# low_backup module
# Authors: Nicholas Alexander && Otacilio Lacerda

import commands
import os

BATTERY = os.environ['BATTERY_PATH'] + 'battery.py'
EXECUTE = "./"
USER_HOST = "root"

def queryProductInformation(deviceIp):
    """ Update device name by getting device product name and os version
    informations.

    Use osso-product-info command to get the device and device OS short
    names and set each to it correspondent attribute.

    """

    info = commands.getoutput("ssh -l %s %s osso-product-info" %
                                        (USER_HOST, deviceIp))

    deviceName = _extractOssoInfo(info, "shortName")
    deviceOs = _extractOssoInfo(info, "shortOS")
    ossoVersion = _extractOssoInfo(info, "ossoVersion")
    if deviceName != -1 and deviceOs != -1:
        deviceName = deviceName.strip("'")
        deviceOs = deviceOs.strip("'")
    else:
        deviceName = "NO INFORMATION"
        deviceOs = "NO INFORMATION"

    return (deviceName, deviceOs, ossoVersion)

def queryDeviceStorage(deviceIp):
    """Returns a list of tuples, each tuple representing a memory status.

    Tuples are in this format: (total, used)

    Returns:
        mem_infos -- List with all tuples holding memory info

    """
    info = commands.getoutput("ssh -l root %s df" %
                              deviceIp).splitlines()
    mem_infos = [-1, -1, -1]
    for line in info:
        if line.find("/dev/mtdblock4") != -1:
            if line[-1] == "/":
                total_used = _get_memory(line, "/dev/mtdblock4")
                mem_infos.pop(0)
                mem_infos.insert(0, total_used)
        
        elif line.find("/media/mmc1") != -1:
            total_used = _get_memory(line, "/dev/mmcblk0p1")
            mem_infos.pop(1)
            mem_infos.insert(1, total_used)
        
        elif line.find("/media/mmc2") != -1:
            total_used = _get_memory(line, "/dev/mmcblk1p1")
            mem_infos.pop(2)
            mem_infos.insert(2, total_used)
 
    return mem_infos

def queryDeviceBattery(deviceIp):
    """Return device current battery status in a string.

    This method runs a python script in the device that returns the battery
    status, this status is represented by one string with the percentage of
    battery current charge or the number -1 case battery is charging.

    Returns:
    text -- Text with the battery status

    """

    # Calls script that returns device battery status    
    os.system("scp %s %s@%s:/tmp" % (BATTERY, USER_HOST, deviceIp))
    battery_status = commands.getoutput("ssh -l %s %s /usr/bin/python \
                                        /tmp/battery.py" % (USER_HOST, 
                                                            deviceIp))
    return battery_status

def _get_memory(line, path):
    """Retrieve and return total and used memory information from the given 
    line using the memory path to retrieve the right information.

    This function is to be used with a line of the return of a df command.

    Arguments:
    line -- The line where the memory information is
    path -- The path in the begining of the line

    Returns:
    total -- Total memory
    used -- Amount of used memory

    """
    number_of_infos = 0
    i = len(path) + 1
    while number_of_infos < 2:
        char = line[i]
        if char != " ":
            start = i
            end = line.find(" ", start + 1)
            if number_of_infos == 0:
                total = line[start: end]
            elif number_of_infos == 1:
                used = line[start: end]
            i = end
            number_of_infos += 1
        i += 1
    return total, used

def _extractOssoInfo(osso_string, info_type="name"):
    """Read the osso-product-info command return string and extract the
    needed info depeding on info_type argument.

    Arguments:
    osso_string -- The string returned by osso-product-info command
    info_type -- the kind of information to b extracted, can be:
        name - returns device full name (default)
        OS - returns device OS full name
        shortName - returns device short name
        shortOS - returns device short OS name

    Returns:
    info -- String with the needed information
    -1 -- Case the information couldn't be found in the given string

    """
    detailed_type = ""
    if info_type == "shortName":
        detailed_type = "OSSO_PRODUCT_NAME"
    elif info_type == "shortOS":
        detailed_type = "OSSO_PRODUCT_RELEASE_NAME"
    elif info_type == "name":
        detailed_type = "OSSO_PRODUCT_FULL_NAME"
    elif info_type == "OS":
        detailed_type = "OSSO_PRODUCT_RELEASE_FULL_NAME"
    elif info_type == "ossoVersion":
        detailed_type = "OSSO_VERSION"
    else:
        detailed_type = "OSSO_PRODUCT_FULL_NAME"

    types_list = osso_string.splitlines()
    info = -1
    for type_line in types_list:
        if type_line.startswith(detailed_type):
            # The second argument is the information itself since informations
            # are displayed like: OSSO_PRODUCT_RELEASE_NAME='OS 2008'
            info = type_line.split("=")[1]

    return info