#!/usr/bin/env python
# encoding: utf-8

"""
Emulate a vt100 terminal in cmd.exe

By wrapping sys.stdout / sys.stderr with Ansiterm,
the vt100 escape characters will be interpreted and
the equivalent actions will be performed with Win32
console commands.

"""

import sys, os, re, threading

try:
	if not (sys.stderr.isatty() and sys.stdout.isatty()):
		raise ValueError('not a tty')

	from ctypes import Structure, windll, c_short, c_ulong, c_int, byref, c_wchar

	class COORD(Structure):
		_fields_ = [("X", c_short), ("Y", c_short)]

	class SMALL_RECT(Structure):
		_fields_ = [("Left", c_short), ("Top", c_short), ("Right", c_short), ("Bottom", c_short)]

	class CONSOLE_SCREEN_BUFFER_INFO(Structure):
		_fields_ = [("Size", COORD), ("CursorPosition", COORD), ("Attributes", c_short), ("Window", SMALL_RECT), ("MaximumWindowSize", COORD)]

	class CONSOLE_CURSOR_INFO(Structure):
		_fields_ = [('dwSize',c_ulong), ('bVisible', c_int)]

	sbinfo = CONSOLE_SCREEN_BUFFER_INFO()
	csinfo = CONSOLE_CURSOR_INFO()
	hconsole = windll.kernel32.GetStdHandle(-11)
	windll.kernel32.GetConsoleScreenBufferInfo(hconsole, byref(sbinfo))
	if sbinfo.Size.X < 9 or sbinfo.Size.Y < 9: raise ValueError('small console')
	windll.kernel32.GetConsoleCursorInfo(hconsole, byref(csinfo))
except Exception:
	pass
else:
	is_vista = getattr(sys, "getwindowsversion", None) and sys.getwindowsversion()[0] >= 6

	try:
		_type = unicode
	except NameError:
		_type = str

	to_int = lambda number, default: number and int(number) or default
	wlock = threading.Lock()

	STD_OUTPUT_HANDLE = -11
	STD_ERROR_HANDLE = -12

	class AnsiTerm(object):
		"""
		emulate a vt100 terminal in cmd.exe
		"""
		def __init__(self):
			self.encoding = sys.stdout.encoding
			self.hconsole = windll.kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
			self.cursor_history = []
			self.orig_sbinfo = CONSOLE_SCREEN_BUFFER_INFO()
			windll.kernel32.GetConsoleScreenBufferInfo(self.hconsole, byref(self.orig_sbinfo))

		def screen_buffer_info(self):
			sbinfo = CONSOLE_SCREEN_BUFFER_INFO()
			windll.kernel32.GetConsoleScreenBufferInfo(self.hconsole, byref(sbinfo))
			return sbinfo

		def clear_line(self, param):
			mode = param and int(param) or 0
			sbinfo = self.screen_buffer_info()
			if mode == 1: # Clear from begining of line to cursor position
				line_start = COORD(0, sbinfo.CursorPosition.Y)
				line_length = sbinfo.Size.X
			elif mode == 2: # Clear entire line
				line_start = COORD(sbinfo.CursorPosition.X, sbinfo.CursorPosition.Y)
				line_length = sbinfo.Size.X - sbinfo.CursorPosition.X
			else: # Clear from cursor position to end of line
				line_start = sbinfo.CursorPosition
				line_length = sbinfo.Size.X - sbinfo.CursorPosition.X
			chars_written = c_int()
			windll.kernel32.FillConsoleOutputCharacterA(self.hconsole, c_wchar(' '), line_length, line_start, byref(chars_written))
			windll.kernel32.FillConsoleOutputAttribute(self.hconsole, sbinfo.Attributes, line_length, line_start, byref(chars_written))

		def clear_screen(self, param):
			mode = to_int(param, 0)
			sbinfo = self.screen_buffer_info()
			if mode == 1: # Clear from begining of screen to cursor position
				clear_start = COORD(0, 0)
				clear_length = sbinfo.CursorPosition.X * sbinfo.CursorPosition.Y
			elif mode == 2: # Clear entire screen and return cursor to home
				clear_start = COORD(0, 0)
				clear_length = sbinfo.Size.X * sbinfo.Size.Y
				windll.kernel32.SetConsoleCursorPosition(self.hconsole, clear_start)
			else: # Clear from cursor position to end of screen
				clear_start = sbinfo.CursorPosition
				clear_length = ((sbinfo.Size.X - sbinfo.CursorPosition.X) + sbinfo.Size.X * (sbinfo.Size.Y - sbinfo.CursorPosition.Y))
			chars_written = c_int()
			windll.kernel32.FillConsoleOutputCharacterA(self.hconsole, c_wchar(' '), clear_length, clear_start, byref(chars_written))
			windll.kernel32.FillConsoleOutputAttribute(self.hconsole, sbinfo.Attributes, clear_length, clear_start, byref(chars_written))

		def push_cursor(self, param):
			sbinfo = self.screen_buffer_info()
			self.cursor_history.append(sbinfo.CursorPosition)

		def pop_cursor(self, param):
			if self.cursor_history:
				old_pos = self.cursor_history.pop()
				windll.kernel32.SetConsoleCursorPosition(self.hconsole, old_pos)

