#  Copyright 2008-2015 Nokia Solutions and Networks
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

# Windows highlighting code adapted from color_console.py. It is copyright
# Andre Burgaud, licensed under the MIT License, and available here:
# http://www.burgaud.com/bring-colors-to-the-windows-console-with-python/

from contextlib import contextmanager
import os
import sys
try:
    from ctypes import windll, Structure, c_short, c_ushort, byref
except ImportError:  # Not on Windows or using Jython
    windll = None

from robot.errors import DataError
from robot.utils import console_encode, isatty, WINDOWS


class HighlightingStream(object):

    def __init__(self, stream, colors='AUTO'):
        self.stream = stream
        self._highlighter = self._get_highlighter(stream, colors)

    def _get_highlighter(self, stream, colors):
        options = {'AUTO': Highlighter if isatty(stream) else NoHighlighting,
                   'ON': Highlighter,
                   'OFF': NoHighlighting,
                   'ANSI': AnsiHighlighter}
        try:
            highlighter = options[colors.upper()]
        except KeyError:
            raise DataError("Invalid console color value '%s'. Available "
                            "'AUTO', 'ON', 'OFF' and 'ANSI'." % colors)
        return highlighter(stream)

    def write(self, text, flush=True):
        self.stream.write(console_encode(text, stream=self.stream))
        if flush:
            self.flush()

    def flush(self):
        self.stream.flush()

    def highlight(self, text, status=None, flush=True):
        if self._must_flush_before_and_after_highlighting():
            self.flush()
            flush = True
        with self._highlighting(status or text):
            self.write(text, flush)

    def _must_flush_before_and_after_highlighting(self):
        # Must flush on Windows before and after highlighting to make sure set
        # console colors only affect the actual highlighted text. Problems
        # only encountered with Python 3, but better to be safe than sorry.
        return WINDOWS and not isinstance(self._highlighter, NoHighlighting)

    def error(self, message, level):
        self.write('[ ', flush=False)
        self.highlight(level, flush=False)
        self.write(' ] %s\n' % message)

    @contextmanager
    def _highlighting(self, status):
        highlighter = self._highlighter
        start = {'PASS': highlighter.green,
                 'FAIL': highlighter.red,
                 'ERROR': highlighter.red,
                 'WARN': highlighter.yellow}[status]
        start()
        try:
            yield
        finally:
            highlighter.reset()


def Highlighter(stream):
    if os.sep == '/':
        return AnsiHighlighter(stream)
    return DosHighlighter(stream) if windll else NoHighlighting(stream)


class AnsiHighlighter(object):
    _ANSI_GREEN = '\033[32m'
    _ANSI_RED = '\033[31m'
    _ANSI_YELLOW = '\033[33m'
    _ANSI_RESET = '\033[0m'

    def __init__(self, stream):
        self._stream = stream

    def green(self):
        self._set_color(self._ANSI_GREEN)

    def red(self):
        self._set_color(self._ANSI_RED)

    def yellow(self):
        self._set_color(self._ANSI_YELLOW)

    def reset(self):
        self._set_color(self._ANSI_RESET)

    def _set_color(self, color):
        self._stream.write(color)


class NoHighlighting(AnsiHighlighter):

    def _set_color(self, color):
        pass


class DosHighlighter(object):
    _FOREGROUND_GREEN = 0x2
    _FOREGROUND_RED = 0x4
    _FOREGROUND_YELLOW = 0x6
    _FOREGROUND_GREY = 0x7
    _FOREGROUND_INTENSITY = 0x8
    _BACKGROUND_MASK = 0xF0
    _STDOUT_HANDLE = -11
    _STDERR_HANDLE = -12

    def __init__(self, stream):
        self._handle = self._get_std_handle(stream)
        self._orig_colors = self._get_colors()
        self._background = self._orig_colors & self._BACKGROUND_MASK

    def green(self):
        self._set_foreground_colors(self._FOREGROUND_GREEN)

    def red(self):
        self._set_foreground_colors(self._FOREGROUND_RED)

    def yellow(self):
        self._set_foreground_colors(self._FOREGROUND_YELLOW)

    def reset(self):
        self._set_colors(self._orig_colors)

    def _get_std_handle(self, stream):
        handle = self._STDOUT_HANDLE \
            if stream is sys.__stdout__ else self._STDERR_HANDLE
        return windll.kernel32.GetStdHandle(handle)

    def _get_colors(self):
        csbi = _CONSOLE_SCREEN_BUFFER_INFO()
        ok = windll.kernel32.GetConsoleScreenBufferInfo(self._handle, byref(csbi))
        if not ok:  # Call failed, return default console colors (gray on black)
            return self._FOREGROUND_GREY
        return csbi.wAttributes

    def _set_foreground_colors(self, colors):
        self._set_colors(colors | self._FOREGROUND_INTENSITY | self._background)

    def _set_colors(self, colors):
        windll.kernel32.SetConsoleTextAttribute(self._handle, colors)


if windll:

    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_ = [("dwSize", _COORD),
                    ("dwCursorPosition", _COORD),
                    ("wAttributes", c_ushort),
                    ("srWindow", _SMALL_RECT),
                    ("dwMaximumWindowSize", _COORD)]
