"""
``astyle`` provides classes for adding style (foreground and background color;
bold; blink; etc.) to terminal and curses output.
"""


import sys, os

try:
	import curses
except ImportError:
	curses = None


__docformat__ = "reStructuredText"


COLOR_BLACK   = 0
COLOR_RED     = 1
COLOR_GREEN   = 2
COLOR_YELLOW  = 3
COLOR_BLUE    = 4
COLOR_MAGENTA = 5
COLOR_CYAN    = 6
COLOR_WHITE   = 7

A_BLINK     = 1<<0 # Blinking text
A_BOLD      = 1<<1 # Extra bright or bold text
A_DIM       = 1<<2 # Half bright text
A_REVERSE   = 1<<3 # Reverse-video text
A_STANDOUT  = 1<<4 # The best highlighting mode available
A_UNDERLINE = 1<<5 # Underlined text


class Style(object):
	"""
	Store foreground color, background color and attribute (bold, underlined
	etc.).
	"""
	__slots__ = ("fg", "bg", "attrs")

	COLORNAMES = {
		"black": COLOR_BLACK,
		"red": COLOR_RED,
		"green": COLOR_GREEN,
		"yellow": COLOR_YELLOW,
		"blue": COLOR_BLUE,
		"magenta": COLOR_MAGENTA,
		"cyan": COLOR_CYAN,
		"white": COLOR_WHITE,
	}
	ATTRNAMES = {
		"blink": A_BLINK,
		"bold": A_BOLD,
		"dim": A_DIM,
		"reverse": A_REVERSE,
		"standout": A_STANDOUT,
		"underline": A_UNDERLINE,
	}

	def __init__(self, fg, bg, attrs=0):
		"""
		Create a ``Style`` object with ``fg`` as the foreground color,
		``bg`` as the background color and ``attrs`` as the attributes.

		Examples:

			>>> Style(COLOR_RED, COLOR_BLACK)
			>>> Style(COLOR_YELLOW, COLOR_BLUE, A_BOLD|A_UNDERLINE)
		"""
		self.fg = fg
		self.bg = bg
		self.attrs = attrs

	def __call__(self, *args):
		text = Text()
		for arg in args:
			if isinstance(arg, Text):
				text.extend(arg)
			else:
				text.append((self, arg))
		return text

	def __eq__(self, other):
		return self.fg == other.fg and self.bg == other.bg and self.attrs == other.attrs

	def __ne__(self, other):
		return self.fg != other.fg or self.bg != other.bg or self.attrs != other.attrs

	def __repr__(self):
		color2name = ("black", "red", "green", "yellow", "blue", "magenta", "cyan", "white")
		attrs2name = ("blink", "bold", "dim", "reverse", "standout", "underline")

		return "<%s fg=%s bg=%s attrs=%s>" % (
			self.__class__.__name__, color2name[self.fg], color2name[self.bg],
			"|".join([attrs2name[b] for b in range(6) if self.attrs&(1<<b)]) or 0)

	def fromstr(cls, value):
		"""
		Create a ``Style`` object from a string. The format looks like this:
		``"red:black:bold|blink"``.
		"""
		# defaults
		fg = COLOR_WHITE
		bg = COLOR_BLACK
		attrs = 0

		parts = value.split(":")
		if len(parts) > 0:
			fg = cls.COLORNAMES[parts[0].lower()]
			if len(parts) > 1:
				bg = cls.COLORNAMES[parts[1].lower()]
				if len(parts) > 2:
					for strattr in parts[2].split("|"):
						attrs |= cls.ATTRNAMES[strattr.lower()]
		return cls(fg, bg, attrs)
	fromstr = classmethod(fromstr)

	def fromenv(cls, name, default):
		"""
		Create a ``Style`` from an environment variable named ``name``
		(using ``default`` if the environment variable doesn't exist).
		"""
		return cls.fromstr(os.environ.get(name, default))
	fromenv = classmethod(fromenv)


def switchstyle(s1, s2):
	"""
	Return the ANSI escape sequence needed to switch from style ``s1`` to
	style ``s2``.
	"""
	attrmask = (A_BLINK|A_BOLD|A_UNDERLINE|A_REVERSE)
	a1 = s1.attrs & attrmask
	a2 = s2.attrs & attrmask

	args = []
	if s1 != s2:
		# do we have to get rid of the bold/underline/blink bit?
		# (can only be done by a reset)
		# use reset when our target color is the default color
		# (this is shorter than 37;40)
		if (a1 & ~a2 or s2==style_default):
			args.append("0")
			s1 = style_default
			a1 = 0

		# now we know that old and new color have the same boldness,
		# or the new color is bold and the old isn't,
		# i.e. we only might have to switch bold on, not off
		if not (a1 & A_BOLD) and (a2 & A_BOLD):
			args.append("1")

