/*
 * Copyright (c) 2000, 2021, Oracle and/or its affiliates.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2.0,
 * as published by the Free Software Foundation.
 *
 * This program is also distributed with certain software (including
 * but not limited to OpenSSL) that is licensed under separate terms, as
 * designated in a particular file or component or in included license
 * documentation.  The authors of MySQL hereby grant you an additional
 * permission to link the program and your derivative works with the
 * separately licensed software that they have included with MySQL.
 * This program is distributed in the hope that it will be useful,  but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 * the GNU General Public License, version 2.0, for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

/*
** Ask for a password from tty
** This is an own file to avoid conflicts with curses
*/

// modified to be standalone for mysqlsh

#include "my_config.h"

#if defined(HAVE_GETPASS) && !defined(__APPLE__)
// Don't use getpass() since it doesn't handle ^C (and it's deprecated)
// Except in macos, where it works
#undef HAVE_GETPASS
#endif

#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <cstdio>
#include <cstring>

#include "mysqlsh/get_password.h"
#include "mysqlshdk/libs/utils/utils_general.h"

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef HAVE_GETPASS
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif  // HAVE_PWD_H
#else   // ! HAVE_GETPASS
#ifdef _WIN32
#include <conio.h>
#else  // ! _WIN32
#include <assert.h>
#include <fcntl.h>
#ifdef HAVE_TERMIOS_H
#include <termios.h>
#define TERMIO struct termios
#else  // ! HAVE_TERMIOS_H
#ifdef HAVE_TERMIO_H
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif  // HAVE_SYS_IOCTL_H
#include <termio.h>
#define TERMIO struct termio
#else  // ! HAVE_TERMIO_H
#include <sgtty.h>
#define TERMIO struct sgttyb
#endif  // ! HAVE_TERMIO_H
#endif  // ! HAVE_TERMIOS_H
#endif  // ! _WIN32
#endif  // ! HAVE_GETPASS

#ifdef HAVE_GETPASSPHRASE  // For Solaris
#define getpass(A) getpassphrase(A)
#endif  // HAVE_GETPASSPHRASE

namespace {

const size_t k_password_length = 80;

#ifndef HAVE_GETPASS
const char k_end_of_text = 3;  // Ctrl+C
const char k_end_of_text_str[] = {k_end_of_text, '\0'};
#endif  // ! HAVE_GETPASS

const char *get_password_prompt(const char *prompt) {
  return prompt ? prompt : "Enter password: ";
}

}  // namespace

#ifdef _WIN32
// we're just going to fake it here and get input from the keyboard
char *mysh_get_tty_password(const char *opt_message) {
  char to[k_password_length] = {0};
  char *pos = to, *end = to + sizeof(to) - 1;
  int tmp;

  _cputs(get_password_prompt(opt_message));

  for (;;) {
    tmp = _getch();

    // A second call must be read with control arrows
    // and control keys
    if (tmp == 0 || tmp == 0xE0) tmp = _getch();

    if (tmp == '\b' || tmp == 127) {
      if (pos != to) {
        _cputs("\b \b");
        pos--;
        continue;
      }
    }

    if (tmp == '\n' || tmp == '\r' || tmp == k_end_of_text) break;

    if (iscntrl(tmp) || pos == end) continue;

    _cputs("*");
    *(pos++) = tmp;
  }

  *pos = 0;

  _cputs("\n");

  auto ret_val = tmp == k_end_of_text ? strdup(k_end_of_text_str) : strdup(to);

  // BUG#28915716: Cleans up the memory containing the password
  shcore::clear_buffer(to, k_password_length);

  return ret_val;
}

#else  // !_WIN32
#ifndef HAVE_GETPASS

namespace {

class Disable_echo {
 public:
  explicit Disable_echo(int fd, bool close_fd = false)
      : m_fd{fd}, m_close_fd{close_fd} {
    TERMIO tmp;

