# Copyright (C) 2007, One Laptop Per Child
#
# This program 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 2 of the License, or
# (at your option) any later version.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

import os
import logging
from gettext import gettext as _

import gobject
import dbus

from sugar import profile
from sugar.datastore import datastore

HAL_SERVICE_NAME = 'org.freedesktop.Hal'
HAL_MANAGER_PATH = '/org/freedesktop/Hal/Manager'
HAL_MANAGER_IFACE = 'org.freedesktop.Hal.Manager'
HAL_DEVICE_IFACE = 'org.freedesktop.Hal.Device'
HAL_VOLUME_IFACE = 'org.freedesktop.Hal.Device.Volume'

MOUNT_OPTION_UID = 500
MOUNT_OPTION_UMASK = 000

_volumes_manager = None

class VolumesManager(gobject.GObject):

    __gtype_name__ = 'VolumesManager'

    __gsignals__ = {
        'volume-added': (gobject.SIGNAL_RUN_FIRST,
                         gobject.TYPE_NONE,
                         ([object])),
        'volume-removed': (gobject.SIGNAL_RUN_FIRST,
                           gobject.TYPE_NONE,
                           ([object]))
    }

    def __init__(self):
        gobject.GObject.__init__(self)

        self._volumes = []

        # Internal flash is not in HAL
        internal_fash_id = datastore.mounts()[0]['id']
        self._volumes.append(Volume(internal_fash_id, _('Journal'),
                                    'activity-journal', profile.get_color(),
                                    None, False))

        bus = dbus.SystemBus()
        proxy = bus.get_object(HAL_SERVICE_NAME, HAL_MANAGER_PATH)
        self._hal_manager = dbus.Interface(proxy, HAL_MANAGER_IFACE)
        self._hal_manager.connect_to_signal('DeviceAdded', self._hal_device_added_cb)

        for udi in self._hal_manager.FindDeviceByCapability('volume'):
            if self._is_device_relevant(udi):
                try:
                    self._add_hal_device(udi)
                except Exception, e:
                    logging.error('Exception when mounting device %r: %r' % (udi, e))

    def get_volumes(self):
        return self._volumes

    def _get_volume_by_udi(self, udi):
        for volume in self._volumes:
            if volume.udi == udi:
                return volume
        return None

    def _hal_device_added_cb(self, udi):
        bus = dbus.SystemBus()
        device_object = bus.get_object(HAL_SERVICE_NAME, udi)
        device = dbus.Interface(device_object, HAL_DEVICE_IFACE)
        if device.QueryCapability('volume'):
            logging.debug('VolumesManager._hal_device_added_cb: %r', udi)
            if self._is_device_relevant(udi):
                self._add_hal_device(udi)

    def _is_device_relevant(self, udi):
        bus = dbus.SystemBus()
        device_object = bus.get_object(HAL_SERVICE_NAME, udi)
        device = dbus.Interface(device_object, HAL_DEVICE_IFACE)

        # Ignore volumes without a filesystem.
        if device.GetProperty('volume.fsusage') != 'filesystem':
            return False
        # Ignore root.        
        if device.GetProperty('volume.mount_point') == '/':
            return False

        storage_udi = device.GetProperty('block.storage_device')
        obj = bus.get_object(HAL_SERVICE_NAME, storage_udi)
        storage_device = dbus.Interface(obj, HAL_DEVICE_IFACE)

        # Ignore non-removable storage.        
        if not storage_device.GetProperty('storage.hotpluggable'):
            return False

        return True
            
    def _add_hal_device(self, udi):
        logging.debug('VolumeToolbar._add_hal_device: %r' % udi)

        bus = dbus.SystemBus()
        device_object = bus.get_object(HAL_SERVICE_NAME, udi)
        device = dbus.Interface(device_object, HAL_DEVICE_IFACE)

        # listen to mount/unmount
        device.connect_to_signal('PropertyModified',
                lambda *args: self._hal_device_property_modified_cb(udi, *args))

        bus.add_signal_receiver(self._hal_device_removed_cb,
                                'DeviceRemoved', 
                                HAL_MANAGER_IFACE, HAL_SERVICE_NAME,
                                HAL_MANAGER_PATH, arg0=udi)

        if device.GetProperty('volume.is_mounted'):
            volume_id = self._mount_in_datastore(udi)
            return
        
        label = device.GetProperty('volume.label')
        fs_type = device.GetProperty('volume.fstype')
        valid_options = device.GetProperty('volume.mount.valid_options')
        options = []

        if 'uid=' in valid_options:
            options.append('uid=%i' % MOUNT_OPTION_UID)

        if 'umask=' in valid_options:
            options.append('umask=%i' % MOUNT_OPTION_UMASK)

        if 'noatime' in valid_options:
            options.append('noatime')

        if 'utf8' in valid_options:
            options.append('utf8')

        if 'iocharset=' in valid_options:
            options.append('iocharset=utf8')

        mount_point = label
        if not mount_point:
            mount_point = device.GetProperty('volume.uuid')

        volume = dbus.Interface(device_object, HAL_VOLUME_IFACE)

