# Copyright (C) 2006-2007 Red Hat, Inc.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.

import logging
import re

import gobject
import gtk
import hippo
import rsvg
import cairo
import time

from sugar.graphics.xocolor import XoColor
from sugar.graphics import style
from sugar.graphics.palette import Palette, CanvasInvoker

class _IconCacheIcon:
    def __init__(self, name, fill_color, stroke_color, now):
        self.data_size = None
        self.handle = self._read_icon_data(name, fill_color, stroke_color)
        self.last_used = now
        self.usage_count = 1

    def _read_icon_data(self, filename, fill_color, stroke_color):
        icon_file = open(filename, 'r')
        data = icon_file.read()
        icon_file.close()

        if fill_color:
            entity = '<!ENTITY fill_color "%s">' % fill_color
            data = re.sub('<!ENTITY fill_color .*>', entity, data)

        if stroke_color:
            entity = '<!ENTITY stroke_color "%s">' % stroke_color
            data = re.sub('<!ENTITY stroke_color .*>', entity, data)

        self.data_size = len(data)
        return rsvg.Handle(data=data)

class _IconCache:
    _CACHE_MAX = 50000   # in bytes

    def __init__(self):
        self._icons = {}
        self._theme = gtk.icon_theme_get_default()
        self._cache_size = 0

    def _get_real_name_from_theme(self, name):
        info = self._theme.lookup_icon(name, 50, 0)
        if not info:
            raise ValueError("Icon '" + name + "' not found.")
        fname = info.get_filename()
        del info
        return fname

    def _cache_cleanup(self, key, now):
        while self._cache_size > self._CACHE_MAX:
            evict_key = None
            oldest_key = None
            oldest_time = now
            for icon_key, icon in self._icons.items():
                # Don't evict the icon we are about to use if it's in the cache
                if icon_key == key:
                    continue

                # evict large icons first
                if icon.data_size > self._CACHE_MAX:
                    evict_key = icon_key
                    break
                # evict older icons next; those used over 2 minutes ago
                if icon.last_used < now - 120:
                    evict_key = icon_key
                    break
                # otherwise, evict the oldest
                if oldest_time > icon.last_used:
                    oldest_time = icon.last_used
                    oldest_key = icon_key

            # If there's nothing specific to evict, try evicting
            # the oldest thing
            if not evict_key:
                if not oldest_key:
                    break
                evict_key = oldest_key

            self._cache_size -= self._icons[evict_key].data_size
            del self._icons[evict_key]

    def get_handle(self, name, fill_color, stroke_color):
        if not name:
            return None

        if name[0:6] == "theme:": 
            name = self._get_real_name_from_theme(name[6:])

        if fill_color or stroke_color:
            key = (name, fill_color, stroke_color)
        else:
            key = name

        # If we're over the cache limit, evict something from the cache
        now = time.time()
        self._cache_cleanup(key, now)

        if self._icons.has_key(key):
            icon = self._icons[key]
            icon.usage_count += 1
            icon.last_used = now
        else:
            icon = _IconCacheIcon(name, fill_color, stroke_color, now)
            self._icons[key] = icon
            self._cache_size += icon.data_size
        return icon.handle


class CanvasIcon(hippo.CanvasBox, hippo.CanvasItem):
    __gtype_name__ = 'CanvasIcon'

    __gproperties__ = {
        'icon-name'     : (str, None, None, None,
                           gobject.PARAM_READWRITE),
        'xo-color'      : (object, None, None,
                           gobject.PARAM_WRITABLE),
        'fill-color'    : (object, None, None,
                           gobject.PARAM_READWRITE),
        'stroke-color'  : (object, None, None,
                           gobject.PARAM_READWRITE),
        'size'          : (int, None, None, 0, 1024, 0,
                           gobject.PARAM_READWRITE),
        'cache'         : (bool, None, None, False,
                           gobject.PARAM_READWRITE),
        'active'        : (bool, None, None, True,
                           gobject.PARAM_READWRITE),
        'badge-name'    : (str, None, None, None,
                           gobject.PARAM_READWRITE)
    }

    _cache = _IconCache()

    def __init__(self, **kwargs):
        self._buffers = {}
        self._cur_buffer = None
        self._size = 0
        self._fill_color = None
        self._stroke_color = None
        self._icon_name = None
        self._cache = False
        self._handle = None
        self._active = True
        self._palette = None
        self._badge_name = None
        self._badge_handle = None

        hippo.CanvasBox.__init__(self, **kwargs)
        
        self.connect_after('motion-notify-event', self._motion_notify_event_cb)

    def _clear_buffers(self):
        icon_key = self._get_current_buffer_key(self._icon_name)
        badge_key = None
        if self._badge_name:
            badge_key = self._get_current_buffer_key(self._badge_name)
        for key in self._buffers.keys():
            if key != icon_key:
                if not badge_key or (key != badge_key):
                    del self._buffers[key]
        self._buffers = {}

    def do_set_property(self, pspec, value):
        if pspec.name == 'icon-name':
            if self._icon_name != value and not self._cache:
                self._clear_buffers()
            self._icon_name = value
            self._handle = None
            self.emit_paint_needed(0, 0, -1, -1)
        elif pspec.name == 'xo-color':
            self.props.fill_color = style.Color(value.get_fill_color())
            self.props.stroke_color = style.Color(value.get_stroke_color())
        elif pspec.name == 'fill-color':
            if self._fill_color != value:
                if not self._cache:
                    self._clear_buffers()
                self._fill_color = value
                self._handle = None
                self.emit_paint_needed(0, 0, -1, -1)
        elif pspec.name == 'stroke-color':
            if self._stroke_color != value:
                if not self._cache:
                    self._clear_buffers()
                self._stroke_color = value
                self._handle = None
                self.emit_paint_needed(0, 0, -1, -1)
        elif pspec.name == 'size':
            if self._size != value and not self._cache:
                self._clear_buffers()
            self._size = value
            self.emit_request_changed()
        elif pspec.name == 'cache':
            self._cache = value
        elif pspec.name == 'active':
            if self._active != value:
                if not self._cache:
                    self._clear_buffers()
                self._active = value
                self._handle = None
                self.emit_paint_needed(0, 0, -1, -1)
        elif pspec.name == 'badge-name':
            if self._badge_name != value and not self._cache:
                self._clear_buffers()
            self._badge_name = value
            self._badge_handle = None
            self.emit_paint_needed(0, 0, -1, -1)

