# Interface towards the websites used

#------------------------------------------------------------------------------

import const

import threading
import sys
import urllib2
import hashlib
import datetime
import codecs

#---------------------------------------------------------------------------------------

def readline(f):
    """Read a line from the given file.

    The line is stripped and empty lines are discarded."""
    while True:
        line = f.readline()
        if not line: return ""
        line = line.strip()
        if line:
            return line

#---------------------------------------------------------------------------------------

class BookedFlight(object):
    """A flight that was booked."""
    TYPECODE2TYPE = { "736" : const.AIRCRAFT_B736,
                      "73G" : const.AIRCRAFT_B737,
                      "738" : const.AIRCRAFT_B738,
                      "733" : const.AIRCRAFT_B733,
                      "734" : const.AIRCRAFT_B734,
                      "735" : const.AIRCRAFT_B735,
                      "DH4" : const.AIRCRAFT_DH8D,
                      "762" : const.AIRCRAFT_B762,
                      "763" : const.AIRCRAFT_B763,
                      "CR2" : const.AIRCRAFT_CRJ2,
                      "F70" : const.AIRCRAFT_F70,
                      "LI2" : const.AIRCRAFT_DC3,
                      "TU3" : const.AIRCRAFT_T134,
                      "TU5" : const.AIRCRAFT_T154,
                      "YK4" : const.AIRCRAFT_YK40 }

    def __init__(self, id, f):
        """Construct a booked flight with the given ID.

        The rest of the data is read from the given file."""

        self.id = id
        self.callsign = readline(f)

        date = readline(f)

        self.departureICAO = readline(f)
        self.arrivalICAO = readline(f)

        self._readAircraftType(f)
        self.tailNumber = readline(f)
        self.numPassengers = int(readline(f))
        self.numCrew = int(readline(f))
        self.bagWeight = int(readline(f))
        self.cargoWeight = int(readline(f))
        self.mailWeight = int(readline(f))
        self.route = readline(f)

        departureTime = readline(f)
        self.departureTime = datetime.datetime.strptime(date + " " + departureTime,
                                                        "%Y-%m-%d %H:%M:%S")
                                               
        arrivalTime = readline(f)
        self.arrivalTime = datetime.datetime.strptime(date + " " + arrivalTime,
                                                      "%Y-%m-%d %H:%M:%S")

        if not readline(f)==".NEXT.":
            raise Exception("Invalid line in flight data")

    def _readAircraftType(self, f):
        """Read the aircraft type from the given file."""
        line = readline(f)
        typeCode = line[:3]
        if typeCode in self.TYPECODE2TYPE:
            self.aircraftType = self.TYPECODE2TYPE[typeCode]
        else:
            raise Exception("Invalid aircraft type code: '" + typeCode + "'")
        
    def __repr__(self):
        """Get a representation of the flight."""
        s = "<Flight: %s-%s, %s, %s-%s," % (self.departureICAO,
                                           self.arrivalICAO,
                                           self.route,
                                           self.departureTime, self.arrivalTime)
        s += " %d %s," % (self.aircraftType, self.tailNumber)
        s += " pax=%d, crew=%d, bag=%d, cargo=%d, mail=%d" % \
             (self.numPassengers, self.numCrew,
              self.bagWeight, self.cargoWeight, self.mailWeight)
        s += ">"
        return s
        
#------------------------------------------------------------------------------

class Result(object):
    """A result object.

    An instance of this filled with the appropriate data is passed to the
    callback function on each request."""

    def __repr__(self):
        """Get a representation of the result."""
        s = "<Result:"
        for (key, value) in self.__dict__.iteritems():
            s += " " + key + "=" + unicode(value)
        s += ">"
        return s

#------------------------------------------------------------------------------

class Request(object):
    """Base class for requests.

    It handles any exceptions and the calling of the callback.

    If an exception occurs during processing, the callback is called with
    the two parameters: a boolean value of False, and the exception object.

    If no exception occurs, the callback is called with True and the return
    value of the run() function.

    If the callback function throws an exception, that is caught and logged
    to the debug log."""
    def __init__(self, callback):
        """Construct the request."""
        self._callback = callback

    def perform(self):
        """Perform the request.

        The object's run() function is called. If it throws an exception,
        the callback is called with False, and the exception. Otherwise the
        callback is called with True and the return value of the run()
        function. Any exceptions thrown by the callback are caught and
        reported."""
        try:
            result = self.run()
            returned = True
        except Exception, e:
            result = e
            returned = False

        try:
            self._callback(returned, result)
        except Exception, e:
            print >> sys.stderr, "web.Handler.Request.perform: callback throwed an exception: " + str(e)

#------------------------------------------------------------------------------

class Login(Request):
    """A login request."""
    iso88592decoder = codecs.getdecoder("iso-8859-2")
    
    def __init__(self, pilotID, password, callback):
        """Construct the login request with the given pilot ID and
        password."""
        super(Login, self).__init__(callback)

        self._pilotID = pilotID
        self._password = password

    def run(self):
        """Perform the login request."""
        md5 = hashlib.md5()
        md5.update(self._pilotID)
        pilotID = md5.hexdigest()
        
        md5 = hashlib.md5()
        md5.update(self._password)
        password = md5.hexdigest()

        url = "http://www.virtualairlines.hu/leker2.php?pid=%s&psw=%s" % \
              (pilotID, password)

        result = Result()

        f = urllib2.urlopen(url)

        status = readline(f)
        result.loggedIn = status == ".OK."

        if result.loggedIn:
            result.pilotName = self.iso88592decoder(readline(f))[0]
            result.exams = readline(f)
            result.flights = []

            while True:
                line = readline(f)
                if not line or line == "#ENDPIREP": break

                flight = BookedFlight(line, f)
                result.flights.append(flight)

        return result
        
#------------------------------------------------------------------------------

class Handler(threading.Thread):
    """The handler for the web services.

    It can process one request at a time. The results are passed to a callback
    function."""
    def __init__(self):
        """Construct the handler."""
        super(Handler, self).__init__()

        self._requests = []
        self._requestCondition = threading.Condition()

        self.daemon = True

    def login(self, pilotID, password, callback):
        """Enqueue a login request."""
        self._addRequest(Login(pilotID, password, callback))

    def run(self):
        """Process the requests."""
        while True:
            with self._requestCondition:
                while not self._requests:
                    self._requestCondition.wait()
                request = self._requests[0]
                del self._requests[0]

            request.perform()
    
    def _addRequest(self, request):
        """Add the given request to the queue."""
        with self._requestCondition:
            self._requests.append(request)
            self._requestCondition.notify()

#------------------------------------------------------------------------------

if __name__ == "__main__":
    import time
    
    def callback(returned, result):
        print returned, unicode(result)
        
    handler = Handler()
    handler.start()

    handler.login("P096", "V5fwj", callback)
    time.sleep(3)    

#------------------------------------------------------------------------------