOOL visible,
                                          DWORD* error) {
    CONSOLE_CURSOR_INFO cursor_info;
  
    if (!GetConsoleCursorInfo(handle->handle, &cursor_info)) {
      *error = GetLastError();
      return -1;
    }
  
    cursor_info.bVisible = visible;
  
    if (!SetConsoleCursorInfo(handle->handle, &cursor_info)) {
      *error = GetLastError();
      return -1;
    }
  
    return 0;
  }
  
  static int uv_tty_write_bufs(uv_tty_t* handle,
                               const uv_buf_t bufs[],
                               unsigned int nbufs,
                               DWORD* error) {
    /* We can only write 8k characters at a time. Windows can't handle */
    /* much more characters in a single console write anyway. */
    WCHAR utf16_buf[MAX_CONSOLE_CHAR];
    WCHAR* utf16_buffer;
    DWORD utf16_buf_used = 0;
    unsigned int i, len, max_len, pos;
    int allocate = 0;
  
  #define FLUSH_TEXT()                                                 \
    do {                                                               \
      pos = 0;                                                         \
      do {                                                             \
        len = utf16_buf_used - pos;                                    \
        if (len > MAX_CONSOLE_CHAR)                                    \
          len = MAX_CONSOLE_CHAR;                                      \
        uv_tty_emit_text(handle, &utf16_buffer[pos], len, error);      \
        pos += len;                                                    \
      } while (pos < utf16_buf_used);                                  \
      if (allocate) {                                                  \
        uv__free(utf16_buffer);                                        \
        allocate = 0;                                                  \
        utf16_buffer = utf16_buf;                                      \
      }                                                                \
      utf16_buf_used = 0;                                              \
   } while (0)
  
  #define ENSURE_BUFFER_SPACE(wchars_needed)                          \
    if (wchars_needed > ARRAY_SIZE(utf16_buf) - utf16_buf_used) {     \
      FLUSH_TEXT();                                                   \
    }
  
    /* Cache for fast access */
    unsigned char utf8_bytes_left = handle->tty.wr.utf8_bytes_left;
    unsigned int utf8_codepoint = handle->tty.wr.utf8_codepoint;
    unsigned char previous_eol = handle->tty.wr.previous_eol;
    unsigned char ansi_parser_state = handle->tty.wr.ansi_parser_state;
  
    /* Store the error here. If we encounter an error, stop trying to do i/o */
    /* but keep parsing the buffer so we leave the parser in a consistent */
    /* state. */
    *error = ERROR_SUCCESS;
  
    utf16_buffer = utf16_buf;
  
    uv_sem_wait(&uv_tty_output_lock);
  
    for (i = 0; i < nbufs; i++) {
      uv_buf_t buf = bufs[i];
      unsigned int j;
  
      if (uv__vterm_state == UV_SUPPORTED && buf.len > 0) {
        utf16_buf_used = MultiByteToWideChar(CP_UTF8,
                                             0,
                                             buf.base,
                                             buf.len,
                                             NULL,
                                             0);
  
        if (utf16_buf_used == 0) {
          *error = GetLastError();
          break;
        }
  
        max_len = (utf16_buf_used + 1) * sizeof(WCHAR);
        allocate = max_len > MAX_CONSOLE_CHAR;
        if (allocate)
          utf16_buffer = uv__malloc(max_len);
        if (!MultiByteToWideChar(CP_UTF8,
                                 0,
                                 buf.base,
                                 buf.len,
                                 utf16_buffer,
                                 utf16_buf_used)) {
          if (allocate)
            uv__free(utf16_buffer);
          *error = GetLastError();
          break;
        }
  
        FLUSH_TEXT();
  
        continue;
      }
  
      for (j = 0; j < buf.len; j++) {
        unsigned char c = buf.base[j];
  
        /* Run the character through the utf8 decoder We happily accept non */
        /* shortest form encodings and invalid code points - there's no real */
        /* harm that can be done. */
        if (utf8_bytes_left == 0) {
          /* Read utf-8 start byte */
          DWORD first_zero_bit;
          unsigned char not_c = ~c;
  #ifdef _MSC_VER /* msvc */
          if (_BitScanReverse(&first_zero_bit, not_c)) {
  #else /* assume gcc */
          if (c != 0) {
            first_zero_bit = (sizeof(int) * 8) - 1 - __builtin_clz(not_c);
  #endif
            if (first_zero_bit == 7) {
              /* Ascii - pass right through */
              utf8_codepoint = (unsigned int) c;
  
