# Copyright 2007 Mitchell N. Charity
# Copyright 2009, 2012 Walter Bender
# Copyright 2012 Flavio Danesse
#
# This file is part of Ruler.
#
# Ruler is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ruler 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 for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ruler.  If not, see <http://www.gnu.org/licenses/>

import gi
from gi.repository import Gtk
from gi.repository import Gdk
from gi.repository import GObject

import dbus

import os
import subprocess
from string import find

from gi.repository import Pango
from gi.repository import PangoCairo

XO1 = 'xo1'
XO15 = 'xo1.5'
XO175 = 'xo1.75'
UNKNOWN = 'unknown'


def get_hardware():
    """ Determine whether we are using XO 1.0, 1.5, or "unknown" hardware """
    product = _get_dmi('product_name')
    if product is None:
        if os.path.exists('/etc/olpc-release') or \
           os.path.exists('/sys/power/olpc-pm'):
            return XO1
        elif os.path.exists('/sys/devices/platform/lis3lv02d/position'):
            return XO175  # FIXME: temporary check for XO 1.75
        else:
            return UNKNOWN
    if product != 'XO':
        return UNKNOWN
    version = _get_dmi('product_version')
    if version == '1':
        return XO1
    elif version == '1.5':
        return XO15
    else:
        return XO175


def _get_dmi(node):
    ''' The desktop management interface should be a reliable source
    for product and version information. '''
    path = os.path.join('/sys/class/dmi/id', node)
    try:
        return open(path).readline().strip()
    except:
        return None


def mm(dpi, n):
    """ Convert n pixels to units mm """
    return n / 25.40 * dpi


def dimensions_mm(dpi, w, h):
    """ Return screen width, height in units mm """
    return int(w * 25.40 / dpi), int(h * 25.40 / dpi)


def calc_dpi():
    xft_dpi = Gtk.Settings.get_default().get_property('gtk-xft-dpi')
    dpi = float(xft_dpi / 1024)
    return dpi, True

#
# Cairo-related utilities
#
def set_background_color(c, w, h):
    c.save()
    c.rectangle(0, 0, w, h)
    Gdk.cairo_set_source_color(c, Gdk.color_parse('white'))
    c.fill()
    c.restore()


def set_color(c, name):
    Gdk.cairo_set_source_color(c, Gdk.color_parse(name))


def write(c, text, name, size, centered=False, at_top=False):
    pc = PangoCairo.create_context(c)

    font = Pango.FontDescription(name)
    font.set_size(int(round(size * Pango.SCALE)))
    lo = PangoCairo.create_layout(pc)
    lo.set_font_description(font)
    lo.set_text('X', -1)
    baseline_offset = lo.get_baseline() / Pango.SCALE
    if not at_top:
        c.rel_move_to(0, -baseline_offset)

    lo.set_font_description(font)
    lo.set_text(text, -1)
    if hasattr(lo, 'get_logical_extents'):
        extents = lo.get_logical_extents()
        ex = extents.get_width() / Pango.SCALE
    else:
        ex = size
        ex *= len(text)

    if centered:
        c.rel_move_to(-ex / 2, 0)
    PangoCairo.update_layout(c, lo)
    PangoCairo.show_layout(c, lo)
    c.rel_move_to(ex, 0)

    if not at_top:
        c.rel_move_to(0, -baseline_offset)


def check_output(command, warning):
    ''' Workaround for old systems without subprocess.check_output'''
    if hasattr(subprocess, 'check_output'):
        try:
            output = subprocess.check_output(command)
        except subprocess.CalledProcessError:
            log.warning(warning)
            return None
    else:
        import commands

        cmd = ''
        for c in command:
            cmd += c
            cmd += ' '
        (status, output) = commands.getstatusoutput(cmd)
        if status != 0:
            log.warning(warning)
            return None
    return output