text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2015 Damien P. George
   *
   * 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 "py/runtime.h"
  #include "py/mphal.h"
  #include "py/mpthread.h"
  
  #include <sys/time.h>
  #include <windows.h>
  #include <unistd.h>
  #include <bcrypt.h>
  
  HANDLE std_in = NULL;
  HANDLE con_out = NULL;
  DWORD orig_mode = 0;
  
  STATIC void assure_stdin_handle() {
      if (!std_in) {
          std_in = GetStdHandle(STD_INPUT_HANDLE);
          assert(std_in != INVALID_HANDLE_VALUE);
      }
  }
  
  STATIC void assure_conout_handle() {
      if (!con_out) {
          con_out = CreateFile("CONOUT$", GENERIC_READ | GENERIC_WRITE,
              FILE_SHARE_READ | FILE_SHARE_WRITE,
              NULL, OPEN_EXISTING, 0, 0);
          assert(con_out != INVALID_HANDLE_VALUE);
      }
  }
  
  void mp_hal_stdio_mode_raw(void) {
      assure_stdin_handle();
      GetConsoleMode(std_in, &orig_mode);
      DWORD mode = orig_mode;
      mode &= ~ENABLE_ECHO_INPUT;
      mode &= ~ENABLE_LINE_INPUT;
      mode &= ~ENABLE_PROCESSED_INPUT;
      SetConsoleMode(std_in, mode);
  }
  
  void mp_hal_stdio_mode_orig(void) {
      assure_stdin_handle();
      SetConsoleMode(std_in, orig_mode);
  }
  
  // Handler to be installed by SetConsoleCtrlHandler, currently used only to handle Ctrl-C.
  // This handler has to be installed just once (this has to be done elswhere in init code).
  // Previous versions of the mp_hal code would install a handler whenever Ctrl-C input is
  // allowed and remove the handler again when it is not. That is not necessary though (1),
  // and it might introduce problems (2) because console notifications are delivered to the
  // application in a separate thread.
  // (1) mp_hal_set_interrupt_char effectively enables/disables processing of Ctrl-C via the
  // ENABLE_PROCESSED_INPUT flag so in raw mode console_sighandler won't be called.
  // (2) if mp_hal_set_interrupt_char would remove the handler while Ctrl-C was issued earlier,
  // the thread created for handling it might not be running yet so we'd miss the notification.
  BOOL WINAPI console_sighandler(DWORD evt) {
      if (evt == CTRL_C_EVENT) {
          if (MP_STATE_MAIN_THREAD(mp_pending_exception) == MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception))) {
              // this is the second time we are called, so die straight away
              exit(1);
          }
          mp_sched_keyboard_interrupt();
          return TRUE;
      }
      return FALSE;
  }
  
  void mp_hal_set_interrupt_char(char c) {
      assure_stdin_handle();
      if (c == CHAR_CTRL_C) {
          DWORD mode;
          GetConsoleMode(std_in, &mode);
          mode |= ENABLE_PROCESSED_INPUT;
          SetConsoleMode(std_in, mode);
      } else {
          DWORD mode;
          GetConsoleMode(std_in, &mode);
          mode &= ~ENABLE_PROCESSED_INPUT;
          SetConsoleMode(std_in, mode);
      }
  }
  
  void mp_hal_move_cursor_back(uint pos) {
      if (!pos) {
          return;
      }
      assure_conout_handle();
      CONSOLE_SCREEN_BUFFER_INFO info;
      GetConsoleScreenBufferInfo(con_out, &info);
      info.dwCursorPosition.X -= (short)pos;
      // Move up a line if needed.
      while (info.dwCursorPosition.X < 0) {
          info.dwCursorPosition.X = info.dwSize.X + info.dwCursorPosition.X;
          info.dwCursorPosition.Y -= 1;
      }
      // Caller requested to move out of the screen. That's not possible so just clip,
      // it's the caller's responsibility to not let this happen.
      if (info.dwCursorPosition.Y < 0) {
          info.dwCursorPosition.X = 0;
          info.dwCursorPosition.Y = 0;
      }
      SetConsoleCursorPosition(con_out, info.dwCursorPosition);
  }
  
  void mp_hal_erase_line_from_cursor(uint n_chars_to_erase) {
      assure_conout_handle();
      CONSOLE_SCREEN_BUFFER_INFO info;
      GetConsoleScreenBufferInfo(con_out, &info);
      DWORD written;
      FillConsoleOutputCharacter(con_out, ' ', n_chars_to_erase, info.dwCursorPosition, &written);
      FillConsoleOutputAttribute(con_out, info.wAttributes, n_chars_to_erase, info.dwCursorPosition, &written);
  }
  
  typedef struct item_t {
      WORD vkey;
      const char *seq;
  } item_t;
  
  // map virtual key codes to key sequences known by MicroPython's readline implementation
  STATIC item_t keyCodeMap[] = {
      {VK_UP, "[A"},
      {VK_DOWN, "[B"},
      {VK_RIGHT, "[C"},
      {VK_LEFT, "[D"},
      {VK_HOME, "[H"},
      {VK_END, "[F"},
      {VK_DELETE, "[3~"},
      {0, ""} // sentinel
  };
  