    def _choose_colors(self):
        fill_color = None
        stroke_color = None
        if self._active:
            if self._fill_color:
                fill_color = self._fill_color.get_svg()
            if self._stroke_color:
                stroke_color = self._stroke_color.get_svg()
        else:
            stroke_color = color.ICON_STROKE_INACTIVE.get_svg()
            if self._fill_color:
                fill_color = self._fill_color.get_svg()
        return [fill_color, stroke_color]

    def _get_handle(self, name, handle):
        if not handle:
            cache = CanvasIcon._cache

            [fill_color, stroke_color] = self._choose_colors()

            handle = cache.get_handle(name, fill_color, stroke_color)
        return handle

    def _get_icon_handle(self):
        self._handle = self._get_handle(self._icon_name, self._handle)
        return self._handle

    def _get_badge_handle(self):
        self._badge_handle = self._get_handle(self._badge_name,
                                              self._badge_handle)
        return self._badge_handle

    def _get_current_buffer_key(self, name):
        [fill_color, stroke_color] = self._choose_colors()
        return (name, fill_color, stroke_color, self._size)

    def do_get_property(self, pspec):
        if pspec.name == 'size':
            return self._size
        elif pspec.name == 'icon-name':
            return self._icon_name
        elif pspec.name == 'fill-color':
            return self._fill_color
        elif pspec.name == 'stroke-color':
            return self._stroke_color
        elif pspec.name == 'cache':
            return self._cache
        elif pspec.name == 'active':
            return self._active
        elif pspec.name == 'badge-name':
            return self._badge_name

    def _get_icon_size(self, handle):
        if handle:
            dimensions = handle.get_dimension_data()
            return int(dimensions[0]), int(dimensions[1])
        else:
            return [0, 0]

    def _get_size(self, handle):
        if self._size == 0:
            width, height = self._get_icon_size(handle)
        else:
            width = height = self._size

        return [width, height]

    def _get_buffer(self, cr, name, handle, scale_factor=None):
        """Return a cached cairo surface for the SVG handle, or if none exists,
        create a new cairo surface with the right size."""
        buf = None

        key = self._get_current_buffer_key(name)
        if self._buffers.has_key(key):
            buf = self._buffers[key]
        else:
            [icon_w, icon_h] = self._get_icon_size(handle)
            [target_w, target_h] = self._get_size(handle)

            if scale_factor:
                target_w = target_w * scale_factor
                target_h = target_h * scale_factor

            target = cr.get_target()
            buf = target.create_similar(cairo.CONTENT_COLOR_ALPHA,
                                        target_w, target_h)
            ctx = cairo.Context(buf)
            ctx.scale(float(target_w) / float(icon_w),
                      float(target_h) / float(icon_h))
            handle.render_cairo(ctx)

            del ctx
            self._buffers[key] = buf

        return buf

    def do_paint_below_children(self, cr, damaged_box):
        handle = self._get_icon_handle()
        if handle == None:
            return

        icon_buf = self._get_buffer(cr, self._icon_name, handle)
        [width, height] = self.get_allocation()
        icon_x = (width - icon_buf.get_width()) / 2
        icon_y = (height - icon_buf.get_height()) / 2

        cr.set_source_surface(icon_buf, icon_x, icon_y)
        cr.paint()

        if self._badge_name:
            badge_handle = self._get_badge_handle()
            if badge_handle:
                badge_buf = self._get_buffer(cr, self._badge_name, badge_handle, 0.66)
                badge_x = icon_x + icon_buf.get_width() - (icon_buf.get_width() / 4)
                badge_y = icon_y + icon_buf.get_height() - (icon_buf.get_height() / 4)
                cr.set_source_surface(badge_buf, badge_x, badge_y)
                cr.paint()

    def do_get_content_width_request(self):
        handle = self._get_icon_handle()
        [width, height] = self._get_size(handle)
        return (width, width)

    def do_get_content_height_request(self, for_width):
        handle = self._get_icon_handle()
        [width, height] = self._get_size(handle)
        return (height, height)

    def do_button_press_event(self, event):
        self.emit_activated()
        return True

    def _motion_notify_event_cb(self, button, event):
        if event.detail == hippo.MOTION_DETAIL_ENTER:
            self.prelight(True)
        elif event.detail == hippo.MOTION_DETAIL_LEAVE:
            self.prelight(False)
        return False

    def prelight(self, enter):
        """
        Override this method for adding prelighting behavior.
        """
        pass

    def get_palette(self):
        return self._palette
    
    def set_palette(self, palette):
        self._palette = palette
        if not self._palette.props.invoker:
            self._palette.props.invoker = CanvasInvoker(self)

    def set_tooltip(self, text):
        self.set_palette(Palette(text))
    
    palette = property(get_palette, set_palette)

def get_icon_state(base_name, perc):
        step = 5
        strength = round(perc / step) * step
        icon_theme = gtk.icon_theme_get_default()

        while strength <= 100:
            icon_name = '%s-%03d' % (base_name, strength)
            if icon_theme.has_icon(icon_name):
                return 'theme:' + icon_name

            strength = strength + step