cpython/Lib/_pyrepl/windows_console.py

#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
#
#                        All Rights Reserved
#
#
# Permission to use, copy, modify, and distribute this software and
# its documentation for any purpose is hereby granted without fee,
# provided that the above copyright notice appear in all copies and
# that both that copyright notice and this permission notice appear in
# supporting documentation.
#
# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

from __future__ import annotations

import io
from multiprocessing import Value
import os
import sys
import time
import msvcrt

from abc import ABC, abstractmethod
from collections import deque
from dataclasses import dataclass, field
import ctypes
from ctypes.wintypes import (
    _COORD,
    WORD,
    SMALL_RECT,
    BOOL,
    HANDLE,
    CHAR,
    DWORD,
    WCHAR,
    SHORT,
)
from ctypes import Structure, POINTER, Union
from .console import Event, Console
from .trace import trace
from .utils import wlen

try:
    from ctypes import GetLastError, WinDLL, windll, WinError  # type: ignore[attr-defined]
except:
    # Keep MyPy happy off Windows
    from ctypes import CDLL as WinDLL, cdll as windll

    def GetLastError() -> int:
        return 42

    class WinError(OSError):  # type: ignore[no-redef]
        def __init__(self, err: int | None, descr: str | None = None) -> None:
            self.err = err
            self.descr = descr


TYPE_CHECKING = False

if TYPE_CHECKING:
    from typing import IO

VK_MAP: dict[int, str] = {
    0x23: "end",  # VK_END
    0x24: "home",  # VK_HOME
    0x25: "left",  # VK_LEFT
    0x26: "up",  # VK_UP
    0x27: "right",  # VK_RIGHT
    0x28: "down",  # VK_DOWN
    0x2E: "delete",  # VK_DELETE
    0x70: "f1",  # VK_F1
    0x71: "f2",  # VK_F2
    0x72: "f3",  # VK_F3
    0x73: "f4",  # VK_F4
    0x74: "f5",  # VK_F5
    0x75: "f6",  # VK_F6
    0x76: "f7",  # VK_F7
    0x77: "f8",  # VK_F8
    0x78: "f9",  # VK_F9
    0x79: "f10",  # VK_F10
    0x7A: "f11",  # VK_F11
    0x7B: "f12",  # VK_F12
    0x7C: "f13",  # VK_F13
    0x7D: "f14",  # VK_F14
    0x7E: "f15",  # VK_F15
    0x7F: "f16",  # VK_F16
    0x79: "f17",  # VK_F17
    0x80: "f18",  # VK_F18
    0x81: "f19",  # VK_F19
    0x82: "f20",  # VK_F20
}

# Console escape codes: https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences
ERASE_IN_LINE = "\x1b[K"
MOVE_LEFT = "\x1b[{}D"
MOVE_RIGHT = "\x1b[{}C"
MOVE_UP = "\x1b[{}A"
MOVE_DOWN = "\x1b[{}B"
CLEAR = "\x1b[H\x1b[J"


class _error(Exception):
    pass


class WindowsConsole(Console):
    def __init__(
        self,
        f_in: IO[bytes] | int = 0,
        f_out: IO[bytes] | int = 1,
        term: str = "",
        encoding: str = "",
    ):
        super().__init__(f_in, f_out, term, encoding)

        SetConsoleMode(
            OutHandle,
            ENABLE_WRAP_AT_EOL_OUTPUT
            | ENABLE_PROCESSED_OUTPUT
            | ENABLE_VIRTUAL_TERMINAL_PROCESSING,
        )
        self.screen: list[str] = []
        self.width = 80
        self.height = 25
        self.__offset = 0
        self.event_queue: deque[Event] = deque()
        try:
            self.out = io._WindowsConsoleIO(self.output_fd, "w")  # type: ignore[attr-defined]
        except ValueError:
            # Console I/O is redirected, fallback...
            self.out = None

    def refresh(self, screen: list[str], c_xy: tuple[int, int]) -> None:
        """
        Refresh the console screen.