  // likewise, but with Ctrl key down
  STATIC item_t ctrlKeyCodeMap[] = {
      {VK_LEFT, "b"},
      {VK_RIGHT, "f"},
      {VK_DELETE, "d"},
      {VK_BACK, "\x7F"},
      {0, ""} // sentinel
  };
  
  STATIC const char *cur_esc_seq = NULL;
  
  STATIC int esc_seq_process_vk(WORD vk, bool ctrl_key_down) {
      for (item_t *p = (ctrl_key_down ? ctrlKeyCodeMap : keyCodeMap); p->vkey != 0; ++p) {
          if (p->vkey == vk) {
              cur_esc_seq = p->seq;
              return 27; // ESC, start of escape sequence
          }
      }
      return 0; // nothing found
  }
  
  STATIC int esc_seq_chr() {
      if (cur_esc_seq) {
          const char c = *cur_esc_seq++;
          if (c) {
              return c;
          }
          cur_esc_seq = NULL;
      }
      return 0;
  }
  
  int mp_hal_stdin_rx_chr(void) {
      // currently processing escape seq?
      const int ret = esc_seq_chr();
      if (ret) {
          return ret;
      }
  
      // poll until key which we handle is pressed
      assure_stdin_handle();
      BOOL status;
      DWORD num_read;
      INPUT_RECORD rec;
      for (;;) {
          MP_THREAD_GIL_EXIT();
          status = ReadConsoleInput(std_in, &rec, 1, &num_read);
          MP_THREAD_GIL_ENTER();
          if (!status || !num_read) {
              return CHAR_CTRL_C; // EOF, ctrl-D
          }
          if (rec.EventType != KEY_EVENT || !rec.Event.KeyEvent.bKeyDown) { // only want key down events
              continue;
          }
          const bool ctrl_key_down = (rec.Event.KeyEvent.dwControlKeyState & LEFT_CTRL_PRESSED) ||
              (rec.Event.KeyEvent.dwControlKeyState & RIGHT_CTRL_PRESSED);
          const int ret = esc_seq_process_vk(rec.Event.KeyEvent.wVirtualKeyCode, ctrl_key_down);
          if (ret) {
              return ret;
          }
          const char c = rec.Event.KeyEvent.uChar.AsciiChar;
          if (c) { // plain ascii char, return it
              return c;
          }
      }
  }
  
  void mp_hal_stdout_tx_strn(const char *str, size_t len) {
      MP_THREAD_GIL_EXIT();
      write(STDOUT_FILENO, str, len);
      MP_THREAD_GIL_ENTER();
  }
  
  void mp_hal_stdout_tx_strn_cooked(const char *str, size_t len) {
      mp_hal_stdout_tx_strn(str, len);
  }
  
  void mp_hal_stdout_tx_str(const char *str) {
      mp_hal_stdout_tx_strn(str, strlen(str));
  }
  
  mp_uint_t mp_hal_ticks_ms(void) {
      struct timeval tv;
      gettimeofday(&tv, NULL);
      return tv.tv_sec * 1000 + tv.tv_usec / 1000;
  }
  
  mp_uint_t mp_hal_ticks_us(void) {
      struct timeval tv;
      gettimeofday(&tv, NULL);
      return tv.tv_sec * 1000000 + tv.tv_usec;
  }
  
  mp_uint_t mp_hal_ticks_cpu(void) {
      LARGE_INTEGER value;
      QueryPerformanceCounter(&value);
      #ifdef _WIN64
      return value.QuadPart;
      #else
      return value.LowPart;
      #endif
  }
  
  uint64_t mp_hal_time_ns(void) {
      struct timeval tv;
      gettimeofday(&tv, NULL);
      return (uint64_t)tv.tv_sec * 1000000000ULL + (uint64_t)tv.tv_usec * 1000ULL;
  }
  
  void msec_sleep(double msec) {
      if (msec < 0.0) {
          msec = 0.0;
      }
      SleepEx((DWORD)msec, TRUE);
  }
  
  #ifdef _MSC_VER
  int usleep(__int64 usec) {
      msec_sleep((double)usec / 1000.0);
      return 0;
  }
  #endif
  
  void mp_hal_delay_ms(mp_uint_t ms) {
      #ifdef MICROPY_EVENT_POLL_HOOK
      mp_uint_t start = mp_hal_ticks_ms();
      while (mp_hal_ticks_ms() - start < ms) {
          MICROPY_EVENT_POLL_HOOK
      }
      #else
      msec_sleep((double)ms);
      #endif
  }
  
  void mp_hal_get_random(size_t n, void *buf) {
      NTSTATUS result = BCryptGenRandom(NULL, (unsigned char *)buf, n, BCRYPT_USE_SYSTEM_PREFERRED_RNG);
      if (!BCRYPT_SUCCESS(result)) {
          mp_raise_OSError(errno);
      }
  }
  