            } else if (first_zero_bit <= 5) {
              /* Multibyte sequence */
              utf8_codepoint = (0xff >> (8 - first_zero_bit)) & c;
              utf8_bytes_left = (char) (6 - first_zero_bit);
  
            } else {
              /* Invalid continuation */
              utf8_codepoint = UNICODE_REPLACEMENT_CHARACTER;
            }
  
          } else {
            /* 0xff -- invalid */
            utf8_codepoint = UNICODE_REPLACEMENT_CHARACTER;
          }
  
        } else if ((c & 0xc0) == 0x80) {
          /* Valid continuation of utf-8 multibyte sequence */
          utf8_bytes_left--;
          utf8_codepoint <<= 6;
          utf8_codepoint |= ((unsigned int) c & 0x3f);
  
        } else {
          /* Start byte where continuation was expected. */
          utf8_bytes_left = 0;
          utf8_codepoint = UNICODE_REPLACEMENT_CHARACTER;
          /* Patch buf offset so this character will be parsed again as a */
          /* start byte. */
          j--;
        }
  
        /* Maybe we need to parse more bytes to find a character. */
        if (utf8_bytes_left != 0) {
          continue;
        }
  
        /* Parse vt100/ansi escape codes */
        if (ansi_parser_state == ANSI_NORMAL) {
          switch (utf8_codepoint) {
            case '\033':
              ansi_parser_state = ANSI_ESCAPE_SEEN;
              continue;
  
            case 0233:
              ansi_parser_state = ANSI_CSI;
              handle->tty.wr.ansi_csi_argc = 0;
              continue;
          }
  
        } else if (ansi_parser_state == ANSI_ESCAPE_SEEN) {
          switch (utf8_codepoint) {
            case '[':
              ansi_parser_state = ANSI_CSI;
              handle->tty.wr.ansi_csi_argc = 0;
              continue;
  
            case '^':
            case '_':
            case 'P':
            case ']':
              /* Not supported, but we'll have to parse until we see a stop */
              /* code, e.g. ESC \ or BEL. */
              ansi_parser_state = ANSI_ST_CONTROL;
              continue;
  
            case '\033':
              /* Ignore double escape. */
              continue;
  
            case 'c':
              /* Full console reset. */
              FLUSH_TEXT();
              uv_tty_reset(handle, error);
              ansi_parser_state = ANSI_NORMAL;
              continue;
  
            case '7':
              /* Save the cursor position and text attributes. */
              FLUSH_TEXT();
              uv_tty_save_state(handle, 1, error);
              ansi_parser_state = ANSI_NORMAL;
              continue;
  
             case '8':
              /* Restore the cursor position and text attributes */
              FLUSH_TEXT();
              uv_tty_restore_state(handle, 1, error);
              ansi_parser_state = ANSI_NORMAL;
              continue;
  
            default:
              if (utf8_codepoint >= '@' && utf8_codepoint <= '_') {
                /* Single-char control. */
                ansi_parser_state = ANSI_NORMAL;
                continue;
              } else {
                /* Invalid - proceed as normal, */
                ansi_parser_state = ANSI_NORMAL;
              }
          }
  
        } else if (ansi_parser_state & ANSI_CSI) {
          if (!(ansi_parser_state & ANSI_IGNORE)) {
            if (utf8_codepoint >= '0' && utf8_codepoint <= '9') {
              /* Parsing a numerical argument */
  
              if (!(ansi_parser_state & ANSI_IN_ARG)) {
                /* We were not currently parsing a number */
  