        Parameters:
        - screen (list): List of strings representing the screen contents.
        - c_xy (tuple): Cursor position (x, y) on the screen.
        """
        cx, cy = c_xy

        while len(self.screen) < min(len(screen), self.height):
            self._hide_cursor()
            self._move_relative(0, len(self.screen) - 1)
            self.__write("\n")
            self.__posxy = 0, len(self.screen)
            self.screen.append("")

        px, py = self.__posxy
        old_offset = offset = self.__offset
        height = self.height

        # we make sure the cursor is on the screen, and that we're
        # using all of the screen if we can
        if cy < offset:
            offset = cy
        elif cy >= offset + height:
            offset = cy - height + 1
            scroll_lines = offset - old_offset

            # Scrolling the buffer as the current input is greater than the visible
            # portion of the window.  We need to scroll the visible portion and the
            # entire history
            self._scroll(scroll_lines, self._getscrollbacksize())
            self.__posxy = self.__posxy[0], self.__posxy[1] + scroll_lines
            self.__offset += scroll_lines

            for i in range(scroll_lines):
                self.screen.append("")
        elif offset > 0 and len(screen) < offset + height:
            offset = max(len(screen) - height, 0)
            screen.append("")

        oldscr = self.screen[old_offset : old_offset + height]
        newscr = screen[offset : offset + height]

        self.__offset = offset

        self._hide_cursor()
        for (
            y,
            oldline,
            newline,
        ) in zip(range(offset, offset + height), oldscr, newscr):
            if oldline != newline:
                self.__write_changed_line(y, oldline, newline, px)

        y = len(newscr)
        while y < len(oldscr):
            self._move_relative(0, y)
            self.__posxy = 0, y
            self._erase_to_end()
            y += 1

        self._show_cursor()

        self.screen = screen
        self.move_cursor(cx, cy)

    @property
    def input_hook(self):
        try:
            import nt
        except ImportError:
            return None
        if nt._is_inputhook_installed():
            return nt._inputhook

    def __write_changed_line(
        self, y: int, oldline: str, newline: str, px_coord: int
    ) -> None:
        # this is frustrating; there's no reason to test (say)
        # self.dch1 inside the loop -- but alternative ways of
        # structuring this function are equally painful (I'm trying to
        # avoid writing code generators these days...)
        minlen = min(wlen(oldline), wlen(newline))
        x_pos = 0
        x_coord = 0

        px_pos = 0
        j = 0
        for c in oldline:
            if j >= px_coord:
                break
            j += wlen(c)
            px_pos += 1

        # reuse the oldline as much as possible, but stop as soon as we
        # encounter an ESCAPE, because it might be the start of an escape
        # sequene
        while (
            x_coord < minlen
            and oldline[x_pos] == newline[x_pos]
            and newline[x_pos] != "\x1b"
        ):
            x_coord += wlen(newline[x_pos])
            x_pos += 1

        self._hide_cursor()
        self._move_relative(x_coord, y)
        if wlen(oldline) > wlen(newline):
            self._erase_to_end()

        self.__write(newline[x_pos:])
        if wlen(newline) == self.width:
            # If we wrapped we want to start at the next line
            self._move_relative(0, y + 1)
            self.__posxy = 0, y + 1
        else:
            self.__posxy = wlen(newline), y

            if "\x1b" in newline or y != self.__posxy[1]:
                # ANSI escape characters are present, so we can't assume
                # anything about the position of the cursor.  Moving the cursor
                # to the left margin should work to get to a known position.
                self.move_cursor(0, y)

    def _scroll(
        self, top: int, bottom: int, left: int | None = None, right: int | None = None
    ) -> None:
        scroll_rect = SMALL_RECT()
        scroll_rect.Top = SHORT(top)
        scroll_rect.Bottom = SHORT(bottom)
        scroll_rect.Left = SHORT(0 if left is None else left)
        scroll_rect.Right = SHORT(
            self.getheightwidth()[1] - 1 if right is None else right
        )
        destination_origin = _COORD()
        fill_info = CHAR_INFO()
        fill_info.UnicodeChar = " "

        if not ScrollConsoleScreenBuffer(
            OutHandle, scroll_rect, None, destination_origin, fill_info
        ):
            raise WinError(GetLastError())

    def _hide_cursor(self):
        self.__write("\x1b[?25l")

    def _show_cursor(self):
        self.__write("\x1b[?25h")

    def _enable_blinking(self):
        self.__write("\x1b[?12h")

    def _disable_blinking(self):
        self.__write("\x1b[?12l")

    def __write(self, text: str) -> None:
        if self.out is not None:
            self.out.write(text.encode(self.encoding, "replace"))
            self.out.flush()
        else:
            os.write(self.output_fd, text.encode(self.encoding, "replace"))