#if defined(HAVE_TERMIOS_H)
    tcgetattr(m_fd, &m_original);
    tmp = m_original;
    tmp.c_lflag &= ~(ECHO | ISIG | ICANON);
    tmp.c_cc[VMIN] = 1;
    tmp.c_cc[VTIME] = 0;
    tcsetattr(m_fd, TCSADRAIN, &tmp);
#elif defined(HAVE_TERMIO_H)
    ioctl(m_fd, static_cast<int>(TCGETA), &m_original);
    tmp = m_original;
    tmp.c_lflag &= ~(ECHO | ISIG | ICANON);
    tmp.c_cc[VMIN] = 1;
    tmp.c_cc[VTIME] = 0;
    ioctl(m_fd, static_cast<int>(TCSETA), &tmp);
#else
    gtty(m_fd, &m_original);
    tmp = m_original;
    tmp.sg_flags &= ~ECHO;
    tmp.sg_flags |= RAW;
    stty(m_fd, &tmp);
#endif
  }

  ~Disable_echo() {
#if defined(HAVE_TERMIOS_H)
    tcsetattr(m_fd, TCSADRAIN, &m_original);
#elif defined(HAVE_TERMIO_H)
    ioctl(m_fd, static_cast<int>(TCSETA), &m_original);
#else
    stty(m_fd, &m_original);
#endif

    if (m_close_fd) {
      close(m_fd);
    }
  }

  Disable_echo(const Disable_echo &) = delete;
  Disable_echo(Disable_echo &&) = delete;
  Disable_echo &operator=(const Disable_echo &) = delete;
  Disable_echo &operator=(Disable_echo &&) = delete;

 private:
  int m_fd;
  bool m_close_fd;
  TERMIO m_original;
};

class Prompt_password {
 public:
  explicit Prompt_password(const char *msg) : m_msg{msg} { assert(m_msg); }

  bool get(char *buffer, int length) {
    setup_input_output();

    Disable_echo disabled{m_input_fd, m_close_input_fd};

    print(m_msg);
    bool ret = get_password(buffer, length);
    print('\n');

    return ret;
  }

 private:
  void setup_input_output() {
    const int fd = open("/dev/tty", O_RDWR | O_NOCTTY);

    if (fd < 0) {
      m_input_fd = fileno(stdin);
      m_output_fd = fileno(stderr);
      m_close_input_fd = false;
    } else {
      m_input_fd = m_output_fd = fd;
      m_close_input_fd = true;
    }

    m_echo = isatty(m_output_fd);
  }

  bool get_password(char *to, int length) const {
    char *pos = to, *end = to + length - 1;

    for (;;) {
      char tmp;

      if (read(m_input_fd, &tmp, 1) != 1) break;

      if (tmp == '\b' || static_cast<int>(tmp) == 127) {
        if (pos != to) {
          print("\b \b");
          pos--;
          continue;
        }
      }

      if (tmp == '\n' || tmp == '\r') break;

      if (tmp == k_end_of_text) return false;

      if (iscntrl(tmp) || pos == end) continue;

      print('*');
      *(pos++) = tmp;
    }

    *pos = 0;
    return true;
  }

  void print(const char *msg) const {
    if (m_echo) {
      const auto ignore = write(m_output_fd, msg, strlen(msg));
      (void)ignore;
    }
  }

  void print(const char c) const {
    if (m_echo) {
      const auto ignore = write(m_output_fd, &c, 1);
      (void)ignore;
    }
  }

  const char *m_msg = nullptr;
  bool m_echo = false;
  bool m_close_input_fd = false;
  int m_input_fd = -1;
  int m_output_fd = -1;
};

}  // namespace

#endif  // ! HAVE_GETPASS

char *mysh_get_tty_password(const char *opt_message) {
  char buff[k_password_length] = {0};
  const char *message = get_password_prompt(opt_message);

#ifdef HAVE_GETPASS
  char *passbuff = getpass(message);
  // copy the password to buff and clear original (static) buffer
  strncpy(buff, passbuff, sizeof(buff) - 1);
#ifdef _PASSWORD_LEN
  shcore::clear_buffer(passbuff, _PASSWORD_LEN);
#endif  // _PASSWORD_LEN
#else   // ! HAVE_GETPASS
  Prompt_password prompt{message};

  if (!prompt.get(buff, sizeof(buff))) {
    return strdup(k_end_of_text_str);
  }
#endif
  char *ret_val = strdup(buff);
  shcore::clear_buffer(buff, k_password_length);
  return ret_val;
}

#endif  // !_WIN32