                /* Check for too many arguments */
                if (handle->tty.wr.ansi_csi_argc >= ARRAY_SIZE(handle->tty.wr.ansi_csi_argv)) {
                  ansi_parser_state |= ANSI_IGNORE;
                  continue;
                }
  
                ansi_parser_state |= ANSI_IN_ARG;
                handle->tty.wr.ansi_csi_argc++;
                handle->tty.wr.ansi_csi_argv[handle->tty.wr.ansi_csi_argc - 1] =
                    (unsigned short) utf8_codepoint - '0';
                continue;
              } else {
                /* We were already parsing a number. Parse next digit. */
                uint32_t value = 10 *
                    handle->tty.wr.ansi_csi_argv[handle->tty.wr.ansi_csi_argc - 1];
  
                /* Check for overflow. */
                if (value > UINT16_MAX) {
                  ansi_parser_state |= ANSI_IGNORE;
                  continue;
                }
  
                 handle->tty.wr.ansi_csi_argv[handle->tty.wr.ansi_csi_argc - 1] =
                     (unsigned short) value + (utf8_codepoint - '0');
                 continue;
              }
  
            } else if (utf8_codepoint == ';') {
              /* Denotes the end of an argument. */
              if (ansi_parser_state & ANSI_IN_ARG) {
                ansi_parser_state &= ~ANSI_IN_ARG;
                continue;
  
              } else {
                /* If ANSI_IN_ARG is not set, add another argument and */
                /* default it to 0. */
                /* Check for too many arguments */
                if (handle->tty.wr.ansi_csi_argc >= ARRAY_SIZE(handle->tty.wr.ansi_csi_argv)) {
                  ansi_parser_state |= ANSI_IGNORE;
                  continue;
                }
  
                handle->tty.wr.ansi_csi_argc++;
                handle->tty.wr.ansi_csi_argv[handle->tty.wr.ansi_csi_argc - 1] = 0;
                continue;
              }
  
            } else if (utf8_codepoint == '?' && !(ansi_parser_state & ANSI_IN_ARG) &&
                       handle->tty.wr.ansi_csi_argc == 0) {
              /* Ignores '?' if it is the first character after CSI[ */
              /* This is an extension character from the VT100 codeset */
              /* that is supported and used by most ANSI terminals today. */
              continue;
  
            } else if (utf8_codepoint >= '@' && utf8_codepoint <= '~' &&
                       (handle->tty.wr.ansi_csi_argc > 0 || utf8_codepoint != '[')) {
              int x, y, d;
  
              /* Command byte */
              switch (utf8_codepoint) {
                case 'A':
                  /* cursor up */
                  FLUSH_TEXT();
                  y = -(handle->tty.wr.ansi_csi_argc ? handle->tty.wr.ansi_csi_argv[0] : 1);
                  uv_tty_move_caret(handle, 0, 1, y, 1, error);
                  break;
  
                case 'B':
                  /* cursor down */
                  FLUSH_TEXT();
                  y = handle->tty.wr.ansi_csi_argc ? handle->tty.wr.ansi_csi_argv[0] : 1;
                  uv_tty_move_caret(handle, 0, 1, y, 1, error);
                  break;
  
                case 'C':
                  /* cursor forward */
                  FLUSH_TEXT();
                  x = handle->tty.wr.ansi_csi_argc ? handle->tty.wr.ansi_csi_argv[0] : 1;
                  uv_tty_move_caret(handle, x, 1, 0, 1, error);
                  break;
  
                case 'D':
                  /* cursor back */
                  FLUSH_TEXT();
                  x = -(handle->tty.wr.ansi_csi_argc ? handle->tty.wr.ansi_csi_argv[0] : 1);
                  uv_tty_move_caret(handle, x, 1, 0, 1, error);
                  break;
  
                case 'E':
                  /* cursor next line */
                  FLUSH_TEXT();
                  y = handle->tty.wr.ansi_csi_argc ? handle->tty.wr.ansi_csi_argv[0] : 1;
                  uv_tty_move_caret(handle, 0, 0, y, 1, error);
                  break;
  
                case 'F':
                  /* cursor previous line */
                  FLUSH_TEXT();
                  y = -(handle->tty.wr.ansi_csi_argc ? handle->tty.wr.ansi_csi_argv[0] : 1);
                  uv_tty_move_caret(handle, 0, 0, y, 1, error);
                  break;
  