		# Fix underline
		if not (a1 & A_UNDERLINE) and (a2 & A_UNDERLINE):
			args.append("4")

		# Fix blink
		if not (a1 & A_BLINK) and (a2 & A_BLINK):
			args.append("5")

		# Fix reverse
		if not (a1 & A_REVERSE) and (a2 & A_REVERSE):
			args.append("7")

		# Fix foreground color
		if s1.fg != s2.fg:
			args.append("3%d" % s2.fg)

		# Finally fix the background color
		if s1.bg != s2.bg:
			args.append("4%d" % s2.bg)

		if args:
			return "\033[%sm" % ";".join(args)
	return ""


class Text(list):
	"""
	A colored string. A ``Text`` object is a sequence, the sequence
	items will be ``(style, string)`` tuples.
	"""

	def __init__(self, *args):
		list.__init__(self)
		self.append(*args)

	def __repr__(self):
		return "%s.%s(%s)" % (
			self.__class__.__module__, self.__class__.__name__,
			list.__repr__(self)[1:-1])

	def append(self, *args):
		for arg in args:
			if isinstance(arg, Text):
				self.extend(arg)
			elif isinstance(arg, tuple): # must be (style, string)
				list.append(self, arg)
			elif isinstance(arg, str):
				list.append(self, (style_default, arg))
			else:
				list.append(self, (style_default, str(arg)))

	def insert(self, index, *args):
		self[index:index] = Text(*args)

	def __add__(self, other):
		new = Text()
		new.append(self)
		new.append(other)
		return new

	def __iadd__(self, other):
		self.append(other)
		return self

	def format(self, styled=True):
		"""
		This generator yields the strings that will make up the final
		colorized string.
		"""
		if styled:
			oldstyle = style_default
			for (style, string) in self:
				if not isinstance(style, int):
					switch = switchstyle(oldstyle, style)
					if switch:
						yield switch
					if string:
						yield string
					oldstyle = style
			switch = switchstyle(oldstyle, style_default)
			if switch:
				yield switch
		else:
			for (style, string) in self:
				if not isinstance(style, int):
					yield string

	def string(self, styled=True):
		"""
		Return the resulting string (with escape sequences, if ``styled``
		is true).
		"""
		return "".join(self.format(styled))

	def __str__(self):
		"""
		Return ``self`` as a string (without ANSI escape sequences).
		"""
		return self.string(False)

	def write(self, stream, styled=True):
		"""
		Write ``self`` to the output stream ``stream`` (with escape sequences,
		if ``styled`` is true).
		"""
		for part in self.format(styled):
			stream.write(part)


try:
	import ipipe
except ImportError:
	pass
else:
	def xrepr_astyle_text(self, mode="default"):
		yield (-1, True)
		yield from self
	try:
		ipipe.xrepr.when_type(Text)(xrepr_astyle_text)
	except Exception:
		pass


def streamstyle(stream, styled=None):
	"""
	If ``styled`` is ``None``, return whether ``stream`` refers to a terminal.
	If this can't be determined (either because ``stream`` doesn't refer to a
	real OS file, or because you're on Windows) return ``False``. If ``styled``
	is not ``None`` ``styled`` will be returned unchanged.
	"""
	if styled is None:
		try:
			styled = os.isatty(stream.fileno())
		except Exception:
			styled = False
	return styled


def write(stream, styled, *texts):
	"""
	Write ``texts`` to ``stream``.
	"""
	text = Text(*texts)
	text.write(stream, streamstyle(stream, styled))


def writeln(stream, styled, *texts):
	"""
	Write ``texts`` to ``stream`` and finish with a line feed.
	"""
	write(stream, styled, *texts)
	stream.write("\n")


class Stream(object):
	"""
	Stream wrapper that adds color output.
	"""
	def __init__(self, stream, styled=None):
		self.stream = stream
		self.styled = streamstyle(stream, styled)

	def write(self, *texts):
		write(self.stream, self.styled, *texts)

	def writeln(self, *texts):
		writeln(self.stream, self.styled, *texts)

	def __getattr__(self, name):
		return getattr(self.stream, name)


class stdout(object):
	"""
	Stream wrapper for ``sys.stdout`` that adds color output.
	"""
	def write(self, *texts):
		write(sys.stdout, None, *texts)

	def writeln(self, *texts):
		writeln(sys.stdout, None, *texts)

	def __getattr__(self, name):
		return getattr(sys.stdout, name)
stdout = stdout()


class stderr(object):
	"""
	Stream wrapper for ``sys.stderr`` that adds color output.
	"""
	def write(self, *texts):
		write(sys.stderr, None, *texts)

	def writeln(self, *texts):
		writeln(sys.stderr, None, *texts)

	def __getattr__(self, name):
		return getattr(sys.stdout, name)
stderr = stderr()


if curses is not None:
	# This is probably just range(8)
	COLOR2CURSES = [
		COLOR_BLACK,
		COLOR_RED,
		COLOR_GREEN,
		COLOR_YELLOW,
		COLOR_BLUE,
		COLOR_MAGENTA,
		COLOR_CYAN,
		COLOR_WHITE,
	]

	A2CURSES = {
		A_BLINK: curses.A_BLINK,
		A_BOLD: curses.A_BOLD,
		A_DIM: curses.A_DIM,
		A_REVERSE: curses.A_REVERSE,
		A_STANDOUT: curses.A_STANDOUT,
		A_UNDERLINE: curses.A_UNDERLINE,
	}


# default style
style_default = Style.fromstr("white:black")

# Styles for datatypes
style_type_none = Style.fromstr("magenta:black")
style_type_bool = Style.fromstr("magenta:black")
style_type_number = Style.fromstr("yellow:black")
style_type_datetime = Style.fromstr("magenta:black")
style_type_type = Style.fromstr("cyan:black")

# Style for URLs and file/directory names
style_url = Style.fromstr("green:black")
style_dir = Style.fromstr("cyan:black")
style_file = Style.fromstr("green:black")

# Style for ellipsis (when an output has been shortened)
style_ellisis = Style.fromstr("red:black")

# Style for displaying warnings/errors/exceptions
style_warn = Style.fromstr("yellow:black")
style_error = Style.fromstr("red:black")

# Style for displaying non-existing attributes
style_nodata = Style.fromstr("red:black")