        # Try 100 times to get a mount point
        mounted = False
        i = 0
        while not mounted:
            try:
                if i > 0:
                    volume.Mount('%s_%d' % (mount_point, i), fs_type, options)
                else:
                    volume.Mount(mount_point, fs_type, options)
                mounted = True
            except dbus.DBusException, e:
                if i < 100 and e.get_dbus_name() == \
                        'org.freedesktop.Hal.Device.Volume.MountPointNotAvailable':
                    i += 1
                else:
                    raise

    def _hal_device_property_modified_cb(self, udi, count, changes):
        if 'volume.is_mounted' in [change[0] for change in changes]:
            logging.debug('VolumesManager._hal_device_property_modified: %r' % (udi))
            bus = dbus.SystemBus()
            #proxy = bus.get_object(HAL_SERVICE_NAME, HAL_MANAGER_PATH)
            #hal_manager = dbus.Interface(proxy, HAL_MANAGER_IFACE)
            # TODO: Why this doesn't work?
            #if not hal_manager.DeviceExists(udi):
            #    return

            proxy = bus.get_object(HAL_SERVICE_NAME, udi)
            device = dbus.Interface(proxy, HAL_DEVICE_IFACE)
            try:
                is_mounted = device.GetProperty('volume.is_mounted')
            except dbus.DBusException, e:
                logging.debug('e: %s' % e)
                return

            if is_mounted:
                if self._get_volume_by_udi(udi) is not None:
                    # device already mounted in the datastore
                    return
                volume_id = self._mount_in_datastore(udi)
            else:
                self.unmount_from_datastore(udi)
            return

    def _mount_in_datastore(self, udi):
        logging.debug('VolumeToolbar._mount_in_datastore: %r' % udi)

        bus = dbus.SystemBus()
        device_object = bus.get_object(HAL_SERVICE_NAME, udi)
        device = dbus.Interface(device_object, HAL_DEVICE_IFACE)
        
        mount_point = device.GetProperty('volume.mount_point')
        ds_mounts = datastore.mounts()
        for ds_mount in ds_mounts:
            if mount_point == ds_mount['uri']:
                return ds_mount['id']

        mount_id = datastore.mount('inplace:' + mount_point,
                                    dict(title=mount_point))
        if not mount_id:
            self._unmount_hal_device(udi)
            raise RuntimeError('datastore.mount(%r, %r) failed.' % (
                    'inplace:' + mount_point,
                    dict(title=mount_point)))

        volume_name = device.GetProperty('volume.label')
        if not volume_name:
            volume_name = device.GetProperty('volume.uuid')
        volume = Volume(mount_id,
                        volume_name,
                        self._get_icon_for_volume(udi),
                        profile.get_color(),
                        udi,
                        True)
        self._volumes.append(volume)
        self.emit('volume-added', volume)

        logging.debug('mounted volume %s' % mount_point)

    def _hal_device_removed_cb(self, udi):
        logging.debug('VolumesManager._hal_device_removed_cb: %r', udi)
        bus = dbus.SystemBus()
        #proxy = bus.get_object(HAL_SERVICE_NAME, HAL_MANAGER_PATH)
        #hal_manager = dbus.Interface(proxy, HAL_MANAGER_IFACE)
        # TODO: Why this doesn't work?
        #if not hal_manager.DeviceExists(udi):
        #    self._unmount_from_datastore(udi)
        #    self._remove_button(udi)
        #    return

        proxy = bus.get_object(HAL_SERVICE_NAME, udi)
        device = dbus.Interface(proxy, HAL_DEVICE_IFACE)
        try:
            is_mounted = device.GetProperty('volume.is_mounted')
        except dbus.DBusException, e:
            logging.debug('e: %s' % e)
            self.unmount_from_datastore(udi)
            return

        if is_mounted:
            self._unmount_from_datastore(udi)
            self._unmount_hal_device(udi)

    def unmount_from_datastore(self, udi):
        logging.debug('VolumesManager._unmount_from_datastore: %r', udi)
        volume = self._get_volume_by_udi(udi)
        if volume is not None:
            datastore.unmount(volume.id)

            self._volumes.remove(volume)
            self.emit('volume-removed', volume)

    def unmount_hal_device(self, udi):
        logging.debug('VolumesManager._unmount_hal_device: %r', udi)
        bus = dbus.SystemBus()
        device_object = bus.get_object(HAL_SERVICE_NAME, udi)
        volume = dbus.Interface(device_object, HAL_VOLUME_IFACE)
        volume.Unmount([])

    def _get_icon_for_volume(self, udi):
        bus = dbus.SystemBus()
        device_object = bus.get_object(HAL_SERVICE_NAME, udi)
        device = dbus.Interface(device_object, HAL_DEVICE_IFACE)
        
        storage_udi = device.GetProperty('block.storage_device')
        obj = bus.get_object(HAL_SERVICE_NAME, storage_udi)
        storage_device = dbus.Interface(obj, HAL_DEVICE_IFACE)

        storage_drive_type = storage_device.GetProperty('storage.drive_type')
        if storage_drive_type == 'sd_mmc':
            return 'media-flash-sd-mmc'
        else:
            return 'media-flash-usb'

class Volume(object):
    def __init__(self, id, name, icon_name, icon_color, udi, can_unmount):
        self.id = id
        self.name = name
        self.icon_name = icon_name
        self.icon_color = icon_color
        self.udi = udi
        self.can_unmount = can_unmount

    def unmount(self):
        get_volumes_manager().unmount_from_datastore(self.udi)
        get_volumes_manager().unmount_hal_device(self.udi)

def get_volumes_manager():
    global _volumes_manager
    if _volumes_manager is None:
        _volumes_manager = VolumesManager()
    return _volumes_manager