                case 'G':
                  /* cursor horizontal move absolute */
                  FLUSH_TEXT();
                  x = (handle->tty.wr.ansi_csi_argc >= 1 && handle->tty.wr.ansi_csi_argv[0])
                    ? handle->tty.wr.ansi_csi_argv[0] - 1 : 0;
                  uv_tty_move_caret(handle, x, 0, 0, 1, error);
                  break;
  
                case 'H':
                case 'f':
                  /* cursor move absolute */
                  FLUSH_TEXT();
                  y = (handle->tty.wr.ansi_csi_argc >= 1 && handle->tty.wr.ansi_csi_argv[0])
                    ? handle->tty.wr.ansi_csi_argv[0] - 1 : 0;
                  x = (handle->tty.wr.ansi_csi_argc >= 2 && handle->tty.wr.ansi_csi_argv[1])
                    ? handle->tty.wr.ansi_csi_argv[1] - 1 : 0;
                  uv_tty_move_caret(handle, x, 0, y, 0, error);
                  break;
  
                case 'J':
                  /* Erase screen */
                  FLUSH_TEXT();
                  d = handle->tty.wr.ansi_csi_argc ? handle->tty.wr.ansi_csi_argv[0] : 0;
                  if (d >= 0 && d <= 2) {
                    uv_tty_clear(handle, d, 1, error);
                  }
                  break;
  
                case 'K':
                  /* Erase line */
                  FLUSH_TEXT();
                  d = handle->tty.wr.ansi_csi_argc ? handle->tty.wr.ansi_csi_argv[0] : 0;
                  if (d >= 0 && d <= 2) {
                    uv_tty_clear(handle, d, 0, error);
                  }
                  break;
  
                case 'm':
                  /* Set style */
                  FLUSH_TEXT();
                  uv_tty_set_style(handle, error);
                  break;
  
                case 's':
                  /* Save the cursor position. */
                  FLUSH_TEXT();
                  uv_tty_save_state(handle, 0, error);
                  break;
  
                case 'u':
                  /* Restore the cursor position */
                  FLUSH_TEXT();
                  uv_tty_restore_state(handle, 0, error);
                  break;
  
                case 'l':
                  /* Hide the cursor */
                  if (handle->tty.wr.ansi_csi_argc == 1 &&
                      handle->tty.wr.ansi_csi_argv[0] == 25) {
                    FLUSH_TEXT();
                    uv_tty_set_cursor_visibility(handle, 0, error);
                  }
                  break;
  
                case 'h':
                  /* Show the cursor */
                  if (handle->tty.wr.ansi_csi_argc == 1 &&
                      handle->tty.wr.ansi_csi_argv[0] == 25) {
                    FLUSH_TEXT();
                    uv_tty_set_cursor_visibility(handle, 1, error);
                  }
                  break;
              }
  
              /* Sequence ended - go back to normal state. */
              ansi_parser_state = ANSI_NORMAL;
              continue;
  
            } else {
              /* We don't support commands that use private mode characters or */
              /* intermediaries. Ignore the rest of the sequence. */
              ansi_parser_state |= ANSI_IGNORE;
              continue;
            }
          } else {
            /* We're ignoring this command. Stop only on command character. */
            if (utf8_codepoint >= '@' && utf8_codepoint <= '~') {
              ansi_parser_state = ANSI_NORMAL;
            }
            continue;
          }
  
        } else if (ansi_parser_state & ANSI_ST_CONTROL) {
          /* Unsupported control code */
          /* Ignore everything until we see BEL or ESC \ */
          if (ansi_parser_state & ANSI_IN_STRING) {
            if (!(ansi_parser_state & ANSI_BACKSLASH_SEEN)) {
              if (utf8_codepoint == '"') {
                ansi_parser_state &= ~ANSI_IN_STRING;
              } else if (utf8_codepoint == '\\') {
                ansi_parser_state |= ANSI_BACKSLASH_SEEN;
              }
            } else {
              ansi_parser_state &= ~ANSI_BACKSLASH_SEEN;
            }
          } else {
            if (utf8_codepoint == '\007' || (utf8_codepoint == '\\' &&
                (ansi_parser_state & ANSI_ESCAPE_SEEN))) {
              /* End of sequence */
              ansi_parser_state = ANSI_NORMAL;
            } else if (utf8_codepoint == '\033') {
              /* Escape character */
              ansi_parser_state |= ANSI_ESCAPE_SEEN;
            } else if (utf8_codepoint == '"') {
               /* String starting */
              ansi_parser_state |= ANSI_IN_STRING;
              ansi_parser_state &= ~ANSI_ESCAPE_SEEN;
              ansi_parser_state &= ~ANSI_BACKSLASH_SEEN;
            } else {
              ansi_parser_state &= ~ANSI_ESCAPE_SEEN;
            }
          }
          continue;
        } else {
          /* Inconsistent state */
          abort();
        }
  