		def set_cursor(self, param):
			y, sep, x = param.partition(';')
			x = to_int(x, 1) - 1
			y = to_int(y, 1) - 1
			sbinfo = self.screen_buffer_info()
			new_pos = COORD(
				min(max(0, x), sbinfo.Size.X),
				min(max(0, y), sbinfo.Size.Y)
			)
			windll.kernel32.SetConsoleCursorPosition(self.hconsole, new_pos)

		def set_column(self, param):
			x = to_int(param, 1) - 1
			sbinfo = self.screen_buffer_info()
			new_pos = COORD(
				min(max(0, x), sbinfo.Size.X),
				sbinfo.CursorPosition.Y
			)
			windll.kernel32.SetConsoleCursorPosition(self.hconsole, new_pos)

		def move_cursor(self, x_offset=0, y_offset=0):
			sbinfo = self.screen_buffer_info()
			new_pos = COORD(
				min(max(0, sbinfo.CursorPosition.X + x_offset), sbinfo.Size.X),
				min(max(0, sbinfo.CursorPosition.Y + y_offset), sbinfo.Size.Y)
			)
			windll.kernel32.SetConsoleCursorPosition(self.hconsole, new_pos)

		def move_up(self, param):
			self.move_cursor(y_offset = -to_int(param, 1))

		def move_down(self, param):
			self.move_cursor(y_offset = to_int(param, 1))

		def move_left(self, param):
			self.move_cursor(x_offset = -to_int(param, 1))

		def move_right(self, param):
			self.move_cursor(x_offset = to_int(param, 1))

		def next_line(self, param):
			sbinfo = self.screen_buffer_info()
			self.move_cursor(
				x_offset = -sbinfo.CursorPosition.X,
				y_offset = to_int(param, 1)
			)

		def prev_line(self, param):
			sbinfo = self.screen_buffer_info()
			self.move_cursor(
				x_offset = -sbinfo.CursorPosition.X,
				y_offset = -to_int(param, 1)
			)

		def rgb2bgr(self, c):
			return ((c&1) << 2) | (c&2) | ((c&4)>>2)

		def set_color(self, param):
			cols = param.split(';')
			sbinfo = CONSOLE_SCREEN_BUFFER_INFO()
			windll.kernel32.GetConsoleScreenBufferInfo(self.hconsole, byref(sbinfo))
			attr = sbinfo.Attributes
			for c in cols:
				if is_vista:
					c = int(c)
				else:
					c = to_int(c, 0)
				if c in range(30,38): # fgcolor
					attr = (attr & 0xfff0) | self.rgb2bgr(c-30)
				elif c in range(40,48): # bgcolor
					attr = (attr & 0xff0f) | (self.rgb2bgr(c-40) << 4)
				elif c == 0: # reset
					attr = self.orig_sbinfo.Attributes
				elif c == 1: # strong
					attr |= 0x08
				elif c == 4: # blink not available -> bg intensity
					attr |= 0x80
				elif c == 7: # negative
					attr = (attr & 0xff88) | ((attr & 0x70) >> 4) | ((attr & 0x07) << 4)
			windll.kernel32.SetConsoleTextAttribute(self.hconsole, attr)

		def show_cursor(self,param):
			csinfo.bVisible = 1
			windll.kernel32.SetConsoleCursorInfo(self.hconsole, byref(csinfo))

		def hide_cursor(self,param):
			csinfo.bVisible = 0
			windll.kernel32.SetConsoleCursorInfo(self.hconsole, byref(csinfo))

		ansi_command_table = {
			'A': move_up,
			'B': move_down,
			'C': move_right,
			'D': move_left,
			'E': next_line,
			'F': prev_line,
			'G': set_column,
			'H': set_cursor,
			'f': set_cursor,
			'J': clear_screen,
			'K': clear_line,
			'h': show_cursor,
			'l': hide_cursor,
			'm': set_color,
			's': push_cursor,
			'u': pop_cursor,
		}
		# Match either the escape sequence or text not containing escape sequence
		ansi_tokens = re.compile('(?:\x1b\[([0-9?;]*)([a-zA-Z])|([^\x1b]+))')
		def write(self, text):
			try:
				wlock.acquire()
				for param, cmd, txt in self.ansi_tokens.findall(text):
					if cmd:
						cmd_func = self.ansi_command_table.get(cmd)
						if cmd_func:
							cmd_func(self, param)
					else:
						self.writeconsole(txt)
			finally:
				wlock.release()

		def writeconsole(self, txt):
			chars_written = c_int()
			writeconsole = windll.kernel32.WriteConsoleA
			if isinstance(txt, _type):
				writeconsole = windll.kernel32.WriteConsoleW

			TINY_STEP = 3000
			for x in range(0, len(txt), TINY_STEP):
				# According MSDN, size should NOT exceed 64 kb (issue #746)
				tiny = txt[x : x + TINY_STEP]
				writeconsole(self.hconsole, tiny, len(tiny), byref(chars_written), None)

		def flush(self):
			pass

		def isatty(self):
			return True

	sys.stderr = sys.stdout = AnsiTerm()
	os.environ['TERM'] = 'vt100'