"""
Accelerometer module for odeviced.

(C) 2008 John Lee <john_lee@openmoko.com>
(C) 2008 Openmoko, Inc.
GPLv2 or later
"""
from __future__ import with_statement

MODULE_NAME = "odeviced.accelerometer"
__version__ = "0.2.2"

from framework.config import config

from threading import RLock, Thread
import os, struct

import logging
logger = logging.getLogger( MODULE_NAME )

#============================================================================#
class Accelerometer(object):
#============================================================================#
    def retrieve(self):
        raise NotImplementedError

#============================================================================#
class MockAccelerometer(Accelerometer):
#============================================================================#
    def retrieve(self):
        return 0, 0, 0

#============================================================================#
class InputDevAccelerometer(Accelerometer):
#============================================================================#
    """Read values from kernel input device
    """

    # Event types
    EV_SYN = 0x00
    EV_KEY = 0x01
    EV_REL = 0x02
    EV_ABS = 0x03
    EV_MSC = 0x04
    EV_SW = 0x05
    EV_LED = 0x11
    EV_SND = 0x12
    EV_REP = 0x14
    EV_FF = 0x15
    EV_PWR = 0x16
    EV_FF = 0x17
    EV_MAX = 0x1f
    EV_CNT = (EV_MAX+1)

    # Relative axes
    REL_X = 0x00
    REL_Y = 0x01
    REL_Z = 0x02
    REL_RX = 0x03
    REL_RY = 0x04
    REL_RZ = 0x05
    REL_HWHEEL = 0x06
    REL_DIAL = 0x07
    REL_WHEEL = 0x08
    REL_MISC = 0x09
    REL_MAX = 0x0f
    REL_CNT = REL_MAX + 1

    input_event_struct = "@llHHi"
    input_event_size = struct.calcsize(input_event_struct)

    def __init__(self, device):
        super(InputDevAccelerometer, self).__init__()
        self.device_fd = os.open(device, os.O_RDONLY | os.O_SYNC)

    def _unpack(self):
        """struct input_event {
            struct timeval time; /* (long, long) */
            __u16 type;
            __u16 code;
            __s32 value;
        };
        return (tv_sec, tv_usec, type, code, value)
        """
        i = 0
        while True:
            try:
                data = os.read(self.device_fd, InputDevAccelerometer.input_event_size)
            except OSError, e:
                logger.exception( "could not read from accelerometer device node: %s" % e )
                raise
            else:
                if len(data) == InputDevAccelerometer.input_event_size:
                    break;
        return struct.unpack(InputDevAccelerometer.input_event_struct,data)

    def _unpack_xyz(self):
        """return a 3 tuple
        """
        # wait for EV_SYN
        while self._unpack()[2] != InputDevAccelerometer.EV_SYN:
            pass
        # now return (x, y, z)
        return (self._unpack()[4], self._unpack()[4], self._unpack()[4])

#============================================================================#
class Gta02Accelerometer(InputDevAccelerometer):
#============================================================================#
    """Read values from gta02.  for now we use just one.
    >>> g = Gta02Accelerometer()
    >>> g.sample_rate = 400
    >>> g.sample_rate
    400
    >>> g.sample_rate = 100
    >>> g.sample_rate
    100
    """

    INPUT_DEV = "/dev/input/event3"
    SYS_SAMPLE_RATE = "/sys/bus/platform/devices/lis302dl.2/sample_rate"

    def __init__(self, device=None, sample_rate=None):
        if device is None:
            device = Gta02Accelerometer.INPUT_DEV
        super(Gta02Accelerometer, self).__init__(device)
        if sample_rate is not None:
            self.sample_rate = sample_rate

    def _get_sample_rate(self):
        f = open(Gta02Accelerometer.SYS_SAMPLE_RATE, 'r', 0)
        sample_rate = int(f.read())
        f.close()
        return sample_rate

    def _set_sample_rate(self, sample_rate):
        """possible values: 100, 400
        """
        if sample_rate != 100 and sample_rate != 400:
            return
        f = open(Gta02Accelerometer.SYS_SAMPLE_RATE, 'w', 0)
        f.write('%d\n' % sample_rate)
        f.close()

    sample_rate = property(_get_sample_rate, _set_sample_rate)

    def retrieve(self):
        return self._unpack_xyz()


# stuffs for fso
import dbus.service
from helpers import DBUS_INTERFACE_PREFIX, DBUS_PATH_PREFIX
from gobject import idle_add

#============================================================================#
class FSOSubsystem(dbus.service.Object):
#============================================================================#
    DBUS_INTERFACE = DBUS_INTERFACE_PREFIX + ".Accelerometer"
    DBUS_PATH = DBUS_PATH_PREFIX + "/Accelerometer"

    def __init__(self, accelerometer, bus):
        self.path = FSOSubsystem.DBUS_PATH
        self.interface = FSOSubsystem.DBUS_INTERFACE
        self.accelerometer = accelerometer
        dbus.service.Object.__init__(self, bus, self.path)
        logger.info( "%s %s initialized. Serving %s at %s", self.__class__.__name__, __version__, self.interface, self.path )

    @dbus.service.method(DBUS_INTERFACE, '', 'iii')
    def Value(self):
        return self.accelerometer.retrieve()

    @dbus.service.method(DBUS_INTERFACE, '', 'i')
    def GetSampleRate(self):
        return self.accelerometer.sample_rate

    @dbus.service.method(DBUS_INTERFACE, 'i', '')
    def SetSampleRate(self, sample_rate):
        self.accelerometer.sample_rate = sample_rate

#============================================================================#
def factory(prefix, controller):
#============================================================================#
    # FIXME I would let the FSOSubsystem object deal with chosing the device type
    device_map = {'gta02': Gta02Accelerometer,
                  'mock': MockAccelerometer}
    device = config.getValue( MODULE_NAME, "accelerometer_type", "mock" )
    device_class = device_map[ device ]
    f = FSOSubsystem(device_class(), controller.bus)
    return [f, ]


#============================================================================#
def _doctest():
#============================================================================#
    try:
        import doctest
    except ImportError:
        return
    else:
        doctest.testmod()

#============================================================================#
if __name__ == '__main__':
#============================================================================#
    _doctest()