        /* We wouldn't mind emitting utf-16 surrogate pairs. Too bad, the */
        /* windows console doesn't really support UTF-16, so just emit the */
        /* replacement character. */
        if (utf8_codepoint > 0xffff) {
          utf8_codepoint = UNICODE_REPLACEMENT_CHARACTER;
        }
  
        if (utf8_codepoint == 0x0a || utf8_codepoint == 0x0d) {
          /* EOL conversion - emit \r\n when we see \n. */
  
          if (utf8_codepoint == 0x0a && previous_eol != 0x0d) {
            /* \n was not preceded by \r; print \r\n. */
            ENSURE_BUFFER_SPACE(2);
            utf16_buf[utf16_buf_used++] = L'\r';
            utf16_buf[utf16_buf_used++] = L'\n';
          } else if (utf8_codepoint == 0x0d && previous_eol == 0x0a) {
            /* \n was followed by \r; do not print the \r, since */
            /* the source was either \r\n\r (so the second \r is */
            /* redundant) or was \n\r (so the \n was processed */
            /* by the last case and an \r automatically inserted). */
          } else {
            /* \r without \n; print \r as-is. */
            ENSURE_BUFFER_SPACE(1);
            utf16_buf[utf16_buf_used++] = (WCHAR) utf8_codepoint;
          }
  
          previous_eol = (char) utf8_codepoint;
  
        } else if (utf8_codepoint <= 0xffff) {
          /* Encode character into utf-16 buffer. */
          ENSURE_BUFFER_SPACE(1);
          utf16_buf[utf16_buf_used++] = (WCHAR) utf8_codepoint;
          previous_eol = 0;
        }
      }
    }
  
    /* Flush remaining characters */
    FLUSH_TEXT();
  
    /* Copy cached values back to struct. */
    handle->tty.wr.utf8_bytes_left = utf8_bytes_left;
    handle->tty.wr.utf8_codepoint = utf8_codepoint;
    handle->tty.wr.previous_eol = previous_eol;
    handle->tty.wr.ansi_parser_state = ansi_parser_state;
  
    uv_sem_post(&uv_tty_output_lock);
  
    if (*error == STATUS_SUCCESS) {
      return 0;
    } else {
      return -1;
    }
  
  #undef FLUSH_TEXT
  }
  
  
  int uv_tty_write(uv_loop_t* loop,
                   uv_write_t* req,
                   uv_tty_t* handle,
                   const uv_buf_t bufs[],
                   unsigned int nbufs,
                   uv_write_cb cb) {
    DWORD error;
  
    UV_REQ_INIT(req, UV_WRITE);
    req->handle = (uv_stream_t*) handle;
    req->cb = cb;
  
    handle->reqs_pending++;
    handle->stream.conn.write_reqs_pending++;
    REGISTER_HANDLE_REQ(loop, handle, req);
  
    req->u.io.queued_bytes = 0;
  
    if (!uv_tty_write_bufs(handle, bufs, nbufs, &error)) {
      SET_REQ_SUCCESS(req);
    } else {
      SET_REQ_ERROR(req, error);
    }
  
    uv_insert_pending_req(loop, (uv_req_t*) req);
  
    return 0;
  }
  
  
  int uv__tty_try_write(uv_tty_t* handle,
                        const uv_buf_t bufs[],
                        unsigned int nbufs) {
    DWORD error;
  
    if (handle->stream.conn.write_reqs_pending > 0)
      return UV_EAGAIN;
  