    @property
    def screen_xy(self) -> tuple[int, int]:
        info = CONSOLE_SCREEN_BUFFER_INFO()
        if not GetConsoleScreenBufferInfo(OutHandle, info):
            raise WinError(GetLastError())
        return info.dwCursorPosition.X, info.dwCursorPosition.Y

    def _erase_to_end(self) -> None:
        self.__write(ERASE_IN_LINE)

    def prepare(self) -> None:
        trace("prepare")
        self.screen = []
        self.height, self.width = self.getheightwidth()

        self.__posxy = 0, 0
        self.__gone_tall = 0
        self.__offset = 0

    def restore(self) -> None:
        pass

    def _move_relative(self, x: int, y: int) -> None:
        """Moves relative to the current __posxy"""
        dx = x - self.__posxy[0]
        dy = y - self.__posxy[1]
        if dx < 0:
            self.__write(MOVE_LEFT.format(-dx))
        elif dx > 0:
            self.__write(MOVE_RIGHT.format(dx))

        if dy < 0:
            self.__write(MOVE_UP.format(-dy))
        elif dy > 0:
            self.__write(MOVE_DOWN.format(dy))

    def move_cursor(self, x: int, y: int) -> None:
        if x < 0 or y < 0:
            raise ValueError(f"Bad cursor position {x}, {y}")

        if y < self.__offset or y >= self.__offset + self.height:
            self.event_queue.insert(0, Event("scroll", ""))
        else:
            self._move_relative(x, y)
            self.__posxy = x, y

    def set_cursor_vis(self, visible: bool) -> None:
        if visible:
            self._show_cursor()
        else:
            self._hide_cursor()

    def getheightwidth(self) -> tuple[int, int]:
        """Return (height, width) where height and width are the height
        and width of the terminal window in characters."""
        info = CONSOLE_SCREEN_BUFFER_INFO()
        if not GetConsoleScreenBufferInfo(OutHandle, info):
            raise WinError(GetLastError())
        return (
            info.srWindow.Bottom - info.srWindow.Top + 1,
            info.srWindow.Right - info.srWindow.Left + 1,
        )

    def _getscrollbacksize(self) -> int:
        info = CONSOLE_SCREEN_BUFFER_INFO()
        if not GetConsoleScreenBufferInfo(OutHandle, info):
            raise WinError(GetLastError())

        return info.srWindow.Bottom  # type: ignore[no-any-return]

    def _read_input(self) -> INPUT_RECORD | None:
        rec = INPUT_RECORD()
        read = DWORD()
        if not ReadConsoleInput(InHandle, rec, 1, read):
            raise WinError(GetLastError())

        if read.value == 0:
            return None

        return rec

    def get_event(self, block: bool = True) -> Event | None:
        """Return an Event instance.  Returns None if |block| is false
        and there is no event pending, otherwise waits for the
        completion of an event."""
        if self.event_queue:
            return self.event_queue.pop()

        while True:
            rec = self._read_input()
            if rec is None:
                if block:
                    continue
                return None

            if rec.EventType == WINDOW_BUFFER_SIZE_EVENT:
                return Event("resize", "")

            if rec.EventType != KEY_EVENT or not rec.Event.KeyEvent.bKeyDown:
                # Only process keys and keydown events
                if block:
                    continue
                return None

            key = rec.Event.KeyEvent.uChar.UnicodeChar

            if rec.Event.KeyEvent.uChar.UnicodeChar == "\r":
                # Make enter make unix-like
                return Event(evt="key", data="\n", raw=b"\n")
            elif rec.Event.KeyEvent.wVirtualKeyCode == 8:
                # Turn backspace directly into the command
                return Event(
                    evt="key",
                    data="backspace",
                    raw=rec.Event.KeyEvent.uChar.UnicodeChar,
                )
            elif rec.Event.KeyEvent.uChar.UnicodeChar == "\x00":
                # Handle special keys like arrow keys and translate them into the appropriate command
                code = VK_MAP.get(rec.Event.KeyEvent.wVirtualKeyCode)
                if code:
                    return Event(
                        evt="key", data=code, raw=rec.Event.KeyEvent.uChar.UnicodeChar
                    )
                if block:
                    continue

                return None

            return Event(evt="key", data=key, raw=rec.Event.KeyEvent.uChar.UnicodeChar)

    def push_char(self, char: int | bytes) -> None:
        """
        Push a character to the console event queue.
        """
        raise NotImplementedError("push_char not supported on Windows")

    def beep(self) -> None:
        self.__write("\x07")

    def clear(self) -> None:
        """Wipe the screen"""
        self.__write(CLEAR)
        self.__posxy = 0, 0
        self.screen = [""]

    def finish(self) -> None:
        """Move the cursor to the end of the display and otherwise get
        ready for end.  XXX could be merged with restore?  Hmm."""
        y = len(self.screen) - 1
        while y >= 0 and not self.screen[y]:
            y -= 1
        self._move_relative(0, min(y, self.height + self.__offset - 1))
        self.__write("\r\n")

    def flushoutput(self) -> None:
        """Flush all output to the screen (assuming there's some
        buffering going on somewhere).

        All output on Windows is unbuffered so this is a nop"""
        pass

    def forgetinput(self) -> None:
        """Forget all pending, but not yet processed input."""
        while self._read_input() is not None:
            pass

    def getpending(self) -> Event:
        """Return the characters that have been typed but not yet
        processed."""
        return Event("key", "", b"")

    def wait(self, timeout: float | None) -> bool:
        """Wait for an event."""
        # Poor man's Windows select loop
        start_time = time.time()
        while True:
            if msvcrt.kbhit(): # type: ignore[attr-defined]
                return True
            if timeout and time.time() - start_time > timeout:
                return False
            time.sleep(0.01)

    def repaint(self) -> None:
        raise NotImplementedError("No repaint support")


# Windows interop
class CONSOLE_SCREEN_BUFFER_INFO(Structure):
    _fields_ = [
        ("dwSize", _COORD),
        ("dwCursorPosition", _COORD),
        ("wAttributes", WORD),
        ("srWindow", SMALL_RECT),
        ("dwMaximumWindowSize", _COORD),
    ]


class CONSOLE_CURSOR_INFO(Structure):
    _fields_ = [
        ("dwSize", DWORD),
        ("bVisible", BOOL),
    ]


class CHAR_INFO(Structure):
    _fields_ = [
        ("UnicodeChar", WCHAR),
        ("Attributes", WORD),
    ]


class Char(Union):
    _fields_ = [
        ("UnicodeChar", WCHAR),
        ("Char", CHAR),
    ]


class KeyEvent(ctypes.Structure):
    _fields_ = [
        ("bKeyDown", BOOL),
        ("wRepeatCount", WORD),
        ("wVirtualKeyCode", WORD),
        ("wVirtualScanCode", WORD),
        ("uChar", Char),
        ("dwControlKeyState", DWORD),
    ]


class WindowsBufferSizeEvent(ctypes.Structure):
    _fields_ = [("dwSize", _COORD)]


class ConsoleEvent(ctypes.Union):
    _fields_ = [
        ("KeyEvent", KeyEvent),
        ("WindowsBufferSizeEvent", WindowsBufferSizeEvent),
    ]


class INPUT_RECORD(Structure):
    _fields_ = [("EventType", WORD), ("Event", ConsoleEvent)]


KEY_EVENT = 0x01
FOCUS_EVENT = 0x10
MENU_EVENT = 0x08
MOUSE_EVENT = 0x02
WINDOW_BUFFER_SIZE_EVENT = 0x04

ENABLE_PROCESSED_OUTPUT = 0x01
ENABLE_WRAP_AT_EOL_OUTPUT = 0x02
ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x04

STD_INPUT_HANDLE = -10
STD_OUTPUT_HANDLE = -11

if sys.platform == "win32":
    _KERNEL32 = WinDLL("kernel32", use_last_error=True)

    GetStdHandle = windll.kernel32.GetStdHandle
    GetStdHandle.argtypes = [DWORD]
    GetStdHandle.restype = HANDLE

    GetConsoleScreenBufferInfo = _KERNEL32.GetConsoleScreenBufferInfo
    GetConsoleScreenBufferInfo.argtypes = [
        HANDLE,
        ctypes.POINTER(CONSOLE_SCREEN_BUFFER_INFO),
    ]
    GetConsoleScreenBufferInfo.restype = BOOL

    ScrollConsoleScreenBuffer = _KERNEL32.ScrollConsoleScreenBufferW
    ScrollConsoleScreenBuffer.argtypes = [
        HANDLE,
        POINTER(SMALL_RECT),
        POINTER(SMALL_RECT),
        _COORD,
        POINTER(CHAR_INFO),
    ]
    ScrollConsoleScreenBuffer.restype = BOOL

    SetConsoleMode = _KERNEL32.SetConsoleMode
    SetConsoleMode.argtypes = [HANDLE, DWORD]
    SetConsoleMode.restype = BOOL

    ReadConsoleInput = _KERNEL32.ReadConsoleInputW
    ReadConsoleInput.argtypes = [HANDLE, POINTER(INPUT_RECORD), DWORD, POINTER(DWORD)]
    ReadConsoleInput.restype = BOOL

    OutHandle = GetStdHandle(STD_OUTPUT_HANDLE)
    InHandle = GetStdHandle(STD_INPUT_HANDLE)
else:

    def _win_only(*args, **kwargs):
        raise NotImplementedError("Windows only")

    GetStdHandle = _win_only
    GetConsoleScreenBufferInfo = _win_only
    ScrollConsoleScreenBuffer = _win_only
    SetConsoleMode = _win_only
    ReadConsoleInput = _win_only
    OutHandle = 0
    InHandle = 0