    if (uv_tty_write_bufs(handle, bufs, nbufs, &error))
      return uv_translate_sys_error(error);
  
    return uv__count_bufs(bufs, nbufs);
  }
  
  
  void uv_process_tty_write_req(uv_loop_t* loop, uv_tty_t* handle,
    uv_write_t* req) {
    int err;
  
    handle->write_queue_size -= req->u.io.queued_bytes;
    UNREGISTER_HANDLE_REQ(loop, handle, req);
  
    if (req->cb) {
      err = GET_REQ_ERROR(req);
      req->cb(req, uv_translate_sys_error(err));
    }
  
    handle->stream.conn.write_reqs_pending--;
    if (handle->stream.conn.shutdown_req != NULL &&
        handle->stream.conn.write_reqs_pending == 0) {
      uv_want_endgame(loop, (uv_handle_t*)handle);
    }
  
    DECREASE_PENDING_REQ_COUNT(handle);
  }
  
  
  void uv_tty_close(uv_tty_t* handle) {
    assert(handle->u.fd == -1 || handle->u.fd > 2);
    if (handle->u.fd == -1)
      CloseHandle(handle->handle);
    else
      close(handle->u.fd);
  
    if (handle->flags & UV_HANDLE_READING)
      uv_tty_read_stop(handle);
  
    handle->u.fd = -1;
    handle->handle = INVALID_HANDLE_VALUE;
    handle->flags &= ~(UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
    uv__handle_closing(handle);
  
    if (handle->reqs_pending == 0) {
      uv_want_endgame(handle->loop, (uv_handle_t*) handle);
    }
  }
  
  
  void uv_tty_endgame(uv_loop_t* loop, uv_tty_t* handle) {
    if (!(handle->flags & UV_HANDLE_TTY_READABLE) &&
        handle->stream.conn.shutdown_req != NULL &&
        handle->stream.conn.write_reqs_pending == 0) {
      UNREGISTER_HANDLE_REQ(loop, handle, handle->stream.conn.shutdown_req);
  
      /* TTY shutdown is really just a no-op */
      if (handle->stream.conn.shutdown_req->cb) {
        if (handle->flags & UV__HANDLE_CLOSING) {
          handle->stream.conn.shutdown_req->cb(handle->stream.conn.shutdown_req, UV_ECANCELED);
        } else {
          handle->stream.conn.shutdown_req->cb(handle->stream.conn.shutdown_req, 0);
        }
      }
  
      handle->stream.conn.shutdown_req = NULL;
  
      DECREASE_PENDING_REQ_COUNT(handle);
      return;
    }
  
    if (handle->flags & UV__HANDLE_CLOSING &&
        handle->reqs_pending == 0) {
      /* The wait handle used for raw reading should be unregistered when the */
      /* wait callback runs. */
      assert(!(handle->flags & UV_HANDLE_TTY_READABLE) ||
             handle->tty.rd.read_raw_wait == NULL);
  
      assert(!(handle->flags & UV_HANDLE_CLOSED));
      uv__handle_close(handle);
    }
  }
  
  
  /* TODO: remove me */
  void uv_process_tty_accept_req(uv_loop_t* loop, uv_tty_t* handle,
      uv_req_t* raw_req) {
    abort();
  }
  
  
  /* TODO: remove me */
  void uv_process_tty_connect_req(uv_loop_t* loop, uv_tty_t* handle,
      uv_connect_t* req) {
    abort();
  }
  
  
  int uv_tty_reset_mode(void) {
    /* Not necessary to do anything. */
    return 0;
  }
  
  /* Determine whether or not this version of windows supports
   * proper ANSI color codes. Should be supported as of windows
   * 10 version 1511, build number 10.0.10586.
   */
  static void uv__determine_vterm_state(HANDLE handle) {
    DWORD dwMode = 0;
  
    if (!GetConsoleMode(handle, &dwMode)) {
      uv__vterm_state = UV_UNSUPPORTED;
      return;
    }
  
    dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    if (!SetConsoleMode(handle, dwMode)) {
      uv__vterm_state = UV_UNSUPPORTED;
      return;
    }
  
    uv__vterm_state = UV_SUPPORTED;
  }
  